2外文翻译
外文翻译原文science 2
/locate/rggThe stages and duration of formation of gold mineralizationat copper-skarn deposits (Altai–Sayan folded area )I.V. Gaskov *, A.S. Borisenko, V.V. Babich, E.A. NaumovV.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences,prosp. Akad. Koptyuga 3, Novosibirsk, 630090, RussiaReceived 20 March 2009; accepted l6 November 2009AbstractGold mineralization at copper-skarn deposits (Tardanskoe, Murzinskoe, Sinyukhinskoe, Choiskoe) in the Altai–Sayan folded area is related to different hydrothermal-metasomatic formations. It was produced at 400–150 ºC in several stages spanning 5–6 Myr, which determined the diversity of its mineral assemblages. Gold mineralization associated with magnetite bodies is spatially correlated with magnesian and calcareous skarns, whereas gold mineralization in crushing zones and along fault sutures in moderate- and low-temperature hydrothermal-metasomatic rocks (propylites, beresites, serpentinites, and argillizites) is of postskarn formation. Different stages were manifested with different intensities at gold deposits. For example, the Sinyukhinskoe deposit abounds in early high-temperature mineral assemblages; the Choiskoe deposit, in low-temperature ones; and the Tardanskoe and Murzinskoe deposits are rich in both early and late gold minerals. Formation of commercial gold mineralization at different copper-skarn deposits is due to the combination of gold mineralization produced at different stages as a result of formation of intricate igneous complexes (Tannu-Ola, Ust’-Belaya, and Yugala) composed of differentiated rocks from gabbros to granites.© 2010, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.Keywords: gold mineralization; skarns, copper-skarn deposits; hydrothermal-metasomatic formationsIntroductionRecent data on the isotope geology and geochronology of rocks and ores and geological data on the ore genesis gaps proved that ore deposits formed for a much longer time than was assumed earlier (Rundkvist, 1997). This is also true for commercial gold mineralization at many Cu-skarn deposits in the Altai–Sayan folded area (ASFA).Gold-containing Cu-skarn deposits are widespread in many ore districts of the ASFA: Gorny Altai (Sinyukhinskoe,Murzinskoe, Choiskoe), Kuznetsk Alatau (Natal’evskoe, Fe-dorovskoe), Gornaya Shoria (Maisko-Lebedskoe), and Tuva (Tardanskoe, Khopto). Most of them are commercial deposits (Fig. 1).Skarn formation processes at these deposits were related to the Early and Middle Paleozoic granitoid magmatism in the Tannu-Ola (eastern Tuva), Yugala (Sinyukha, northeastern Altai), and Ust’-Belaya (northwestern Altai) intrusive com-plexes (Gusev, 2007; Shokalsky et al., 2000). Formation of commercial gold mineralization was a longer and more intricate process (Gaskov, 2008). In most part of these deposits, gold mineralization is the product of multistage ore process, which is characterized by different mineral composi-tions and spatial occurrences. Almost all these deposits bear gold mineralization spatially and genetically related to skarns and aposkarns in assemblage with magnetite and sulfides (Korobeinikov and Matsyushevskii, 1976; Korobeinikov and Zotov, 2006; Korobeinikov et al., 1987; Vakhrushev, 1972)and gold mineralization isolated from skarns and represented by sulfide-containing (pyrite, chalcopyrite, bornite, chalcocite)hydrothermal products of moderate-temperature assemblage in crushing zones (Shcherbakov, 1974). Often, the deposits also bear epithermal gold-containing assemblage with low-tem-perature sulfides, tellurides, and selenides usually developed at the final stage of mineral formation in rocks of different compositions, including sedimentary, igneous, and skarn (Gas-kov, 2008; Gaskov et al., 2005).The recently obtained ages of ore formation products and igneous rocks (Gaskov, 2008; Rudnev et al., 2004, 2006;Shokalsky et al., 2000) provide a new concept of the sequence of ore formation and its duration and relation with multiphasemagmatism.Russian Geology and Geophysics 51 (2010) 1091–1101*Corresponding author.E-mail address : gaskov@uiggm.nsc.ru (I.V. Gaskov)doi:10.1016/j.rgg.2010.0.0011068-7971/$-see front matter D 2010, IG M, Siberian Branch of the RAS.Published by E lsevier B.V .All rights reserved.V S. .Sabolev 9Let us dwell on the specific features of gold mineralization at particular deposits.Gold mineralization at Cu-skarn depositsThe Tardanskoe deposit is localized in the zone of the Kaa-Khem deep fault, in the exocontact part of the Kopto-Baisyut gabbro-diorite-plagiogranite massif (Fig. 2) (Korobe-inikov and Zotov, 2006; Korobeinikov et al., 1987). At the massif contact, Lower Cambrian volcanogenic-carbonate de-posits are transformed into magnesian and calcareous skarns described in detail earlier (Korobeinikov, 1999; Korobeinikov and Matsyushevskii, 1976; Korobeinikov et al., 1997). The skarn bodies are spatially close to aposkarn metasomatites bearing actinolite, tremolite, epidote, serpentine, chlorite, talc,quartz, carbonate, magnetite, and hematite.Gold mineralization at the deposit is of two types: (1) in skarn-magnetite rocks and (2) in metasomatites of linear crushing zones. These types have specific mineralogical and geochemical features.Gold mineralization in skarn-magnetite ores is widespread at the deposit. It is described elsewhere (Korobeinikov and Matsyushevskii, 1976; Korobeinikov and Zotov, 2006; Koro-beinikov et al., 1987; Kudryavtseva, 1969). Gold is spatially related to areas of sulfide mineralization, and its contents are in direct correlation with the amount of sulfide minerals.Gold-sulfide mineralization is extremely unevenly distributed and is localized at the sites of magnetite ores that underwent cataclasis as well as in magnetite microcracks and interstices.The total amount of sulfides (pyrite, chalcopyrite, bornite, and scarcer sphalerite, pyrrhotite, and arsenopyrite) is 1–3%. Gold occurs as fine thin (0.3–0.01 mm) native segregations. This is mainly high-fineness gold (820–990) (Fig. 3, a ) with impuri-ties of silver (up to 13.6%) and copper (up to 5.07%).According to Korobeinikov (1999) and Korobeinikov and Matsyushevskii (1976), the temperatures of formation of magnetite ores were 430–550 ºC, whereas the gold-sulfide assemblage and the hosting metasomatites (actinolite, tre-molite, serpentine, talc) were produced at 250–320 ºC (Gaskov et al., 2005; Vakhrushev, 1972).Gold mineralization in crushing zones is localized in steeply dipping linear tectonic structures of NW, NE, and NS strikes (Fig. 2), which develop after different rocks, including volcanosedimentary, igneous, and skarn ones. These zones reach several hundred meters in length and few tens of meters in width. The petrographic composition of these zones is di-verse and depends mainly on the composition of initial rocks that underwent transformation later. The rocks are metaso-matic, close in composition to propylites, listwaenites, talc-containing and sericite-quartz metasomatites, and beresite-like rocks. Almost each type of hydrothermal-metasomatic rocks is intimately associated with ore minerals. Though the total volume of these minerals does not exceed 3–5%, they are extremely diverse in composition and are extremely unevenly distributed. Along with sulfide minerals typical of Cu-skarn deposits (chalcopyrite, pyrite, bornite, chalcocite,digenite, sphalerite, galena), the mineralized zones of the deposit abound in tellurides—hessite (Ag 2Te), tellurobis-muthite (Bi 2Te 3), and tetradymite (Bi 2Te 2S),—and low-tem-perature Co and Ni sulfides and sulfoarsenides (Table 1). The latter have a variable composition and often consist of intermediate phases of continuous mineral series, e.g., allo-clasite(CoAsS)–arsenopyrite(FeAsS) or siegenite(CoNi 2S 4)–violarite(FeNi 2S 4).Gold occurs mainly as native fine thin (0.01–0.5 mm)disseminations in rock microcracks and as inclusions in pyrite,chalcopyrite, and bornite. The gold fineness varies over a broad range of values—from 440 to 820 (Fig. 3, b ). The lowest-fineness gold segregations are compositionally similar to electrum and have high contents of Ag (up to 54.78%) and Hg impurity (up to 3.65%).On the flanks of mineralized crushing zones, there is sometimes gold mineralization in low-temperature argillitized rocks of chlorite-kaolinite-carbonate-hydromica composition.This gold is of low fineness (no more than 600). The mainimpurities are Ag (20–66%) and Hg (up to 5.47%). The formation temperatures of sulfide-telluride assemblages andFig. 1. Schematic occurrence of gold-bearing Cu-skarn deposits in the Altai-Sayan folded area: 1, Murzinskoe; 2, Sinyukhinskoe; 3, Choiskoe; 4, Maisko-Lebedskoe;5, Fedorovskoe; 6, Natal’evskoe; 7, Tardanskoe; 8, Kopto.1092I.V. Gaskov et al. / Russian Geology and Geophysics 51 (2010) 1091–1101gold mineralization in metasomatites and argillitized rocks are within 200–75 ºC.The Murzinskoe deposit is localized at the contact of a small stock-like granodiorite body of the Ust’-Belaya gabbro-diorite complex (Fig. 4). In the exocontact zone, calcareous skarns composed of garnet, pyroxene, wollastonite, and mag-netite develop after the calcareous sandstones of the Murzinka Formation (D1-2). In the local zones, there are aposkarnFig. 2. Schematic geologic structure of the Tardanskoe deposit (compiled after the data of K.M. Kil’chichakov and L.V. Kopylova and our new data). 1–4, Lower Paleozoic deposits: 1, andesitic porphyrites and tuffs with siltstone and sandstone interbeds in the lower part of the Tumat-Taiga Formation (Cm 1tm 1); 2, quartz porphyrites with interbeds of andesitic porphyrites and limestones in the upper part of the Tumat-Taiga Formation (Cm 1tm 2); 3, limestones and calcareous shales of the Tapsa Formation (Cm 1tp); 4, Lower and Middle Silurian conglomerates and sandstones (S 1-2); 5, Quaternary deposits (Q IV ); 6, 7, Lower Paleozoic igneous rocks of the Tannu-Ola complex (γδO 1-2): 6, gabbro-diorite-plagiogranite formation; 7, small granite-porphyry and quartz diorite bodies; 8, calcareous and magnesian skarns; 9, hydrothermal-metasomatic rocks in mineralized crushing zones; 10, gold orebodies; 11, tectonic zones; 12, geologic boundaries.I.V. Gaskov et al. / Russian Geology and Geophysics 51 (2010) 1091–11011093Fig. 3. Variations in gold fineness in gold ores from skarn-magnetite bodies (a) and in ores from mineralized crushing zones (b) at the Tardanskoe deposit.Table 1. Mineral parageneses in gold-bearing ores produced at different stages and composition of host rocks at Au-Cu-skarn depositsDeposit Early aposkarn Au-sulfide mineralization in magnetite-skarn rocks Late Au-telluride-sulfide mineralization in superposed crushingzonesOre parageneses Host rocks Ore parageneses Host rocksTardanskoe Magneite (Fe3O4)Pyrite (FeS2)Chalcopyrite (CuFeS2)Bornite (Cu5FeS4)Sphalerite (ZnS)Pyrrhotite (FeS)Arsenopyrite (FeAsS)Gold (Au)Magnesian skarns (pyroxene +fassayite + phlogopite +pargasite + forsterite + spinel).Calcareous skarns (pyroxene +garnet + epidote +wollastonite + skapolite).Aposkarn serpentine andserpentine-chlorite rocksCobaltite (CoFe)AsSGlaucodot (Co,Fe)AsSSiegenite (CoNi2S4)Violarite (FeNi2S4)Hessite (Ag2Te)Gold (Au)Propylites, listvaenites, talc-serpentine-containing andsericite-quartz metasomatites,and argillitized rocksMurzinskoe Magnetite (Fe3O4)Chalcopyrite (CuFeS2)Pyrite (FeS2)Bornite (Cu5FeS4)Sphalerite (ZnS)Galena (PbS)FahloreArsenopyrite (FeAsS)Clinobisvanite (BiVO4)Gold (Au)Calcareous skarns (garnet +pyroxene + wollastonite).Aposkarn metasomatic rocks(quartz + epidote + chlorite +actinolite)Cinnabar (HgS)Metacinnabarite (HgS)Bismuthine (Bi2S3)Aikinite (CuPbBiS3)Emplectite (CuBiS2)Berryite [Pb2(Cu,Ag)3Bi5S11]Naumannite (Ag2Se)Polybasite (Ag16Sb2S11)Barite (BaSO4)Gold (Au)Quartz and quartz-carbonateveins, near-vein metasomatitesof quartz-chlorite-carbonatecomposition, and argillitizedrocksSinyukhinskoe Magnetite (Fe3O4)Pyrite (FeS2)Chalcopyrite (CuFeS2)Bornite (Cu5FeS4)Chalcocite (Cu2S)Sphalerite (ZnS)Pyrrhotite (FeS)Cubanite (CuFe2S3)Gold (Au)Wollastonite, garnet-wollastonite, garnet-pyroxeneand pyroxene skarns, andaposkarn metasomatic rocks(chlorite + actinolite + calcite)Tetradymite (Bi2TeS)Siegenite (CoNi2S4)Cobaltite ((CoNiFe)AsS)Melonite (NiTe2)Wittichenite (Cu3BiS3)Hessite (Ag2Te)Petzite (AuAg3Te2)Altaite (PbTe)Clausthalite (PbSe)Gold (Au)Local zones of actinolite-chlorite-calcite-quartzcompositionChoiskoe Magnetite (Fe3O4)Pyrite (FeS2)Chalcopyrite (CuFeS2)Gold (Au)Garnet, garnet-pyroxene,garnet-wollastonite, andpyroxene-epidote skarnsTetradymite (BiTe2S)Ingodite (Bi2TeS)Joseite (Bi4TeS2)Hedleyite (Bi2Te)Tellurobismuthite (Bi2Te3)Bismuthite (Bi2S3),Native bismuth (Bi)Gold (Au)Quartz and quartz-carbonateveins and quartz-carbonate-chlorite metasomatites1094I.V. Gaskov et al. / Russian Geology and Geophysics 51 (2010) 1091–1101metasomatic rocks consisting of quartz, epidote, calcite,chlorite, actinolite, and, more seldom, tourmaline, apatite, and rodonite.Gold mineralization at the Murzinskoe deposit was earlier ascribed to gold-skarn type. But recent data have shown that only a minor part of the deposit ores — scarce postskarn sulfide mineralization spatially associated with skarn-magnet-ite bodies—can be referred to this type. Most of the commer-cial ores occur in mineralized crushing zones. They form gold-sulfide mineralization in quartz and quartz-carbonate veins and near-vein metasomatites in a 300–400 m thick zone stretching in the N-NW direction for more than 3 km (Fig. 4).The crust of weathering widespread at the deposit contains hypergene copper minerals: malachite, chrysocolla, azurite,chalcocite, coveline, and high-fineness gold.Gold-sulfide mineralization spatially associated with skarn-magnetite bodies is superposed on skarn rocks. It was produced either at the regressive stage of the skarn formation or at the postskarn hydrothermal-metasomatic stage and was accompanied by the formation of moderate- and low-tempera-ture metasomatic minerals—chlorite, actinolite, epidote, and quartz. Sulfide mineralization is unevenly distributed and occurs as veinlet-disseminated chalcopyrite, pyrite, bornite,and sphalerite. It amounts to few percent. Gold occurs as fine thin (0.5–0.01 mm) native segregations. It is mainly of high fineness (840–994) (Fig. 5, a ).In crushing zones (Fig. 4), gold mineralization was found in quartz-carbonate-sulfide veinlets and veins in hydrothermal-metasomatic rocks of quartz-chlorite-carbonate composition with kaolinite, hydromica, and adularia (argillizite formation)developing after different rocks—skarns, hornfelses, shales,siltstones, and limestones,—often beyond skarning and horn-felsing zones. The quartz veins are 0.1 to 2.0 m (on average,0.4 m) thick, of N-S strike and eastern dip. In contrast to the gold-skarn-magnetite type, this mineralization is of more complex composition. In addition to minerals typical of skarn deposits (chalcopyrite, pyrite, bornite, sphalerite, and galena),it includes fahlore, arsenopyrite (FeAsS), cinnabar (HgS),metacinnabarite (HgS), bismuthine (Bi 2S 3), aikinite (CuPb BiS 3), emplectite (CuBiS 2), berryite [Pb 2(Cu,Ag)3Bi 5S 11],naumannite (Ag 2Se), polybasite (Ag 16Sb 2S 11), scheelite (Ca 3WO 4), hematite (Fe 2O 3), clinobisvanite (BiVO 4), bariteFig. 4. Schematic geologic structure of the Murzinskoe deposit. 1, mica-sili-ceous shales (O 1); 2, sandstones, siltstones, and aleuropelites (S 1); 3, terri-genous-carbonate deposits (D 1-2): a , conglomerates, b , limestones, c , sand-stones; 4, granodiorites of the Ust’-Belaya complex (D 3); 5, altered rocks and metasomatites: a , hornfelses, b , skarns, c , quartz-tourmaline metasomatites;6, mineralized crushing zones; 7, faults: a , established, b , predicted; 8, other types of mineralization: a , Murzinka-3 (Au), b, skarn Fe.Fig. 5. Variations in the fineness of gold associated with skarn-magnetite bodies (a ) and gold from ores of mineralized crushing zones (b ) at the Murzin-skoe deposit.I.V. Gaskov et al. / Russian Geology and Geophysics 51 (2010) 1091–11011095(BaSO 4), and gold (Table 1). The content of gold in the ores varies over a broad range of values, from 0.1 to 232 ppm.This gold occurs as fine (<0.1 mm) thin segregations in assemblage with sulfides. Its fineness also greatly varies (640–840), but, compared with the first type of ores, low-fine-ness gold prevails here (Fig. 5, b ).The presence of cinnabar, sulfides and sulfosalts of Bi, Se,and Sb, and barite, predominance of low-fineness gold and electrum, and low-temperature wallrock alteration (formation of kaolinite, hydromica, and adularia) differ these ores from earlier formed ores in skarn-magnetite bodies. The gap between the skarn and ore formation processes is evidenced from the presence of basite dikes cutting the skarns, which bear superposed gold mineralization of this type. At the same time, the presence of gold–cinnabar intergrowths and fine dissemination of gold in cinnabar, presence of Hg-minerals (cinnabar, Hg-sphalerite, saucovite) in the ores, and high contents of As, Sb, and Ti (typical elements of many Au-Hg deposits) permit this mineralization to be referred to as epithermal Au-Hg type (Borisenko et al., 2006). Thermometric studies showed that the homogenization temperatures of fluid inclusions in quartz veins in the northern and central parts ofthe mineralized zone are 215–200 ºC and decrease to 160–130 ºC in the southern part.Fig. 6. Schematic geologic structure of the Sinyukhinskoe deposit (compiled by Gusev (2007) and supplemented by our data). 1, loose Quaternary deposits; 2–6, rocksof the Choya (O 1cs), Elanda (C−2-3el), Ust’-Sema (C −2us), and Upper Ynyrga (C −2vy) Formations: 2, conglomerates, 3, siltstones, 4, sandstones, 5, limestones,6, andesite-basaltic porphyrites; 7–9, rocks of the Yugala (Sinyukha) complex: 7, granites and granodiorites of the early phase (γδD 2-3), 8, granites of the late phase (γD 2-3), 9, dolerite and gabbro-dolerite dikes; 10, plagiogranites of the Sarakoksha complex (ν C −2); 11, skarns; 12, sites with gold mineralization (1, Pervyi Rudnyi (First Ore), 2, Zapadnyi (Western), 3, Faifanov, 4, West Faifanov, 5, Ynyrga, 6, Nizhnii (Lower), 7, Tushkenek, 9, Gorbunov); 13, faults.1096I.V. Gaskov et al. / Russian Geology and Geophysics 51 (2010) 1091–1101The Sinyukhinskoe deposit is localized in northeastern Altai, at the contact of the large (600 km 2) complex Sarakok-sha pluton and Cambrian volcanosedimentary strata of the Ust’-Sema Formation (Shcherbakov, 1967; Vakhrushev, 1972)(Fig. 6). According to Shokalsky et al. (2000) and Gusev (2007), this massif includes the Lower Cambrian Sarakoksha diorite-tonalite-plagiogranite complex and Lower Devonian Yugala gabbro-diorite-granite complex (Sinyukha complex (Gusev, 2003)). It is in the latter complex that the commercial mineralization of the Sinyukha ore field is localized. In the contact zone of the Sinyukha massif, skarns of different compositions are developed in horizons of carbonate rocks and tuffs. Wollastonite and garnet-wollastonite varieties are the most widespread, and garnet-pyroxene and pyroxene ones are scarcer. Near the contact with basic effusive bodies, small magnetite orebodies have been revealed among garnet-py-roxene skarns.Gold mineralization occurs mainly among wollastonite,garnet-wollastonite, and pyroxene-wollastonite skarns and is intimately associated with an assemblage of sulfide minerals.The latter are dominated by bornite, chalcocite, chalcopyrite,and pyrite, which compose ore zones in these rocks and are present in the form of nest-disseminations and stockworks. In local zones of actinolite-chlorite-calcite-quartz composition we found minor amounts of sphalerite, pyrrhotite, cubanite, and tetradymite. There are also occasional findings of rare miner-als, such as siegenite (CoNi 2S 4), cobaltite ((CoNiFe)AsS),melonite (NiTe 2), wittichenite (Cu 3BiS 3), gessite (Ag 2Te),petzite (AuAg 3Te 2), altaite (PbTe), and clausthalite (PbSe)(Table 1). The total content of sulfides does not exceed 5–10%. The sulfides are extremely unevenly distributed—from occasional dissemination to densely disseminated, almost massive ores. The composition of sulfide mineralization slightly changes with depth: Gold-chalcocite-bornite assem-blage is changed by gold-chalcopyrite one. The accumulation of gold-sulfide mineralization was accompanied by the hy-drothermal-metasomatic alteration of the host skarns with the formation of actinolite, chlorite, and calcite near ore veins and nests. Magnetite ores are poorer in gold, and sulfide-free rocks(marbles and diorite-porphyry and granite-porphyry dikes)virtually lack it.Fig. 7. Variations in gold fineness in ores from the Sinyukhinskoe deposit.Fig. 8. Schematic geologic structure of the Choiskoe deposit (compiled by Gusev and Gusev (1998) and supplemented by our data). 1–5, rocks of the Ishpa (O 1is) andTandosha (C−2-3td) Formations: 1, conglomerates, 2, siltstones, 3, sandstones, 4, limestones, 5, felsic tuffs; 6–7, granitoids of the Yugala complex: 6, granites and granodiorites of the early phase (γδD 2-3), 7, leucocratic granites of the late phase (γD 2-3); 8, granite-porphyry, diorite, and lamprophyre dikes (γδD 2-3); 9, skarns;10, gold mineralization occurrences (1, occurrence of the Central skarn deposit, 2, Pikhtovyi, 3, Smorodinovyi); 11, faults.I.V. Gaskov et al. / Russian Geology and Geophysics 51 (2010) 1091–11011097Gold often occurs in ores as native segregations in the form of hooks, fine wires, lumps, and sheets intimately intergrown with bornite, chalcocite, and chalcopyrite. Sometimes, native gold segregations are observed as fine inclusions in cracks and interstices of skarn minerals, most often, wollastonite. These gold particles are mainly no larger than hundredths of millimeter. The gold of primary ores of the Sinyukhinskoe deposit is of high fineness varying over a narrow range of values (911–964) (Fig. 7). The fineness of gold decreases to 860–870 only in its parageneses with tellurides, selenides, and rare sulfide minerals (Roslyakova et al., 1999). The main impurities in gold are silver (up to 19%) and copper (up to 1.7%). The content of Hg does not exceed 0.1%. By the formation conditions, these ores are postskarn hydrothermal,with their deposition temperatures not exceeding 350 ºC (Roslyakova et al., 1999; Shcherbakov, 1972).The Choiskoe deposit is localized 20 km northeast of the Sinyukha ore field, in the zone of contact between the Upper Cambrian terrigenous-carbonate deposits of the Ishpa Forma-tion and the Choya granitoid massif referred to the Lower Devonian Yugala gabbro-diorite-granite complex (Fig. 8). The Choya granitoid massif is small at the surface (1 × 5 km) and extends from west to east, tracing the Choya fault (Gusev,2007). The deposit abounds in dikes of dolerite porphyrites,diorites, and granite-porphyry and in rocks of the lamprophyre series—kersantites, minette, and spessartites. The zone of contact between the granitoids of the Choya massif and the horizons of limestones and terrigenous-carbonate rocks is composed of skarns, which form linear zones extending in the NE direction, like the other rocks. Most bodies are of persistent thickness, ~100 m. By composition, the skarn bodies are divided into zones of garnet, garnet-pyroxene, pyroxene,garnet-wollastonite, and pyroxene-epidote skarns. In the skarn zones and near lamprophyre bodies, poor scheelite-molybde-nite mineralization in quartz veins was established (Gusev,1998).Gold mineralization at the deposit occurs in linear tectonic zones and is not spatially associated with skarns. It develops as quartz veins and quartz-carbonate and quartz-carbonate-chlorite veinlets and nests with gold-sulfide mineralization in crushing and brecciation zones in both the skarns and the granitoids of the Choya massif (Fig. 8).The mineral composition of these objects is nearly the same—gold-sulfide and gold-telluride parageneses. A numberof rare tellurides have been revealed among the Choya deposit ores: tetradymite (BiTe 2S), ingodite (Bi 2TeS), joseite (Bi 4TeS 2), hedleyite (Bi 2Te), tellurobismuthite (Bi 2Te 3), bis-muthine (Bi 2S 3), and native bismuth (Table 1). Magnetite,pyrite, and chalcopyrite, typical minerals of Cu-skarn deposits,are extremely scarce here. The total content of sulfides does not exceed few percent. They occur mainly as fine thin dissemination and do not form large accumulations and nests.Gold in the Choya deposit ores occurs as fine inclusions in sulfide and telluride minerals in quartz veinlets and as intergrowths with ore minerals. The gold particles are hun-dredths and tenths of millimeter in size. By chemical compo-sition, the gold is divided into two groups: medium-fineness (843–880) and high-fineness (940–959); the latter is probably of exogenous nature (Fig. 9). The gold contains Ag (3–12.5 wt.%) and Hg (0–0.48 wt.%) impurities and Cu traces.The thermometric studies showed that homogenization of primary gas-liquid inclusions into liquid proceeds at 126–150 ºC in quartz and at 105–128 ºC in calcite from ore-bear-ing veins.The sequence and duration of formation of gold mineralization and its correlation with magmatism As seen from the above data, gold mineralization at all considered Cu-skarn deposits has a complex multistage for-mation history. But the same stages at different deposits ran with different intensities. For example, at the Sinyukhinskoe deposit, mainly early high-temperature mineral assemblages are widespread, whereas at the Choiskoe deposit, low-tempera-ture ones. The Tardanskoe and Murzinskoe deposits bear both early and late minerals. To elucidate the peculiarities of gold-ore formation, establish the correlation between different types of gold mineralization and magmatic activity, and evaluate the duration of ore formation, we performed Ar-Ar and U-Pb dating of different mineralization and igneous rocks from the Tardanskoe and Murzinskoe deposits.Our investigations have shown that the formation of gold mineralization at the Tardanskoe deposit lasted for a longer time than it was supposed earlier. Skarn mineralization formed at the contact of diorites with carbonate rocks as a result of the intrusion of the Kopto-Baisyut massif. Ar-Ar biotite dating of the massif yielded an age of 485.7 ± 4.4 Ma corresponding to the Early Ordovician (Table 2). The skarns at the massif contact as well as magnetite ores and gold-sulfide mineraliza-tion (pyrite, chalcopyrite, pyrrhotite, bornite, gold) spatially and genetically associated with skarn-magnetite bodies are of similar age. Gold was deposited together with sulfides, as evidenced from the direct correlation between the contents of gold and sulfides (especially chalcopyrite) and from gold inclusions in the sulfides. The formation of skarn and aposkarn mineralization was followed (with some temporal gap) by the intrusion of dike and stock-like small granitoid bodies, which is indicated by their cutting of the sulfide-bearing skarn and magnetite bodies. Ar-Ar dating of these granite bodies yielded an age of 484.2 ±4.3 Ma (Table 2).Fig. 9. Variations in gold fineness in ores from the Choiskoe deposit.1098I.V. Gaskov et al. / Russian Geology and Geophysics 51 (2010) 1091–1101。
图像处理外文翻译 (2)
附录一英文原文Illustrator software and Photoshop software difference Photoshop and Illustrator is by Adobe product of our company, but as everyone more familiar Photoshop software, set scanning images, editing modification, image production, advertising creative, image input and output in one of the image processing software, favored by the vast number of graphic design personnel and computer art lovers alike.Photoshop expertise in image processing, and not graphics creation. Its application field, also very extensive, images, graphics, text, video, publishing various aspects have involved. Look from the function, Photoshop can be divided into image editing, image synthesis, school tonal color and special effects production parts. Image editing is image processing based on the image, can do all kinds of transform such as amplifier, reducing, rotation, lean, mirror, clairvoyant, etc. Also can copy, remove stain, repair damaged image, to modify etc. This in wedding photography, portrait processing production is very useful, and remove the part of the portrait, not satisfied with beautification processing, get let a person very satisfactory results.Image synthesis is will a few image through layer operation, tools application of intact, transmit definite synthesis of meaning images, which is a sure way of fine arts design. Photoshop provide drawing tools let foreign image and creative good fusion, the synthesis of possible make the image is perfect.School colour in photoshop with power is one of the functions of deep, the image can be quickly on the color rendition, color slants adjustment and correction, also can be in different colors to switch to meet in different areas such as web image design, printing and multimedia application.Special effects production in photoshop mainly by filter, passage of comprehensive application tools and finish. Including image effects of creative and special effects words such as paintings, making relief, gypsum paintings, drawings, etc commonly used traditional arts skills can be completed by photoshop effects. And all sorts of effects of production aremany words of fine arts designers keen on photoshop reason to study.Users in the use of Photoshop color function, will meet several different color mode: RGB, CMY K, HSB and Lab. RGB and CMYK color mode will let users always remember natural color, users of color and monitors on the printed page color is a totally different approach to create. The monitor is by sending red, green, blue three beams to create color: it is using RGB (red/green/blue) color mode. In order to make a complex color photographs on a continuous colour and lustre effect, printing technology used a cyan, the red, yellow and black ink presentation combinations from and things, reflect or absorb all kinds of light wavelengths. Through overprint) this print (add four color and create color is CMYK (green/magenta/yellow/black) yan color part of a pattern. HSB (colour and lustre/saturation/brightness) color model is based on the way human feelings, so the color will be natural color for customer computer translation of the color create provides an intuitive methods. The Lab color mode provides a create "don't rely on equipment" color method, this also is, no matter use what monitors.Photoshop expertise in image processing, and not graphics creation. It is necessary to distinguish between the two concepts. Image processing of the existing bitmap image processing and use edit some special effects, the key lies in the image processing processing; Graphic creation software is according to their own idea originality, using vector graphics to design graphics, this kind of software main have another famous company Adobe Illustrator and Macromedia company software Freehand.As the world's most famous Adobe Illustrator, feat graphics software is created, not graphic image processing. Adobe Illustrator is published, multimedia and online image industry standard vector illustration software. Whether production printing line draft of the designers and professional Illustrator, production multimedia image of artists, or Internet page or online content producers Illustrator, will find is not only an art products tools. This software for your line of draft to provide unprecedented precision and control, is suitable for the production of any small design to large complex projects.Adobe Illustrator with its powerful function and considerate user interface has occupied most of the global vector editing software share. With incomplete statistics global 37% of stylist is in use Adobe Illustrator art design. Especially the patent PostScript Adobe companybased on the use of technology, has been fully occupied professional Illustrator printed fields. Whether you're line art designers and professional Illustrator, production multimedia image of artists, or Internet page or online content producers, had used after Illustrator, its formidable will find the function and concise interface design style only Freehand to compare. (Macromedia Freehand is launched vector graphics software company, following the Macromedia company after the merger by Adobe Illustrator and will decide to continue the development of the software have been withdrawn from market).Adobe company in 1987 when they launched the Illustrator1.1 version. In the following year, and well platform launched 2.0 version. Illustrator really started in 1988, should say is introduced on the Mac Illustrator 88 version. A year after the upgrade to on the Mac version3.0 in 1991, and spread to Unix platforms. First appeared on the platform in the PC version4.0 version of 1992, this version is also the earliest Japanese transplant version. And in the MAC is used most is5.0/5.5 version, because this version used Dan Clark's do alias (anti-aliasing display) display engine is serrated, make originally had been in graphic display of vector graphics have a qualitative leap. At the same time on the screen making significant reform, style and Photoshop is very similar, so for the Adobe old users fairly easy to use, it is no wonder that did not last long, and soon also popular publishing industry launched Japanese. But not offering PC version. Adobe company immediately Mac and Unix platforms in launched version6.0. And by Illustrator real PC users know is introduced in 1997, while7.0 version of Mac and Windows platforms launch. Because the 7.0 version USES the complete PostScript page description language, make the page text and graphics quality got again leap. The more with her and Photoshop good interchangeability, won a good reputation. The only pity is the support of Chinese 7.0 abysmal. In 1998 the company launched landmark Adobe Illustrator8.0, making version - Illustrator became very perfect drawing software, is relying on powerful strength, Adobe company completely solved of Chinese characters and Japanese language support such double byte, more increased powerful "grid transition" tool (there are corresponding Draw9.0 Corel, but the effect the function of poor), text editing tools etc function, causes its fully occupy the professional vector graphics software's supremacy.Adobe Illustrator biggest characteristics is the use of beisaier curve, make simpleoperation powerful vector graphics possible. Now it has integrated functions such as word processing, coloring, not only in illustrations production, in printing products (such as advertising leaflet, booklet) design manufacture aspect is also widely used, in fact has become desktop publishing or (DTP) industry default standard. Its main competitors are in 2005, but MacromediaFreehand Macromedia had been Adobe company mergers.So-called beisaier curve method, in this software is through "the pen tool" set "anchor point" and "direction line" to realize. The average user in the beginning when use all feel not accustomed to, and requires some practice, but once the master later can follow one's inclinations map out all sorts of line, and intuitive and reliable.It also as Creative Suite of software suit with important constituent, and brother software - bitmap graphics software Photoshop have similar interface, and can share some plug-ins and function, realize seamless connection. At the same time it also can put the files output for Flash format. Therefore, can pass Illustrator let Adobe products and Flash connection.Adobe Illustrator CS5 on May 17, 2010 issue. New Adobe Illustrator CS5 software can realize accurate in perspective drawing, create width variable stroke, use lifelike, make full use of paint brush with new Adobe CS Live online service integration. AI CS5 has full control of the width zoom along path variable, and stroke, arrows, dashing and artistic brushes. Without access to multiple tools and panel, can directly on the sketchpad merger, editing and filling shape. AI CS5 can handle a file of most 100 different size, and according to your sketchpad will organize and check them.Here in Adobe Illustrator CS5, for example, briefly introduce the basic function: Adobe IllustratorQuick background layerWhen using Illustrator after making good design, stored in Photoshop opens, if often pattern is in a transparent layer, and have no background ground floor. Want to produce background bottom, are generally add a layer, and then executed merge down or flatten, with background ground floor. We are now introducing you a quick method: as long as in diagram level on press the upper right version, choose new layer, the arrow in the model selection and bottom ", "background can quickly produce. However, in Photoshop 5 after the movementmerged into one instruction, select menu on the "new layer is incomplete incomplete background bottom" to finish.Remove overmuch type clothWhen you open the file, version 5 will introduce the Illustrator before Illustrator version created files disused zone not need. In order to remove these don't need in the zone, click on All Swatches palette Swatches icon and then Select the Select clause in the popup menu, and Trash Unused. Click on the icon to remove irrelevant type cloth. Sometimes you must repeat selection and delete processes to ensure that clear palette. Note that complex documents will take a relatively long time doing cleanup.Put the fabric to define the general-screeningIn Illustrator5 secondary color and process color has two distinct advantages compared to establish for easy: they provide HuaGan tonal; And when you edit the general-screening prescription, be filled some of special color objects will be automatically updated into to the new color. Because process color won't let you build tonal and provides automatic updates, you may want to put all the fabric is defined as the general-screening. But to confirm Illustrator, when you are in QuarkXPress or when PageMaker quaclrochramatic must keep their into process of color.Preferred using CMYKBecause of Illustrator7 can let you to CMYK, RGB and HSB (hue, saturation, bright) color mode, so you want to establish color the creation of carefully, you can now contains the draft with the combination of these modes created objects. When you do, they may have output various kinds of unexpected things will happen. Printing output file should use CMYK; Only if you don't use screen display manuscript RGB. If your creation draft will also be used for printing and screen display, firstly with CMYK create printing output file, then use to copy it brings As ordered the copy and modify to the appropriate color mode.Information source：" Baidu encyclopedia "附录二中文译文Illustrator软件与Photoshop软件的区别Photoshop与Illustrator都是由Adobe公司出品的，而作为大家都比较熟悉的Photoshop软件，集图像扫描、编辑修改、图像制作、广告创意，图像输入与输出于一体的图形图像处理软件，深受广大平面设计人员和电脑美术爱好者的喜爱。
5-2 外文文献翻译
外文参考文献与翻译1、外文原文Analysis on the model of Chinese foreign tradeThis paper clarified contact actual implementation in China shall actively future import substitution and export-oriented strategy model combining the compound in view, and expounds the select and implement the strategic mode of economic exhibition should consider the problem.A country's foreign economic development strategy mode can be summarized as import substitution and export-oriented two basic modes of population, the market in China, its large capacity development space, but also vast exist, and per capita underdeveloped productivity development and utilization of natural resources are limited and economic efficiency, low enough and limited capital accumulation restraints. This kind of situation determines that China cannot implement single import-substituted strategy, also cannot implement single export-oriented strategy should be implemented, and import substitution and export-oriented combination of complex strategy, can we make full use of and development of domestic and foreign two resources and markets, to better achieve strategic balance and China's economic development goals.1. Implementation of import substitution and export-orientedstrategy model combining with China1.1 In China since last century the development situation of ppBy the middle of the last century, in a single planned economic system restriction and the influence of political and economic environment at home and abroad, China's foreign economic development strategy, with a single plan experience associated economic system closing economic development strategy mode namely single import-substituted strategy mode. In this economy under the guidance of the strategic thought, from the 1950s to the late 1970s, after 20 years of construction and development, our preliminary realizedindustrialization, creating a more complete suitable for China's national conditions of industrial system, and have achieved some results. However, implementing a single import substitution didn't achieve desired success. When our country is economically backward agricultural country, the construction funds shortage, industrial technology is low, national low per capita income, residents purchasing power and consumption level is very low, this kind of situation has determined the domestic market at the limited space in China. Therefore, in the implementation of import substitution strategy, development in the process of import substitution industry difficulties and of all obstacles. Meanwhile, the industrial system in China in countries under the highly protected is established and developed, enterprise mainly rely on increase production inputs to expand the scale of production, to realize the economic growth, its economic infrastructure, technology strength rather weak, the industrial equipment dated, enterprise's lack of market ideas, a lack of market awareness, consumption, high cost of enterprise and economic high quality and economic benefit is low, the international market competition ability and export disabilities, this kind of situation is serious impact on the alternative levels of improving, and restricted the development of import and export trade in China. First incompetence, and export export ability inadequacy and influenced directly restricts the import, introduce advanced technology from abroad, and the end result is the proportion of China in international trade from the 1953 1.5% dropped to 1977 o. 6%. And in the same period, Japan and other emerging east Asian economies but borrowing and seize this period world economic prosperity and international trade development will bring great opportunity, implement export-oriented strategy, make full use of the international market and its resources, and actively develop export-oriented economy, the development of its economy, its much to raise the economic strength. Unfortunately, our country missed the chance to develop export-oriented economy.1.2 Since China's reform and opening trade developmentIn 1979 China began to gradually implement opening, economic reform policy. Started from a single planned economy into planned economy to market economy, combining economic system then to 1992 established a system of socialist market economy. China's economic development strategy is also associated with the reform of the economic structure and get innovation, in the implementation of import substitution strategy is introduced,meanwhile, export orientation strategy, began to develop export-oriented economy and achieved considerable development. Our country is a developing country, industrialization development process is in the intermediate stage, according to the international development of the general rule of industrialized countries, a period of our country should implement Jackie import substitution and export orientation and development strategy, this is actually "composite" industrialization development strategy. According to the international division of labor theory, a comparative advantage in our country should be within the industry, such as labor-intensive industries through foreign absorbing funds, technology, project, talent and so on a series of can in a relatively short period of time effectively improve our country industrialization level, improve our product international market competition ability of the measures and formulate actively encourage export foreign trade policy, encourage and make efforts to expand the product export. However, in the international market competition developed countries in manipulation and control status, developing countries at a not equal status, developing country exports primary products imported products for export trading prices of primary products, developing countries disadvantage. Therefore, our country should in product, price, cost of a comparative advantage not capital intensive industries and tech-intensive industry field, continue to implement the strategy of import substitution to set up, consolidate, the development of domestic industrial base, perfect our country's industrial development system.2. Import substitution and combination of export-orientedstrategy is necessary2.1 China international and domestic market2.1.1 China trade development prospectsFor our country, our domestic market for development space, although economic volume is broad, only accounted for 25% of the Japanese, American 12%. But China's economic growth rate faster growth rate of 7% - every year, more than 9%, far higher than the 3% to 4% in developed countries. The national economy growth, determines the rapid growth of the national income, the rapid growth of the national income personal income increase makes residents, thereby improving the residents purchasing power and consumption levels, itexpanded the total social needs. Then, if the single export-oriented strategy, mainly rely on imported from abroad commodity to meet the need of domestic market consumption market, obviously doesn't work, is also unable to realize. Can predict, in our country's huge population base in front, the future of social purchasing power and aggregate demand will continue to improve, new consumer market will keep formation and appear. The expansion of domestic market this market and the growth of total, is not only the market "quantity" of simple expansion, and the market's "mass ' 'get promoted continuously. From this point, China's domestic market in the future for quite a long time, it is quite wide development space for the enterprise, it will be a huge market opportunities, it is import substitution industrial development opens up a broad prospect and space. Therefore, our country industrialization development direction, and its overall goal should be facing domestic market, its product market objectives should be also the domestic market of the consumers. That is, through meet domestic market demand, from domestic market to promote economic development. Therefore, impossible to China's economy as a whole and all industrial areas have included the export-oriented orbit.2.1.2 China's import and export orientedOf course, we cannot therefore refute export-oriented, if not export orientation, do not expand export, import substitution industry also could not succeed. In the development of import substitution of economy at the same time, should because when, in parts of the situation, part industry, part of the enterprise the export orientation strategy, establish the export-oriented economy. In order to make full use of the international economic conditions obtained through the development of export, import advanced technology and foreign equipment, production replace imported products supply domestic market, economic globalization and regional economic integration has become the trend of the economic development, if we put too much emphasis on the domestic market and ignore the huge international market is untimely; Similarly, if put too much emphasis on the international market and ignore the domestic market on economic growth role is one-sided. We should make full use of both domestic and overseas market to provide power for sustained economic growth, which is implemented to China's national conditions, namely, the economic development strategy, import substitution and export orientation and development strategy, essence is a "composite ' 'industrialization development strategy.3. Economic development strategy model selection anddetermined3.1 Should be taken into account in the domestic and international economic and political environment impactFor a nation to choose economic development strategy, establish economic development model, we should consider international economic and political environment, domestic social economic system and national economic development foundation and development goals of influence and restriction role. Must a country period of economic development strategy, economic development pattern should adapt and obey the period of international economic and political environment, domestic social economic system and the development of domestic economy based and development objectives, and with the international economic and political environment, domestic social economic system and the development of domestic economy foundation and development goals change constantly adjusted by due to the above, avoid the development of influence and restriction factor to changes in the economic and strategic decision making mistakes. International economic and political environment contains the international political environment and change period, international security environment and change, the international economic relations and its development trend, the international market dynamic and change trend and international economic relations theory and theories of the emergence, development, innovation and its role and influence. International economic and political environment is to develop export-oriented mode have to first consider the question, of course, international economic and political environment on import substitution industrialization is also a major influence. For the domestic social and economic system, main is to focus on this period of national economic system present situation and future trends and possible targets and related measures and policiesAnd regulations, etc. Domestic economic development foundation or refers to a country, including this situation of resource endowment, economic development at the stage and level, the domestic market product supply and demand relation and changes, economic structure and industrial technology present situation and upgrade of economic development tendency, and strategic goals and positioning, etc.Comprehensive national conditions, China's economic system, the international environment and the internal factors of economic and strategic consideration, the implementation of import substitution and export-oriented combination of economic development strategy will be long-term choice of science, and in the process of continuously according to information feedback, promptly to economic development strategy and the corresponding economic model appropriate adjustments, innovation, taking the strain of the new situation hair and requirements.3.2 The applicable conditions strategic mode to implement step, multilayered composite strategyFor this problem, should be taken into account in import substitution type and export-led strategic advantage and applicable environment and conditions, and two strategic mutual stimulative effect. Generally speaking, should not a comparative advantage in the capital tech-intensive industry, continue to import substitution competency of strategy. Because our country is still more weak industrial base, and economic development, industrial development imbalance in foundation is bad, the industry in the field of production the durable alternative consumer products is necessary, shall continue in the durable consumer goods industries in implementing import substitution, achieved certain industrial scale and industrial level, its import substitution fields namely expanded to the consumer durables industry and basic industries and development to export-oriented industries. And in industry developing fast, technical level is higher, and even reached the international advanced level of industrial areas should implement durable consumer goods, and to replace export-driven economic development. Meanwhile, a comparative advantage in China within the labor-intensive industries in introducing foreign capital, continued through a series of measures to increase competitiveness, adopt of export encouraged policies implementation export-led strategy.3.3 The government should take the necessary compound protection policy and incentivesImplement complex strategic pattern, the government should take the necessary compound protection policy and incentives. As to the import substitution industry cultivationand the protection and promotion of the industrial level, export orientation industry support and encourage and promote the original import substitution industry upgrading and translated into export-oriented industries. Practice has proved, import substitution and export-oriented model smoothly with whether the implementation of its success, all need consistent with the condition, need corresponding policy means and tools, and forming a corresponding mechanism and play a role. Meanwhile, the hybrid strategy model selection and implementation should also be considered, fully mobilize the enthusiasm of different market subjects, coordinating all social economic subject, in all sectors of the economy and regional balance development, and continuing to inject new vitality into the economic development and power, make development, the innovation to become the aware behavior, make enterprises from different social economic subject parties bits, all levels play its internal power and vigor, form complex economic model effect.3.4 Should export orientation and comprehensive evaluation of import-substituted strategy modeFor import substitution and export-oriented strategy pattern appraisal, should combine two strategic mode the essential contents of the structure and the development conditions and environmental analysis scientific conclusions could be drawn. The same countries in different stages of development of implementing import-substituted strategy or export-oriented strategy in the allocation of resources when different emphasis. Import-substituted strategy emphasize development and use of domestic market resources, export orientation strategy emphasized in comparative advantage, emphasize the international division of labor, develop and utilize international market resources. These two ideas respectively expounds import-substituted strategy and export-oriented strategy thinking of the meaning, but he does not throw import-substituted strategy or export-oriented strategy paper tries to know, combined, evaluation and utilization, no comprehensive analysis of their interaction and mutual influence and consequences, because appear not too full. Only put import-substituted strategy and export-oriented strategy development strategic comprehensive up comprehensive analysis, by comparing to clear their respective advantages, suitable condition and selection weaknesses and negative effect, can achieve in the implementation developing its long, avoid its short, realize two strategy model of complementary and alternative, accomplished alreadyfully develop domestic market, and develop international market; Made full use of domestic resources, and make full use of international resources.2、中文翻译中国对外贸易模式研究本文联系实际阐明我国今后应积极实施进口替代和出口导向相结合的复合型战略模式的观点，并阐述了在选择和实施经济展战略模式时应考虑的问题。
外文翻译：汽车制动系统2
Automobile Brake SystemThe braking system is the most important system in cars. If the brakes fail，the result can be disastrous. Brakes are actually energy conversion devices，which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes，the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow，stop，or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primarypurpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.The brake system is composed of the following basic components: the “master cylinder” which is located under the hood，and is directly connected to the brake pedal，converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid，specially designed to work in extreme conditions，fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag，which (hopefully) slows the car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).Basically，all car brakes are friction brakes. When the driver applies the brake，the control device forces brake shoes，or pads，against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.In most modern brake systems (see Figure 15.1)，there is a fluid-filled cylinder，called master cylinder，which contains two separate sections，there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. When the brake is pushed down，brake fluid is sent from the master cylinder to the wheels. At the wheels，the fluid pushes shoes，or pads，against revolving drums or disks. The friction between the stationary shoes，or pads，and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels，which，in turn，slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over a short period of time or goes down to about two thirds full，have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility，such as at the front wheels，which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair，the best procedure is to replace the compete line. If this is not practical，a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes，it consists of the brake drum，an expander，pull back springs，a stationary back plate，two shoes with friction linings，and anchor pins. The stationaryback plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes，the driver pushes pedal，the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes，the driver release the pedal，the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes，it has a metal disk instead of a drum. A flat shoe，or disk-brake pad，is located on each side of the disk. The shoes squeeze the rotating disk to stop the car. Fluid from the master cylinder forces the pistons to move in，toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type，the fixed-caliper type，and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.The brake system assemblies are actuated by mechanical，hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed，the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released，the piston returns to the initial position，the pull back springs retract the shoes，the fluid is forced back to the master cylinder and braking ceases.The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. A lever is pulled and the rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again，he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing. For this reason，it is separate from the foot brake uses cable or rods instead of the hydraulic system.Anti-lock Brake SystemAnti-lock brake systems make braking safer and more convenient，Anti-lock brakesystems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years，and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently，several automakers have introduced more sophisticated anti-lock system. Investigations in Europe，where anti-lock braking systems have been available for a decade，have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock，the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally，the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes like a driver might but at a much faster rate.In addition to their basic operation，anti-lock systems have two other things in common. First，they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times，the system stands ready to function but does not interfere with normal braking. Second，if the anti-lock system fail in any way，the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABSⅡ)，is a second generation design wildly used by European automakers such as BWM，Mercedes-Benz and Porsche. ABSⅡsystem consists of : four wheel speed sensor，electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with thewheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding，and as the teeth of the gear wheel move through this field，an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.The control unit’s function can be divided into three parts: signal processing，logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed，the logic section sends commands to the modulator assembly.Modulator assemblyThe hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder，it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves，two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation，the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation，it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.汽车制动系统制动系统是汽车中最重要的系统。
毕业论文 外文翻译格式
毕业论文外文翻译格式毕业论文外文翻译格式在撰写毕业论文时，外文翻译是一个重要的环节。
无论是引用外文文献还是翻译相关内容，都需要遵循一定的格式和规范。
本文将介绍一些常见的外文翻译格式，并探讨其重要性和应用。
首先，对于引用外文文献的格式，最常见的是使用APA（American Psychological Association）格式。
这种格式要求在引用外文文献时，先列出作者的姓氏和名字的首字母，然后是出版年份、文章标题、期刊名称、卷号和页码。
例如：Smith, J. D. (2010). The impact of climate change on biodiversity. Environmental Science, 15(2), 145-156.在翻译外文文献时，需要注意保持原文的准确性和完整性。
尽量避免意译或添加自己的解释，以免歪曲原文的意思。
同时，还需要在翻译后的文献后面加上“译者”和“翻译日期”的信息，以便读者可以追溯翻译的来源和时间。
其次，对于翻译相关内容的格式，可以参考国际标准组织ISO（International Organization for Standardization）的格式。
这种格式要求在翻译相关内容时，先列出原文，然后是翻译后的文本。
例如：原文：The importance of effective communication in the workplace cannot be overstated.翻译：工作场所有效沟通的重要性不容忽视。
在翻译相关内容时，需要注意保持原文的意思和语气。
尽量使用准确的词汇和语法结构，以便读者能够理解和接受翻译后的内容。
同时，还需要在翻译后的文本后面加上“翻译者”和“翻译日期”的信息，以便读者可以追溯翻译的来源和时间。
此外，对于长篇外文文献的翻译，可以考虑将其分成若干章节，并在每个章节前面加上章节标题。
这样可以使读者更容易理解和阅读翻译后的内容。
土建专业外文翻译2
附录1翻译适当有效的建筑材料是限制富有经验的结构工程师成就的主要原因之一。
早期的建筑者几乎都只使用木材，石头，砖块和混凝土。
尽管铸铁在修建埃及的金字塔中已被人们使用, 但是把它作为建筑材料却由于大量熔炼它比较困难而被限制。
藉由产业革命，然而，受到把铸铁作为建筑材料和在大量融炼它的能力的两者对其双重需要的影响。
John Smeaton，一个英国土木工程师, 在十八的世纪中时，是第一广泛地使用铸铁作为建筑材料的。
在1841之后，可锻金属被发展成更可靠的材料并且广泛地被应用。
尽管可锻金属优于铸铁,但仍有很多结构破坏从而需要有更可靠的材料。
钢便是这一需要的答案。
1856年的贝色麦转转炉炼钢法和后来发展的马丁平炉炼钢法的发明使以竞争的价格形成了生产建筑用钢并且兴起了建筑用钢在下个百年的快速发展。
钢的最严重缺点是它容易被氧化而需要被油漆或一些其他的适当涂料保护。
当钢被用于可能发生火灾环境时, 钢应该包围在一些耐火的材料中, 例如石料或混凝土。
通常，钢的组合结构不易被压碎除非是在冶金成分不好，低温的不利组合, 或空间压力存在的情况下。
建筑用铝仍然不广泛被在土木工程结构中用,虽然它的使用正在稳定地增加。
藉着铝合金作为一个适当的选择和对其进行热处理,可获得各式各样的强度特性。
一些合金所展现的抗压强度特性相似于钢, 除线形弹性模量大约是7,000,000 牛/平方厘米，相当于刚的三分之一。
质量轻和耐氧化是铝的两个主要优点。
因为它的特性对热处理是非常敏感的,当铆接或焊接铝的时候，一定要小心仔细。
一些技术已为制造预制铝组合配件及形成若干的美丽的设计良好的外型结构的铝制结构而发展起来。
组合房屋配件制造的一般程序藉由螺栓连接，这似乎是利用建筑用铝的最有前途的方法。
加强和预应力混凝土是主要的建筑材料。
天然的水泥混凝土已经被使用长达数世纪之久。
现代的混凝土建筑兴起于十九世纪中叶,尽管人造水泥被Aspidin ，一个英国人于1825年申请了专利. 虽然一些建筑者和工程师在十九世纪后期用钢筋混凝土作实验, 但作为一种建筑材料它占统治地位是在二十世纪初期。
第二专业外文翻译原版
Listen to the customerV.KUMARJ.Mack Robinson College of Business,Georgia State University,Atlanta,GaThe year 2009 was a difficult year for Domino’s Pizza, an established restaurant chain known for its prompt delivery and superior service. Sluggish sales, a social media scandal (employees posted a video of themselves on YouTube tampering with the food) and the results of a consumers’ taste preference survey placing the pizza chain last did not help the morale of the company. Consumers’ preferences were changing and Domino’s needed to catch up with its competitors.On December 16, 2009, just shy of its 50th birthday, the pizza chain announced it was introducing a new and improved pizza. Everything from the crust to the cheese to the sauce had been changed from the original recipe. The chief marketing officer, Russell Weiner, announced in a press release. ” We’ve created a pizza to reflect what consumers are looking for. We’re not talking about a slightly altered version of our previous pizza. It’s a com pletely new pizza reinvented from the crust up, and we are proud of it. To us, it’s as big as McDonald’s changing the Big Mac, or Burger King reinventing the Whopper. We spent the last 18 months reinventing the brand in anticipation of our 50th anniversary. Our inspiration came from the thousands of direct consumer feedback messages on several social media channels.”Although many critics are skeptical of the new Domino’s pizza, equating it with the “new Coke” debacle, Weiner mentions an increasingly impo rtant marketing strategy ---maximizing the value of customer knowledge or feedback. In this article, we discuss how firms can utilize social media to gather valuable insights from customers and, in turn, how those insights can be utilized by the firm.Complaints and Compliments Lead To CashCustomers’ insights have value. Their feedback can serve as report cards to firms about existing products and services and tell firms if they are meeting customer expectations. Customer feedback not only identifies areas in need of improvement,but also helps provide suggestions and solutions for future upgrades and modifications. Customer insights also offer new ideas for completely new products and services. Given that the failure rate of new products is between 40 and 75 percent, firms should be particularly concerned about what their customers say they what and need. If firms can utilize their customers’ knowledge the failure rate of new products can be greatly reduced. Also, by listening to customers, firms can improve service quality. New and improved products and services can lead to higher profits. There is clearly a financial value to be gained by utilizing customer Knowledge Value (CKV) (See Kumar, V., Lerzan Aksoy, Bas Donkers, Rajkumar Venkatesan, Thorsten Wiesel and Sebastian Tillmanns, ” Customer Engagement Value: Defining, Measuring and Maximizing, ” forthcoming , Journal of Service Research). Explicitly, CKV is the value a customer adds to the firm through his or her feedback.For example, CKV can be the additional profits earned or the money saved as a result of a customers’ idea. If customers’ complaints, compliments and comments are properly managed and addressed, firms will definitely benefit from stronger and healthier relationships with their customers. In addition, if firms offer new products and services that meet their customers’ needs better than those offered by competitors, they will see higher profits. Companies that quickly implement strategies to maximize the CKV of their customers will realize financial benefits that competitors who do not utilize customer knowledge will not realize.Constructive CriticismThe key to obtaining customer feedback and utilizing customer knowledge is to establish a quick and easy medium for communication. Providing feedback should be natural, interactive and effortless—and for these reasons social media is particularly useful tool to maximize the CKV of customers. Perhaps the biggest advantage of social media is the direct and unforced line of communication it creates between the firm and the customer. Social media can be defined as a group of Internet-based application that build on the ideological and technological foundation of web 2.0 and that allow the creation and exchange of user-generated content.Through social media channels customers do not have to take the effort to call acustomer service number to leave a comment or take time to fill out a comment card. Social media not only makes gathering insights from consumers easier than traditional means (telephone , hotlines, company websites, surveys etc.) but it also makes it easier to get quality feedback . This is because consumers using social media are already engaged exploring the social media channel. Firms do not have to chase customers for their feedback but instead have attentive customers coming to them voluntarily. Also ，it is more likely that users of social media will give both compliment and complaints, as opposed to customers angrily calling a customer service hotline. It is usually only very emotional and dissatisfied customers who take the time to make a phone call or write a letter to a company, whereas on Facebook fan pages(profile pages for firms) it is common for happy customers to leave positive remarks or constructive criticism. It is vital to note here that firms should not be afraid of criticism no social media channels. Firms need to know what they are doing right in addition to what they are doing wrong.Social media enables firms to conserve and maintain an open dialogue with customers. By allowing customers to communicate in real time, customers believe they are being heard and hence are more likely to offer valuable insights. The reciprocity of social media is particularly powerful. Customers’ opinions and comments commonly receive responses and are not just left unheard in the virtual world. Also, in an open dialogue, firms are better able to assess latent customer needs. Customers may not always explicitly state what they need, but by reading in between the lines firms may be able to discover hidden needs and be able to address those needs before their competitors can.Social media enable firms to acquire knowledge similar to that of expensive focus groups, but at a fraction of the cost and in mass numbers. Furthermore, unlike traditional market research techniques that frequently “hound the customer down,” social media allows firms to create a friendly space where customers share their feelings and knowledge. There are several social media channels, each one distinct, that firms van choose to employ.Fan Pages Make Feedback FunFirms must decide how they want to involve their customers in the new product development process. Customers can act either as sources of information or as co-developers. Co-developers are individuals who work with the firm to help create new products and services.In the first case, firms pay attention to what customers have to say and make adjustments to meet customer expectations. In the second case, customers actually collaborate with the firm and are deeply involved with the development of new products. Their level of participation is much higher than that of customers who act as sources of information. In this scenario, customers are empowered and feel ownership in the firm. Recent research advocates that firms treat their customer as a active players rather than a passive audience. However, it is still vital to encourage customers to behave as sources of information.Facebook fan pages are essentially firm profile pages that let firms launch strategies that encourage their customers to behave as knowledge resource. These pages are a touch point for firms and customers. Here firms can, in real time, interact with customers; the more interactive firms make their fan pages, the more likely fans will be to share their knowledge with the firm. Fan pages are excellent places for firms to facilitate discussion and give fans topics of conversation. More important, they engage customers and retrieve information in a non-intrusive way.One strategy to keep customers coming back with their feedback and ideas is to offer exclusive coupons and deals on fan pages. Special coupon codes for free shipping or other discounts are great incentives that keep customers engaged. Customers also see a firm’s fan page as a place to express emotions about the firm. Here, unlike other traditional avenues, customers frequently post admiration for the firm. An interesting hypothesis worth investigation is that customer comments on social networking sites create a halo effect. It is possible that lots of positive feedback from some users influences other users to like a given product even more after reading the positive feedback. Nonetheless, it is important that firms consistently communicate with their fans and constantly provide them with topics of discussion. On these fan pages, many firms explicitly ask for feedback.Knowing What Your Customers KnowFan pages are also an excellent means for firms to learn what their customers know. David Yurman, an upscale jeweler, directly asks (as opposed to requesting photos) its fans on Facebook how they wear its products. Obtaining customer knowledge gives firms the valuable opportunity to learn about their own products from a new perspective.Social networking sites are an excellent platform for launching contests that motivate customers to share their knowledge and work with firms. Contests make firm profile pages more interactive and also give customers an incentive to give firms specific information. Express, a clothing company , launched a contest that entered a customer in a drawing for $250 gift card for every clothing review he or she submitted. For every picture a customer submitted wearing Express clothing he or she would be entered five times in the drawing. These product reviews potentially provided management with accounts of firsthand experience of how the clothing fit, how it was accepted by its customer base and how the clothing was used (day vs. night, office vs. casual etc.). Through incentive Express was able to retrieve vital information about its products from its customer base.While social networking site are best used to treat customers as sources of information, they can also be used to encourage customers to act as co-value creators. One company that uses contests to incentivize customers to actually participate in the new product development process is Threadless Tees, an online t-shirt printing business whose model is built upon customer participation. Its fan page has a link to its company Web site, which encourages customers to participate in the creation of new designs.Virtual Communities Help Create ValueVirtual communities and blogs allow firms to encourage customers to act as both sources of information and, perhaps more valuable, as co-developers. While social networking sites have vast numbers of customers contributing their insights, virtual communities and blogs provide feedback from a smaller but typically more knowledgeable group of customers. In virtual communities, members with commoninterests share valuable information with one another. Firms should definitely seek this information and take advantage of this shared knowledge.Organizations can also create their own virtual communities for a specific audience and explicitly ask for suggestion.For instance, the University of Tesas at Austin has recently launched a university wide program called Ideas of Texas to note creative problem solving on the campus.Firm-created virtual communities are vital for incorporating customers’ insights into the new product and service development process. They also allow for firms to actually ask their customers’ insights and attribute them to increased profits and savings. The idea is for firms to create virtual communities made up of a small but knowledgeable group of customers. Firms should facilitate discussion with these members only to acquire the knowledge they want, but to discover widen customer insights of which they were unaware. Firms must engage in dialogue with these members and it is important that reports are created by the firm at consistent intervals time to ensure that insights are properly recorded and evaluated.In this open dialogue situation, members can freely averse with one another and the firm. Also, because they will ownership in the firm due to their heightened value as co-developers, they will be more motivated to offer bright new ideas. These members can be involved in every stage of the new product development process from idea conception to evaluation of the new idea to development of a prototype to even spreading word of mouth during the launch of the new product. Ultimately they can be credited for value creation (profit, sales etc.) by the firm. The profits realized from the new products these customers helped to design and create through their insights and involvement can be attributed as their CKV.While some companies may only want to collaborate with these members, others may want to incentivize membership to the community through profit sharing or shared intellectual property .In this scenario, customers who are highly involved in the development of new products actually get a cut of the profits or own the patents. Either way, using virtual communities as an idea bank keeps the pipeline of ideas for new products flowing, so when one idea does not meet a firm’s objectives anotheridea is waiting to become a reality.Monetizing Customer FeedbackAllowing community members to vote on different aspects of a new product or service is another method of evaluating customer insights. Brewtopia, a company that specializes in brewing customized beer for its customers, was conceived based on the notion that customers should play an active role in the creation of products. The startup created an online community in which members voted upon every last detail of the beer, from alcohol content to the packaging. The beer was then brewed according to the customer specifications. The initial members were compensated with” viral equity” and were promised dividends based on how well the beer sold. The members were particularly motivated to develop a high quality beer not only because they were beer connoisseurs but because they felt ownership in Brewtopia. Furthermore, the unique customer-driven concept created demand for the beer before it was even released. And Brewtopia w as quickly in serious talks with Trader Joe’s supermarkets to distribute the product. Brewtopia shows how utilization of customer knowledge can be monetized and how customers can be credited for their ideas.Creating Organizational CultureWhile methods like the Three P approach or the voting approach are a means to evaluate customer insights, they are only a portion of the customer knowledge management process. It is vital that firms are organized in a manner such that new ideas are quickly communicated to upper management, efficiently delegated to project managers and then turned into reality.The concept of knowledge departments may be new to many firms but may aid in interdepartmental communication. The general idea is to have a manager in charge of a team of employees create highly engaging social networking sites, virtual communities and blogs. They facilitate discussion and employ the strategies mentioned to learn what their customers know. They should create reports on a regular basis evaluating th eir customers’ ideas and feedback.The knowledge manager, in turn, should analyze the reports and look at the big picture of what customers are saying. It should then be the knowledge manager’s dutyto quickly address customer concerns within the organization. For example, he or she could give recommendations to the CMO, who in turn could assess how these recommendations fit within the firm’s objectives and then delegate projects to project managers. The point is for customer ideas and feedback to quickly move through the organization and more importantly not get lost or forgotten .Customer knowledge is only valuable if it utilized by the firm.Let Customers Know Their ValueWhile customer concerns should be addressed within the firm, it is equally important that customers know that their voices have been heard.It is very important that, when customers post complaints on fan pages or blogs, a company representative responds in a meaningful manner. After a customer expressed on one firm’s fan page that she wi shed the firm would ship to Canada, a representative promptly responded that the firm was looking into it. These types of actions greatly strengthen the customer relationship. It is also a good idea to let customers know that they participated in the new product development process by inspiring new ideas. When firms make customers feel important they strengthen the customer relationship, which research has shown has a great competitive edge.However, it is important to note that though utilizing customer feedback is very important there are certain caveats firms should keep in mind. First, firms must take into consideration the credibility of the people offering feedback. It is quite possible that competitors can purposely leave misleading feedback. While this is entirely unethical it is not unthinkable. Also, firms must be very careful not to become too reliant upon customers for innovation ideas. Firms must still concentrate on encouraging employees to offer insights and suggestions for new products and services. Finally, firms should also remember that, though social media has an increasingly wide reach, it is still only used by a segment of the market. Thus, traditional market research methods may still be the only way to listen to their feedback so they are not neglected.Key TakeawaysIn summary, customer feedback is of great value to firms because it allows firmsto learn what their customers know. This knowledge greatly aids in the new product and service development process. When firms truly understand what their customers want and how to deliver their customers’ exceptions, they have an edge over their completion. Furthermore, because the concept of using customer feedback to generate value is still fairly new, especially in a business-to-consumer context, firms that adopt this perspective will experience greater competitive advantage. Firms must decide how they want their customers to contribute their knowledge: They can act as sources of information or as co-developers. Social media can be used to encourage customers to play both roles. While sites like Facebook can primarily be utilized to generate ideas from customers, firm-created virtual communities can encourage customers to co-develop new products with firms.Firm must have an internal organizational structure that takes advantage of customer generated ideas and must be able to quickly respond to customer concerns. The goal of firms should be to keep the pipeline of ideas flowing. Utilizing customer feedback ultimately strengthens firms’ relation ships with their customers by increasing interaction and showing customers that their insights and concerns are not only acknowledged, but addressed.。
数控铣床毕业设计外文翻译 2
7.1 INTRODUCTIONAfter lathes, milling machines are the most widely used for manufacturing applications. In milling, the workpiece is fed into a rotating milling cutter, which is a multi-point tool as shown in Fig. 7.1, unlike a lathe, which uses a single point cutting tool. The tool used in milling is called the milling cutter.Fig. 7.1Schematic diagram of a milling operationThe milling process is characterised by:(i)Interrupted cutting Each of the cutting edges removes materialfor only a part of the rotation of the milling cutter. As a result, the cutting edge has time to cool before it again removes material.Thus the milling operation is much more cooler compared to the turning operation. This allows for a much larger material rates.(ii)Small size of chips Though the size of the chips is small, in view of the multiple cutting edges in contact a large amount of material is removed and as a result the component is generally completed ina single pass unlike the turning process which requires a largenumber of cuts for finishing.(iii)Variation in chip thickness This contributes to the non-steady state cyclic conditions of varying cutting forces during the contact of the cutting edge with the chip thickness varying from zero to maximum size or vice versa. This cyclic variation of the force can excite any of the natural frequencies of the machine tool system and is harmful to the tool life and surface finish generatedA milling machine is one of the most versatile machine tools. It is adaptable for quantity production as well as in job shops and tool rooms. The versatility of milling is because of the large variety of accessories and tools available with milling machines. The typical tolerance expected from the process is about ±0.050 mm.7.2 TYPES OF MILLING MACHINESTo satisfy various requirements milling machines come in a number of sizes and varieties. In view of the large material removal ratesmilling machines come with a very rigid spindle and large power. The varieties of milling machines available are:(i) Knee and Column type(a) horizontal(b) vertical(c) universal(d) turret typeThese are the general purpose milling machines, which have a high degree of flexibility and are employed for all types of works including batch manufacturing. A large variety of attachments to improve the flexibility are available for this class of milling machines.(ii) Production (Bed) type(a) simplex(b) duplex(c) triplexThese machines are generally meant for regular production involving large batch sizes. The flexibility is relatively less in these machines which is suitable for productivity enhancement.(iii) Plano millersThese machines are used only for very large workpieces involving table travels in meters.(iv) Special type(a) Rotary table(b) Drum type(c) Copy milling (Die sinking machines)(d) Key way milling machines(e) Spline shaft milling machinesThese machines provide special facilities to suit specific applications that are not catered to by the other classes of milling machines.7.2.1 Knee and Column Milling MachinesThe knee(升降台) and column type is the most commonly used machine in view of its flexibility and easier setup. A typical machine construction is shown in Fig. 7.2 for the horizontal axis. The knee houses the feed mechanism and mounts the saddle and table. The table basically has the T-slots running along the X-axis for the purpose of work holding. The table moves along the X-axis on the saddle while the saddle moves along the Y-axis on the guide ways provided on the knee.The feed is provided either manually with a hand wheel or connected for automatic by the lead screw, which in turn is coupled to the main spindle drive. The knee can move up and down (Z-axis) on a dovetail provided on the column.Fig. 7.2 Horizontal knee and column type milling machineThe massive column at the back of the machine houses all the power train including the motor and the spindle gearbox. The power for feeding the table lead screw is taken from the main motor through a separate feed gearbox. Sometimes a separate feed motor is provided for the feed gearbox as well.While the longitudinal and traverse motions are provided with automatic motion, the raising of the knee is generally made manually.The spindle is located at the top end of the column. The arbour used to mount the milling cutters is mounted in the spindle and is provided with a support on the other end to take care of the heavy cutting forces by means of an overarm with bearing. As shown in Fig.7.2 the overarm extends from the column with a rigid design. The spindle nose has the standard Morse taper of the suitable sizedepending upon the machine size.The milling cutters are mounted on the arbour at any desired position, the rest of the length being filled by standard hardened collars of varying widths to fix the position of the cutter. The arbour is clamped in the spindle with the help of a draw bar and then fixed with nuts.Milling machines are generally specified on the following basis:(i) Size of the table, which specifies the actual working area on the table and relates to the maximum size of the workpiece that can be accommodated.(ii) Amount of table travel, which gives the maximum axis movement that is possible.(iii) Horse power of the spindle, which actually specifies the power of the spindle motor used. Smaller machines may come with 1 to 3 hp while the production machines may go from 10 to 50 hp.Another type of knee and column milling machine is the vertical axis type. Its construction is very similar to the horizontal axis type, except for the spindle type and location.The vertical axis milling machine is relatively more flexible (Fig. 7.4) and suitable for machining complex cavities such as die cavities in tool rooms. The vertical head is provided with a swiveling facility in horizontal direction whereby the cutter axis can be swivelled. This isuseful for tool rooms where more complex milling operations are carried out.The spindle is located in the vertical direction and is suitable for using the shank mounted milling cutters such as end mills, In view of the location of the tool, the setting up of the workpiece and observing the machining operation is more convenient.Fig, 7.3 Vertical knee and column type milling machineFig.7.4 Some of the milling operations normally carried out on vertical axis machinesThe universal machine has the table which can be swivelled in a horizontal plane at about 45o to either the left or right. This makes the universal machine suitable for milling spur and helical gears as well as worm gears and cams.7.2.2 Bed Type Milling MachineIn production milling machines it is desirable to increase the metal removal rates. If it is done on conventional machines by increasingthe depth of cut, there is possibility of chatter. Hence another varietyof milling machines named as bed type machines are used which are made more rugged and are capable of removing more material. The ruggedness is obtained as a consequence of the reduction in versatility.The table in the case of bed type machines is directly mounted on the bed and is provided with only longitudinal motion.The spindle moves along with the column to provide the cutting action. Simplex machines (Fig. 7.5) are the ones with only one spindle head while duplex machines have two spindles (Fig. 7.6). The two spindles are located on either side of a heavy workpiece and remove material from both sides simultaneously.Fig. 7.5 Simplex bed type milling machineFig. 7.6 Duplex bed type milling machine7.3 MILLING CUTTERSThere are a large variety of milling cutters available to suit specific requirements. The versatility of the milling machine is contributed toa great extent by the variety of milling cutters that are available.7.3.1 Types of Milling CuttersMilling cutters are classified into various types based on a variety of methods.(i) Based on construction:(a) Solid(b) Inserted tooth typeBased on mounting:(a) Arbor mounted(b) Shank mounted(c) Nose mountedBase on rotation:(a) Right hand rotation (counter clockwise)(b) Left hand rotation (clockwise)Based on helix:(a) Right hand helix(b) Left hand helixMilling cutters are generally made of high speed steel or cemented carbides. The cemented carbide cutters can be of a brazed tip variety or with indexable tips. The indexable variety is more common since it is normally less expensive to replace the worn out cutting edges than to regrind them.Plain milling cutters These are also called slab milling cutters and are basically cylindrical with the cutting teeth on the periphery as shown in Fig. 7.7. These are generally used for machining flat surfaces.Fig. 7.7 Arbor mounted milling cutters for general purposeLight duty slab milling cutters generally have a face width, which is small of the order of 25 mm. They generally have straight teeth and large number of teeth.Heavy duty slab milling cutters come with a smaller number of teeth to allow for more chip space. This allows taking deeper cuts and consequently high material removal rates.Helical milling cutters have a very small number of teeth but a large helix angle. This type of cutter cuts with a shearing action, which can produce a very fine finish. The large helix angle allows the cutter to absorb most of the end load and therefore the cutter enters and leaves the workpiece very smoothly.Side and face milling cutters These have the cutting edges not only onthe face like the slab milling cutters, but also on both the sides. As aresult, these cutters become more versatile since they can be used for side milling as well as for slot milling.Staggered tooth side milling cutters are a variation where the teeth are arranged in an alternate helix pattern. This type is generally used for milling deep slots, since the staggering of teeth provides for greater chip space.Another variation of the side and face cutter is the half side milling cutter, which has cutting edges only on one side. This arrangement provides a positive rake angle and is useful for machining on only one side. These have a much smoother cutting action and a long tool life. The power consumed is also less for these cutters.Fig. 7.8Special forms of arbor mounted milling cuttersSlitting saws The other common form of milling cutters in the arbor mounted category is the slitting saw. This is very similar to a saw blade inappearance as well as function. Most of these have teeth around the circumference while some have side teeth as well. The thickness of these cutters is generally very small and is used for cutting off operations or for deep slots.Special form cutters In addition to the general type of milling cutters described above, there are a large number of special form milling cutters available which are used for machining specific profiles.Angular milling cutters are made in single or double angle cutters for milling any angle such as 30, 45 or 60o Form relieved cutters are made of various shapes such as circular, corner rounding, convex or concave shapes.T-slot milling cutters are used for milling T-slots such as those in the milling machine table. The central slot is to be milled first using an end mill before using the T-slot milling cutter. Woodruff key seat milling cutters are used for milling as the name suggests, woodruff key seats Some other special form cutters are dovetail milling cutters and gear milling cutters.End mills These are shank mounted as shown in Fig. 7.9 and are generally used in vertical axis milling machines. They are used for milling slots, key ways and pockets where other type of milling cutters cannot be used. A depth of cut of almost half the diameter can be taken with the end mills.The end mills have the cutting edge running through the length of the cutting portion as well as on the face radially up to a certain length. The helix angle of the cutting edge promotes smooth and efficient cutting even at high cutting speeds and feed rates. High cutting speeds(转速?) are generally recommended for this type of milling cutters.Fig. 7.9 Shank mounted milling cutters and various types of end mills There are a large variety of end mills. One of the distinctions is based on the method of holding, i.e., the end mill shank can be straight or tapered. The straight shank is used on end mills of small size and held in the milling machine spindle with the help of a suitable collet. The tapered shank can be directly mounted in the spindle with the help of the selfholding taper. If the taper is small compared to the spindle taper, then an adopter accommodating both the tapers is used.The end teeth of the end mills may be terminated at a distance from the cutter center or may proceed till the center (Fig. 7.9 f). Those with the cutting edge up to the center are called slot drills or end cutting end mills since they have the ability to cut into the solid material (Fig. 7.9 g). The other type of end mills which have a larger number of teeth cannot cut into solid material and hence require a pilot hole drilled before a pocket is machined.The cutting edge along the side of an end mill is generally straight and sometimes can be tapered by grinding on a tool and cutter grinder such that the draft required for mould and die cavities can be automatically generated.第七章铣削7.1介绍除了车床，铣床是制造应用中最广泛使用的。
外文翻译原文
Stability of hybrid system limit cycles: application to the compass gait biped RobotIan A. Hiskens'Department of Electrical and Computer EngineeringUniversity of Illinois at Urbana-ChampaignUrbana IL 61801 USAAbstractLimit cycles are common in hybrid systems. However the non-smooth dynamics of such systems makes stability analysis difficult. This paper uses recent extensions of trajectory sensitivity analysis to obtain the characteristic multipliers of non-smooth limit cycles. The stability of a limit cycle is determined by its characteristic multipliers. The concepts are illustrated using a compass gait biped robot example.1 IntroductionHybrid system are characterized by interactions between continuous (smooth) dynamics and discrete events. Such systems are common across a diverse range of application areas. Examples include power systems [l], robotics [2, 3], manufacturing [4] and air-traffic control [5]. In fact, any system where saturation limits are routinely encountered can be thought of as a hybrid system. The limits introduce discrete events which (often) have a significant influence on overall behaviour.Many hybrid systems exhibit periodic behaviour. Discrete events, such as saturation limits, can act to trap the evolving system state within a constrained region of state space. Therefore even when the underlying continuous dynamics are unstable, discrete events may induce a stable limit set. Limit cycles (periodic behaviour) are often created in this way. Other systems, such as robot motion, are naturally periodic.Limit cycles can be stable (attracting), unstable (repelling) or non-stable (saddle). The stability of periodic behaviour is determined by characteristic (or Floquet) multipliers. A periodic solution corresponds to a fixed point of a Poincare map. Stability of the periodic solution is equivalent to stability of the fixed point. The characteristic multipliers are the eigenvalues of the Poincare map linearized about the fixed point. Section 4 reviews the connection between this linearized map and trajectory sensitivities.Poincare maps have been used to analyse the stability of limit cycles in various forms of hybrid systems. However calculation of the underlying trajectory sensitivities has relied upon particular system structures, see for example [7, 8], or numerical differencing, for example [6]. This paper uses a recent generalization of trajectory sensitivity analysis [9] to efficiently detemine the stability of limit cycles in hybrid systems.A hybrid system model is given in Section 2. Section 3 develops the associated variational equations. This is followed in Section 4 by a review of stability analysis of limit cycles. Conclusions and extensions are presented in Section 5.2 ModelDeterministic hybrid systems can be represented by a model that is adapted from a differential-algebraic (DAE) structure. Events are incorporated via impulsive action and switching of algebraic equations, giving the Impulsive Switched (DAIS) modelwheren x R ∈ are dynamic states and my R ∈ are algebraic states;(.)δ is the Dirac delta;(.)u is the unit-step function;,:n mnj f h RR +→；(0)(),:i n mng gR R ±+→; some elements of each(.)gwill usually be identicallyzero, but no elements of the composite g should be identically zero; the()i g± aredefined with the same form as g in (2), resulting in a recursive structure for g;,dey yare selected elements of y that trigger algebraic switching and state reset(impulsive) events respectively;dyandeymay share common elements.The impulse and unit-step terms of the DAIS model can be expressed in alternative forms:Each impulse term of the summation in (1) can be expressed in the state reset formwhere the notation x+denotes the value of x just after the reset event, whilstx-andy-refer to the values of x and y just prior to the event.The contribution of each()i g± in (2) can be expressed aswith (2) becomingThis form is often more intuitive than (2).It can be convenient to establish the partitionswherex -are the continuous dynamic states, for example generator angles, velocities andfluxes;z are discrete dynamic states, such as transformer tap positions and protection relay logic states;λ are parameters such as generator reactances, controller gains and switching times. The partitioning of the differential equations f ensures that away from events,x -evolves according to .(,)x y f x --=, whilst z and λ remain constant. Similarly,the partitioning of the reset equationsjhensures thatx -and λ remain constantat reset events, but the dynamic states z are reset to new values given by(,)jh y x z--+=-. The model can capture complex behaviour, from hysteresis and non-windup limits through to rule-based systems [l]. A more extensive presentation of this model is given in [9].Away from events, system dynamics evolve smoothly according to the familiardifferential-algebraic modelwhere g is composed of(0)gtogether with appropriate choices of()i g- or()i g+ ,depending on the signs of the corresponding elements of yd. At switching events (2),some component equations of g change. To satisfy the new g = 0 equation, algebraic variables y may undergo a step change. Reset events (3) force a discrete change in elements of x. Algebraic variables may also step at a reset event to ensure g= 0 is satisfied with the altered values of x. The flows of and y are defined respectively aswhere x(t) and y(t) satisfy (l),(2), along with initial conditions,3 'Ikajectory SensitivitiesSensitivity of the flowsxφandyφto initial conditionsxare obtained bylinearizing (8),(9) about the nominal trajectory,The time-varying partial derivative matrices given in (12),(13) are known as trajectory sensitiuities, and can be expressed in the alternative formsThe formxx ,xy provides clearer insights into the development of thevariational equations describing the evolution of the sensitivities. The alternative form 0(,)x t x φ, 0(,)yt x φ highlights the connection between the sensitivities and the associated flows. It is shown in Section 4 that these sensitivities underlie the linearization of the Poincare map, and so play a major role in determining the stability of periodic solutions.Away from events, where system dynamics evolve smoothly, trajectory sensitivities 0xx andxy are obtained by differentiating (6),(7) withrespect to 0x.This giveswhere/xf x f≡∂∂, and likewise for the other Jacobian matrices. Note that,,,xyxyf fg gare evaluated along the trajectory, and hence are time varyingmatrices. It is shown in 19, 101 that the numerical solution of this(potentially high order) DAE system can be obtained as a by-product of numerically integrating the original DAE system (6),(7). The extra computational cost is minimal. Initial conditions forxx are obtained from (10) aswhere I is the identity matrix. Initial conditions for 0zy follow directly from(17),Equations (16),(17) describe the evolution of the sensitivitiesxx andxybetween events. However at an event, the sensitivities are generally discontinuous. It is necessary to calculate jump conditions describing the step change inxx andxy . For clarity, consider a single switching/reset event, so the model (1),(2) reduces(effectively) to the formLet （(),()x y ττ） be the point where the trajectory encounters the triggering hypersurface s(x,y) = 0, i.e., the point where an event is initiated. This point is called the junction point and r is the junction time. It is assumed the encounter is transversal.Just prior to event triggering, at time τ-, we haveSimilarly,,y x++are defined for time τ+, just after the event has occurred. It isshown in [9] that the jump conditions for the sensitivitiesxx are given byThe assumption that the trajectory and triggering hypersurface meet transversally ensures a non-zero denominator for 0x τ The sensitivitiesxy . immediatelyafter the event are given byFollowing the event, i.e., for t τ+>, calculation of the sensitivities proceeds according to (16),(17) until the next event is encountered. The jump conditions provide the initial conditions for the post-event calculations.4 Limit Cycle AnalysisStability of limit cycles can be determined using Poincare maps [11, 12]. This section provides a brief review of these concepts, and establishes the connection with trajectory sensitivities.A Poincark map effectively samples the flow of a periodic system once every period. The concept is illustrated in Figure 1. If the limit cycle is stable, oscillations approach the limit cycle over time. The samples provided by the corresponding Poincare map approach a fixed point. A non-stable limit cycle results in divergent oscillations. For such a case the samples of the Poincare map diverge.To define a Poincare map, consider the limit cycle Γshown in Figure 1. Let ∑ be a hyperplane transversal to Γ at*x. The trajectory emanating from*xwill again encounter ∑ at*xafter T seconds, where T is the minimum period of the limit cycle. Due to the continuity of the flowxφwith respect to initial conditions, trajectories starting on ∑ in a neighbourhood of*x. will, in approximately T seconds, intersect ∑ in the vicinity of*x. Hencexφand ∑define a mappingwhere()kT x ττ≈ is the time taken for the trajectory to return to ∑. Complete details can hefound in [11,12]. Stability of the Paincare map (22) is determined by linearizing P at the fixed point*x, i.e.,From the definition of P(z) given by (22), it follows that DP(*x) is closely related to thetrajectory sensitivities***(,)(,)xxT T x x xφφ∂≡∂. In fact, it is shown in [11] thatwhereσ is a vector normal to ∑.The matrix*(,)xT x φis exactly the trajectory sensitivity matrix after one period of the limitcycle, i.e., starting from*xand returning to*x. This matrix is called the Monodromymatrix .It is shown in [11] that for an autonomous system, one eigenvalue of *(,)xT x φ isalways 1, and the corresponding eigenvector lies along **(,)f y x The remaining eigenvalues*(,)xT x φof coincide with the eigenvalues of DP(*x ), and are known as the characteristicmultipliers mi of the periodic solution. The characteristic multipliers are independent of the choice of cross-section ∑ . Therefore, for hybrid systems, it is often convenient to choose ∑ as a triggering hypersurface corresponding to a switching or reset event that occurs along the periodic solution.Because the characteristic multipliers mi are the eigenvalues of the linear map DP(x*), they determine the stability of the Poincarb map P(kx), and hence the stability of the periodic solution.Three cases are of importance: 1. Alli m lie within the unit circle, i.e., 1im<,i ∀.The map is stable, so the periodicsolution is stable. 2. Allim lie outside the unit circle. The periodic solution is unstable.3. Someim lie outside the unit circle. The periodic solution is non-stable.Interestingly, there exists a particular cross-section*∑, such thatwhere *ς∈∑.This cross-section*∑is the hyperplane spanned by the n - 1 eigenvectors of*(,)xT x φthat are not aligned with **(,)f y x . Therefore the vector *σthat is normal to*∑ is the left eigenvector of *(,)xT x φ corresponding to the eigenvalue 1. The hyperplane*∑is invariant under*(,)xT x φ, i.e., **(,)f y x maps vectors *ς∈∑back into*∑.5 ConclusionsHybrid systems frequently exhibit periodic behaviour. However the non-smooth nature of such systems complicates stability analysis. Those complications have been addressed in this paper throughapplication of a generalization of trajectory sensitivity analysis. Deterministic hybrid systems can be represented by a set ofdifferential-algebraic equations, modified to incorporate impulse (state reset) action and constraint switching. The associated variational equations establish jump conditions that describe the evolution of sensitivities through events. These equations provide insights into expansion/contraction effects at events. This is a focus of future research.Standard Poincar6 map results extend naturally to hybrid systems. The Monodromy matrix is obtained by evaluating trajectory sensitivities over one period of the (possibly non-smooth) cyclical behaviour. One eigenvalue of this matrix is always unity. The remaining eigenvalues are the characteristic multipliers of the periodic solution. Stability is ensured if all multipliers lieReferences[l] LA. Hiskens and M.A. Pai, “Hybrid systems view of power system modelling,” in Proceedings of the IEEE International Symposium on Circuits and Systems, Geneva, Switzerland, May 2000.[2] M.H. Raibert, Legged Robots That Balance, MIT Press, Cambridge, MA, 1986.[3] A. Goswami, B. Thuilot, and B. Espiau, “A study of the passive gait of a compass-like biped ro bot: symmetry and chaos,’’ International Journal of Robotics Research, vol. 17, no. 15, 1998.[4] S. Pettersson, “Analysis and design of hybrid systems,” Ph.D. Thesis, Department of Signals and Systems, Chalmers University of Technology, Goteborg, Sweden, 1999.[5] C. Tomlin, G. Pappas, and S. Sastry, “Conflict resolution for air traffic management:A study in multiagent hybrid systems,” IEEE Transactions on Automatic Control, vol. 43, no. 4, pp. 509-521, April 1998.[6] A. Goswami, B. Espiau, and A. Keramane, “Limit cycles in a passive compass gait biped and passivity-mimicking contr ol laws,” Journal of Au tonomous Robots, vol. 4, no. 3, 1997. 171 B.K.H. Wong, H.S.H. Chung, and S.T.S. Lee, ‘Computation of the cycle state-variable sensitivity matrix of PWM DC/DC converters and its applica tion,” IEEE Transactions on Circuit s and Systems I, vol. 47, no. 10, pp. 1542-1548, October 2000.[8] M. Rubensson, B. Lennartsson, and S. Petters son, “Convergence to limit cycles in hybrid systems - an example,” in Prepri nts of 8th International Federation of Automatic Control Symposium on Large Scale Systems: Theo y d Applications, Rio Patras, Greece, 1998, pp. 704-709.[9] I.A. Hiskens and M.A. Pai, “Trajectory sensitivity analysis of hyhrid systems,” IEEE Transactions on Circuits and Systems I, vol. 47, no. 2, pp. 204-220, February 2000.[10]D. Chaniotis, M.A. Pai, and LA. Hiskens, “Sen sitivity analysis of differential-algebraic systems using the GMRES method - Ap plication to power systems,” in Proceedings of the IEEE International Symposium on Circuits and Systems, Sydney, Australia, May 2001.[11]T.S Parker and L.O. Chua, Practical Numerical Algorithms for Chaotic Systems, Springer-Verlag, New York, NY, 1989.[12]R. Seydel, Practical Bifurcation and Stability Analysis, Springer-Verlag. New York, 2nd edition, 1994.。
通货膨胀会计外文资料翻译 (2)
毕业设计(论文)外文资料翻译题目:Inflation Accounting附件： 1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文通货膨胀会计自从我们开始认识我们周遭的事物, 我们常常从我们的祖父母那里听到关于他们那个时代的东西,尤其是黄金和酥油是非常便宜的.那时我们常常想为什么他们的那个时代的东西非常便宜,而我们的这个时代的东西开始变得昂贵. 因此, 这个问题使我们感到困惑.但是现在, 随着我们的知识的增加和认识, 我们已经知道了通货膨胀这中现象, 用一种外行的理解是国家定价的增长或货币的贬值是已知背后的最大的原因.现在出现的问题究竟是不是通货膨胀?在当今世界, 通货膨胀是一个全球性的现象. 在资本主义世界的今天,几乎没有任何国家不受通货膨胀幽灵般的困扰.不同的经济学家用不同的词语定义通货膨胀, Prof.Crowther 定义的通货膨胀是“随着国家币值的下降, 或者是价格的上涨.” Prof.Paul Einzig 说“通货膨胀是一个不平衡的状态,总体表现是购买力扩张的原因或者是价格水平增长的影响.”两个定义都强调了物价上涨.通货膨胀的最基本的因素不是需求的增加就是供应的减少.通货膨胀对企业的影响通货膨胀对企业的影响可以分为两部分理解1.影响成本和收益2.影响资产和负债至于通货膨胀对成本和收益的影响是忧虑的, 肯定的, 两者都将上升. 但是他们的结果是否表现出超常的利润是被公司旧的价格的可用的期初存货的多少和被公司受理的工资的需求的多少决定的.在货币资产和负债中, 一个公司将失去被债权人和取得在真实项目中的被债务人.如果我们说其他的资产如建筑物, 土地和其他证券, 则公司将在货币方面有持有收益,但是在实质情况中还是有一定的影响, 因此,在价格方面的增长是一方面, 货币币值的下降是另一方面.通货膨胀会计及其意义通货膨胀影响产出和资产价格上涨的形式. 因为财务会计通常是以历史成本为记帐原则, 因此他们不考虑资产和产出价格上涨的影响. 这样的结果很可能会导致利润上的虚增, 资产价格的低估以及误导企业的决策.因此, 在以历史成本为记帐原则编制的财务报表通常被证明是历史事实的一种陈述, 并不能反映企业当前的商业价值. 这就剥夺了如管理者, 股东以及债权人等的报表使用者去获取正确的财务信息从而做出正确的经营决策的权力.因此,这就导致了对通货膨胀会计的需要. 通货膨胀会计是一个会计制度范围的术语描述, 设计并去纠正当通货膨胀存在时历史成本会计产生的上升的问题.通货膨胀会计的意义是从固有的历史成本会计制度的限制中产生的.以下是历史成本会计的局限性:1.历史成本会计不考虑, 因受通货膨胀影响, 从资产的货币价值上升产生的未实现的持有性收益.2.折旧费用的目标是在资产的使用寿命期间摊销其成本, 并在将来为其更换储备. 但是, 他并没有考虑到受通货膨胀影响的结果可能导致折旧费用不足的替换成本.3.根据历史成本会计, 以旧的价格获得的存货实现的收益是按当年的价格计算的. 在通货膨胀期间, 由于持有收益和经营收益的最大化, 可能导致利润上的虚增.4.从历史收益上,不容易去预测未来盈利.通货膨胀会计的历史在过去的几年中, 通货膨胀会计已经被作为一种补充运用在英国和美国的财务报表中, 关于在通货膨胀期间调整财务账目的方法已经争论了50多年的时间.早在1900年代初, 美国和英国的会计师就以经讨论过通货膨胀对财务报表的影响, 开始于指标的数据理论和购买力. Irving Fisher 在1911年出版的书《The Purchasing Power of Money》被Henry W.Sweeney 在1936年出版的关于恒定购买力会计的书中《Stabilized Accounting》作为起源. Sweeney的这一模型通过美国注册会计师协会为他们的研究性学习(ARS6)报告《the Financial Effects of Price-Level Changes》所应用, 后来又被应用到会计准则委员会(美国), 金融标准委员会(美国),会计标准指导委员会(英国). Sweeney主张用涵盖在国民生产总值之上的价格指标.在1979年3月,美国财务会计准则委员会(FASB)写了恒定美元会计, 当中主张使用消费价格指数为所有的城市消费者(CPI-U)去调整帐目, 因为其可在每月计算一次.在大萧条期间, 一些公司重述他们的财务报表, 以反映通货膨胀. 在过去50年的时间里, 标准制定组织应经鼓励企业用价格水平调整的方法去补充以成本为基础的财务报表. 在20世纪70年代的高通货膨胀时期, 当美国证券交易委员会(SEC)发行ASR190时, 财务会计准则委员会(FASB)正在审查关于价格水平调整报表的草案, 这需要美国大约1000家最大的公司提供基于替换成本的补充信息. 财务会计准则委员会撤回了草案.然而为了迎合通货膨胀会计的需要, 国际会计准则委员会(IASB)推出了世界闻名的会计准则IAS29.通货膨胀会计的方法为了衡量通货膨胀对财务报表的影响,使用的技术如下:当前购买力法(CPP)根据这一价格变动调整帐目的方法, 在财务报表中所有的项目都被重述在一个固定的货币单位的项目里, 也即一般购买力.为了衡量价格水平的变化, 并用一般物价指数把这一变化纳入到财务报表当中去, 这就意味着我们的目标很可能是一个晴雨表. 该指数被用于转换在资产负债表和利润表中各个项目的价值. 这个方法考虑了账户一般货币购买力的变化以及忽略了给定项目价格的实际上升或下降. 在当前的购买力下, 购买力法(CPP)涉及了历史数据的翻新.为了这一目标, 在这一时期的最后时刻, 历史数据被转换成了购买力的价格. 被要求的两个指标数据: 一个显示在期末的一般价格水平上, 另一个反映相同的数据在交易日.这种方法下的利润一段时间内在净资产价值方面上是增长的, 在当前购买力的项目中所有的价格是被估计出来的.现行成本会计(CCA)的方法现行成本会计是对当前购买力法的替代方法. 现行成本会计方法相当于在盈利中现行的收益与被消耗资源的现行成本.一般物价水平的变动通过指标数据去衡量. 具体价格发生变化, 如没有任何价格变动的特定资产的价格发生变化. 可以根据这一方法去解决, 资产按照当前的成本估价, 即资产被替换时的成本.通货膨胀会计的局限性虽然通货膨胀会计是一种更实际的做法,并能反映公司真实地财务情况, 但是有些限制不允许它成为一个普及的会计系统. 以下是他的限制:1.价格水平的变化是一个持续的过程.2.这个系统使计算变得乏味, 因为有太多的转换和计算.3.该系统没有被税务机关给予优惠.结论:在地球上的每一个人都受到通货膨胀的影响, 一些人表现出积极,但是大部分人表现的消极, 因为通货膨胀导致了一般购买力的侵蚀.历史成本会计没有考虑帐户中资产价值的变化, 由于通货膨胀影响的资产负债表和利润表, 不能真实的反映企业的价值及所需要的有效的决策信息.通货膨胀会计已经剔除了这个缺陷, 通过根据一般或具体价格水平的方法去调整数据.尽管对财务报表提出了正确的方法, 但是通货膨胀会计由于某些限制仍然没有得到广泛的普及. 但是随着在这一领域更多的研究和会计软件的开发, 毫无疑问, 调整后的通货膨胀会计就是财务会计的未来.附件2：外文原文Inflation Accounting/Faculty_Column/FC1103/fc1103.htmlSince we started understanding things around us, we all used to listen from our Grandparents about the things and articles especially Gold & Ghee being cheaper in their times.That time we used to think that why the things were cheaper in our Grandparent’ time and why had they started becoming costlier. So this question would keep us puzzled.But now as we have grown in our knowledge and understanding, we have come to know about the phenomenon of Inflation which in layman’s language is known as the state of rising pricing or the falling value of maney was the greatest reason behind this.Now emerges the question that what exactly is the Inflation?Inflation is a global phenomenon in present day times. There is hardly any country in the capitalist world today which is not afficted by spectre of inflation.Different economists have defined inflation in different words like Prof.Crowther has defined inflation “as a state in which the value of money is falling, ie, prices are tising.” In the words of Prof.Paul Einzig, “Inflation is that state of disequilibrium in which an expansion of purchasing power tend s to cause or is the effect of an increase of price level.” Both the definition have emphasized on the rising prices of the goods.The basic factors behind the inflation are either the rising demand or the shortening of supply due to any reason.Effect of Inflation on BusinessThe impact of inflation on business can be bifurcated into two parts like1.Impact on costs and revenue2.Impact on assets and liabilitiesAs far as impact of inflation on costs and revenues is concerned, definitely both will rise but whether they result into extraordinary profits will be determined by that how much opening stock was available at old prices with the company and how much later the demand for increasing wages is entertained by the company.In case of monetary assets and liabilities, accompany will lose of being creditor and gain in case of being debtor in real terms.If we talk about other assets like building, land and other securities, the company will be having holding gains in monetary terms but may have neutral impact in real terms due to the rise in prices on the one hand but fall in value of money on the other.Inflation Accounting and its significanceThe impact of inflation comes in the form of rising prices of output and assets. As the financial accounts are kept on Historical cost basis, so they don’t take into consideration the impact of rise in the prices of assets and output. This may sometimes result into the overstated profits, under priced assets and misleading picture of Business etc.So, the financial statements prepared under historical accounting are generally proved to be statements of historical facts and do not reflect the current worth of business. This deprives the users of accounts like management, shareholders, and creditors etc. to have a right picture of business to make appropriate decisions.Hence, this leads towards the need for Inflation Accounting. Inflation accounting is a term describing a range of accounting systems designed to correct problems arising from historical cost accounting in the presence of inflation.The significance of inflation accounting emerges from the inherent limitations of the historical cost accounting system.Following are the limitations of historical accounting:1.Historical accounts do not consider the unrealized holding gains arising from the rise in themonetary value of the assets due to inflation.2.The objective of charging depreciation is to spread the cost of the asset over its useful life andmake reserve for its replacement in the future. But it does not take into account the impact of inflation over the replacement cost which may result into the inadequate charge of depreciation.3.Under historical accounting, inventories acquired at old prices are marched against revenuesexpressed at current prices. In the period of inflation, this may lead to the overstatement of profits due mixing up of holding gains and operating gains.4.Future earnings are not easily projected from historical earnings.History of Inflation AccountingIn the last few years, inflation accounting has been adopted as a supplementary financial statement in the United States and the United Kingdom. This comes after more than 50 years of debate about methods of adjusting financial accounts for inflation.Accountants in the United Kingdom and the United States have discussed the effect of inflation on financial statements since the early 1900s, beginning with index number theory and purchasing power. Irving Fisher’s 1911 book the Purchasing Power Accounting. This model by Sweeney was used by The American Institute of Certified Public Accountants for their 1936 research study(ARS6) Reporting the Financial Effects of Price-Level Changes, and later used by the Accounting Principles Board (USA), The Financial Standards Board (USA), and the Accounting Standards Steering Committee (UK). Sweeney advocated using a price index that covers everything in the gross national product. In March 1979, the Financial Accounting Standards Board (FASB) wrote Constant Dollar Accounting, which advocated using the Consumer Price Index for Al Urban Consumers (CPI-U) to adjust accounts because it is calculate every month.During the Great Depression, some corporations restated their financial statements to reflect inflation. At times during the past 50 years standard-setting organizations have encouraged companies to supplement cost-based financial statements with price-level adjusted statements. During a period of high inflation in the 1970s, the FASB was reviewing a draft proposal for price-level adjusted statements when the Securities and Exchange Commission (SEC) issued ASR 190, which required approximately 1,000 of the largest US corporations to provide supplemental information based on replacement cost. The FASB withdrew the draft proposal.Still to cater to the needs of an Inflation Accounting, the IASB came out with Accounting Standard known as IAS29.Techniques of Inflation AccountingTo measure the impact of inflation on financial statements, following are the techniques used: Current Purchasing Power (CPP) MethodUnder this method of adjusting accounts to price changes, all items in the financial statements are restated in terms of a constant unit of money ie in terms of general purchasing power. For measuring changes in the price level and incorporating the changes in the financial statements we use General Price Index, which may be considered to be a barometer meant for the purpose. The index is used to convert the values of various items in the Balance Sheet and Profit and Loss Account. This method takes into account the changes in the general purchasing power of money and ignores the actual rise or fall in the price of the given item. CPP method involves the refurnishing of historical figures at current purchasing power. For this purpose, historical figures are converted into value of purchasing power at the end of the period. Two index numbers are required: one showing the general price level at the end of the period and the other reflecting the same at the date of the transaction.Profit under this method is an increase in the value of the net asset over a period, all valuations being made in terms of current purchasing power.Current Cost Accounting (CCA) MethodThe Current Cost Accounting is an alternative to the Current Purchasing Power Method. The CCA method matches current revenues with the current cost of the resources which are consumed in earning them.Changes in the general price level are measured by Index Numbers. Specific price change occurs if price of a particular asset change without any general price change. Under this method, asset are valued at current cost which is the cost at which asset can be replaced as on a date.While the Current Purchasing Power (CPP) method is known as the General Price Level approach, the Current Cost Accounting (CCA) method is known as Specific Price Level approach or Replacement Cost Accounting.Limitations of Inflation AccountingThough Inflation Accounting is more practical approach for the true reflection of financial status of the company, there are certain limitations which are not allowing this to be a popular system of accounting. Following are the limitations:1.Change in the price level is a continuous process.2.This system makes the calculations a tedious task because of too many conversions andcalculations.3.This system has not been given preference by tax authorities.ConclusionEvery person on this earth has been affected by Inflation, some positively but most of the people negatively because the Inflation leads to the erosion of general purchasing power. The Inflation spares none and it equally influences the Businesses like the people.Historical cost accounting does not take into account the change in the rise in the value of assets and its impact on Balance Sheet and P&L Account due to inflation and does not reflect the real worth of the business which is very required for effective decision making.Inflation Accounting has removed this drawback by providing methods for adjusting the figure accounting to General or Specific Price levels.Despite a right method of presenting financial statements, Inflation Accounting is still not widely prevalent due to certain limitations. But with more research and development of accounting software in this field, there is no doubt that Inflation adjusted accounting is the future of Financial Accounting.。
可编程序控制器外文翻译2
外文原文Programmable Logic Controllers versus Personal Computers forProcess ControlIndustrial Engineering DepartmentUniversity of Puerto RicoP.O. Box 5000Mayaguez, Puerto Rico 00681ABSTRACTIt is proposed that Personal Computers (PCs) can be used effectively for the same industrial applications as Programmable Logic Controllers (PLCs). The basic concepts related to the operation of a PLC to emulate the behavior of a relay panel are explained. This is used to build a simple model for using standard PCs in the same applications as PLCs. This is demonstrated using a simple example of an automated process, Sample code in a standard high level language is presented that can be used as a template for future developments. Finally, the potential advantages and enhancements that can result in using PCs for process control are presented. Keywords: Programmable Logic Controller, Personal Computer, Automation, Ladder Logic, Relay PanelsINTRODUCTIONPersonal Computers (PCs) can be used effectively for the same applications as Programmable Logic Controllers (PLCs). A modem PLC is a computer-based device designed to control a process. It relates information coming from sensors that monitor the state of a process, with the status of some actuators that are capable of changing it. This relationship is established in most cases in Boolean logic. Typical sensors used in industrial applications include limit switches, proximity sensors, and other binary sensors. Actuators may include solenoids, motor starters, and othersimilar devices. Figure 1shows a simplified model of an industrial application where a PLC might be used.Fig. 1: Model of Simple ProcessRELAY PANELSPLCs wore designed to replace relay panels. These are custom made controllers dedicated to a particular application. They can be expensive for complex systems, cannot be easily reconfigured, are difficult to troubleshoot, consume lots of energy, have a relatively moderate speed of operation, and have low reliability. Relay panels are not the most suitable alternative for a moderate to complex industrial application where flexibility, ease of maintenance and troubleshooting are very important. On the other hand, they are relatively low-tech and are easy to understand by electricians and non-engineering personnel.The electrical control circuits of relay panels are generally drawn using so-called electric ladder diagrams. They differ slightly from conventional wiring diagrams in that they do not show the physical arrangement of the components, but emphasize the function of each circuit. They are a set of parallel circuits that in essence represent a hardwired program that controls the sequence of operations in a given process. Being electrical circuits in parallel gives the advantage of solving all the control logic simultaneously and practically instantaneously. Figure 2 represents an electric ladder diagram for a relay panel that can be used to control the process presented in fig. 1.Fig. 2: Electric Ladder DiagramPLCs are typically computer-based, solid-state, single-processor devices that emulate the behavior of an electric ladder diagram. Since they are sequential machines, to emulate the workings of parallel circuits that respond instantaneously, PLCs use an input/output image table and a scanning cycle.An input/output image table is a memory structure that stores all the relevant information about the current scanning cycle. It can be subdivided in three basic parts: the input table, the output table, and the internal relay table, The current state of the inputs (sensors) is kept in the input table; the desired state of the outputs (actuators) is kept in the output table; and the state of the virtual control relays is kept in the internal relay table.When a program is being nm in a PLC it is continuously executing a scanning cycle (fig. 3). The scanning cycle has two major parts (in an actual PLC it has other parts but two are relevant here for the sake of the discussion): the input/output scan, and the program scan. In the input/output scan the current state of the inputs is read from the input points and stored in the input table, and the desired state of theFig. 3: PLC Scanning Cycleoutputs (from the output table) is sent to the output points. The program scan solves the Boolean logic that relates the information in the input table, with that in the output and internal relay tables. Also, the information in the output and internal relay tables is updated during the program scan. In a PLC this Boolean logic is typically represented in a graphical language that looks very much like the electrical circuit that it emulates. This language is known as ladder logic. In fig. 4 there is a ladder logic program that can be used to control the process in fig. 1. Note the similarities with the electric ladder diagram in fig. 2. The advantage of the PLC scanning cycle scheme is that it allows multiple princesses to be controlled concurrently as in a relay panel.Fig, 4: PLC Ladder LogicPLCs overcome all of the relay panel shortcomings and currently are the most widely used industrial automation controllers. At the time of their introduction they were very successful because their language, ladder logic, was based tm electricladder diagrams which engineers and electricians of the time were already familiar with. Nevertheless, PLCs have some shortcomings of their own that are evident when compared with other available technology. Some of the most limiting ones include: them is no industry-standard hardware or software platform, they may limit the programmer as to the control actions and manipulations that can be made, and offer relatively low computing power for the money.PERSONAL COMPUTERSAnother technology that could be used for the same purpose is the standard personal computer (PC). The PC is becoming increasingly popular for process control.A PC-based controller model is proposed here which could replace PLCs in any industrial control application and would open up a world of possibilities in software development, standard components, and connectivity in general. This medal includes an industry-standard PC running any modem operating system, a set of standard input/output modules equivalent to those found in a typical PLC, and an application developed in any high level programming language which will implement a PLC scanning cycle.A SIMPLE EXAMPLEThe proposed model will be presented through a sample program coded in Turbo Pascal~ for the control of the process shown in fig. 1. Assume that sensors are connected to the PC through input port hex address 3BD, and that actuators are connected to output port hen address 3BC, as shown in figs. 5 and 6 respectively.Fig. 5: Input ConnectionsFig. 6: Output ConnectionsThe sample Pascal program is shown in fig. 7. The image tables: input, output, and internal relays, are implemented using Pascal Boolean variables. When any of these variables is TRUE, that represents an ON state; and whoa they are FALSE that represents an OFF state. When exchanging signals with the input and output points an ON state is represented by a logical "0" and an OFF state with a logical "1".The main program is an emulation of the PLC scanning cycle presented in fig. 3. In this simplified example it is assumed that the PLC will be running its program until a key is pressed on the PC keyboard. Other device can be used if it is desired to use the PC keyboard for other more productive purpose.The input/output scan is emulated using subroutine I_ O_Scan. There, the 8 bit input port (fig. 5) is read and the status of the individual bits stored in the input table. Also the status of the output points from the output table is written to the 8 bit output port (see fig. 6). The Program _Scan subroutine is a direct translation of the ladder diagram in fig. 4. For every rung in the ladder logic there is an if-then-else statement. The Initialize and Finalize subroutines worn added to handle the state of the output points and internal relays during the startup and shutdown of the PLC program.Fig.7:Sample Pascal ProgramIt should be noted that this is a very simplified example whose purpose is to provide a framework for control program development on a PC combining the programming paradigms of standard procedural high-level languages with the familiar PLC ladder logic. Although it cannot be fully demonstrated in this paper, it provides a simple way of simultaneous control of parallel processes without considering the intricacies of a particular operating system. It demonstrates that complex custom software does not have to be created to make this technology work.The proposed model would be very easy to adapt and implement even in-house because it can still use ladder logic, so no new technological skills are necessary. Any typical PLC instructions can be added to the model very easily, including timers, counters, one-shots, and so on. Other custom PLC instructions suited to a particular application can be included that use the features of high level languages, making it more powerful than standard PLC ladder logic.ADV ANTAGES OF PERSONAL COMPUTERSThe PC is a standard hardware/software platform. PCs improve at a rapid pace, become cheaper, and have mom power than PLCs. Pentium systems widely available today outperform even the fastest margins of 20:1 or more. A newgeneration of PCs becomes available every six to nine months. By contrast new generation of PLC hardware becomes available every two to three years. PCs with at least 16Mbytes are commonplace, while PLCs still have memory in the order of Kbytes. The PC supports more standard peripherals available from many vendors such as CD ROM drives, sound cards, voles recognition, networking facilities, and so on. at very affordable prices. The PC is available worldwide, on short notice, from many vendors;It has been envisioned that the next generation industrial controls should provide an open architecture and a single software development environment. The trend will be to move away from closed, proprietary systems due to the advantages an open architecture provides. It gives more flexibility since users do have to "marry" to a particular supplier. There is easier access to the latest technology since numerous independent developers are continuously advancing the functionality and ease of use of PC-compatible hardware and software. Also, it provides cost effectiveness because its largo market ensures a competitive environment and economies of scale that drive prices to their lowest level.The PC can provide a totally integrated solution that incorporates the functions of the PLC, the man-machine interface, and the programming terminal. It can provide process simulation/emulation so that complete software development can be done independent of the hardware. Also, it can provide sophisticated troubleshooting and diagnostic tools, providing in-depth analysis of the state of the machine, possible causes for malfunction, and recommended remedies. You can even run off-the-shelf Windows software for data analysis while the control system is running. Standard Windows data exchange methods can be readily applied to move information between the control system and the rest of the enterprise.PCs for industrial control might be successful today for reasons analogous to those for the PLCs at the time of their introduction; engineers today are well versed in computer programming and technology. Many sites already have significant PC programming expertise on hand. Also, the typical PC language paradigms lend themselves more readily to flowcharting techniques and languages of recentdevelopment for control programming, such as Sequential Function Charts.DISADV ANTAGES OF PERSONAL COMPUTERSCommercial-grade PCs are not normally designed to tolerate the shock, vibration, temperature, and electrical noise frequently found on the manufacturing floor~:1. Even though hardware that meets these environmental conditions is readily available as both PLCs and PCs, this may increase the cost of implementing PC-based control. PCs may not be cost effective for applications with few I/O points (90% of the market). Very cheap PLCs are available for that market. PCs are visualized as solutions for more complex systems with many I/O points and complex control strategies. PC-based input/output interfacing may be as expensive, and more difficult to implement than that for PLCs141. PLCs are faster to restart after a power failure. They also have better ability to retain data so they are easier to restart from where they left off.中文翻译可编程序控制器与个人计算机在过程控制中的对比工业工程部门波多里哥大学P .O . 信箱5000Mayaguez, 波多里哥00681摘要有人提议,个人计算机(PCs) 和可编程序的逻辑控制器(PLCs )一样，能有效地使用在工业应用上。
经典外文翻译两篇,中英对照
外文原文 1Building Materials Selection and SpecificationFae'q A. A. RadwanFaculty of Engineering, Near East University, KKTC, Lefkosa, Mersin 10, TurkeyAbstract: The limitations in the selection of the building materials and to the sustainability of any building construction materials that can be used are presented. The practices and techniques that can be used in reducing and minimizing the environmental impacts of building are discussed. Recommendations of using secondary and recycled materials in the construction of buildings are given. Framework for methods of assessment of the sustainability in building construction for environmental performance is presented.Key Words: Limitations, sustainability, environmental impacts, framework, climate.1. IntroductionThere is an apparently unbounded range of possibilities for the selection of building materials for the construction of structures of almost any shape or stature. Its quality will affect the structure function and long life, and requirements may differ with climate, soil, site size, and with the experience and knowledge of the designer. The factors that have the most outstanding solutions are impermeability, control of heat, air, and water flow, and the stability of the structure [1-3].Raw materials extraction, manufacturing processes, and the transportation of the materials to the project site have a multitude of impacts on the environment. These include the disruption of habitats and ecological systems, use of water, and, through energy use, the emissions of air pollutants and climate change gases. Building materials also have major impacts on the building occupants manufacture, construction of buildings and the use of building materials make a significant environmental impact internally, locally and globally. But it is not easy to deliver information to make adequate inclusion decisions considering the whole life cycle of a building. Decisions on sustainable building integrate a number of strategies during the design, construction and operation of building projects. Selection of sustainable building materials represents an important strategy in the design of a building.2.SustainabilityIn recent years, the concept of sustainability has been the subject of much disputation by academics and professionals alike. In 1987, the World Conference on Environment and Development defined sustainable development as development that meets the needs of the present without compromising the ability of future generations to meet their own needs (WCED, 1987).Sustainability must address ecological impacts, regardless of conflicting interpretations of the WCED definition.A good sustainable product must give as much satisfaction as possible for the user. If not, it will be unsuccessful on the market and an economic failure.It is also important to inform people as to what basis a certain product is considered to be sustainable or not and why they should buy it [4- 5].When developing a new product, it is illustrative to move between the three corners Ecology, Equity and Economy in order to obtain a suitable balance so that each category can be fulfilled in the best way.·Ecology (environmental protection).·Equity (social equity).·Economy (economic growth).2.1 Materials Selection and SustainabilityAmong the notable technological developments of the 20th century has been the development of tens of thousands of new materials for use in construction and engineering. The construction industry has also grown to the point where it is a very large consumer of energy and materials. Concern for the environment and the impact of human activity on the Earth's ecological systems has now become clear sighted.We are faced with the problems of material selection and the environmental consequences of their use. Environmentalists have proposed various methods for assessing the impact of materials and energy use, these include ecological foot printing, ecological rucksacks, embodied energy and carbon dioxide values, and so on. Engineers have put forward rational selection methods for the choice of materials. These techniques will be reviewed and explored in an attempt to provide an environmentally-aware, materials selection method- logy for use in construction.Strictly, the term sustainable means that something is capable of being sustained not for an hour, or a day, or a week, month or year, but indefinitely.The implication is that if some process which uses materials and energy is described as sustainable, then the materials and energy which are consumed arecapable of being replaced by natural or other processes as fast as they are consumed. In many cases materials and energy appear to be consumed at a faster rate than they are being replaced. However, to make a judgment, we would need to know what the respective supply and consumption rates are in other words we need some quantitative or numerical index to help us [2].2.2 Environmental CriteriaSince construction uses such large quantities of materials, it has a major impact on the environment. In order to assess and evaluate such impact, a number of criteria or indices have been devised by economists, engineers and environmentalists, and the more important of these are the following [2].2.2.1 Embodied EnergyThis is quite simply the amount of energy consumed in manufacturing a unit quantity of a material, and it is usually expressed in kJ/kg. Its value is determined by the efficiency of the manufacturing plant. Values range from 275 GJ/tonne for aluminum (a high value) to 0.1 GJ/tonne for gravel aggregates (a low value) [2].2.2.2 Embodied Carbon DioxideEmbodied C02 is similar to embodied energy. It is the weight of C02 emitted during manufacture of unit weight of the material, and is usually expressed as kg of C02 per ton.Again, the value will depend upon the efficiency of the manufacturing plant [2].2.2.3 Ecological RucksackThe ecological rucksack concept was devised as a way of assessing material efficiency by F. Schmidt一Bleek [6]. He recognized that many tonnes of raw material could be extracted and processed to make just one kilogram of material. For example, the environmental rucksack for the precious metal platinum is 250,000:1.2.3 Rational Selection MethodThere are various approaches to the problem of selecting materials from the huge numbers now available. Designers can have recourse to materials property charts and data books. Alternatively, they can talk to their colleagues, hoping that by widening the knowledge circle, they will not omit a significant group of materials. Another strategy is simply to specify the same or a similar material to those used in previous, similar designs. All these are valid approaches, but they may result in the specification of a less than ideal material and overall, a less than optimal solution to the problem [3-5].The basis of the rational selection methods devised to date is a recognition that the performance of a component, artifact or structure is limited by the properties of the materials from which it is made. It will be rare for the performance of the item to depend solely on one material property; in nearly all cases, it is a combination of properties, which is important. To give an example, in lightweight design, strength to weight ratio of, and stiffness to weight ratio E/pwill be important. Ref. [3] has put forward the idea of plotting material properties against each other to produce material property maps. On these maps, each class of material occupies a field in material property space, and sub-fields map the space occupied by individual materials.These materials property charts are very information-rich they carry a large amount of information in a compact but accessible form. Interestingly, they reveal correlations between material properties, which can help in checking and estimating data, and they can also be used in performance optimization, in a manner such as that set out as follow.If we consider the complete range of materials, it immediately becomes apparent that for each property of an engineering material there is a characteristic range of values, and this range can be very large. For example, consider stiffness (Young's Modulus E). Materials range from jelly (very low stiffness) up to diamond (very high stiffness). The properties can span five decades (orders of magnitude),A number of conclusions can be drawn, including:(1) A rational selection method such the one put forward by Ashby is capable of incorporating environmental parameters such as embodied energy and C02 or the environmental rucksack concepts, thereby making possible rational selections based on environmental considerations.(2) This method is not as simple to use as the environmental preference method or the environmental profiles method. However, this rational method could be used to generate data for the environmental profiles and preference methods.(3) The construction industry needs to take steps to better integrate itself into the materials cycle. The quantity of demolition waste needs to be reduced, and more of it should be recycled. To this end, the building designers need to keep full records of materials of construction, and buildings need to be designed for easy dismantling at the end of their useful lives.2. 4 Ashby's Materials Selection MethodologyMaterials selection charts一Property interaction (not always causal)一First order optimization●Performance indices●Multiple constrains●Multiple design goals●Shape and material interaction一“Enhanced" performance indicesProcess selection [3, 4].3. Foundations and Construction ComponentIn any consideration of which building materials and alternatives can feasibly be integrated into the foundations of a large-scale development there are several limitations that must be considered.In terms of the actual materials that may be used, there are three main limitations. First, because of the large scale and heavy loads that the foundations must support, strength is imperative. Any materials must be consistently strong and able to effectively distribute the weight of the structure. The second major limitation is climate. In areas with sub-zero winter conditions, frost heave is a major consideration. For this reason, foundations must be deep enough to support the structure despite any changes in near-surface volume; shallow foundations will be insufficient unless certain innovative steps are taken. The limitation of climate also influences any decision on insulating foundations. Finally, there is the consideration of cost. This consideration is reliant on material availability, cost per unit, and building techniques and associated labor. For these reasons, the only materials that can feasibly be used are concrete and steel. Therefore, the alternatives for minimizing impact lie more in the methods of construction and any realistic structural changes that can be made.The three main foundation components of concrete, steel, and insulation will be examined as the only reasonable materials for the construction of a building with limitations such as the foundations [1].3.1 ConcreteIt is the fundamental component of the foundation construction, receiving the building loads through walls or posts and distributes them down and outwards through the footings. Concrete and cement have ecological advantages which include durability, long life, heat storage capability, and (in general) chemical inertness [8].The life cycle concerns of concrete are as follows. First, there is land and habitat loss from mining activities. Furthermore, the quality of both air and water quality suffer from the acquisition, transportation, and manufacture. Carbon dioxide emissions are also a negative environmental impact accrued through the production and use of concrete. Similarly, dust and particulate are emitted at most stages of the concrete life-cycle. $oth carbon dioxide and particulate matter have negative impacts on air quality [1]. Water pollution is also another concern associated with the production of concrete at the production phase. Fly ash is by-product of the energy production from coal-fired plants and increasing its proportion in cement is environmentally beneficial in two ways. First, it helps in reducing the amount of solid waste which requires disposal. As well, fly ash in the cement mixture reduced the overall energy use by changing the consistency of the concrete. Fly ash, increases concrete strength, improves sulfate foundation, decreases permeability, reduced the water ratio required, and improves the pump ability and workability of the concrete [9]. Now in the United States, the Environmental Protection Agency requires that all buildings that receive federa funding contain fly ash and most concrete producer: have access to this industrial waste [9].There are alternative methods of both making concrete and building foundations with this concrete that have environmental benefits, no matter the structure scale or climate. These include Autoclaved Aerated Concrete, the increased integration of fly ash into the cement mixture, and the use of pre-cast foundation systems to reduce resource use. Through consideration and possible integration of these alternatives, impacts could potentially be reduced.3.2 SteelAs wood resources are becoming limited, steel is increasingly popular with builders. In the case of a large-scale building, steel reinforcement is basically a necessity for overall strength and weight distribution.The initial life cycle impacts of steel use are similar to those of concrete. These include land and habitat loss from mining activities, and air and water quality degradation from materials acquisition and manufacture [1]. However, the largest proportion of steel used nowadays contains a percentage of recycled materials. In terms of improving environmental conditions by reducing impacts, this is the only real recommendation for the use of steel in building foundations; to purchase recycled steel products. Not only would this reduce industrial and commercial solid waste,such a decision would also reward the manufacturers of such products.3. 3 InsulationNew and innovative pre-cast building foundations are becoming increasingly available and feasible for implementation. These new systems can reduce the overall raw material use, as well as conserve energy through the creation of an efficient building envelope. A further used of this rigid insulation as a skirt around the building foundations helps to eliminate any potential frost problems, improve drainage, and help further reduce heat loss. A polyethylene air and water vapor barrier is applied above the insulating layer, as is a three to four inch layer of sand. These shallow foundation systems have excellent insulating properties, decreased use of raw materials for concrete, and comparatively low demands for labor. However, the use of rigid insulation is increased. Also, in soils where frost and drainage is a consideration additional piles in the centre of the foundation may be required to prevent movement. This increases the relative land disturbance, although it remains still much less than that of deep foundation systems. Shallow foundations are structurally sound and are becoming increasingly common in colder climates. There are strength considerations associated with these new techniques which must be addressed by someone with the technical ability to do so, before they can be feasibly recommended for the building of the new residence.As discussed above, there are limitations to the sustainability of any foundation construction materials used. In other words, there are environmental impacts associated with all types of foundations. For these reasons, a primary recommendation is the use of secondary materials (fly ash and recycled steel) in the construction of foundations.4. FrameworkThe material components of the building envelope, that is, the foundation, wall construction, insulation and roof, have been analyzed within a framework of primarily qualitative criteria that aim to evaluate the sustainability of alternate materials relative to the materials cited in the current foundation design. This analytical process has enabled the identification of several construction materials that can be feasibly integrated into current design and construction standards of the building envelope.The tools and strategies described below are useful in analyzing the relative benefits of different materials[9-14].Life-Cycle Assessment (LCA). LCA is a comprehensive analysis that takes intoconsideration all aspects of a material over its entire lifetime: raw materials extraction; manufacturing and processing; transport; use; and post-use recycling, reuse, or disposal. This approach enables a true "apples to apples" comparison between materials.The BEES system (Building for Environmental and Economic Sustainability) developed by the National Institute of Standards and Technology is the most widely used methodology. BEES provides materials with a score that can be compared to other similar products. At this time, however, a fairly limited number of materials have completed the BEES analysis.Life-Cycle Costing. Life-Cycle Costing is an analysis of the short- and long-term costs associated with a material, from purchase to ultimate recycling or disposal. This includes frequency of replacement, maintenance costs, and costs that are avoided through use of the material (or system). LCC is useful in looking beyond a comparison based solely on first costs. Similar to LCA, this type of analysis is not available for all materials, but a back-of-the-envelope calculation is usually fairly easy to work up.Certification. Many conventional building products are approved or certified by independent third party or government groups. The Forest Stewardship Council certifies the certifiers (Smart Wood and SCS) that assess whether forestry companies are using sustainable management practices to harvest wood. The Carpet and Rug Institute provides a Green Label for carpets that meet certain low-VOC criteria. Green Guard certifies products that meet strict indoor air quality criteria. The Department of Energy's Energy Star label identifies equipment and appliances that meet or exceed standards for energy efficiency. Scientific Certification Systems and Green Seal certify recycled-content claims and other green product claims made by manufacturers.5. ConclusionOver-consumption, resource utilization, pollution and over-population are examples of the perhaps most basic problems for the environment in the future. A more sustainable future can be achieved by producing more sustainable products causing less environmental impact. Materials and design are and will always be very important areas when developing more sustainable products.The Life Cycle Assessment concept might be the most effective way of determining the environmental impacts for all product stages from extract of material to the product disposal stage. A price must be set for restoration on everyenvironmental impact. Information can be received from official authorities pertaining to the environment in different countries. Renewable and easy recyclable materials are preferably used together with a design for easy recycling and repair of the products. Minimization of the energy connected to the product is also important. Full sustainability can never be achieved for products according to thermodynamic laws. However, the attempt to achieve more sustainability is a requisite if we want to preserve the earth for the coming generations. Education, research and spreading of information will be very important for the future in order to receive more sustainable products especially because the market demand is important in order to develop successful sustainable products.References[1] M. Davison, J. Persmann, J. Reid, J. Stange and T. Weins, Green BuildingMaterials Residence, A WATgreen/ERS 285 study.[2] J. L. Sturges, Construction Materials Selection and Sustainability, School of theBuilt Environment, Leeds Metropolitan University, UK.[3] M. F. Ashby, Materials Selection in Mechanical Design, Pergamon, Oxford, 1992.[4] M. F. Ashby and K. Johnson, Materials and Design: The Art And Science ofMaterials Selection in Product Design, Oxford: Butterworth-Heinemann, 2002 [5] L. Y. Ljungberg, Materials selection and design for development of sustainableproducts, Materials and Design 28(2007)466-479.[6] F. Berkhout and D. Smith, Products and the environment: an integrated approachto policy, Eur. Environ 9 (1999)174-185.[7] F. Schmidt-Bleek, Carnoules Declaration of the FactorTen Club, WuppertalInstitute, Germany, 1994.[8] A．Wilson，Building green on a budget,Environmental Building News8(5)(1999)．[9] G．E．Dieter，Engineering Design，McGraw-Hill，New York，l991．[10] Sandy Patience (Ed．)，The Role of Evidence in The Selection of BuildingProducts and Materials，Constructing Excellence in The Built Environment．[11] M．D．Bovea and R．Vidal，Increasing product value by integrating environmentalimpacts costs and customer valuation，J Resour Conserv Recycling 41(2004) 133-145．[12] N．S．Ermolaeva,M．B．G．Castro and P．V．Kandachar, Materials selectionfor an automotive structure by integrating structural optimization with environmental impact assessment，Materials and Design 25 (2004) 689．698．[13] M．Goedkoop and R．Spiensma，The Eco-Indicator 99：A Dam age OrientedMethod for Life Cycle Impact Assessment，Amersfooft：PRe consultant B．V．，2000．中文翻译 1建材选择和规格Fae'q A. A. RadwanFaculty of Engineering, Near East University, KKTC, Lefkosa, Mersin 10, Turkey摘要：建材选择的限制和可利用的任何建筑物工程材料的持久性显现出来。
软件工程专业毕业设计外文文献翻译
软件工程专业毕业设计外文文献翻译1000字本文将就软件工程专业毕业设计的外文文献进行翻译，能够为相关考生提供一定的参考。
外文文献1: Software Engineering Practices in Industry: A Case StudyAbstractThis paper reports a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The study investigated the company’s software development process, practices, and techniques that lead to the production of quality software. The software engineering practices were identified through a survey questionnaire and a series of interviews with the company’s software development managers, software engineers, and testers. The research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company follows a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The findings of this study provide a valuable insight into the software engineering practices used in industry and can be used to guide software engineering education and practice in academia.IntroductionSoftware engineering is the discipline of designing, developing, testing, and maintaining software products. There are a number of software engineering practices that are used in industry to ensure that software products are of high quality, reliable, and maintainable. These practices include software development processes, software configuration management, software testing, requirements engineering, and project management. Software engineeringpractices have evolved over the years as a result of the growth of the software industry and the increasing demands for high-quality software products. The software industry has developed a number of software development models, such as the Capability Maturity Model Integration (CMMI), which provides a framework for software development organizations to improve their software development processes and practices.This paper reports a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The objective of the study was to identify the software engineering practices used by the company and to investigate how these practices contribute to the production of quality software.Research MethodologyThe case study was conducted with a large US software development company that produces software for aerospace and medical applications. The study was conducted over a period of six months, during which a survey questionnaire was administered to the company’s software development managers, software engineers, and testers. In addition, a series of interviews were conducted with the company’s software development managers, software engineers, and testers to gain a deeper understanding of the software engineering practices used by the company. The survey questionnaire and the interview questions were designed to investigate the software engineering practices used by the company in relation to software development processes, software configuration management, software testing, requirements engineering, and project management.FindingsThe research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company’s software development process consists of five levels of maturity, starting with an ad hoc process (Level 1) and progressing to a fully defined and optimized process (Level 5). The company has achieved Level 3 maturity in its software development process. The company follows a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The software engineering practices used by the company include:Software Configuration Management (SCM): The company uses SCM tools to manage software code, documentation, and other artifacts. The company follows a branching and merging strategy to manage changes to the software code.Software Testing: The company has adopted a formal testing approach that includes unit testing, integration testing, system testing, and acceptance testing. The testing process is automated where possible, and the company uses a range of testing tools.Requirements Engineering: The company has a well-defined requirements engineering process, which includes requirements capture, analysis, specification, and validation. The company uses a range of tools, including use case modeling, to capture and analyze requirements.Project Management: The company has a well-defined project management process that includes project planning, scheduling, monitoring, and control. The company uses a range of tools to support project management, including project management software, which is used to track project progress.ConclusionThis paper has reported a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The study investigated the company’s software development process,practices, and techniques that lead to the production of quality software. The research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company uses a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The findings of this study provide a valuable insight into the software engineering practices used in industry and can be used to guide software engineering education and practice in academia.外文文献2: Agile Software Development: Principles, Patterns, and PracticesAbstractAgile software development is a set of values, principles, and practices for developing software. The Agile Manifesto represents the values and principles of the agile approach. The manifesto emphasizes the importance of individuals and interactions, working software, customer collaboration, and responding to change. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases. This paper presents an overview of agile software development, including its principles, patterns, and practices. The paper also discusses the benefits and challenges of agile software development.IntroductionAgile software development is a set of values, principles, and practices for developing software. Agile software development is based on the Agile Manifesto, which represents the values and principles of the agile approach. The manifesto emphasizes the importance of individuals and interactions, working software, customer collaboration, and responding to change. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases.Agile Software Development PrinciplesAgile software development is based on a set of principles. These principles are:Customer satisfaction through early and continuous delivery of useful software.Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage.Deliver working software frequently, with a preference for the shorter timescale.Collaboration between the business stakeholders and developers throughout the project.Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.The most efficient and effective method of conveying information to and within a development team is face-to-face conversation.Working software is the primary measure of progress.Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.Continuous attention to technical excellence and good design enhances agility.Simplicity – the art of maximizing the amount of work not done – is essential.The best architectures, requirements, and designs emerge from self-organizing teams.Agile Software Development PatternsAgile software development patterns are reusable solutions to common software development problems. The following are some typical agile software development patterns:The Single Responsibility Principle (SRP)The Open/Closed Principle (OCP)The Liskov Substitution Principle (LSP)The Dependency Inversion Principle (DIP)The Interface Segregation Principle (ISP)The Model-View-Controller (MVC) PatternThe Observer PatternThe Strategy PatternThe Factory Method PatternAgile Software Development PracticesAgile software development practices are a set ofactivities and techniques used in agile software development. The following are some typical agile software development practices:Iterative DevelopmentTest-Driven Development (TDD)Continuous IntegrationRefactoringPair ProgrammingAgile Software Development Benefits and ChallengesAgile software development has many benefits, including:Increased customer satisfactionIncreased qualityIncreased productivityIncreased flexibilityIncreased visibilityReduced riskAgile software development also has some challenges, including:Requires discipline and trainingRequires an experienced teamRequires good communicationRequires a supportive management cultureConclusionAgile software development is a set of values, principles, and practices for developing software. Agile software development is based on the Agile Manifesto, which represents the values and principles of the agile approach. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases. Agile software development has many benefits, including increased customer satisfaction, increased quality, increased productivity, increased flexibility, increased visibility, and reduced risk. Agile software development also has some challenges, including the requirement for discipline and training, the requirement for an experienced team, the requirement for good communication, and the requirement for a supportive management culture.。
外文翻译2(气敏传感器)
英文文献Semiconductor Gas SensorsResearch and development of gas sensors have shown great advances during the past decade. Semiconductor gas sensors mainly using SnO2 elements have been prevailing as detectors or alarms for leakage of LP (Liquefied Propane) gas and town gas, in addition to other applications. Gas sensors based on MOSFET, first proposed in 1975, have attracted interests of many researchers of many researchers, and have been developed to a point of commercialization as a hydrogen detectors. Solid electrolytes, represented by stabilized zirconia, have proven to be very promising sensors materials for oxygen, SO2,etc. This paper aims at reviewing briefly recent advances and trends in semiconductors gas sensors which were developed in a recent few years.Semiconductors gas sensors detect gases from a change in electrical resistance of an element made with a semi conductive metal oxide, typically SnO2 sensor. Although sensors utilizing γ-Fe2O3 or α-Fe2O3 have been put into practical use, SnO2 sensor still has an overwhelming market share. The production of semiconductor gas sensors has grown into a large industry: more than 5 million pieces were production in 1983.Most of them have been used in domestic homes as detectors or alarms for gas leakage. Field statistic has shown that gas alarms are quite effective to prevent an outbreak of gas leakage accident; the accident rate. Anyway semiconductors have been so far given much credit as an important device for home security and the installation rate of gas alarms is increasing year after year. Several years ago a problem arose about SnO2 gas sensor when it was adopted at places like kitchens of underground restaurants where various inflammable gases came out into atmosphere from fuels and cooking very frequently during working time. In such a dirty atmosphere, the gas sensor tended to given an alarm at an inflammable gas concentration which was lowered gradually with an elapse of operation time. It has been pointed out that the problem was contributed by electric resistance of the sensor element due to its sintering at unexpectedly high working temperatures. The problem has been solved after revisions were made to the sensor element.半导体气敏传感器在过去的十年间，气敏传感器的研究和发展已经有了很大的进步。
机械毕业设计英文外文翻译217机械设计理论 (2)
外文资料翻译原文（二）Machine design theoryThe machine design is through designs the new product or improves the old product to meet the human need the application technical science. It involves the project technology each domain, mainly studies the product the size, the shape and the detailed structure basic idea, but also must study the product the personnel which in aspect the and so on manufacture, sale and use question. Carries on each kind of machine design work to be usually called designs the personnel or machine design engineer. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineerig material, materials mechanics and machine manufacture technology has the deep elementary knowledge.If front sues, the machine design goal is the production can meet the human need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must first determine whether the people do need this kind of productMust regard as the machine design is the machine design personnel carries on using creative ability the product design, the system analysis and a formulation product manufacture technology good opportunity. Grasps the project elementary knowledge to have to memorize some data and the formula is more important than. The merely service data and the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all operations. For example, even if places wrong a decimal point position, also can cause the correct design to turn wrongly.A good design personnel should dare to propose the new idea, moreover is willing to undertake the certain risk, when the new method is not suitable, use original method. Therefore, designs the personnel to have to have to have the patience, because spends the time and the endeavor certainly cannot guarantee brings successfully. A brand-new design, the request screen abandons obsoletely many, knows very well the method for the people. Because many person of conservativeness, does this certainly is not an easy matter. A mechanical designer should unceasingly explore the improvement existing product the method, should earnestly choose originally, the process confirmation principle of design in this process, with has not unified it after the confirmation new idea.Newly designs itself can have the question occurrence which many flaws and has not been able to expect, only has after these flaws and the question are solved, can manifest new goods come into the market the product superiority. Therefore, a performance superior product is born at the same time, also is following a higher risk. Should emphasize, if designs itself does not request to use the brand-new method, is not unnecessary merely for the goal which transform to use the new method.In the design preliminary stage, should allow to design the personnel fully to display the creativity, not each kind of restraint. Even if has had many impractical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, then perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts.How does the psychologist frequently discuss causes the machine which the people adapts them to operate. Designs personnel''s basic responsibility is diligently causes the machine to adapt the people. This certainly is not an easy work, because certainly doesnot have to all people to say in fact all is the most superior operating area and the operating process.Another important question, project engineer must be able to carry on the exchange and the consultation with other concerned personnel. In the initial stage, designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel, and is approved. This generally is through the oral discussion, the schematic diagram and the writing material carries on. In order to carry on the effective exchange, needs to solve the following problem:(1) designs whether this product truly does need for the people? Whether there is competitive ability(2) does this product compare with other companies'' existing similar products?(3) produces this kind of product is whether economical?(4) product service is whether convenient?(5) product whether there is sale? Whether may gain?Only has the time to be able to produce the correct answer to above question. But, the product design, the manufacture and the sale only can in carry on to the above question preliminary affirmation answer foundation in. Project engineer also should through the detail drawing and the assembly drawing, carries onthe consultation together with the branch of manufacture to the finally design proposal.Usually, can have some problem in the manufacture process. Possibly can request to some components size or the common difference makes some changes, causes the components the production to change easily. But, in the project change must have to pass through designs the personnel to authorize, guaranteed cannot damage the product the function. Sometimes, when in front of product assembly or in the packing foreign shipment experiment only then discovers in the design some kind of flaw. These instances exactly showed the design is a dynamic process. Always has a better method to complete the design work, designs the personnel to be supposed unceasingly diligently, seeks these better method. Recent year, the engineerig material choice already appeared importantly. In addition, the choice process should be to the material continuously the unceasing again appraisal process. The new material unceasingly appears, but some original materials can obtain the quantity possibly can reduce. The environmental pollution, material recycling aspect and so on use, worker''s health and security frequently can attach the new limiting condition to the choice of material. In order to reduce the weight or saves the energy, possibly can request the use different material. Comes fromdomestic and international competition, to product service maintenance convenience request enhancement and customer''s aspect the and so on feedback pressure, can urge the people to carry on to the material reappraises. Because the material does not select when created the product responsibility lawsuit, has already had the profound influence. In addition, the material and between the material processing interdependence is already known by the people clearly. Therefore, in order to can and guarantees the quality in the reasonable cost under the premise to obtain satisfaction the result, project engineer makes engineers all to have earnestly carefully to choose, the determination and the use material.Makes any product the first step of work all is designs. Designs usually may divide into several explicit stages: (a) preliminary design; (b) functional design; (c) production design. In the preliminary design stage, the designer emphatically considered the product should have function. Usually must conceive and consider several plans, then decided this kind of thought is whether feasible; If is feasible, then should makes the further improvement to or several plans. In this stage, the question which only must consider about the choice of material is: Whether has the performance to conform to the request material to be possible to supply the choice;If no, whether has a bigger assurance all permits in the cost and the time in the limit develops one kind of new material.In the functional design and the engineering design stage, needs to make a practical feasible design. Must draw up the quite complete blueprint in this stage, chooses and determines each kind of components the material. Usually must make the prototype or the working model, and carries on the experiment to it, the appraisal product function, the reliability, the outward appearance and the service maintenance and so on. Although this kind of experiment possibly can indicate, enters in the product to the production base in front of, should replace certain materials, but, absolutely cannot this point take not earnestly chooses the material the excuse. Should unify the product the function, earnestly carefully considers the product the outward appearance, the cost and the reliability. Has the achievement very much the company when manufacture all prototypes, selects the material should the material which uses with its production in be same, and uses the similar manufacture technology as far as possible. Like this has the advantage very much to the company. The function complete prototype if cannot act according to the anticipated sales volume economically to make, or is prototypical and the official production installment has in the quality and the reliable aspect is very greatly different, then thiskind of prototype does not have the great value. Project engineer is best can completely complete the material in this stage the analysis, the choice and the determination work, but is not remains it to the production design stage does. Because, is carries on in the production design stage material replacement by other people, these people are inferior to project engineer to the product all functions understanding. In the production design stage, is should completely determine with the material related main question the material, causes them to adapt with the existing equipment, can use the existing equipment economically to carry on the processing, moreover the material quantity can quite be easy to guarantee the supply.In the manufacture process, inevitably can appear to uses the material to make some changes the situation. The experience indicated that, may use certain cheap materials to take the substitute. However, in the majority situation, in will carry on the production later to change the material to have in to start before the production to change the price which the material will spend to have to be higher than. Completes the choice of material work in the design stage, may avoid the most such situations. Started after the production manufacture to appear has been possible to supply the use the new material is replaces the material the most commonreason. Certainly, these new materials possibly reduce the cost, the improvement product performance. But, must carry on the earnest appraisal to the new material, guarantees its all performance all to answer the purpose. Must remember that, the new material performance and the reliable very few pictures materials on hand such understood for the people. The majority of products expiration and the product accident caused by negligence case is because in selects the new material to take in front of substitution material, not truly understood their long-term operational performance causes.The product responsibility lawsuit forces designs the personnel and the company when the choice material, uses the best procedure. In the material process, five most common questions are: (a) did not understand or cannot use about the material application aspect most newly the best information paper; (b) has not been able to foresee and to consider the dusk year possible reasonable use (for example to have the possibility, designs the personnel also to be supposed further to forecast and the consideration because product application method not when creates consequence. ecent years many products responsibilities lawsuit case, because wrongly uses the plaintiff which the product receives the injury to accuse produces the factory, and wins the decision); (c) uses the materialdata not entire perhaps some data are indefinite, works as its long-term performance data is the like this time in particular; (d) the quality control method is not suitable and not after the confirmation; (e) the personnel which completely is not competent for the post by some chooses the material.Through to the above five questions analysis, may obtain these questions is does not have the sufficient reason existence the conclusion. May for avoid these questions to these questions research analyses the appearance indicating the direction. Although uses the best choice of material method not to be able to avoid having the product responsibility lawsuit, designs the personnel and the industry carries on the choice of material according to the suitable procedure, may greatly reduce the lawsuit the quantity. May see from the above discussion, the choice material people should to the material nature, the characteristic and the processing method have comprehensive and the basic understanding.外文资料翻译译文（二）机械设计理论机械设计是一门通过设计新产品或者改进老产品来满足人类需求的应用技术科学。
建筑设计论文外文翻译-(2)
实用文档设计（论文）外文参考资料及译文译文题目：Discussion on The Planning and Designof Commercial Buildings学生姓名：XXX学号：09******83专业：建筑学所在学院：XX学院指导教师： XX职称：副教授201X年XX月XX日实用文档原文：Discussion on The Planning and Designof Commercial BuildingsAbstract: the commercial building in residential buildings has become, most attract sb.'s attention, the largest building is influenced by the type of energy and landscape of the city planning, design of commercial buildings will face more problems. This paper discusses how to carry on planning and design of commercial buildings, the construction of a rational, reasonable, appropriate business building, so as to create a good social and economic benefits. Keywords: construction planning; commercial buildings; architectural designPrefaceComprehensive is the development trend of modern commercial buildings, architects in the design of commercial buildings and functions are changing, different positioning of planning, business characteristics and local cultural influence commercial building mode, which requires us to continuously improve our project products, create more in line with the business needs of the best plan and design works, and finally let investors and consumers feel a constant value, so that they feel superior combination of spatial continuous operation, let the customer feel shopping pleasure, feel the beauty of life and the world.mercial architectural schemeCommercial buildings are generally large investment, high risk, long cycle, the successful operation of returns, different commercial patterns determine different commercial building form, and commercial pattern is determined and market positioning, the positioning accuracy of the architect, to commercial building various functions, property, facilities should have full understanding and effective organization, and different commercial construction planning ideas to produce commercial architectural design works are different, economic benefits of investment has great difference. Good architectural planning has decided the success or failure of architectural design.1.Market survey of commercial building design must be based on the market survey results. Based on the characteristics and trend of foreign consumption, economic conditions, traffic conditions, the surrounding commercial pattern, city infrastructure, city development planning, full market research business situation, on the project itself, choose format, format portfolio, the distribution of industrial chain and area proportion, industry selection, distribution and area ratio to the shops, division, architectural form, area and the floor function, people oriented system, project environment and supporting facilities are set in advance. Provide design basis for the architect to design.2.Mode demand regardless of commercial building is rental, sale or rental run combination, the most important is to determine the main format, for commercial buildings,different types of decision model is different, its business scale, function flow, and so on are designed by itself to determine, different formats have different functional requirements, and design the use is required by the business decisions rather than the developer to advocate. The lack of directional design basis, the design appears to be universal, but shoot at random. Once the function with the shop owner conflict, the design must be from the beginning. Language planning can increase the early unnecessary cost and later investment difficulty. Therefore, architects should design according to different formats of different architectural space mode analysis and recommendations.3.In commercial buildings in the process of planning, commercial real estate is the key to grasp the global experts and architects. Commercial real estate planner requires multidisciplinary personnel coordination ability of organization, according to the project of regional history and culture characteristic, according to local consumer preferences, in particular, the design project of the overall concept, culture orientation and market orientation is determined. At present, the commercial real estate projects generally organized by developers to overall planning, the investment in the project needs and business management experts, business format store managers and retail marketing planner, planner, communication landscape planners, architects, etc. In the implementation of construction plan, still need to urban planner, computer talented person to participate, to form a complete construction plans. Neither side may be arranged to replace, the architectural design is inclusive and absorbing these opinions, solutions and professional values of materialized labor and can form a complete architectural planning and design.4.Sustainable development and the characteristics of commercial building is a public place, with the development of business, commercial buildings in 5-6 years will be to do a decoration, simple and durable quality, less as far as possible need to repair and maintenance, and at the same time, according to the different project environment and commercial content is flexible to adapt and ultimately the value of investors and consumers are continuous. Complete function, rich forms, and space is varied, characteristic, design must be the contemporary tendency of time again at the same time, in all sorts of culture and the differences between s resonate.mercial building designCommercial building design is for the purpose of the construction project to produce a good and lasting economic benefits, the architect in commercial building design is to realize project to achieve a dynamic model of investment return, is to complete a final acceptance by consumers and continuous use of building products. Prophase planning orientation, investment, operation and management, each situation is very complex, has brought great influence, architecture design is an important link. And architects for commercial architecture design is inclusive and absorbing these opinions, solutions and professional values of materialized labor and can form a complete works of architectural design.(1)Formats combination designThe composition of commercial complex is decided by the business itself industry value chain, what kind of business combination is better for business. Architects should accordingto the preliminary planning and positioning, the first investment, operation and management of the planning scheme, starting from the basic function and practical application of building, clear the relationship between the function, space, environment, in line with The Times to design not only requires a new breath, also requires a reasonable and clear arrangement of the whole space functional requirements, and actively guide the passenger flow, manufacturing flow, different articles require different forms of space and location, reasonable distribution area, the partition of floor paving segmentation and supporting facilities design can avoid all kinds of goods mixed Chen, mixed traffic situation, the architect should create rich, flexible, comply with the appropriate space to contain different aspects of business combination technology needs. Must do to make it a complex, the industrial chain, industrial chain out after the value chain came out, can produce all kinds of benefits.(2)Pattern designPlanning, design of commercial building in different commercial real estate development mode, have completely different results. Rent is not only sales, emphasizing on management and value-added shops, if considering concurrently, also consider the preferences and requirements of the buyer shops. Commercial buildings due to the different requirements for merchants function layout is different, also different brands to the layout of the same forms are different. By the limit of commercial buildings, or different development cycle, or running effect is different. Those who do not conform to the business law of commercial building design, although space modeling is rich, has implied the bad management of hidden trouble. Therefore, meet the demand of merchants, digest the negative influence of all kinds of changes, architects in the design of the flexible space combination, providing different pattern design, to the use of a variety of forms do fully consider function of balance and coordination. Commercial building itself the function of the combination is very complex, for commercial, residential, office each mixed complex project, the process will be more difficult. Commercial and apartment part often deployed in a low-end, office and hotel in the high-end. The advantages of this design can facilitate the building line layout; Low-end flat layer in the core tube location is advantageous to the toilet set up; High-end part of the landscape advantage is more advantageous to project high value products. But in the concrete project, but should also fully consider building itself the vertical transportation efficiency of the impact on business. In the design of architectural plane layout, space efficiency will approach combined with architectural form and structure. For example, many senior project adopted the practice of Angle, when the design according to the economy, it can increase economic returns of about 30%, but in the specific project be careful not to damage to the corner form.(3)The guidance system designStream of people, logistics, decision function layout reasonable guidance system is the key to the success of commercial building design. Make sure people line, logistics, inward and outward, channel form, to make the layout of the commercial function, consumer groups have a wide range of interest and today free time, thus providing rich architectural space, integrating shopping, entertainment, leisure and so on need comprehensive shopping mall is their needs. Rich function as much as possible to meet the requirements of the customers, but also satisfy the buyers (pavement investors, business investors) needs to provide convenient logistics channel. And express more interest in the construction details. And then to createnew business environment. Let the consumer feel the pleasure shopping consumption, feel the beauty of life and the world at the same time, create more economic benefits for store operators.(4)Green building and characteristicGreen building on the one hand can save energy, on the other hand the sustainable of benefits will far outweigh the prophase investment so as to achieve the value of overall implementation, green buildings gives the possibility of ability of sustainable development and alteration, when architects in the design of commercial buildings so there is no need to do best, do it right, and not have to do much more luxurious style reflected is the commercial buildings, stronger in proper. Commercial buildings tend to be the center of the city commercial culture, different cities have different style, therefore, the architects in the use of his style and technique, need deep understanding urban commercial culture characteristics, extract the essence of the regional culture, architectural design make commercial buildings should have cultural features, local feature, more want to highlight the characteristics of the formats, spatial characteristics, cultural characteristics used in commercial buildings, not only can sense the material shell, are showing strong commercial buildings.3.ConclusionModern commercial architecture planning and design major programs, including the investment purpose and the understanding of the business environment for investors, commercial content on the project, the location of the business environment of consumer behavior, commercial buildings, the understanding of the business concept research, commercial building project planning, design process and method of design, for project construction total plane design and auxiliary space design professional design, space form and form design, the project design space and form of management main body,property requirements,facilities and equipment requirements,architectural engineering and construction of the professional requirement.中文译文：浅谈商业建筑规划设计摘要：商业建筑现已成为除居住建筑以外，最引人注目的，对城市活力和景观影响最大的建筑类型，商业建筑规划设计将面临更广泛的问题。
5、外文文献翻译(附原文)产业集群,区域品牌,Industrial cluster ,Regional brand
外文文献翻译（附原文）外文译文一：产业集群的竞争优势——以中国大连软件工业园为例Weilin Zhao,Chihiro Watanabe，Charla-Griffy-Brown[J]. Marketing Science,2009(2):123-125.摘要：本文本着为促进工业的发展的初衷探讨了中国软件公园的竞争优势。
产业集群深植于当地的制度系统，因此拥有特殊的竞争优势。
根据波特的“钻石”模型、SWOT模型的测试结果对中国大连软件园的案例进行了定性的分析。
产业集群是包括一系列在指定地理上集聚的公司，它扎根于当地政府、行业和学术的当地制度系统，以此获得大量的资源，从而获得产业经济发展的竞争优势。
为了成功驾驭中国经济范式从批量生产到开发新产品的转换，持续加强产业集群的竞争优势,促进工业和区域的经济发展是非常有必要的。
关键词：竞争优势；产业集群；当地制度系统；大连软件工业园；中国；科技园区；创新；区域发展产业集群产业集群是波特[1]也推而广之的一个经济发展的前沿概念。
作为一个在全球经济战略公认的专家,他指出了产业集群在促进区域经济发展中的作用。
他写道：集群的概念,“或出现在特定的地理位置与产业相关联的公司、供应商和机构，已成为了公司和政府思考和评估当地竞争优势和制定公共决策的一种新的要素。
但是，他至今也没有对产业集群做出准确的定义。
最近根据德瑞克、泰克拉[2]和李维[3]检查的关于产业集群和识别为“地理浓度的行业优势的文献取得了进展”。
“地理集中”定义了产业集群的一个关键而鲜明的基本性质。
产业由地区上特定的众多公司集聚而成,他们通常有共同市场、,有着共同的供应商,交易对象,教育机构和其它像知识及信息一样无形的东西，同样地,他们也面临相似的机会和威胁。
在全球产业集群有许多种发展模式。
比如美国加州的硅谷和马萨诸塞州的128鲁特都是知名的产业集群。
前者以微电子、生物技术、和风险资本市场而闻名,而后者则是以软件、计算机和通讯硬件享誉天下[4]。
换热器外文翻译 (2)
Heat ExchangersKey Terms Baffles—evenly spaced partitions in a shell and tube heat exchanger that support the tubes, prevent vibration, control fluid velocity and direction, increase turbulent flow, and reduce hot spots. Channel head—a device mounted on the inlet side of a shell-and-tube heat exchanger that is used to channel tube-side flow in a multipass heat exchanger.Condenser—a shell-and-tube heat exchanger used to cool and condense hot vapors.Conduction—the means of heat transfer through a solid, nonporous material resulting from molecular vibration. Conduction can also occur between closely packed molecules.Convection—the means of heat transfer in fluids resulting from currents. Counterflow—refers to the movement of two flow streams in opposite directions; also called countercurrent flow.Crossflow—refers to the movement of two flow streams perpendicular to each other.Differential pressure—the difference between inlet and outlet pressures; represented as ΔP, or delta p.Differential temperature—the difference between inlet and outlet temperature; represented as ΔT, or delta t.Fixed head—a term applied to a shell-and-tube heat exchanger that has the tube sheet firmly attached to the shell.Floating head—a term applied to a tube sheet on a heat exchanger that is not firmly attached to the shell on the return head and is designed to expand (float) inside the shell as temperature rises. Fouling—buildup on the internal surfaces of devices such as cooling towers and heat exchangers, resulting in reduced heat transfer and plugging.Kettle reboiler—a shell-and-tube heat exchanger with a vapor disengaging cavity, used to supply heat for separation of lighter and heavier components in a distillation system and to maintain heat balance. Laminar flow—streamline flow that is more or less unbroken; layers of liquid flowing in a parallel path.Multipass heat exchanger—a type of shell-and-tube heat exchanger that channels the tubeside flow across the tube bundle (heating source) more than once.Parallel flow—refers to the movement of two flow streams in the same direction; for example, tube-side flow and shell-side flow in a heat exchanger; also called concurrent.Radiant heat transfer—conveyance of heat by electromagnetic waves from a source to receivers.Reboiler—a heat exchanger used to add heat to a liquid that was onceboiling until the liquid boils again.Sensible heat—heat that can be measured or sensed by a change in temperature.Shell-and-tube heat exchanger—a heat exchanger that has a cylindrical shell surrounding a tube bundle.Shell side—refers to flow around the outside of the tubes of ashell-and-tube heat exchanger. See also Tube side.Thermosyphon reboiler—a type of heat exchanger that generates natural circulation as a static liquid is heated to its boiling point.Tube sheet—a flat plate to which the ends of the tubes in a heat exchanger are fixed by rolling, welding, or both.Tube side—refers to flow through the tubes of a shell-and-tube heat exchanger; see Shell side.Turbulent flow—random movement or mixing in swirls and eddies of a fluid. Types of Heat Exchangers换热器的类型Heat transfer is an important function of many industrial processes. Heat exchangers are widely used to transfer heat from one process to another.A heat exchanger allows a hot fluid to transfer heat energy to a cooler fluid through conduction and convection. A heat exchanger provides heating or cooling to a process. A wide array of heat exchangers has been designed and manufactured for use in the chemical processing industry. In pipe coil exchangers, pipe coils are submerged in water or sprayed with water to transfer heat. This type of operation has a low heat transfer coefficient and requires a lot of space. It is best suited for condensing vapors with low heat loads.The double-pipe heat exchanger incorporates a tube-within-a-tube design. It can be found with plain or externally finned tubes. Double-pipe heat exchangers are typically used in series-flow operations in high-pressure applications up to 500 psig shell side and 5,000 psig tube side.A shell-and-tube heat exchanger has a cylindrical shell that surrounds a tube bundle. Fluid flow through the exchanger is referred to as tubeside flow or shell-side flow. A series of baffles support the tubes, direct fluid flow, increase velocity, decrease tube vibration, protect tubing, and create pressure drops.Shell-and-tube heat exchangers can be classified as fixed head, single pass; fixed head, multipass; floating head, multipass; or U-tube.On a fixed head heat exchanger (Figure 7.1), tube sheets are attached to the shell. Fixed head heat exchangers are designed to handle temperature differentials up to 200°F (93.33°C). Thermal expansion prevents a fixed head heat exchanger from exceeding this differential temperature. It is best suited for condenser or heater operations.Floating head heat exchangers are designed for high temperature differentia is above 200°F (93.33°C).During operation, one tube sheet is fixed and the other “floats” inside the shell.The floatingend is not attached to the shell and is free toexpand.Figure 7.1 Fixed Head Heat ExchangerReboilers are heat exchangers that are used to add heat to a liquid that was once boiling until the liquid boils again. Types commonly used in industry are kettle reboilers and thermosyphon reboilers.Plate-and-frame heat exchangers are composed of thin, alternating metal plates that are designed for hot and cold service. Each plate has an outer gasket that seals each compartment. Plate-and-frame heat exchangers have a cold and hot fluid inlet and outlet. Cold and hot fluid headers are formed inside the plate pack, allowing access from every other plate on the hot and cold sides. This device is best suited for viscous or corrosive fluid slurries. It provides excellent high heat transfer. Plate-and-frame heat exchangers are compact and easy to clean. Operating limits of 350 to 500°F (176.66°C to 260°C) are designed to protect the internal gasket. Because of the design specification, plate-and-frame heat exchangers are not suited for boiling and condensing. Most industrial processes use this design in liquid-liquid service.Air-cooled heat exchangers do not require the use of a shell in operation. Process tubes are connected to an inlet and a return header box. The tubes can be finned or plain. A fan is used to push or pull outside air over the exposed tubes. Air-cooled heat exchangers are primarily used in condensing operations where a high level of heat transfer is required.Spiral heat exchangers are characterized by a compact concentric design that generates high fluid turbulence in the process medium. As do otherexchangers, the spiral heat exchanger has cold-medium inlet and outlet and a hot-medium inlet and outlet. Internal surface area provides the conductive transfer element. Spiral heat exchangers have two internal chambers.The Tubular Exchanger Manufacturers Association (TEMA) classifies heat exchangers by a variety of design specifications including American Society of Mechanical Engineers (ASME) construction code, tolerances, and mechanical design:●Class B, Designed for general-purpose operation (economy and compactdesign)●Class C. Designed for moderate service and general-purpose operation(economy and compact design)●Class R. Designed for severe conditions (safety and durability) Heat Transfer and Fluid FlowThe methods of heat transfer are conduction, convection, and radiant heat transfer (Figure 7.2). In the petrochemical, refinery, and laboratory environments, these methods need to be understood well. A combination of conduction and convection heat transfer processes can be found in all heat exchangers. The best conditions for heat transfer are large temperature differences between the products being heated and cooled (the higher the temperature difference, the greater the heat transfer), high heating or coolant flow rates, and a large cross-sectional area of the exchanger.ConductionHeat energy is transferred through solid objects such as tubes, heads,baffles, plates, fins, and shell, by conduction. This process occurs when the molecules that make up the solid matrix begin to absorb heat energy from a hotter source. Since the molecules are in a fixed matrix and cannot move, they begin to vibrate and, in so doing, transfer the energy from the hot side to the cooler side.ConvectionConvection occurs in fluids when warmer molecules move toward cooler molecules. The movement of the molecules sets up currents in the fluid that redistribute heat energy. This process will continue until the energy is distributed equally. In a heat exchanger, this process occurs in the moving fluid media as they pass by each other in the exchanger. Baffle arrangements and flow direction will determine how this convective process will occur in the various sections of the exchanger.Radiant Heat TransferThe best example of radiant heat is the sun’s warming of the earth. The sun’s heat is conveyed by electromagnetic waves. Radiant heat transfer is a line-of-sight process, so the position of the source and that of the receiver are important. Radiant heat transfer is not used in a heat exchanger.Laminar and Turbulent FlowTwo major classifications of fluid flow are laminar and turbulent (Figure 7.3). Laminar—or streamline—flow moves through a system in thin cylindrical layers of liquid flowing in parallel fashion. This type of flow will have little if any turbulence (swirling or eddying) in it. Laminar flow usually exists atlow flow rates. As flow rates increase, the laminar flow pattern changes into a turbulent flow pattern. Turbulent flow is the random movement or mixing of fluids. Once the turbulent flow is initiated, molecular activity speeds up until the fluid is uniformly turbulent.Turbulent flow allows molecules of fluid to mix and absorb heat more readily than does laminar flow. Laminar flow promotes the development of static film, which acts as an insulator. Turbulent flow decreases the thickness of static film, increasing the rate of heat transfer. Parallel and Series FlowHeat exchangers can be connected in a variety of ways. The two most common are series and parallel (Figure 7.4). In series flow (Figure 7.5), the tube-side flow in a multipass heat exchanger is discharged into the tubeside flow of the second exchanger. This discharge route could be switched to shell side or tube side depending on how the exchanger is in service. The guiding principle is that the flow passes through one exchanger before it goes to another. In parallel flow, the process flow goes through multiple exchangers at the same time.Figure 7.5 Series Flow Heat ExchangersHeat Exchanger EffectivenessThe design of an exchanger usually dictates how effectively it can transfer heat energy. Fouling is one problem that stops an exchanger’s ability to transfer heat. During continual service, heat exchangers do not remain clean. Dirt, scale, and process deposits combine with heat to form restrictions inside an exchanger. These deposits on the walls of the exchanger resist the flow that tends to remove heat and stop heat conduction by i nsulating the inner walls. An exchanger’s fouling resistance depends on the type of fluid being handled, the amount and type of suspended solids in the system, the exchanger’s susceptibility to thermal decomposition, and the velocity and temperature of the fluid stream. Fouling can be reduced by increasing fluid velocity and lowering the temperature. Fouling is often tracked and identified usingcheck-lists that collect tube inlet and outlet pressures, and shell inlet and outlet pressures. This data can be used to calculate the pressure differential or Δp. Differential pressure is the difference between inlet and outlet pressures; represented as ΔP, or delta p. Corrosion and erosion are other problems found in exchangers. Chemical products, heat, fluid flow, and time tend to wear down the inner components of an exchanger. Chemical inhibitors are added to avoid corrosion and fouling. These inhibitors are designed to minimize corrosion, algae growth, and mineral deposits.Double-Pipe Heat ExchangerA simple design for heat transfer is found in a double-pipe heat exchanger.A double-pipe exchanger has a pipe inside a pipe (Figure 7.6). The outside pipe provides the shell, and the inner pipe provides the tube. The warm and cool fluids can run in the same direction (parallel flow) or in opposite directions (counterflow or countercurrent).Flow direction is usually countercurrent because it is more efficient. This efficiency comes from the turbulent, against-the-grain, stripping effect of the opposing currents. Even though the two liquid streams never come into physical contact with each other, the two heat energy streams (cold and hot) do encounter each other. Energy-laced, convective currents mix within each pipe, distributing the heat.In a parallel flow exchanger, the exit temperature of one fluid can only approach the exit temperature of the other fluid. In a countercurrent flowexchanger, the exit temperature of one fluid can approach the inlet temperature of the other fluid. Less heat will be transferred in a parallel flow exchanger because of this reduction in temperature difference. Static films produced against the piping limit heat transfer by acting like insulating barriers.The liquid close to the pipe is hot, and the liquid farthest away from the pipe is cooler. Any type of turbulent effect would tend to break up the static film and transfer heat energy by swirling it around the chamber. Parallel flow is not conducive to the creation of turbulent eddies. One of the system limitations of double-pipe heat exchangers is the flow rate they can handle. Typically, flow rates are very low in a double-pipe heat exchanger, and low flow rates are conducive to laminar flow. Hairpin Heat ExchangersThe chemical processing industry commonly uses hairpin heat exchangers (Figure 7.7). Hairpin exchangers use two basic modes: double-pipe and multipipe design. Hairpins are typically rated at 500 psig shell side and 5,000 psig tube side. The exchanger takes its name from its unusual hairpin shape. The double-pipe design consists of a pipe within a pipe. Fins can be added to the internal tube’s external wall to increase heat transfer. The multipipe hairpin resembles a typical shell-and-tube heat exchanger, stretched and bent into a hairpin.The hairpin design has several advantages and disadvantages. Among its advantages are its excellent capacity for thermal expansion because of its U-tube type shape; its finned design, which works well with fluids that have a low heat transfer coefficient; and its high pressure on the tube side. In addition, it is easy to install and clean; its modular design makes it easy to add new sections; and replacement parts are inexpensive and always in supply. Among its disadvantages are the facts that it is not as cost effective as most shell-and-tube exchangers and it requires special gaskets.Shell-and-Tube Heat ExchangersThe shell-and-tube heat exchanger is the most common style found inindustry. Shell-and-tube heat exchangers are designed to handle high flow rates in continuous operations. Tube arrangement can vary, depending on the process and the amount of heat transfer required. As the tube-side flow enters the exchanger—or “head”—flow is directed into tubes that run parallel to each other. These tubes run through a shell that has a fluid passing through it. Heat energy is transferred through the tube wall into the cooler fluid. Heat transfer occurs primarily through conduction (first) and convection (second). Figure 7.8 shows a fixed head,single-pass heat exchanger.Fluid flow into and out of the heat exchanger is designed for specific liquid–vapor services. Liquids move from the bottom of the device to the top to remove or reduce trapped vapor in the system. Gases move from top to bottom to remove trapped or accumulated liquids. This standard applies to both tube-side and shell-side flow.Plate-and-Frame Heat ExchangersPlate-and-frame heat exchangers are high heat transfer and high pressure drop devices. They consist of a series of gasketed plates, sandwiched together by two end plates and compression bolts (Figures 7.20 and 7.21). The channels between the plates are designed to create pressure drop and turbulent flow so high heat transfer coefficients can be achieved.The openings on the plate exchanger are located typically on one of the fixed-end covers.As hot fluid enters the hot inlet port on the fixed-end cover, it is directed into alternating plate sections by a common discharge header. The header runs the entire length of the upper plates. As cold fluid enters the countercurrent cold inlet port on the fixed-end cover, it is directed into alternating plate sections. Cold fluid moves up the plates while hot fluid drops down across the plates. The thin plates separate the hot and cold liquids, preventing leakage. Fluid flow passes across the plates one time before entering the collection header. The plates are designed with an alternating series of chambers. Heat energy is transferred through the walls of the plates by conduction and into the liquid by convection. The hot and cold inlet lines run the entire length of the plate heater and function like a distribution header. The hot and cold collection headers run parallel and on the opposite side of the plates from each other. The hot fluid header that passes through the gasketed plate heat exchanger is located in the top. This arrangement accounts for the pressure drop and turbulent flow as fluid drops over the plates and into the collection header. Cold fluid enters the bottom of the gasketed plate heat exchanger and travels countercurrent to the hot fluid. The cold fluid collection header is located in the upper section of the exchanger.Plate-and-frame heat exchangers have several advantages and disadvantages. They are easy to disassemble and clean and distribute heat evenly so there are no hot spots. Plates can easily be added or removed. Other advantages of plate-and-frame heat exchangers are their low fluid resistance time, low fouling, and high heat transfer coefficient. In addition, if gaskets leak, they leak to the outside, and gaskets are easy to replace.The plates prevent cross-contamination of products. Plate-and-frame heat exchangers provide high turbulence and a large pressure drop and are small compared with shell-and-tube heat exchangers.Disadvantages of plate-and-frame heat exchangers are that they have high-pressure and high-temperature limitations. Gaskets are easily damaged and may not be compatible with process fluids.Spiral Heat ExchangersSpiral heat exchangers are characterized by a compact concentric design that generates high fluid turbulence in the process medium (Figure 7.22). This type of heat exchanger comes in two basic types: (1) spiral flow on both sides and (2) spiral flow–crossflow. Type 1 spiral exchangers are used in liquid-liquid, condenser, and gas cooler service. Fluid flow into the exchanger is designed for full counterflow operation. The horizontal axial installation provides excellent self-cleaning of suspended solids.Type 2 spiral heat exchangers are designed for use as condensers, gas coolers, heaters, and reboilers. The vertical installation makes it an excellent choice for combining high liquid velocity and low pressure drop on the vapor-mixture side. Type 2 spirals can be used in liquid-liquid systems where high flow rates on one side are offset by low flow rates on the other.Air-Cooled Heat ExchangersA different approach to heat transfer occurs in the fin fan or air-cooled heat exchanger. Air-cooled heat exchangers provide a structured matrix of plain or finned tubes connected to an inlet and return header (Figure 7.23). Air is used as the outside medium to transfer heat away from the tubes. Fans are used in a variety of arrangements to apply forced convection for heattransfer coefficients. Fans can be mounted above or below the tubes in forced-draft or induced-draft arrangements. Tubes can be installed vertically or horizontally.The headers on an air-cooled heat exchanger can be classified as cast box, welded box, cover plate, or manifold. Cast box and welded box types have plugs on the end plate for each tube. This design provides access for cleaning individual tubes, plugging them if a leak is found, and rerolling to tighten tube joints. Cover plate designs provide easy access to all of the tubes. A gasket is used between the cover plate and head. The manifold type is designed for high-pressure applications.Mechanical fans use a variety of drivers. Common drivers found in service with air-cooled heat exchangers include electric motor and reduction gears, steam turbine or gas engine, belt drives, and hydraulic motors. The fan blades are composed of aluminum or plastic. Aluminum blades are d esigned to operate in temperatures up to 300°F (148.88°C), whereas plastic blades are limited to air temperatures between 160°F and 180°F(71.11°C, 82.22°C).Air-cooled heat exchangers can be found in service on air compressors, in recirculation systems, and in condensing operations. This type of heat transfer device provides a 40°F (4.44°C) temperature differential between the ambient air and the exiting process fluid.Air-cooled heat exchangers have none of the problems associated with water such as fouling or corrosion. They are simple to construct and cheaper to maintain than water-cooled exchangers. They have low operating costs and superior high temperature removal (above 200°F or 93.33°C). Their disadvantages are that they are limited to liquid or condensing service and have a high outlet fluid temperature and high initial cost of equipment. In addition, they are susceptible to fire or explosion in cases of loss of containment.。
外文翻译 2
附件1：外文资料翻译译文WCDMA系统Ahmed Hassan2.1背景GSM系统最初设计是提供语音和低速率的数据业务。
用户数据速率的无线接口使用单个物理信道，即一个时隙一个TDMA帧，最初速率是9.6 kbps.在第二期GSM系统中，两种新业务通过允许MS占用多个时隙来提高用户数据速率，就是所谓的2.5G。
这两种业务是高速电路交换数据（HSCSD）和通用分组无线服务（GPRS）。
为了在GSM网络上获得更高的数据访问，HSCSD允许个人占用多个连续时隙，而不是限制在GSM TDMA标准中每个用户只占用特定的时隙。
HSCSD为了数据传输放松了GSM标准中原先指定的差错编码控制算法，使可用的应用数据速率达到14.4kbps。
HSCSD让用户通过占用四个连续时隙使传输速率达到57.6kbps。
相比之下，GPRS在无线端口上使用分组连接，仅仅当信息传送时，用户占用一个或多个通信信道。
HSCSD是一种理想的实时互动网络会议，而GPRS 是非实时性的网络应用，包括检索电子邮件、传真、不对称网络浏览。
当GSM 无线信道的八个时隙都分给GPRS时，用户的最高速率可以达到171.2kbps(八个时隙乘以21.4kbps).另一个增加用户数据速率的方法是采用更高层次的调制方案:增强型数据速率GSM演进技术（EDGE）。
EDGE的加强GSM数据速率的背后驱动力是提高调制方法。
EDGE可以根据不同的信道条件在两种调制方式中转换。
EDGE在质量差信道使用GMSK调制方式，在质量好的信道使用8-PSK调制方式。
这是通过借助链路适配功能允许MS和BS根据需要选择这两种不同的调制方式。
因此，调制方式的选择应根据无线链路的质量来提供更高的速率。
EDGE在单一的GSM信道为一个独立专用用户提供高达384kbps的数据速率。
这些选择为通过GSM技术接入网络和支持各种创新手机提供了重大的改善。
然而，所有这些选择对多媒体和巨大的速率依然有限制，这导致了3G系统的改革。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
毕业设计(论文)外文翻译英文翻译题目一：Concurrent Design of Plastics Injection Moulds 英文翻译题目二：学院名称：机械工程学院专业：材料成型及控制工程班级：成型104姓名：杨施泽学号10403070427 指导教师：陈永清2013年12月31日Concurrent Design of Plastics Injection Moulds 英文题目一翻译内容全文指导教师评语指导教师签字年月日英文题目二翻译内容指导教师评语指导教师签字年月日塑料注塑模具并行设计Assist.Prof.Dr. A. YAYLA /Prof.Dr. Paş a YAYLA摘要近年塑料制品制造业迅速成长。
其中最受欢迎的制作过程是注塑零件。
注塑模具的设计对产品质量、效率和产品加工非常重要。
模具公司想保持竞争优势,就必须缩短模具设计和制造的周期。
模具行业是对工业的一个重要支持行业，在产品开发过程中作为一个产品设计师和制造商之间的联系。
产品开发经历了从传统的串行开发设计制造到有组织的并行设计和制造过程中,被认为是在非常早期的阶段的设计。
并行工程的概念(CE)不再是新的,但它仍然是适用于当今的相关环境。
团队合作精神、管理参与、总体设计过程和整合IT工具仍然是并行工程的本质。
CE过程的应用设计的注射过程包括同时考虑塑件设计、模具设计和注塑成型机的选择、生产调度和成本中尽快设计阶段。
介绍了注射模具的基本结构设计。
在该系统的基础上,模具设计公司分析注塑模具设计过程，该注射模设计系统包括模具设计过程及模具知识管理。
最后的原则概述了塑料注射模并行工程过程并对其原理应用到设计。
关键词:塑料注射模设计、并行工程、计算机辅助工程、成型条件、塑料注塑、流动模拟1、简介注塑模具总是昂贵的,不幸的是没有模具就不可能生产零件。
每一个模具制造商都有他自己的方法来设计模具,有许多不同的设计与建造模具。
当然最关键的参数之一,是要考虑到模具设计阶段是大量的计算注射的方法、浇注的的方法、研究注射成型机容量和特点。
模具的成本、质量和制件质量是分不开的针对今天的计算机辅助充型模拟软件包能准确地预测任何部分充填模式环境中。
这允许快速模拟实习,帮助找到模具的最佳位置。
工程师可以在电脑上执行成型试验前完成零件设计。
工程师可以预测过程系统设计和加工窗口,并能获得信息累积所带来的影响,如部分过程变量影响性能、成本、外观等。
2、注射成型法注塑成型是最有效的方法之一,将塑料最好的一面呈现。
这是普遍用于制造复杂的制件,优点是简单、经济、准确与少浪费。
塑料零件的批量生产主要采用模具。
产品设计制造过程包括模具的结构必须经过外观评价和结构优化。
当设计师创造注射模具组件时，他们面临一个巨大的多种选择，并行工程需要一个工程师考虑制产品在发展阶段时的过程设计。
一个好的产品设计为了满足市场其制造过程是不可能太贵的。
CAD/CAM整合了过程仿真、快速成形制造能减少风险,进一步提高产品开发的有效性。
3、注塑模具设计重要的计算机辅助注射模具设计任务是相当复杂的。
计算机辅助工程(CAE)分析工具提供了巨大的优势让设计工程师考虑几乎所有模具、注塑参数没有真正利用的地方。
在可能性的设计、理念设计师，给工程师们机会去消除潜在的问题,开始真正的生产。
此外,在虚拟环境中,设计师可以快速而方便地评估特定的成型参数敏感性的质量和生产最终产品。
所有这些分析工具使所有模具设计将在一天甚至数小时完成,而不需要几周或几个月来做真正的实验反复试验。
CAE用于早期设计的部分,模具和注塑模具参数、节约成本是实质功能不仅是最好的部分,而且还能节省和缩短开发产品推向市场的时间。
在所有方面的成型过程中需要满足塑料部分设置的公差,包括零件的尺寸和形状,树脂的化学结构、填料使用,模具型腔布置、浇注、模具冷却并释放机制使用。
面对这复杂性,设计师经常使用电脑设计工具,如有限元分析(FEA)和充型分析(MFA),减少开发时间和成本。
有限元分析确定部分结构的应变、应力和挠度,在那里这些参数可以很好地被定义。
冲型分析位置和大小进行优化树脂流动。
它还定义了焊缝的位置、面积过大的压力,以及如何影响墙壁和肋厚度流动。
其它有限元分析设计工具包括模具冷却温度分布,分析周期时间和收缩为空间控制和预测冻结应力、翘曲变形等情况。
采用CAE分析部分压缩模如图1所示。
分析周期始于创造一个CAD模型和有限元网格的模具腔。
在注入条件规定,充型、纤维取向、固化和热历史、收缩和翘曲变形等情况进行仿真。
该材料的性能计算模型模拟可用于结构的行为的一部分。
如果需要部分设计浇口位置及加工条件可以在电脑上修改,直到一个可接受的零件的表达式。
摘要分析了一个优化完成部分可采用降低weldline(亦即也knitline),优化力量、控制温度和固化、最小收缩和翘曲变形等情况。
模具加工的前身是手工制作,如检查每一剪机床维修工。
自动化的增长和普遍使用的电脑数值控制或CNC加工中心使这过程变得更加简便。
设计的时间也被大大降低通过使用特殊的软件能够产生刀具路径直接从CAD数据文件提取。
主轴速度高达100000每分钟转速提一步提出了高速加工。
切削材料已经证明了惊人的表现而不使用任何的剪切/冷却液,什么都没有。
作为一个结果,加工过程复杂的型心和型腔已经加快了。
这是一个好消息,产生一个模具所花费的时间不断的被减少。
坏消息是,另一方面,甚至所有这些进步、设计和制造的模具仍然要花很长时间,是非常昂贵的。
图1的注射模CAE分析部分许多公司的经理人现在体会部署新产品推向市场迅速发展是多么的重要。
企业的繁荣关键在于新产品。
他们推动企业的收入、市场份额、底线和股票价格。
一个公司能够发明优质的产品和合理的价格领先其竞争不仅实现了100%的打败市场竞争对手的产品,但之前到达也倾向于保持主导地位甚至几年之后终于宣布竞争产品(史密斯,1991)。
对大多数产品来说,这两个优势是戏剧性的。
现在产品快速发展的一个关键方面的竞争成功。
图2显示,只有3 - 7%的产品结构与一般的工业或电子公司是小于5岁。
公司在第一四分位,这个数字增加到15 - 25%。
一流的公司,它是60 - 80%(汤普森,1996)。
最好的公司在不断开发新产品。
在惠普,超过80%的利润结果从产品小于2岁!(Neel,1997)图2重要的新产品(雅克布,2000)以先进的计算机技术和人工智能,努力已经被指向降低成本和交货时间在设计和制造注塑模具。
注塑模具设计主要感兴趣的地区,因为它是一个复杂的过程涉及到很多表面设计等各零件的模具,每个都需要专家的知识和经验。
李et.艾尔。
(1997)提出了一种系统的方法关于注塑模具设计的知识库和并行工程环境。
4并行工程在模具设计中并行工程(CE)是一个系统性的方法来集成产品开发过程。
它代表了团队合作的价值观、信任和分享,以这样的方式,决策是通过协商一致,包括视角并联,从一开始就产品的整个生命周期(埃文斯,1998)。
从本质上讲,CE提供合作、合作、集体和同步工程的工作环境。
一个并行工程的方法是基于五个关键要素:1、过程2、多学科小组3、综合设计模型4、设施5、软件基础设施图3的方法对塑料注射模设计,工程b)串并行工程在塑料模具制造业、CE是很重要的,由于高成本加工和长交货期。
通常,CE 利用制造原型模具在设计之初相位分析和调整设计。
生产制造模具是作为最后一步。
制造过程,包括模具的结构必须经过外观评价和结构优化的产品设计。
CE要求工程师考虑生产过程中产品设计的发展阶段。
一个好的设计产品是满足市场如果其制造过程是不可能的。
CAD/CAM整合过程模拟、快速成形制造能减少风险,从效率和进一步提高产品开发的有效性。
多年来,设计师已经被限制在他们可以产出通常必须设计制造(DFM)——那就是,调整他们的设计意图,使元件(或总成)生产使用一个特定的进程或程序。
此外,如果一个模具用于产生一个项目,而因此自动设计对固有限制在一开始就相处得很好。
以注塑为例,以处理一个组件成功,即使在最小程度上,下面的设计元素需要考虑的内容:1、.几何.拔模斜度.非内角形状.近恒壁厚.复杂性.分裂线位置.表面抛光材料选择元件的合理化(减少组件)成本在注塑、生产的模具生产注射模具元件通常是最长的部分产品开发过程。
当利用快速造型、CAD需要长时间,因此成为瓶颈。
废水处理工程的工艺设计和注塑塑料涉及相当复杂且耗时的活动,包括零件设计、模具设计、注塑成型机的选择、生产排程、工装和成本估算。
所有这些活动是传统上由部分设计和模具制作人员按注射模顺序的方式完成后塑料部件的设计。
很明显的,这些序列阶段可能会导致长的产品开发时间。
但随着社会的过程中实施并行工程所有参数影响产品设计、模具设计、机械的选择、生产排程、模具和加工成本被认为是尽早塑料部件的设计。
使用时有效,CAE方法节省了部分设计及制造巨大的成本和时间。
这些工具几乎让工程师测试部分处理它在其正常使用寿命表现怎样。
材料供应商,设计师和制造商应该运用这些工具同时在设计之初阶段利用CAE增加塑料成本效益。
CAE技术使人们有可能取代传统,顺序决策程序和并行设计过程,其中各方之间是如何产生互动和分享信息,图3塑料注塑、CAE及相关设计数据提供一个综合的环境,为便于并行工程的设计、制造和模具部分,以及材料的选择和模拟优化工艺控制参数。
定性费用有关的部分比较设计上的变化被显示在图4，显示出一个事实,那就是当设计已经改好了在早期阶段在计算机屏幕上时,与成本有关的顺序的10.000倍,如果低于部分生产。
这些改变可能发生在塑料部件模具的改变,如浇口位置、厚度变化、生产延迟,质量成本、机械安装时间,或是设计变更在塑料部件。
图4的成本在部分改变设计产品开发周期(张志刚,2001年版)在早期设计阶段,设计师设计模具部分必须完成零件设计基于各自的经验相似的部分。
但是随着部分变得更为复杂,它变得相当困难的加工性能预测及部分不使用计算机辅助工具。
因此,即使是相对复杂的部分,使用计算机辅助工具,防止变化和昂贵的设计过程中出现的问题,可以注射后。
为成功实施并行工程,必须有归属感从人人参与。
5个案研究图5显示初始CAD(计算机辅助设计)塑料部分用于喷灌消防栓的腿。
一个基本特征,部分的部分保持平注射后,在注射操作原因变形问题。
另一个重要特点的塑料部件必须是一种高效的抗弯刚度。
一批料中加入了不同取向的部分如图5 b。
这些应设计成一种方式,它有贡献的重量最小部分的,而且是可行的。
在模具的设计流程,分析了塑料部分进行了模具仿真分析软件让选拔的最佳浇口位置图6。
这个数字表明最好的点浇口位置的中间馈线的中心部分。
作为失真和陶瓷注射后的部分,至关重要的是,从功能的角度,它必须被保持在最低水平,同样也使用软件里面分析。