化工专业外文翻译

化工专业外文翻译
化工专业外文翻译

第 1 章外文翻译的基本内容

丁二烯的生产方法就世界范围而言先后经历了乙醇脱氢法、丁烯催化脱氢法、丁烷催化脱氢法、丁烯氧化脱氢法和乙烯副产C 馏分分离法。

1.乙醇催化脱氢法

乙醇催化脱氢生产丁二烯的方法1928年首先在原苏联工业化,该方法以氧化镁和氧化硅为催化剂.反应产物除生成丁二烯外还生成乙醛、乙醚、高级醇等多种副产品。每生产1吨丁二烯约需消耗3吨乙醇,该方法的经济性差,目前已被淘汰。

2.丁烯催化脱氢法

丁烯催化脱氢生产丁二烯首先由美国新泽西美孚石油开发公司开发。1943年第一套工业化装置投产.随后Shell和Dow公司也开发成功新的催化剂,从而也产生了Shel工艺和Dow工艺,该方法的工业化使得丁二烯的生产由酒精为原料转为以石油为原料。丁烯催化脱氢过程中,原料丁烯需混合大量水蒸汽以降低烃分压,来提高丁烯的转化率及生成丁二烯的选择性。该方法以Dow工艺的丁烯转化率和丁二烯的选择性为最高,分别达到35%~45%和90%-'94%。3.丁烷催化脱氢法

丁烷的来源要比丁烯丰富,价格也便宜,除可来自乙烯副产C 馏分外,还可来自天然气及油田气。

丁烷催化脱氢有一步法和两步法两种工艺:

Houdry一步法生产工艺由美国Houdry公司开发,1959年工业化,该工艺的催化剂经改进后,在美国及其他国家得到广泛应用。Houdry工艺丁烷一步脱氢采用由18%~20%氧化铬浸渍的氧化铝作催化剂,过程无需用水蒸气稀释原料,反应沉积在催化剂表面的结炭.在催化剂再生过程中再用空气烧去,总收率为62%'.-63%。Philips两步法生产工艺由美国Philips公司开发,1953年工业化,该方法丁烷转化率为30%,总收率为50%"60%。此外,原苏联也于1960-1963年开发了类似Philips的两步法工艺。由于两步法流程较长.操作复杂,故其应

用远没有一步法广泛。

4.丁烯氧化脱氢法

氢由于受反应平衡影响.单程转化率不高,为了使平衡向着有利于生产丁二烯的方向,可用氧脱去反应生成的氢,这样便可以大幅度提高丁烯的转化率及生成丁二烯的选择性。这一工艺由美国PetroTex公司在1965年首先工业化.随后许多催化脱氢工厂将其改为氧化脱氢生产丁二烯。氧化脱氢生产丁二烯单程转化率达70%.选择性为80%-'92%。我国在60年代开发成功丁烯氧化脱氢生产丁二烯技术,成为当时我国丁二烯生产的主要方法。

5.由乙烯装置副产C 馏分中分离丁二烯

石油烃蒸汽裂解是生产乙烯、丙烯、丁二烯等的重要方法,在分离乙烯和丙烯的同时.分离出裂解 C 馏分,其中含有大量的丁二烯,是目前生产丁二烯的主要原料,而由 C 馏分分离丁二烯则是目前生产丁二烯的主要方法.当前世界绝大多数丁二烯产品是用这一方法生产的。由于 C 馏分中各组分的沸点比较接近,需采用萃取精馏方可将丁二烯分离出来。由于使用溶剂的不同而有以下不同方法:糠醛法、乙腈法、二甲基甲酰胺法、二甲基乙酰胺法、N一甲基吡咯烷酮法等。在工业上得到广泛使用的是乙腈法、二甲基甲酰胺法和N 一甲基吡咯烷酮法。

5.1乙腈法

该法最早由美国Shell公司开发成功,并于1956年实现工业化生产。它以含水10%的乙腈(AC 为溶剂,由萃取、闪蒸、压缩、高压解吸、低压解吸和溶剂回收等工艺单元组成。1977年Shel公司在改造中增加了冷凝器和水洗塔,并将闪蒸和低压解吸的气相合并压缩.其中约8%经冷凝送往水洗塔洗去溶剂,塔顶气相返回原料蒸馏塔,这样就除去了C 烃中的C 烃。其余气体一部分送往高压解吸塔.另一部分作为再沸气体送往萃取蒸馏塔塔底以提供热能.从而省去了一台再沸器,降低了蒸汽用量。水洗塔底溶剂的约1%送往溶剂回收精制系统,以保证循环溶剂的质量。对炔烃含量较高的原料需要进行加氢处理,或采用精密精馏、两段萃取才能得到纯度较高的丁二烯。目前,该方法以意大利SIR工艺和日本JSR工艺为代表。

意大利SIR工艺以含水5%的ACN为溶剂,采用5塔流程(氨洗塔、第一萃取精馏塔、第二萃取精馏塔、脱轻塔和脱重塔)。在第一萃取精馏塔前加一氨水洗涤塔,用以除去原料中0.04%"0.08%(质量百分数)的醛酮。炔烃由第二萃取蒸馏塔第75块塔板侧线采出,送往接触冷凝器。脱重塔塔底和接触冷凝器底部物料合并,其热能回收后用于原料蒸发器。该工艺不仅能使丁二烯收率达到96%'98%.还能使丁二烯与炔烃分离,丁二烯产品纯度可以达到99.5%以上。该技术的特点是流程简单,溶剂解吸在萃取精馏塔下段完成;第一萃取精馏塔采用两点进料,有利于改善塔内液相的浓度分布.减少该塔上段的液相负荷,降低能耗;在第一萃取精馏塔下部设置一台换热器,起中间再沸器的作用,可充分利用塔底热能提高烃类从溶剂中的分离效率;采用在第二萃取精馏塔第75块塔板侧线除炔烃的技术,使丁二烯与炔烃几乎完全分离。

日本IRS工艺以含水10%的ACN 为溶剂,采用两段萃取蒸馏,第一萃取蒸馏塔由两塔串联而成。该工艺经过了1980年和1988年两次重大的改造。1980年的改造采用热偶合技术,即将第二萃取蒸馏塔顶全部富含丁二烯的蒸汽.不经冷凝直接送入脱重塔中段.同时将脱重塔内下降液流的一部分从中段塔盘上抽出,送往第二萃取蒸馏塔作为塔顶回流液,这样第二萃取蒸馏塔塔顶不需要冷凝器,这部分的热量将全部加到脱重塔,使该塔塔底再沸器的热负荷比热偶合前降低40%左右,从而实现大幅度节能。1988年的改造主要解决系统热能回收问题.即在提浓塔和脱轻塔安装中间冷凝器,将提浓塔从进料板附近上、下两段串联相接,这样即可使上塔负荷大幅度降低,又不会影响塔的操作条件。将塔分为上下两段,下塔操作压力提高.塔内温度相应升高,这样中间冷凝器就可回收到高品位的热能。此外,溶剂回收塔塔底废水的热能,可用于该塔进料管线的预热器,加上解析塔从侧线采出炔烃也可回收部分热能,因而该工艺在同类工艺中的能耗是最低的采用ACN法生产丁二烯的特点是:①沸点低,萃取、汽提操作温度低,易防止丁二烯自聚;②汽提可在高压下操作,省去了丁二烯气体压缩机,减少了投资;③粘度低,塔板效率高,实际塔板数少;④毒性微弱,在操作条件下对碳钢腐蚀性小;⑤丁二烯分别与正丁烷、丁二烯二聚物等形成共沸物,溶剂精制过程复杂,操作费用高;⑥蒸汽压高,随尾气排出的溶剂损失大;⑦用于回收溶剂的水洗塔较多,相对流程长。

5.2二甲基甲酰胺法

二甲基甲酰胺法(DMF法)又名GPB法,由日本瑞翁公司于1965年实现工业化生产,并建成一套4.5万吨/年生产装置。该生产工艺包括四个工序,即

第一萃取蒸馏工序、第二萃取蒸馏工序、精馏工序和溶剂回收工序。原料c 汽化后进人第一萃取精馏塔.溶剂DMF由塔的上部加入。溶解度小的丁烷、丁烯、c,使丁二烯的相对挥发度增大,并从塔顶分出,而丁二烯、炔烃等和溶剂一起从塔底导出,进入第一解吸塔被完全解吸出来,冷却并经螺杆压缩机压缩后进人第二萃取精馏塔进一步分离。不含 c 组分的溶剂从解吸塔底高温采出,用作萃取精馏、精馏、蒸发等工序的热源,热量回收后重新循环使用。炔烃、丙二烯、硫化物、羰基化合物这些有害杂质在溶剂中的溶解度较高,为防止乙烯基乙炔爆炸,并进一步回收溶剂中的丁二烯,第二萃取塔底排出的富溶剂送往丁二烯回收塔,塔顶为粗丁二烯。回收塔塔顶馏出的丁二烯和少量杂质返回第二萃取塔前的压缩机人口,塔釜含炔烃的溶剂送至第二解吸塔,从该塔塔顶分出乙烯基乙炔,稀释后用作锅炉燃料,釜液为溶剂,循环回萃取精馏塔。经两段萃取精馏得到的粗丁二烯中的杂质采用普通精馏除去。比丁二烯挥发度大的c,、水分等,在脱轻塔顶除去,比丁二烯挥发度小的残余2一丁烯、1,2-丁二烯、c 以及在生产过程中产生的少量丁二烯二聚物在脱重塔塔底除去。脱重塔顶可以得到纯度在99.5%以上的聚合级丁二烯。

DMF法工艺的特点是:①对原料c 的适应性强,丁二烯含量在15%-60%范围内都可生产出合格的丁二烯产品;②生产能力大,成本低,工艺成熟,安全性好、节能效果较好,产品、副产品回收率高达97%;⑧由于DMF对丁二烯的溶解能力及选择性比其他溶剂高,所以循环溶剂量较小,溶剂消耗量低;④无水DMF可与任何比例的c 馏分互溶,因而避免了萃取塔中的分层现象;⑤DMF与任何c 馏分都不会形成共沸物,有利于烃和溶剂的分离,但由于其沸点较高,溶剂损失小;⑥热稳定性和化学稳定性良好;⑦由于其沸点高,萃取塔及解吸塔的操作温度都较高,易引起双烯烃和炔烃的聚合;⑧无水情况下对碳钢无腐蚀性,但在水分存在下会分解生成甲酸和二甲胺,因而有一定的腐蚀性。

5.3 N一甲基吡咯烷酮法

N一甲基吡咯烷酮法(NMP法)由德国BASF公司开发成功,并于1968年实现工业化生产.建成一套7.5万吨/年生产装置。其生产工艺主要包括萃取蒸馏、脱气和蒸馏以及溶剂再生工序。粗c 馏分气化后进入主洗涤塔底部,含有8%水的N一甲基吡咯烷酮萃取剂由塔顶进入,丁二烯和更易溶解的组分及部分丁烷和丁烯被吸收,同时不含丁二烯的丁烷和丁烯从塔顶排出。主洗塔底部的富溶剂进入精馏塔,在此溶剂吸收的丁烷和丁烯被更易溶的丁二烯、丙二烯和乙炔置换出来,含有乙炔和丙二烯的丁二烯从精馏塔侧线以气态采出进入后洗塔。在后洗塔中,用新鲜溶剂将其他组分溶解,粗丁二烯由其塔顶蒸出后冷凝液化进入蒸馏工序,塔釜富溶剂返回精馏塔的中段。精馏塔釜的富溶剂先进人闪蒸罐中部脱气,再进入脱气塔脱烃,并控制NMP中的水平衡.少量炔烃从侧线离开脱气塔。其余脱下的烃经冷却塔进入循环压缩机,最后返回精馏塔底部。从后洗塔出来的粗丁二烯在第一蒸馏塔脱除甲基乙炔,在第二蒸馏塔中脱除1,2一丁二烯和c 烃,由第二蒸馏塔顶得到丁二烯产品。汽提后的溶剂抽出总量的0,2%进行再生,以免杂质积累。NMP法工艺的特点是:①溶剂性能优良,毒性低,可生物降解,腐蚀性低;②原料范围较广,可得到高质量的丁二烯,产品纯度可达9.7%-99.9%;③c炔烃无需加氢处理,流程简单,投资低,操作方便,经济效益高;④NMP具有优良的选择性和溶解能力,沸点高、蒸汽压低,因而运转中溶剂损失小;⑤热稳定性和化学稳定性极好,即使发生微量水解,其产物也无腐蚀性。因此装置可全部采用普通碳钢。确切地比较各种丁二烯生产方法的经济性是困难的,比较一致的看法是催化脱氢法的成本最高,氧化脱氢法次之,由乙烯装置副产的c 馏分分离法最为便宜。乙烯装置副产 C 馏分只相当燃料的价格,因此分离得到丁二烯的成本比脱氢法低30%-40%。从目前乙烯的生产规模及发展趋势来看,由乙烯装置副产的C 馏分分离丁二烯仍将是丁二烯的主要来源,氧化脱氢法只是用来弥补乙烯副产的不足,而催化脱氢法基本被淘汰。

第 2 章外文翻译

The production methods of butadiene world for ethanol dehydrogenation was experienced dinitramine, catalytic dehydrogenase, butane catalytic oxidation of dhea, dinitramine dehydrogenation and ethylene byproduct C fractions separation.

1 ethanol dehydrogenation catalysis

Ethanol dehydrogenation production methods of catalytic butadiene 1928 firstly in the former Soviet industrialization, this method for magnesium oxide catalyst and silicon product besides butadiene generation. The formation of higher alcohols, aldehydes, ether as many by-products. 1 ton per production butadiene need about three tons of alcohol consumption, this method, the economy has been eliminated.

2 catalytic dehydrogenation was dinitramine

Catalytic dehydrogenation production yield by butadiene first New Jersey mobil oil development company development. In 1943, the first set of industrialization. Then Shell and device developed new Dow company also produces a catalyst, and also the Shel technology and craft, the method of Dow industrial production of butadiene made by alcohol as raw materials into petroleum-based. Dhea dinitramine, catalytic materials to mix water with a yield reduced pressure, to improve the hydrocarbon generation and the yield rate of butadiene selective. This method takes the Dow process of conversion and selectivity of butadiene dinitramine, respectively for the highest 35% ~ 45 and 90 - '94.

3 butane catalytic dehydrogenase

The source of butane than rich, the price is cheaper dinitramine, besides can come from byproduct C), still can come from outside the distillate of gas and oil gas.

Butane catalytic dehydrogenation and two-step method has two kinds:

Houdry one-step production technology development Co., Houdry by the United States in 1959, the process of industrialization, the catalyst improvement in the United States and other countries have widely application. Houdry butane step by dehydrogenation technology 18% ~ 20% chrome oxide as the catalyst, the impregnation process of alumina without using water vapor deposition reaction in raw material, the dilution of carbon catalysts. In the process of catalyst regeneration with air, and the overall yield was burned to 62% '- 63. Philips two-step process by American Philips, 1953 industrialization

development company, this method for butane conversion for 50% of total yield 30%, 60%. In addition, "the former Soviet union in 1960-1963 developed the two-step process similar to Philips two-step process. Due to long. Complex operation, its application is not one-step widely.

4 dinitramine oxidation method of dhea

Due to the influence of hydrogen reaction rate is not high. One, in order to make the balance to be the direction of butadiene, producing oxygen reacts to the hydrogen, so it can greatly improve the yield rate and generate butadiene selectivity. This process by American PetroTex company in 1965 first. Then many industrialized factories will instead of the catalytic oxidation of dhea dhea butadiene production. Oxidation rate of dhea production butadiene one-way 70% selectivity for 80 - '92 percent. Our successful development in the 1960s dinitramine oxidation production technology, butadiene dhea becomes the main method of butadiene in production.

5.From ethylene plant in C isolated butadiene fractions

Petroleum hydrocarbons steam cracking is the production of ethylene, propylene, butadiene, etc, and the important method in the separation of ethylene and propylene and separated from cracking C fractions., which contains a lot of butadiene, is the main raw material, production of butadiene by C distillate is currently producing butadiene separation method of butadiene and the vast majority of the world. The product is with a butadiene method of production. Due to C in distillate close with the boiling point of butadiene extraction distillation can be separated. By using different solvents under different methods: furfural, acetonitrile method, DMF, methyl ethyl amide, n. a methyl pyrrole method, etc. Widely used in industry is acetonitrile method, DMF and N a methyl pyrrole method.

5.1 acetonitrile method

The earliest Shell company developed by the United States in 1956 and industrial production. It is to cut 10% acetonitrile solvent (AC, the extraction, braising, compression, high pressure, low desorption desorption and solvent recovery process units. 1977 Shel company in renovation of the condenser and increased, and water

tower and low voltage braising desorption gas combined compression. About 8% by condensation water tower to wash the solvent distillation column gas phase returns, raw materials from the C C hydrocarbon gases. The rest of hydrocarbon to high tower. Another part as desorption transformation reboiler gas extraction distillation tower bottom to provide heat. Eliminating a transformation reboiler, reduces the steam. Rinse about 1% to bottom solvent refined, the solvent recovery system to ensure the quality of circular solvent. GuiTing high content of raw materials needed by the precision processing, or hydrogenation distillation and extraction of two to get high purity of butadiene. Currently, this method in Italy and Japan JSR process technology SIR represented.

Italy in aqueous 5% SIR ACN solvent, using 5 tower processes (ammonia washing tower, first extraction distillation and extraction distillation, off the light and heavy) off. In the first extraction distillation before washing tower, add a ammonia removal raw materials used in 0.04% "0.08% (quality percentage of aldehydes ketones). GuiTing extraction distillation tower from the first 75 pieces tower, to contact effluence lateral-line plate condenser. Dropping multiplicity.it tower and condenser bottom bottom, the material combined heat recovery after the raw material for the evaporator. Not only can make butadiene yield reached 96% '98 percent also can make butadiene and GuiTing separation, butadiene and product purity can reach above. This technique 99.5% characteristic is simple and solvent extraction column in the next section desorption completed by two first extraction distillation, feeding, favorable renovation thermal coupling technique, is the second extraction distillation column of steam. All contain butadiene without condensation directly into dropping multiplicity.it tower. Also will drop off heavy tower from the middle part of the fluid flow out on the tray, sent to the second extraction distillation tower, such as fluid backflow second extraction distillation column condenser, this section does not need to add to the heat off all the tower, heavy bottom were coupled heat load capacity about 40% lower before, so as to achieve further energy-saving. In 1988, the transformation mainly resolves the problem of heat recovery system. In tower and light towers will install intermediate condenser tower from incoming plate and two

nearby series, so can reduce the load, and will not affect the operation conditions. Will be divided into two sections, the tower under operating pressure increase. The tower temperature rises, that can be recycled to the middle of condenser high heat. In addition, the solvent recovery of waste heat bottom tower, which can be used to feed the tower, plus the preheater pipe GuiTing produced from lateral-line analytical tower is recyclable heat, so this technology part in the same process is the lowest energy consumption by ACN method is characteristic of butadiene production of low boiling point: (1), extraction, stripping operation low temperature, easy to prevent butadiene since together, 2 stripper can operate under high pressure gas compressors, saves the butadiene, reduce investment, 3 low viscosity, plates, high efficiency, actual plates, 4 toxicity, under operating conditions of carbon steel corrosion, 5 and positive butane; butadiene butadiene dimer etc formed azeotrope, solvent refined process is complicated, the high cost of operation, Fourthly, high steam pressure with exhaust solvent loses much. 7 recovered solvents washing tower for more, relatively long flow.

5.2 DMF

DMF method (DMF) and GPB method, by Japanese creon company in 1965 and industrial production, a set of 4.5 million tons/year production equipment. The production process, including four processes

The first extraction distillation process, the second extraction distillation process, distillation process and the solvent recovery process. Who first lifo vaporization raw c extraction solvent distillation tower. The upper joined by DMF. The solubility of small, dinitramine, c, butane butadiene makes the relative volatility increases, and from the tower, and GuiTing butadiene, etc and solvent is derived from the bottom, enter first desorption tower was completely, cooling and desorption by screw compressor compression lifo extraction distillation separation of the second person to further. Do not contain c components from the bottom of the solvent extraction temperature as desorption extractive distillation, distillation, evaporation process such as heat source, quantity of heat recovery after recycling. GuiTing, propylene and sulfide, carbonyl

compounds these harmful impurities in the solubility of solvent, in order to prevent the vinyl acetylene explosion, and further, the second of recovered solvents butadiene extraction from the bottom to the rich solvents recovery tower, butadiene succinic tower for thick

Acrylic. Recovery tower top fractions of a second and a few impurity butadiene extraction tower before the return, tower kettle including compressor population GuiTing solvent to second from the tower, desorption tower top gives vinyl acetylene, diluted used for fuel, boiler, circular back extraction solvent distillation. The two butadiene extraction distillation crude distillation remove impurities by ordinary. The larger than butadiene volatility, moisture, c, the tower in light and small volatility of butadiene ratio, yield a residual 2-1 in the production of butadiene, c and process of the small butadiene in heavy tower. The bottom Dropping multiplicity.it tower above can be obtained in the purity of polymer butadiene 99.5% level.

The method is characteristic of DMF: (1) the adaptability of raw materials, c butadiene content within the scope of 15-60 can produce qualified products; butadiene 2 large production capacity, low cost, mature technology, Ann

All good energy saving effect, good products, by-products recovery reaches as high as 97%, Because of the butadiene DMF) of dissolved and selective than other solvents, so smaller cycles, solvent solvent consumption is low, 4 no water and no proportion of DMF mutually dissolved, thus avoiding c aromatics extraction tower statified phenomenon, 5 any c distillate with DMF are not formed azeotrope, be helpful for hydrocarbon and solvent separation, but due to its high boiling point solvents, loss, 6 thermal stability and good chemical stability, 7 because of its high boiling point, the extraction and desorption tower operation tower temperature is higher, easy cause double olefins and GuiTing polymerization, No water circumstance of), but in non-corrosive steel under the existing water can decompose generate formate and too, so there must be the corrosive.

5.3 N a methyl pyrrole method

N a methyl pyrrole method (NMP) by BASF company in Germany, and the

successful development of industrial production in 1968. Built a set of 7.5 million tons/year production equipment. The production process including extraction distillation, degassing and distillation and solvent regeneration process. Thick c fractions gasification lifo drawn, capturing washing water containing 8% of N a methyl pyrrole extraction column by entering, butadiene and easily dissolved components and parts of butane and dinitramine, excluding the absorption of butane and yield were from the tower. Wash the bottom of the solvent distillation, solvent into in the absorption of butane and yield were more of butadiene, propylene limonene and acetylene replacement, contains the acetylene and propylene limonene distillation of butadiene extraction from the pores in gaseous after entering wash. The washing tower, with fresh solvent composition dissolve and other butadiene by its top after the condensing steam distillation process, liquefied into solvent distillation tower kettle returns through the middle of the rich. The kettle solvent distillation advanced person braising cans of central degas, before entering the degassing tower, and elimination of water balance control NMP. Small GuiTing from lateral-line leave degassing tower. The rest of the cooling off into the circulation compressor, finally return column bottom. After washing DaChu come from coarse butadiene in first distillation, in the second removal methyl acetylene distillation tower removal 1,2 a butadiene and c by distillation column, the hydrocarbon butadiene get products. After stripping out the amount of solvent 0,2 % regeneration, lest impurities accumulated. The method is characteristic of NMP: excellent performance, low toxicity solvents, biodegradable, low resistance, (2) raw material, can get a wider range of high quality product purity of butadiene, 11-99.9%, 3 GuiTing c without hydrogenation, simple process, low investment, convenient operation, high economic benefit, (NMP excellent selectivity and dissolve High boiling point ability, the solution of steam, solvent, low loss, 5 thermal stability and chemical stability is extremely good, even happen, its product is trace hydrolysis &noncorrosive. Therefore all USES ordinary steel devices. Exactly is the method of butadiene production efficiency is difficult, the consensus is the highest cost dhea catalytic oxidation method, the method of dhea, ethylene plant by byproduct of c is the most expensive fractions separation. C) device,

only the price of fuel fraction is obtained, so the cost of butadiene and low dhea law than 30 to 40 percent. From the production scale of ethylene and developing trend of ethylene plant, by byproduct of C fractions butadiene will still be separated, the major source of butadiene oxidation method to compensate dhea is insufficient, ethylene, and catalytic dehydrogenation law basic eliminated.

ASP外文翻译原文

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毕业设计外文翻译资料

外文出处: 《Exploiting Software How to Break Code》By Greg Hoglund, Gary McGraw Publisher : Addison Wesley Pub Date : February 17, 2004 ISBN : 0-201-78695-8 译文标题: JDBC接口技术 译文: JDBC是一种可用于执行SQL语句的JavaAPI(ApplicationProgrammingInterface应用程序设计接口)。它由一些Java语言编写的类和界面组成。JDBC为数据库应用开发人员、数据库前台工具开发人员提供了一种标准的应用程序设计接口,使开发人员可以用纯Java语言编写完整的数据库应用程序。 一、ODBC到JDBC的发展历程 说到JDBC,很容易让人联想到另一个十分熟悉的字眼“ODBC”。它们之间有没有联系呢?如果有,那么它们之间又是怎样的关系呢? ODBC是OpenDatabaseConnectivity的英文简写。它是一种用来在相关或不相关的数据库管理系统(DBMS)中存取数据的,用C语言实现的,标准应用程序数据接口。通过ODBCAPI,应用程序可以存取保存在多种不同数据库管理系统(DBMS)中的数据,而不论每个DBMS使用了何种数据存储格式和编程接口。 1.ODBC的结构模型 ODBC的结构包括四个主要部分:应用程序接口、驱动器管理器、数据库驱动器和数据源。应用程序接口:屏蔽不同的ODBC数据库驱动器之间函数调用的差别,为用户提供统一的SQL编程接口。 驱动器管理器:为应用程序装载数据库驱动器。 数据库驱动器:实现ODBC的函数调用,提供对特定数据源的SQL请求。如果需要,数据库驱动器将修改应用程序的请求,使得请求符合相关的DBMS所支持的文法。 数据源:由用户想要存取的数据以及与它相关的操作系统、DBMS和用于访问DBMS的网络平台组成。 虽然ODBC驱动器管理器的主要目的是加载数据库驱动器,以便ODBC函数调用,但是数据库驱动器本身也执行ODBC函数调用,并与数据库相互配合。因此当应用系统发出调用与数据源进行连接时,数据库驱动器能管理通信协议。当建立起与数据源的连接时,数据库驱动器便能处理应用系统向DBMS发出的请求,对分析或发自数据源的设计进行必要的翻译,并将结果返回给应用系统。 2.JDBC的诞生 自从Java语言于1995年5月正式公布以来,Java风靡全球。出现大量的用java语言编写的程序,其中也包括数据库应用程序。由于没有一个Java语言的API,编程人员不得不在Java程序中加入C语言的ODBC函数调用。这就使很多Java的优秀特性无法充分发挥,比如平台无关性、面向对象特性等。随着越来越多的编程人员对Java语言的日益喜爱,越来越多的公司在Java程序开发上投入的精力日益增加,对java语言接口的访问数据库的API 的要求越来越强烈。也由于ODBC的有其不足之处,比如它并不容易使用,没有面向对象的特性等等,SUN公司决定开发一Java语言为接口的数据库应用程序开发接口。在JDK1.x 版本中,JDBC只是一个可选部件,到了JDK1.1公布时,SQL类包(也就是JDBCAPI)

论文及外文翻译格式(标准)

附件5 论文及外文翻译写作格式样例 附录1 内封格式示例(设置成小二号字,空3行) 我国居民投资理财现状及发展前景的研究 (黑体,加粗,小二,居中,空2行) The Research on Status and Future of Inhabitants’ Investment and Financial Management in China (Times New Roman体,加粗,小二,居中,实词首字母大写,空5行) 院系经济与管理学院(宋体,四号,首行缩进6字符) 专业公共事业管理(宋体,四号,首行缩进6字符) 班级 6408101 (宋体,四号,首行缩进6字符) 学号 200604081010 (宋体,四号,首行缩进6字符) 姓名李杰(宋体,四号,首行缩进6字符) 指导教师张芸(宋体,四号,首行缩进6字符) 职称副教授(宋体,四号,首行缩进6字符) 负责教师(宋体,四号,首行缩进6字符) (空7行) 沈阳航空航天大学(宋体,四号,居中) 2010年6月(宋体,四号,居中)

附录2 摘要格式示例(设置成三号,空2行) 摘要(黑体,加粗,三号,居中,两个字之间空两格) (空1行) 我国已经步入经济全球化发展的21世纪,随着市场经济的快速增长和对外开放的进一步深化,我国金融市场发生了巨大的变化。一方面,投资理财所涉及到的领域越来越广,不仅仅是政府、企业、社会组织进行投资理财,居民也逐步进入到金融市场中,开始利用各种投资工具对个人、家庭财产进行打理,以达到资产保值、增值,更好的用于消费、养老等的目的;另一方面,我国居民投资理财观念逐渐趋于成熟化、理性化;同时,其投资理财工具以及方式手段亦越来越向多元化、完善化发展。 本论文以我国居民投资理财为研究对象,综合运用现代经济学、金融学和管理学的理论;统计学、概率学的方法和工具,主要对我国居民投资理财的历史演变、发展现状、意识观念、存在的问题和主要投资理财工具进行了分析和探讨,并提出了改善和促进我国居民理财现状的对策和建议,指出了普通居民合理化投资理财的途径。 摘要以浓缩的形式概括研究课题的内容,摘要应包括论文的创新性及其理论和实际意义。摘要中不宜使用公式、图表,不标注引用文献编号。中文摘要在300-500字左右。(首行缩进两个字符,宋体,小四,行距最小值:22磅)(空1行) 关键词:(宋体,小四,加粗,左缩进:0)投资理财资理财工具通货膨胀(宋体,小四,每个关键词之间空两格,关键词的个数在3到5个之间)

毕业设计外文翻译附原文

外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华

外文资料名称: Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处:Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件: 1.外文资料翻译译文 2.外文原文

应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金,洪城铱昌,宰瑾李, 刘链柱译 摘要:旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率,压降,并切成尺寸被粒度对应于分级收集的50%的效率进行了研究。颗粒切成大小降低入口面积,体直径,减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法,用于收集在家庭中产生的粉尘。 摘要及关键词:吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子,工作场所,或其他建筑,因此,室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物,毒物,食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤,预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中,吸入压力下降说唱空转成比例地清洗的时间,以及纸过滤器也应定期更换,由于压力下降,气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形,在粗颗粒(>2.0微米)模式为主要的外部来源,如风吹尘,海盐喷雾,火山,从工厂直接排放和车辆废气排放,以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式,典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克,可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。

毕业设计外文翻译原文.

Optimum blank design of an automobile sub-frame Jong-Yop Kim a ,Naksoo Kim a,*,Man-Sung Huh b a Department of Mechanical Engineering,Sogang University,Shinsu-dong 1,Mapo-ku,Seoul 121-742,South Korea b Hwa-shin Corporation,Young-chun,Kyung-buk,770-140,South Korea Received 17July 1998 Abstract A roll-back method is proposed to predict the optimum initial blank shape in the sheet metal forming process.The method takes the difference between the ?nal deformed shape and the target contour shape into account.Based on the method,a computer program composed of a blank design module,an FE-analysis program and a mesh generation module is developed.The roll-back method is applied to the drawing of a square cup with the ˉange of uniform size around its periphery,to con?rm its validity.Good agreement is recognized between the numerical results and the published results for initial blank shape and thickness strain distribution.The optimum blank shapes for two parts of an automobile sub-frame are designed.Both the thickness distribution and the level of punch load are improved with the designed blank.Also,the method is applied to design the weld line in a tailor-welded blank.It is concluded that the roll-back method is an effective and convenient method for an optimum blank shape design.#2000Elsevier Science S.A.All rights reserved. Keywords:Blank design;Sheet metal forming;Finite element method;Roll-back method

毕业设计(论文)外文资料翻译〔含原文〕

南京理工大学 毕业设计(论文)外文资料翻译 教学点:南京信息职业技术学院 专业:电子信息工程 姓名:陈洁 学号: 014910253034 外文出处:《 Pci System Architecture 》 (用外文写) 附件: 1.外文资料翻译译文;2.外文原文。 指导教师评语: 该生外文翻译没有基本的语法错误,用词准确,没 有重要误译,忠实原文;译文通顺,条理清楚,数量与 质量上达到了本科水平。 签名: 年月日 注:请将该封面与附件装订成册。

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2016年外文翻译撰写要求与格式规范x

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工具,使施工经理有效处理一个项目,以实现其在前期建设和在施工阶段的目标。在施工阶段,一个常见的问题要求各方参与一个项目,尤其是一个所有者,最终项目的预算到底是多少?或什么时候该项目能被完成? 在跟踪和控制一个建设项目时,预测项目的性能是非常必要的。目前已经提出了几种方法,如基于挣值技术、模糊逻辑、社会判断理论和神经网络。将挣值法视为一个确定的方法,其一般假设,无论是性能效率可达至报告日期保持不变,或整个项目其余部分将计划超出申报日期(克里斯坦森,1992;弗莱明和坎普曼,2000 ;阿萨班尼,1999;维卡尔等人,2000)。然而,挣值法的基本概念在研究确定潜在的进度延误、成本和进度的差异成本超支的地区。吉布利(1985)利用平均每个成本帐户执行工作的实际成本,也称作单位收入的成本,其标准差来预测项目完工成本。各成本帐户每月的进度是一个平均平稳过程标准偏差,显示预测模型的可靠性,然而,接受的单位成本收益在每个报告期在变化。埃尔丁和休斯(1992)和阿萨班尼(1999)利用分解组成成本的结构来提高预测精度。迪克曼和Al-Tabtabai(1992)基于社会判断理论提出了一个方法,该方法在预测未来的基础上的一组线索,源于人的判断而不是从纯粹的数学算法。有经验的项目经理要求基于社会判断理论方法的使用得到满意的结果。Moselhi等人(2006)应用“模糊逻辑”来预测潜在的成本超支和对建设工程项目的进度延迟。该方法的结果在评估特定时间状态的项目和评价该项目的利润效率有作用。这有助于工程人员所完成的项目时间限制和监控项目预算。Kaastra和博伊德(1996)开发的“人工神经网络”,此网络作为一种有效的预测工具,可以利用过去“模式识别”工作和显示各种影响因素的关系,然后预测未来的发展趋势。罗威等人(2006)开发的成本回归模型能在项目的早期阶段估计建筑成本。总共有41个潜在的独立变量被确定,但只有四个变量:总建筑面积,持续时间,机械设备,和打桩,是线性成本的关键驱动因素,因为它们出现在所有的模型中。模型提出了进一步的洞察了施工成本和预测变量的各种关系。从模型得到的估计结果可以提供早期阶段的造价咨询(威廉姆斯(2003))——最终竞标利用回归模型预测的建设项目成本。 人工神经网络已被广泛用在不同的施工功能中,如估价、计划和产能预测。神经网络建设是Moselhi等人(1991)指出,由Hegazy(1998)开发了一个模型,该模型考虑了项目的外在特征,估计加拿大的公路建设成本: ·项目类型 ·项目范围

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204/JOURNAL OF BRIDGE ENGINEERING/AUGUST1999

JOURNAL OF BRIDGE ENGINEERING /AUGUST 1999/205 ends.The stress state in each cylindrical strip was determined from the total potential energy of a nonlinear arch model using the Rayleigh-Ritz method. It was emphasized that the membrane stresses in the com-pression region of the curved models were less than those predicted by linear theory and that there was an accompanying increase in ?ange resultant force.The maximum web bending stress was shown to occur at 0.20h from the compression ?ange for the simple support stiffness condition and 0.24h for the ?xed condition,where h is the height of the analytical panel.It was noted that 0.20h would be the optimum position for longitudinal stiffeners in curved girders,which is the same as for straight girders based on stability requirements.From the ?xed condition cases it was determined that there was no signi?cant change in the membrane stresses (from free to ?xed)but that there was a signi?cant effect on the web bend-ing stresses.Numerical results were generated for the reduc-tion in effective moment required to produce initial yield in the ?anges based on curvature and web slenderness for a panel aspect ratio of 1.0and a web-to-?ange area ratio of 2.0.From the results,a maximum reduction of about 13%was noted for a /R =0.167and about 8%for a /R =0.10(h /t w =150),both of which would correspond to extreme curvature,where a is the length of the analytical panel (modeling the distance be-tween transverse stiffeners)and R is the radius of curvature.To apply the parametric results to developing design criteria for practical curved girders,the de?ections and web bending stresses that would occur for girders with a curvature corre-sponding to the initial imperfection out-of-?atness limit of D /120was used.It was noted that,for a panel with an aspect ratio of 1.0,this would correspond to a curvature of a /R =0.067.The values of moment reduction using this approach were compared with those presented by Basler (Basler and Thurlimann 1961;Vincent 1969).Numerical results based on this limit were generated,and the following web-slenderness requirement was derived: 2 D 36,500a a =1?8.6?34 (1) ? ??? t R R F w ?y where D =unsupported distance between ?anges;and F y =yield stress in psi. An extension of this work was published a year later,when Culver et al.(1973)checked the accuracy of the isolated elas-tically supported cylindrical strips by treating the panel as a unit two-way shell rather than as individual strips.The ?ange/web boundaries were modeled as ?xed,and the boundaries at the transverse stiffeners were modeled as ?xed and simple.Longitudinal stiffeners were modeled with moments of inertias as multiples of the AASHO (Standard 1969)values for straight https://www.360docs.net/doc/ee18749197.html,ing analytical results obtained for the slenderness required to limit the plate bending stresses in the curved panel to those of a ?at panel with the maximum allowed out-of-?atness (a /R =0.067)and with D /t w =330,the following equa-tion was developed for curved plate girder web slenderness with one longitudinal stiffener: D 46,000a a =1?2.9 ?2.2 (2) ? ? ? t R f R w ?b where the calculated bending stress,f b ,is in psi.It was further concluded that if longitudinal stiffeners are located in both the tension and compression regions,the reduction in D /t w will not be required.For the case of two stiffeners,web bending in both regions is reduced and the web slenderness could be de-signed as a straight girder panel.Eq.(1)is currently used in the ‘‘Load Factor Design’’portion of the Guide Speci?cations ,and (2)is used in the ‘‘Allowable Stress Design’’portion for girders stiffened with one longitudinal stiffener.This work was continued by Mariani et al.(1973),where the optimum trans-verse stiffener rigidity was determined analytically. During almost the same time,Abdel-Sayed (1973)studied the prebuckling and elastic buckling behavior of curved web panels and proposed approximate conservative equations for estimating the critical load under pure normal loading (stress),pure shear,and combined normal and shear loading.The linear theory of shells was used.The panel was simply supported along all four edges with no torsional rigidity of the ?anges provided.The transverse stiffeners were therefore assumed to be rigid in their directions (no strains could be developed along the edges of the panels).The Galerkin method was used to solve the governing differential equations,and minimum eigenvalues of the critical load were calculated and presented for a wide range of loading conditions (bedding,shear,and combined),aspect ratios,and curvatures.For all cases,it was demonstrated that the critical load is higher for curved panels over the comparable ?at panel and increases with an increase in curvature. In 1980,Daniels et al.summarized the Lehigh University ?ve-year experimental research program on the fatigue behav-ior of horizontally curved bridges and concluded that the slen-derness limits suggested by Culver were too severe.Equations for ‘‘Load Factor Design’’and for ‘‘Allowable Stress Design’’were developed (respectively)as D 36,500a =1?4?192(3)? ?t R F w ?y D 23,000a =1?4 ?170 (4) ? ? t R f w ?b The latter equation is currently used in the ‘‘Allowable Stress Design’’portion of the Guide Speci?cations for girders not stiffened longitudinally. Numerous analytical and experimental works on the subject have also been published by Japanese researchers since the end of the CURT project.Mikami and colleagues presented work in Japanese journals (Mikami et al.1980;Mikami and Furunishi 1981)and later in the ASCE Journal of Engineering Mechanics (Mikami and Furunishi 1984)on the nonlinear be-havior of cylindrical web panels under bending and combined bending and shear.They analyzed the cylindrical panels based on Washizu’s (1975)nonlinear theory of shells.The governing nonlinear differential equations were solved numerically by the ?nite-difference method.Simple support boundary condi-tions were assumed along the curved boundaries (top and bot-tom at the ?ange locations)and both simple and ?xed support conditions were used at the straight (vertical)boundaries.The large displacement behavior was demonstrated by Mi-kami and Furunishi for a range of geometric properties.Nu-merical values of the load,de?ection,membrane stress,bend-ing stress,and torsional stress were obtained,but no equations for design use were presented.Signi?cant conclusions include that:(1)the compressive membrane stress in the circumfer-ential direction decreases with an increase in curvature;(2)the panel under combined bending and shear exhibits a lower level of the circumferential membrane stress as compared with the panel under pure bending,and as a result,the bending moment carried by the web panel is reduced;and (3)the plate bending stress under combined bending and shear is larger than that under pure bending.No formulations or recommendations for direct design use were made. Kuranishi and Hiwatashi (1981,1983)used the ?nite-ele-ment method to demonstrate the elastic ?nite displacement be-havior of curved I-girder webs under bending using models with and without ?ange rigidities.Rotation was not allowed (?xed condition)about the vertical axis at the ends of the panel (transverse stiffener locations).Again,the nonlinear distribu-

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