Studies on the evolution process of rockbursts in deep tunnels
进化论：历史及过程 英文
The Voyage of the Beagle
On
a cold winter day in 1831, HMS Beagle set sail on a voyage around the world. The main mission of the voyage was to chart poorly known stretches of the South American coast line. On the voyage was 22 year old college graduate Charles Darwin. His main interest was to study the geology, plants, and animals encountered on theixed, they do not change Earth was only 10,000 years old and relatively unchanged.
Darwin Developed a theory of evolution: Ideas from Darwin’s Time
Route of the Beagle
Darwin’s Observations
Darwin
spent most of his time on shore while the ship’s crew surveyed. There he observed and collected thousands of specimens from plants and animals. He studied the organisms and their adaptations from places as different as the Brazilian Jungle to the frigid lands near Antarctica.
滇西古特提斯俯冲_碰撞过程的岩浆作用记录
!292 ! !
范蔚茗 , 彭头平 , 王岳军 /
地学前缘 ( Earth Science F ro nt iers) 2009, 16 ( 6)
火山岩组合 。 元素地球化学特征表明 , 早三叠世火山岩具有典型 的岛弧火 山岩的特征 , 暗示 其很可能形 成于 俯冲的构造环境 ; 中三叠世 晚期的流纹岩与临沧花岗岩基主体具 有非常相 似的地球化 学特征 , 结合其 流纹岩 具有 A 型花岗岩属性 , 表明该区中三叠世火成岩形成于碰撞后的构造背景 ; 而晚三叠世基性 火山岩虽 然在地 球化学特征上显示出与岛弧火山岩相似的高铝和 N b T a 的 亏损 , 但其中 部分火山 岩具有 高镁和 板内玄 武岩 的微量元素比值特征 , 说明这些火山 岩可能形成于碰撞后裂谷 ( post collisional r ifting ) 环境 。 结合区 域上前 人的研究资料 , 我们认为西 南三江地区古特提斯主洋盆的俯冲闭合可能直到早三叠世晚期才完 成 , 其 后的陆 陆 / 弧碰撞作用可能发生在 中三叠世早期 , 中三叠世中晚期该区进入碰撞后演化 阶段 , 晚三叠世开始处于碰撞 后的裂谷阶段 , 古特提斯在 该区的演化最终结束于三叠纪末 。 关键词 : 三叠纪岩浆作用 ; 岛弧 ; 碰撞 后 ; 澜沧江南带 ; 古特提斯 中图分类号 : P 588 1 ! 文献标志码 : A ! 文章编号 : 1005 2321( 2009) 06 0291 12
U校园新一代大学英语(提高篇)综合教程1unit8答案
U 校园新一代大学英语（提高篇）综合教程 1 unit8 答案1.Breaktluoughs2.[evolution i∑:Cd3.transplanted4 destruction5.an IIIIISiOn6.formula7.excellence8.IniSIedλλ ords and expressions 1・21.VitaIitV2.ha∖ e COnIe Into existence3.S(CPPCd in4.essence5.CXPertISC6.fertile7.SPiII Off< oilOCatiOIIS 11.illusion2.ShOrtaSeW3.deliberate4 depression5.IlChICVCd6.InagiCaI7.adaptableλ ocabula∣7 learning strategies 1-2RefereIice:1.ReCent StUdieS ha∖ e borne out2.tιgυrc OUt how to Start the equipment3.but OnIV One StOOd OUt from the rest4.Main COllege StlldentS CllOoSe to (JrOP Ollt Of SChoOlCvCrV VCilr5.The bikes and InOtOrCVCIeS tinned OXlt in the factory6・ though details arc Stln being WOrkCd OUtLaIIgUage focus 1-2RCfCrenee:1.WOUId rather be indoors2.WOUId I atIIer Ilot go back to3.did not accomplish the PrqjCCt4.WoUld I ather find a jobB:Inked i1)superior2)Shift3)deliberate4)IImOXathe5)fertile6)tbπnula7)a<kl8)vigorously9)Shortage10)SurPriSe8-4 iExplore 1: Shanng your ideasSharing your ideas 1Reference:It is StIll UndCr discussion which area IS the 1l Siiicon Valiev” .πι Chine ShCnZlICn is regarded as the IlOlnCtOWn Of entrepreneuιsι it is the PlaCe WlIere the InOSt Well-I<no∖∖n high-tech COnIPanieS in China Were founded. SUCh as Γencent∙ Huawei, and ZTE. Beijing also boasts its CUltIlre Of entrepreneurship. CharaCteriZed by PIaCeS SUCh as ZhonggIUmCIIn and SOftware Park; It is the hub of (he most Well-established IIIternet COmPaIIieS in China, SlICh as BaidIL Netease. SiIUL and SOhU In recent Vuals. the Citv WlIere Alibaba (TrolIP is head quartered. Hangzhou, has risen to PrOIninenCe as another IUlb Oi higlI・tuch Start-UPS in China; theCIty is most WelI-known for ItS PrOSPCrity Of C-COnUnercc. AIl these CitiCS CInbOdy the SPiritS Ot SiliCOn ∖alley: iιmo vatioiL energy, entrepreneurship. IIigh-tecluιolos∖∖ and hard WOrk for the PUrSUlt Of dreams.TenCent is a typical high-tech Start-UP In ChnUL SPeCialiZing in ∖aπoιιs IntCnlet-related Sen iCeS and Pn^dllets. entertainnιeπL AL and technology. ItS InOSt WelI-known SClViCeS and PrOdUCtS include TCnCent QQ. WCChat∙ and I cncent (TaInes. Γhe COnIPany was fbunde<l in 1998 in ShenZherL and now it has grown into One Of Asia's InoSt ValUablC COInPanieS With ContilUled revenue growth each vear.TenCent has Iemarkabk strengths Of teclιnolosv innovation.J J ∙Γhe COre to its inno∖:ItiOn ProCeSS is tlιe rapid laυnch-test-iιnpro∖ e CyCle. RatIlCr (han nailing down a ftιll-tledged PrO<hιct before its IaunClL its development team routinely IaUlICIleS read∖ -(O-IISe new PkItI<>πns With IinIited Ilinetioiiality and COlICCtS USer feedback to iιιη>ro∖ e the ilnal PnHlUCt. TO achieve this, the ConlPany IlaS Created ChanneIS to CnCOUraθc USCr ICCdback< to rapidly ClHnnlUniCatC this to the Rese;IrCh & Dex elopment team, and t□ ensure that the Pr(HlUCt architecture and design PIXKeSS IS SUffiCiently IIeXible to incorporate new functionality quickly. (Companies IIke TenCent enlιance the ability MIhC (∕hιnese CConOIny to achieve accelerated innovation. With rapid SCale-up. IOW cost, and good quality across a Wide range Of iικlustries.(AdaPtCd tioιn M ACCelCratCd innovation: ThC new ChalICngC from China/ by Peter J. WiIliaInSon and Eden Yin. MIT SlOan MaIUlgellIent Review. APril 23, 2014. pp. 29-30)iExplore 28-5 iExplore 2: ReadingVieWilIg 1-21) asking questions2) Inarkctine-Jrixen3) Jifterent4) SOonCr5) CaPital（PlIrtlICr7) business Plan8) entrepreneurλ ie⅜⅜iιι⅛ 1-3Reference:I Ihink these questions are InIPOrtant. I hCy Can help to generate a detailed road InaP Of StartiIIg IlP One l S own business, co∖ enng InIIX)rtant aspects Ot prodllCt Sen ice design and innovation, marketings adequate Iiindiiig. Partnei'Slliρ. etc.I XVOUkl Iike to add Olle question: Are you Ieady aικl Uet ennined to COlnInit yourself to the StalI-up? I he reason is (IUlt to Start onc,s own business re<∣uucs de∖otcd CIlOItS aικl PClsCVClancc. 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Γhis ShoWS that CroSS-disciplinary COnaboration Can generate brilliant ideas and PrOnlOte teamwork PertbrInanCe.iAssess8-9 Unit testλ Ocabulary and StrUCtUre 1-1C A *D C BV oCal>ιιla∣φv and StmCtllre 1-2⅜L expertise2.six e rise toW3.prerequisites4 Calne Inlo existence5. a<l∖entRalIked CloZe IFHCEMGOLJ NReading COnIPrelIenSiOn 1ABCBDIraIlSIatiOII 1-1Rcicrciicc:FaCeCl W ith the grim employment SitIIatiOn OfCOIlegeαraduates. the EdUCatiOn MiIUStrV has CaIkd On UnNersities to Oifer a InOre flexible education SVSteIn. allowing SnIdentS to SUSPend then StlKIieS to Seek business OPPortunItieS Otf CamPUS ・ lτni∖dβsi(ies are required to Ofifer Credit CoUrSeS Onentrepreneurship that in∖ ite entrepreneurs, business owners, academics and in∖ estors to Share their CXPeIliSe with ShIdeIits. StUdeIItS Were also encouraged to OPeIl Online shops and they WoUld be SUpPortCd by Tniancial institutes, non-eo∖ eminent OrganiZatiOIIS. associations and Other companies.TranSlation 1-2Reference:获得学位后返回国内的“海归” C海归”.“海龟“的文字游戏）人数正在迅速增加，据教育部统计.有250万在海外昭学的中国学生回国自2015年有76.4%的海归在国内创业，中关村博雅海外人才创业园是推动留学人员在京创业的重要机制，园区为海外人才创业提供行业指导等方面体系化的服务.这是企业创新发展的有力支持’。
托福TPO25阅读Passage3原文文本+题目+答案解析
托福TPO25阅读Passage3原文文本+题目+答案解析为了帮助大家高效备考托福，为大家带来托福TPO25阅读Passage3原文文本+题目+答案解析，希望对大家备考有所帮助。
▉托福TPO25阅读Passage3原文文本：The Evolutionary Origin of PlantsThe evolutionary history of plants has been marked by a series of adaptations.The ancestors of plants were photosynthetic single-celled organisms that gave rise to plants presumably lacked true roots,stems,leaves,and complex reproductive structures such as flowers.All of these features appe ared later in the evolutionary history of plants.Of today’s different groups of algae,green algae are probably the most similar to ancestral plants.This supposition stems from theclose phylogenetic(natural evolutionary)relationship between the two groups.DNA comparisons have shown that green algae are plants’closest living relatives.In addition,other lines of evidence support the hypothesis that land plants evolved from ancestral green algae used the same type of chlorophyll and accessory pigments in photosynthesis as do land plants.This would not be true of red and brown algae.Green algae store food as starch,as do land plants and have cell walls made of cellulose,similar in composition to those of land plants.Again,the good storage and cell wall molecules of red and brown algae are different.Today green algae live mainly freshwater,suggesting that their early evolutionary history may have occurred in freshwater habitats.If so,the green algae would have been subjected to environmental pressures that resulted in adaptations that enhanced their potential to give rise to land-dwelling or organisms.█The environmental conditions of freshwater habitats,unlike those of ocean habitats,are highly variable.█Water temperature can fluctuate seasonally or even daily and changing level of rainfall can lead to fluctuations in the concentration of chemical in the water or even to period in which the aquatic habitat dries up.█Ancient fresh water green algae must have evolved features that enable them to withstand extremes of temperature and periods of dryness.█These adaptations served their descendant well as they invaded land.The terrestrial world is green now,but it did not start out that way.When plants first made the transition ashore more than 400 million years ago,the land was barren and desolate,inhospitable to life.From a plant’s evolutionary view point,however,it was also a land of opportunity,free of competitors and predators and full of carbon dioxide and sunlight(the raw materials for photosynthesis,which are present in far higher concentrations in air than in water).So once natural selection had shaped the adaptations that helped plants overcome the obstacles to terrestrial living,plants prospered and diversified。
地质英语
The three spheres are very closely connected among themselves. Materials are constantly being transferred from one sphere to another. For example, the exposed water surfaces are constantly undergoing evaporation. Water is thus transferred from the hydrosphere to the atmosphere. Water is also being constantly transferred from the atmosphere to the hydrosphere by rain, hail and dew. Water is a solvent for some constiቤተ መጻሕፍቲ ባይዱuents of the rocks in the lithosphere. These dissolved materials thus pass from the lithosphere to the hydrosphere. There is also direct transference between the atmosphere and the lithosphere in certain chemical actions and during volcanic eruptions.
Geology is a very important science. We depend upon geology for the discovery of mineral deposits needed by the various industries. A lot of minerals are used as fuel and raw materials. Without them industrialization is impossible. Minerals are also used as fertilizers in agriculture. China is very rich in mineral deposits of all kinds. The study of geology will help us to discover them to serve our socialist construction.
新进化论英语
新进化论英语Evolutionary TheoryThe concept of evolution has captivated the scientific community and the general public for centuries. From the groundbreaking work of Charles Darwin to the modern advancements in genetic research, the theory of evolution has undergone a remarkable transformation, shedding light on the intricate processes that govern the natural world. This paper delves into the foundations of evolutionary theory, its key principles, and the evidence that supports its validity, ultimately highlighting its significance in our understanding of the world around us.At the core of evolutionary theory lies the principle of natural selection proposed by Charles Darwin. This mechanism suggests that individuals within a species possess variations in their traits, and those with the most advantageous characteristics are more likely to survive and reproduce, passing on their advantageous traits to their offspring. Over successive generations, this process leads to the gradual adaptation and transformation of species, enabling them to better suit their respective environments.One of the primary lines of evidence supporting the theory of evolution is the fossil record. The discovery of a vast array of fossilized remains, ranging from simple single-celled organisms to complex multicellular life forms, has provided a tangible timeline of the Earth's biological history. The systematic arrangement of these fossils, with the oldest and most primitive forms at the bottom and the more advanced species towards the top, corroborates the notion of gradual change over time. Furthermore, the presence of transitional fossils, such as the famous Tiktaalik, a fish-like creature with limb-like appendages, demonstrates the gradual evolution of organisms and the interconnectedness of various species.Another compelling evidence for evolutionary theory comes from the field of comparative anatomy. Researchers have observed striking similarities in the anatomical structures of diverse organisms, ranging from the pentadactyl (five-fingered) limb structure shared by mammals, birds, and reptiles to the vestigial structures, such as the remnants of pelvic bones in whales, which point to their ancestral land-dwelling origins. These shared characteristics, often referred to as homologous structures, provide strong evidence for the common evolutionary origin of these species.The advent of modern molecular biology has further bolstered the theory of evolution. The discovery of DNA and the understanding of genetic inheritance have shed light on the mechanisms ofevolutionary change at the most fundamental level. Comparative analysis of the genetic sequences of different species has revealed striking similarities, indicating their shared evolutionary lineage. Moreover, the phenomenon of genetic mutations, which can introduce beneficial or deleterious changes, has been observed to drive the process of natural selection and adaptation.In addition to the fossil record, comparative anatomy, and molecular biology, the theory of evolution is supported by numerous other lines of evidence, including biogeography, developmental biology, and the observed instances of evolution in action, such as the development of antibiotic resistance in bacteria.Despite the overwhelming scientific consensus on the validity of evolutionary theory, it has not been without its critics. Some individuals, motivated by religious or ideological beliefs, have challenged the theory, proposing alternative explanations for the origin and diversity of life. However, the scientific community has consistently reaffirmed the robustness of evolutionary theory, and the vast majority of the evidence continues to support its fundamental principles.In conclusion, the theory of evolution has emerged as one of the most comprehensive and well-supported scientific theories in the modern era. From the groundbreaking work of Charles Darwin to thelatest advancements in molecular biology, the evidence for evolution has continued to accumulate, providing a deep understanding of the mechanisms that govern the natural world. As our scientific knowledge continues to expand, the theory of evolution remains a crucial framework for understanding the origins, adaptations, and diversification of life on Earth.。
昆虫离子型受体及其功能研究进展
http : ! www. insect. cry. cndol ： 10.16380/j.kcxb. 2020.11.01211 月 November2020, 63(11)： 1399 -1410昆虫学报ACTAENTOMOLOGICASINICA昆虫离子型受体及其功能研究进展郭金梦，董双林(南京农业大学植物保护学院，南京210095)摘要：昆虫是地球上最大的动物类群，在长期的进化过程中形成了复杂的感受系统，其中以化学感 受(嗅觉和味觉)最为重要&气味受体(odoanl orpyr , OR )和味觉受体(gustatoo oceptor , GR ) 分别在嗅觉和味觉中起关键作用，但近年发现离子型受体#ionotropic receptor, IR)也在一些化学感 受中发挥作用，有些IR 还参与温度和湿度等非化学感受& IR 家族由离子型谷氨酸受体# Pwotopbglutamate receptor, iRluR)进化而来，具有典型的3个跨膜结构域；与OR 相似，每个IR 至少需要一个共受体(ca-receptor )才能发挥功能，现已发现4个IR 共受体(IR8a , IT25a , IR76b 和IR93a )；两个或多个IR 可以共表达于同一个嗅觉神经元，IR 间的不同组合导致神经元不同的气味反应谱&一种昆虫通常含有几个到上百个不等的IR,其中部分IR 为触角特异表达，但绝大多数IR 的功能 及其作用机制仍不清楚&本文综述了 IR 的结构和进化以及昆虫IR 基因鉴定、表达和功能等方面 的研究进展，以期为深入研究昆虫IR 的功能、作用机制及在害虫防治中的应用提供参考&关键词： (化学感受； 型受体；感器；嗅觉；味觉中图分类号：Q966 文献标识码：A 文章编号：0454-6296(2020)11-1399-12Research prgrss in ionotropic rcentor and their functions in insectsGUO Jin-Meng , DONG Shuang-Fin * * ( Colleye of Plant Protection , Nanjing AgTcultural University , Nanjing 210095, China )基金项目：国家自然科学基金项目(31672350, 31872300)作者简介：郭金梦，女，1992年4月生！山东泰安人，博士研究生！研究方向为昆虫生理生化与分子生物学！ E-mail ： ********************* 通讯作者 Corresponding aulCer , E-mail : slkong@ njau. cdu. cn收稿日期 Received ： 2020-04-26 % 接受日期 Accepted ： 2020-07-W8Abstract : As the laraest goup in the animal kingdom , insects have evolved campleo sensoo systems in osponso to various environmental stimuli , in which the chemosensation ( olfaction and gustation ) is the most important. The odorant receptors ( ORs) and gustatoo aceptors ( GRs) play a key ole in olfaction and gustation , eespectieee.Howeeee , in eecentXeaes , ithasbeen eound thationoteopiceeceptoes ( IRs ) are also involved in chemosensation as well as non-chemosensation such as sensation of temperature andhumidity.TheIR eamieyiseeoeeed eeom ionoteopicgeutamateeeceptoes ( iGeuRs ) which contain theee typical transmembrane domains. Similar to ORs , each IR needs to be cacxpossed with al lust one of the four identified ca-receptors(IR8a ,IR25a , IR76b a nd IR93a ) for its nomial function. Two or moreIRs con be cacxpossed in a same ollctoo neuron , and diReont IR combinations lexd to their diOeont responso profiles in neurons. One insect species usuVly contains several to over one hundred IRs, withsome IRs showing antennae-specibc expression pVterns , but most IRs remaining unknown in the functionand the mechanism of action . In this vticm , the resexoh advances in the structuo and evolution of IRs , and theidentieication , eipee s ion and eunction oeIR genesin insectsweeeeeeiewed , hopingtopeoeide some references for the further studies on the function and mechanisms of action of IRs , and the potentialuso of insect IRs as taraels in pest control.Key W o C s ： Insect ; chemosensation % ionotropic receptor ; sensilla % olfaction %gustation1400昆虫学扌艮Ada Entomologicp Sinio63昆虫化学感受(包括味觉和嗅觉)在昆虫觅食、寻找配偶和选择产卵部位以及躲避天敌等行为中起到重要的作用(Hansson and SVnsmyr,2011)(已知的昆虫化学感受相关蛋白主要包括气味结合蛋白(odorant bindiny protein,OBP)、气味受体(odo/nl receptor,OR))化学感受蛋白(chemosensoy patein, CSP))味觉受体(yustatoy receptor,GR))感觉神经蛋白(sensoe neueon membeane peotein, SNMP))离子型受体(ionotropic receptor,IR)和气味降解酶(odorant deyradiny enzymo,ODE)等(Eyun ei a；,2017)oIR子受(ionoteopicgeutamate receptor,ibluR)家族演化而来，是一类保守的配体门控离子通道(liyand-gated ion channel)，在配体分子与其结合后通道打开,导致膜内外离子的流动从而产生膜电位。
轧制过程表面裂纹的演变情况
TECHNICAL ARTICLEResearch on the Evolution Behavior of Surface Transverse Cracks During the Hot Rolling Process of Medium PlatesBo Wang •Jiong-ming Zhang •Yan-zhao Luo •Shun-xi Wang •Wei SongReceived:25November 2014/Revised:22December 2014/Accepted:23December 2014/Published online:6January 2015ÓSpringer Science+Business Media New York and ASM International 2015Abstract The evolution of transverse cracks in slabs during rolling may severely affect the quality of rolled products.One method used for medium plates is reverse breakdown rolling;however,there is little reported in the literature regarding this technique.Further research on the evolution of surface transverse cracks during processing is necessary.The present study investigates the evolution of cracks with different depths during reversing rolling,as analyzed by finite-element simulation and laboratory experimentation.Analysis focused on the stress field and microstructure surrounding a surface transverse crack during the rolling process.Results showed that crack edges opened and became part of slab surfaces as the number of rolling passes increased.Surface transverse cracks of varying depth change shape in a similar manner;however,by analyzing the change in the ratio of width and height,it was observed that the width changes more quickly than depth as the number of rolling passes is increased.Simu-lation results show that in the rolling direction,there is always a tensile stress around two edges of a surface transverse crack during the reversing rolling process.The results demonstrate favorable agreement between experi-mental and simulated results.Keywords Surface transverse crack ÁHot rolling ÁEvolution behavior ÁFinite-element simulationIntroductionSurface transverse cracks have an important effect on quality of continuous casting slabs.If cracks propagate during rolling,then coils are often rejected [1,2].To this effect,further research on the initiation and growth behavior of transverse cracks during the rolling process is necessary.The frequency of crack development is highly depen-dant upon the chemical composition of the material and this has been reported previously in the literature [3–6].For medium and heavy plate,the blooming process usually utilizes reversing rolling,due to its high efficiency and ability to handle wide billet sizes.To date,however,there has been very little research into the evolution of transverse cracks during the reversing rolling process.Hwang et al.[7]investigated the microstructure of center and surface cracks for thick,low-carbon steel plates after hot rolling.They found that large cracks were formed in the case of material inhomogeneity or insufficient homogenization during the reheating process.Ervasti et al.[8,9]explored the effect of roll radii and friction on closure and growth of various-sized surface transverse cracks.They found that it is impossible to avoid the formation of a V-shaped changed to Y-shaped crack after the rolling process.This occurs regardless of the choice of rolling schedule,roll radius,and friction.Yu et al.[10–12]studied the evolution of surface cracks during the hot rolling of slab by finite-element sim-ulation.Their research showed that the crack opening angle after rolling increases with the decreasing initial crack height and with the increasing initial crack open-angle and theB.Wang ÁJ.Zhang ÁY.Luo ÁS.Wang ÁW.SongState Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China e-mail:adherent@B.Wang ÁJ.Zhang (&)ÁY.Luo ÁS.Wang ÁW.SongSchool of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Box No.715,No.30,Xueyuan Road,Haidian District,Beijing 100083,China e-mail:jmz203@Metallogr.Microstruct.Anal.(2015)4:26–32DOI 10.1007/s13632-014-0186-9friction coefficient.Das et al.[13]investigated the evolution of a rectangular groove affected by friction and heat transfer.They found that the crack opening angle increased with the increase of the friction coefficient.All these studies provide valuable information;however,they mainly focused on the parameters which influence the behavior of surface transverse cracks during cold rolling.There is no research on the evolution of surface transverse cracks during the reversing rolling process of medium plates,especially for stress field around crack edges.In the present work,surface transverse crack initia-tion,crack growth,and microstructure development during reversing rolling of low-carbon steel was investigated through experiments and a non-linear finite-element model.The evolution microstructure and stress fields were also analyzed.Finite Element Modeling AnalysisThe schematic drawing of slab rolling with a surface transverse crack at the beginning of a simulation is shown in Fig.1.A 2-D finite element model was established.In order to save calculation time and resources,the finite element model was assumed to be symmetric about its thick plane.The finite model was established as the 1/2of entity of the thickness direction.The rollers were built up for a rigid material and the slab was built using triangular elements.Letter H is depth of the specimen.Five nodes (a,b,c,d and e)were marked to describe the evolution of transverse cracks during the reversing rolling process.To examine the effect of the initial crack depth on the closure and growth of crack,four V-shaped transverse cracks were created on the top surface of model to simulate the real cracks.The width of cracks is 2mm at the top,and the depth is 3,4,5,and 6mm.The main material parameters are shown in Table 1.Rolling schedules are listed in Table 2.It was assumed that the flow stress of the material fol-lowed the exponential constitutive law [14]:r p ¼k 1e m e n expQ RT;ð1Þwhere R =8.31is the gas constant and the constants k 1,m ,n and Q ,respectively,have the values of 4.16,0.23,0.21,and 38000for a carbon-manganese steel.Morphology of Transverse CracksThe cracks with initial depth of 3,4,5,and 6mm have been analyzed from simulation.Figure 2shows the evo-lution of the transverse cracks during different passes;the relationships between the shapes of surface defect after rolling were obtained.It was observed that all transverse cracks spread out during the rolling process and crack edges moved toward the slab surface after the last rolling process.Figure 3shows the evolution of the crack depth after the first,third,fifth,and seventh rolling passes.It was observed that the crack depth decreased when cracks came into contact with the roll and is subjected to pass rolling.The crack depth reduces rapidly by comparing a deeper crack with a shallow one.The different crack depths reduced in a similar fashion;as the rolling process proceeded,the crack depth reduced more slowly.As an example,the crack depth of 3mm has changed to 0.4mm after the rolling process wascompleted.Fig.1Meshing of slab with surface cracksTable 1Material parameters Parameters Steel Density (kg/m 3)7,850Young’s modulus (GPa)210Poisson’s ratio 0.28Specific Heat (J/(kg K))461Table 2Detailed hot rolling schedules of experimentalPass no.01234567Thickness (mm)9075.666.25849.841.633.525.5Rolling reduction (%)01612.412.414.116.419.523.9Rolling rate (m/s)00.60.60.60.60.60.60.6Friction factor0.30.30.30.30.30.30.30.3epth 6mm 5mm 4mm 3mmcrackPass 1Pass 3Pass 5Pass 7D Initial Fig.2Morphology of surface transverse crack at different rolling passes of simulationThe parameter g has been defined to describe the relationship between crack morphology with rolling pas-ses.It describes the change of crack width and depth during different rolling passes and is calculated according to Eq 2g ¼w n =h n w 0=h 0;ð2Þwhere w 0and h 0are the width and height,respectively,of the transverse crack before rolling,and w n and h n are the width and height,respectively,of the transverse crack during roll pass number n (where n =1,3,5,7).Figure 4shows the change in g with an increasing number of rolling passes.It is observed that transverse cracks exhibit the same trend with different depths and thechange rate of g was rapid after the third rolling pass.This becomes more obvious especially after the fifth rolling pass,and this change rate of crack width is faster than depth after the third rolling pass.Stress Analysis of Transverse CracksTransverse cracks of different sizes were found to change shape in a similar manner;therefore,the stress field in the r xy direction for a 6mm depth transverse crack was selected as a representative analysis.The evolution behavior of surface transverse cracks was mainly affected by the rolling force,which was positive for tensile stress and negative for compressive stress.Figure 5,shows the stress distribution in the r xy rolling direction.AsFig.5Stress distribution around the 6mm V-shape crack at Pass 1(a ),Pass 2(b ),Pass 3(c ),Pass 4(d ),Pass 5(f ),Pass 6(f )in the deformation zoneshown in the series of simulation results,there are two types of stressfield along the crack borders.These two types of stress are in the opposite direction during rolling process.In the r xy direction,the evolution of the surface trans-verse cracks was mainly affected by tensile stress.Cracks spread out concentrated by these two opposite stress during rolling process.Figure6shows the stress distribution around nodes b and d which are marked in Fig.1.It was observed that surface transverse cracks were subjected to tensile stress in the area of the deformation zone during different rolling passes. Moreover,the tensile stress increased significantly after the third rolling pass.This explains why the transverse cracks were observed to spread out after the third rolling pass.FEM Verification-Experimental ProceduresIn order to verify the accuracy of thefinite-element model,a series of experiments with low-carbon steel specimens were performed.The size of plate specimens was250(L)9 90(W)990(H)mm.A series of transverse cracks were cre-ated on the surface of the specimens by electric spark cutting (Fig.7);prior to rolling,specimens was heated to1,200°C, and were held for2h in a reheating furnace.The initial rolling temperature was1,020°C,the roll radius was190mm,and the rolling speed was0.6m/min.The width of cracks was 2mm at the top,and the depths were3,4,5,and6mm.Morphology Analysis of Transverse CracksThe evolution of transverse cracks at different rolling passes by laboratory experimentation is shown in Fig.8. From these images,it is clear that the cracks open and become part of slab surface as the rolling passes increased.Figure9shows the evolution of the crack depth after different rolling passes.The crack with a depth of3mm has changed to0.2mm;this crack had little impact on the surface quality after the last rolling pass.As the FE simulation pre-dicted,cracks of different depth reduced in the same way during rolling.As the rolling proceeded,the crack depth reduced more slowly.Figure10shows the change of g at different rolling process passes for the experiment.By analyzing the experimental work and the FE simu-lation results,one can see that all transverse cracks could open and become a part of slab surface after the last rolling pass.It was also observed that transverse cracks with dif-ferent depths wereflattened easily during the reversing rolling process.The simulated results show good agree-ment with the experimental observations.Structure Analysis of Transverse CracksFigure11(a)–(d)are light micrographs of the surface transverse cracks,beginning with a6mm deep crack at different rolling passes(Pass1,3,5and7).The micro-structure surrounding the crack is a mix of the ferrite and pearlite.It was observed that there is a dark band around the crack edge,which suggests that the proportion of ferrite around the crack is higher than that in the matrix;an oxi-dation layer exists about100l m around the crack and extends out at both ends.With an increase of the distance from the crack,the ferrite content gradually decreased. ConclusionsThe evolution behavior and microstructure of surface transverse cracks during the reversing rolling process of medium plates were investigated byfinite-element simu-lation and laboratory experimentation.According to the analysis,the following conclusions are drawn:Fig.7Artificial transverse cracks on the specimen(1)The evolution characteristics between different depths crack are almost identical during the revers-ing rolling process.With the rolling passes increased,crack edges opened and became part of slab surfaces.Initial crack made a little impact on the surface quality after rolling.(2)By analyzing the ratio of width to depth,it is observed that the change rate of crack width is fasterthan depth after the third rolling pass and this phenomenon is more obvious especially after the fifth rolling pass.(3)In the r xy rolling direction,there are two kinds of stress field along the crack borders,and these two kinds of stress are in the opposite direction during rolling process.Moreover,tensile stress became bigger especially after the third rolling pass.Depth 6mm 5mm 4mm 3mmPass 1Pass 3Pass 5Pass 7Fig.8Morphology of surface transverse crack at different rolling passes of experimentation(4)By analyzing microstructure of6mm crack atdifferent rolling passes,it is demonstrated that themicrostructure surrounding the crack is in the ferriteand pearlite form.It suggests that the proportion offerrite around the crack is obviously higher than thatin the matrix;oxidation layer exists about100l maround the crack and extends out at both ends. Acknowledgments The authors gratefully express their apprecia-tion to National Natural Science Fund of China(U1360201)and the National High Technology Research and Development Program of China(863Program)No.2012AA03A505for sponsoring this work. Sincere gratitude and appreciation should be expressed to Professor Jiongming Zhang for his careful guidance.References1.A.Ray,Electron-probe microanalysis:some revelations in theinvestigation of defects in steel products.Mater.Sci.Forum492, 627–634(2005)2.O.B.Isaev,V.V.Emelyanov,V.V.Kislitsa,Y.I.Matrosov,L.S.Lepikhov,Effect of the carbon content of low-alloy steels on the surface quality of continuous-cast semifinished products and rolled plates.Metallurgist48(5–6),210–213(2004)3.J.K.Brimacombe,K.Sorimachi,Crack formation in the contin-uous casting of steel.Metall.Trans.B8(2),489–505(1977) 4.Y.Maehara,K.Yasumoto,H.Tomono,T.Nagamichi,Y.Ohmori,Surface cracking mechanism of continuously cast low carbon low alloy steel slabs.Mater.Sci.Technol.6(9),793–806(1990)5.Y.Maehara,K.Yasumoto,Y.Sugitani,K.Gunji,Effect of car-bon on hot ductility of as-cast low alloy steels.Trans.ISIJ.25(10),1045–1052(1985)6.F.Vodopivec,M.Torkar,M.Debelak,M.Kmetic,F.Haller,F.Kaucic,Influence of aluminium on solidification structure and initial deformability of continuously cast C–Mn–Si–N steel.Mater.Sci.Technol.4(10),917–925(1988)7.B.Hwang,H.S.Lee,Y.G.Kim,S.Lee,Analysis and preventionof side cracking phenomenon occurring during hot rolling of thick low-carbon steel plates.Mater.Sci.Eng.A402(1),177–187 (2005)8.E.Ervasti,U.Sta˚hlberg,Behaviour of longitudinal surface cracksin the hot rolling of steel slabs.J.Mater.Process.Technol.94(2), 141–150(1999)9.E.Ervasti,U.Sta˚hlberg,Transversal cracks and their behaviourin the hot rolling of steel slabs.J.Mater.Process.Technol.101(1),312–321(2000)10.H.L.Yu,X.H.Liu,Thermal–mechanicalfinite element analysisof evolution of surface cracks during slab rolling.Mater.Manuf.Process.24,570–578(2009)11.H.L.Yu,X.H.Liu,C.S.Li,Y.Kusaba,Behavior of transversalcrack on slab corner during VH rolling process.J.Iron.Steel Res.Int.13,31–37(2006)12.H.L.Yu,X.H.Liu,Coupling analysis to multipass VH rollingprocess by FEM.Hot Work.Technol.15,19–26(2008)13.S.Das,E.J.Palmiere,Immpetus.I.C.Howard,The cut-groovetechnique to infer interfacial effects during hot rolling.Metall.Mater.Trans.A35(3),1087–1095(2004)14.A.Wang,P.F.Thomson,P.D.Hodgson,A study of pore closureand welding in hot rolling process.J.Mater.Process.Technol.60(1),95–102(1996)Fig.11Microstructure of6mm crack at Pass1(a),Pass3(b),Pass5(c),Pass7(d)during the hot rolling。
关于恐龙的英语作文
Dinosaurs,the colossal creatures that once roamed the Earth millions of years ago, continue to captivate the imagination of people worldwide.Heres an essay exploring various aspects of these fascinating prehistoric animals.IntroductionDinosaurs,derived from the Greek words deinos meaning terrible and sauros meaning lizard,were a diverse group of reptiles that lived during the Mesozoic Era,which spanned from the Triassic to the Cretaceous periods.Their existence,though long extinct,has left an indelible mark on our understanding of Earths history.Types of DinosaursThe dinosaur family tree is vast and varied.Sauropods,such as the Apatosaurus and Brachiosaurus,were the largest land animals,known for their long necks and tails. Theropods,including the infamous Tyrannosaurus rex and Velociraptor,were bipedal carnivores with sharp teeth and claws.Ornithischians,like the Triceratops and Stegosaurus,were herbivorous dinosaurs with unique features such as horns and plates. Habitat and BehaviorDinosaurs inhabited a range of environments,from lush forests to arid deserts.Fossil evidence suggests that some species migrated in search of food or to reproduce.Social behaviors,such as nesting and caring for young,have been inferred from dinosaur nesting sites and fossilized eggs.Dinosaur ExtinctionThe most widely accepted theory for the extinction of dinosaurs is the impact of a massive asteroid,which occurred around66million years ago.This catastrophic event led to a global winter,disrupting ecosystems and ultimately leading to the demise of the nonavian dinosaurs.However,some scientists also consider volcanic activity and climate change as contributing factors.Dinosaurs and Modern BirdsRecent studies have shown that birds are the direct descendants of a group of twolegged dinosaurs known as theropods.This connection is evident in shared characteristics such as feathers,eggs,and certain skeletal features.The evolution from dinosaurs to birds is a remarkable testament to the adaptability of life on Earth.Dinosaurs in Popular CultureDinosaurs have been a staple in popular culture,featured in movies,books,and television shows.The1993film Jurassic Park brought dinosaurs to life with groundbreaking special effects,sparking a renewed interest in these ancient creatures.Dinosaurs also serve as educational tools,helping to engage children in the sciences.ConclusionThe study of dinosaurs not only sheds light on the history of our planet but also on the process of evolution and the interconnectedness of life.As new fossils are discovered and technologies advance,our understanding of these magnificent creatures continues to grow,revealing more about their lives and the world they inhabited.The enduring fascination with dinosaurs is a testament to their importance in our collective imagination and scientific inquiry.。
新疆西昆仑山地区矿产资源调查现状及找矿方向的思考
找矿技术P rospecting technology 新疆西昆仑山地区矿产资源调查现状及找矿方向的思考盛志华（新疆地矿局第二区域地质调查大队，新疆 昌吉 ８３１１００）摘 要：对新疆西昆仑山地区的造山带，进行动力学演化过程进行分析，调查该区域矿产资源的现状，发现目前该地区存在造山型金矿、热水喷流沉积矿床、热液型铜多金属矿床、低温热液脉型铅锌矿床以及铅锌矿床。
因此针对这些矿场与矿山的自然环境特征，确定不同矿产资源的成矿规律，确定新疆西昆仑山地区矿产资源的找矿方向，为该区域的资源探采提供合理的找矿策略。
关键词：新疆西昆仑山地区；矿产资源；调查现状；找矿方向中图分类号：Ｐ６１８．３２ 文献标识码：Ａ 文章编号：１００２－５０６５（２０２１）０１－００７９－２Present situation of mineral resources investigation and prospecting directionin West Kunlun mountain area, XinjiangSHENG Zhi-hua（Ｔｈｅ ｓｅｃｏｎｄ ｒｅｇｉｏｎａｌ ｇｅｏｌｏｇｉｃａｌ ｓｕｒｖｅｙ ｔｅａｍ ｏｆ Ｘｉｎｊｉａｎｇ Ｂｕｒｅａｕ ｏｆ Ｇｅｏｌｏｇｙ ａｎｄ ｍｉｎｅｒａｌ ｒｅｓｏｕｒｃｅｓ， Ｃｈａｎｇｊｉ ８３１１００， Ｃｈｉｎａ）Abstract: Ｂａｓｅｄ ｏｎ ｔｈｅ ａｎａｌｙｓｉｓ ｏｆ ｔｈｅ ｄｙｎａｍｉｃ ｅｖｏｌｕｔｉｏｎ ｐｒｏｃｅｓｓ ｏｆ ｔｈｅ ｏｒｏｇｅｎｉｃ ｂｅｌｔ ｉｎ ｔｈｅ Ｗｅｓｔ Ｋｕｎｌｕｎ ｍｏｕｎｔａｉｎ ａｒｅａ ｏｆ Ｘｉｎｊｉａｎｇ ａｎｄ ｔｈｅ ｉｎｖｅｓｔｉｇａｔｉｏｎ ｏｆ ｔｈｅ ｃｕｒｒｅｎｔ ｓｉｔｕａｔｉｏｎ ｏｆ ｍｉｎｅｒａｌ ｒｅｓｏｕｒｃｅｓ ｉｎ ｔｈｉｓ ａｒｅａ， ｉｔ ｉｓ ｆｏｕｎｄ ｔｈａｔ ｔｈｅｒｅ ａｒｅ ｏｒｏｇｅｎｉｃ ｇｏｌｄ ｄｅｐｏｓｉｔｓ， ｈｙｄｒｏｔｈｅｒｍａｌ ｅｘｈａｌａｔｉｏｎ ｓｅｄｉｍｅｎｔａｒｙ ｄｅｐｏｓｉｔｓ， ｈｙｄｒｏｔｈｅｒｍａｌ ｃｏｐｐｅｒ ｐｏｌｙｍｅｔａｌｌｉｃ ｄｅｐｏｓｉｔｓ， ｌｏｗ－ｔｅｍｐｅｒａｔｕｒｅ ｈｙｄｒｏｔｈｅｒｍａｌ ｖｅｉｎ ｔｙｐｅ ｌｅａｄ－ｚｉｎｃ ｄｅｐｏｓｉｔｓ ａｎｄ ｌｅａｄ－ｚｉｎｃ ｄｅｐｏｓｉｔｓ． Ｔｈｅｒｅｆｏｒｅ， ａｃｃｏｒｄｉｎｇ ｔｏ ｔｈｅ ｃｈａｒａｃｔｅｒｉｓｔｉｃｓ ｏｆ ｔｈｅ ｎａｔｕｒａｌ ｅｎｖｉｒｏｎｍｅｎｔ ｏｆ ｔｈｅｓｅ ｍｉｎｅｓ ａｎｄ ｍｉｎｅｓ， ｔｈｅ ｍｅｔａｌｌｏｇｅｎｉｃ ｒｅｇｕｌａｒｉｔｙ ｏｆ ｄｉｆｆｅｒｅｎｔ ｍｉｎｅｒａｌ ｒｅｓｏｕｒｃｅｓ ｉｓ ｄｅｔｅｒｍｉｎｅｄ， ａｎｄ ｔｈｅ ｐｒｏｓｐｅｃｔｉｎｇ ｄｉｒｅｃｔｉｏｎ ｏｆ ｍｉｎｅｒａｌ ｒｅｓｏｕｒｃｅｓ ｉｎ ｔｈｅ Ｗｅｓｔ Ｋｕｎｌｕｎ ｍｏｕｎｔａｉｎ ａｒｅａ ｏｆ Ｘｉｎｊｉａｎｇ ｉｓ ｄｅｔｅｒｍｉｎｅｄ， ｓｏ ａｓ ｔｏ ｐｒｏｖｉｄｅ ａ ｒｅａｓｏｎａｂｌｅ ｐｒｏｓｐｅｃｔｉｎｇ ｓｔｒａｔｅｇｙ ｆｏｒ ｔｈｅ ｒｅｓｏｕｒｃｅ ｅｘｐｌｏｒａｔｉｏｎ ａｎｄ ｍｉｎｉｎｇ ｉｎ ｔｈｉｓ ａｒｅａ．Keywords: Ｗｅｓｔ Ｋｕｎｌｕｎ ｍｏｕｎｔａｉｎ ａｒｅａ， Ｘｉｎｊｉａｎｇ； ｍｉｎｅｒａｌ ｒｅｓｏｕｒｃｅｓ； ｓｕｒｖｅｙ ｓｔａｔｕｓ； ｐｒｏｓｐｅｃｔｉｎｇ ｄｉｒｅｃｔｉｏｎ新疆西昆仑山地区位于青藏高原北缘西段，与塔里木盆地、库雅克、克什米尔地区、阿富汗、塔吉克斯坦和吉尔吉斯斯坦相邻，总面积超过了25万平方千米。
developmental biology 英文原版书
developmental biology 英文原版书全文共3篇示例，供读者参考篇1Developmental biology is a field of study that focuses on the process by which organisms grow and develop from a single cell into a complex multicellular organism. It explores the underlying mechanisms that drive the transformation of a single fertilized egg into a fully-formed adult organism. Understanding these processes is crucial for advancing our knowledge of biology and ultimately improving human health.One of the key books in the field of developmental biology is "Developmental Biology" by Scott F. Gilbert. This comprehensive textbook covers the fundamental principles of developmental biology, including the molecular and cellular processes that regulate growth, differentiation, and pattern formation in embryos. The book is widely used in graduate and undergraduate courses in biology and has become a standard reference in the field.The book begins by providing an overview of the history and basic concepts of developmental biology. It then delves into themechanisms that govern cell division, differentiation, and growth in embryos. The text covers a wide range of topics, including the role of genetic and environmental factors in development, the formation of tissues and organs, and the evolution of developmental processes.One of the strengths of "Developmental Biology" is its clear and accessible writing style. The author presents complex concepts in a straightforward manner, making the material easy to understand for readers of all levels. The book also includes numerous illustrations and diagrams that help to visually explain key concepts and processes.In addition to its comprehensive coverage of developmental biology, the book also highlights the interdisciplinary nature of the field. Developmental biology draws on insights from genetics, molecular biology, biochemistry, and other disciplines to provide a holistic understanding of how organisms develop and evolve. By integrating these different perspectives, researchers can gain a deeper understanding of the complex processes that govern development.Overall, "Developmental Biology" is an essential resource for students, researchers, and anyone interested in learning more about the fascinating process of biological development.Whether you are studying biology in school or simply curious about how life begins and unfolds, this book offers a wealth of knowledge and insights that will deepen your understanding of the natural world. Whether you are interested in the molecular mechanisms of development or the evolutionary origins of developmental processes, this book has something to offer for everyone.篇2Developmental biology is a branch of biology that focuses on the process by which organisms develop and grow. It seeks to understand the complex series of events that occur from fertilization to adulthood, including cell proliferation, differentiation, and morphogenesis. One of the key goals of developmental biology is to uncover the genetic and molecular mechanisms that underlie these processes.One of the seminal works in the field of developmental biology is the book "Developmental Biology" by Scott F. Gilbert. First published in 1994 and now in its 11th edition, this comprehensive textbook provides a thorough overview of the principles and mechanisms that govern the development of organisms.The book covers a wide range of topics, including embryonic development, organogenesis, and pattern formation. It also delves into the molecular and genetic basis of development, exploring the role of signaling pathways, transcription factors, and regulatory genes. In addition, the book discusses the evolution of developmental processes and the relationship between development and evolution."Developmental Biology" is widely used in undergraduate and graduate courses in biology, as well as in research labs around the world. It is praised for its clear and concise writing, as well as its thorough coverage of the field. The book is also known for its numerous illustrations and diagrams, which help to clarify complex concepts and processes.In addition to its comprehensive coverage of developmental biology, the book also addresses ethical and societal issues related to development. It explores topics such as stem cell research, cloning, and genetic engineering, providing students and researchers with a well-rounded perspective on the field.Overall, "Developmental Biology" by Scott F. Gilbert is an essential resource for anyone interested in the fascinating field of developmental biology. Its in-depth coverage, clear writing,and comprehensive approach make it a valuable asset for students, teachers, and researchers alike.篇3Title: Overview of Developmental BiologyDevelopmental biology is a field of biology that studies how organisms grow and develop from a single-celled zygote to a complex multicellular organism. It encompasses a wide range of topics, including cell differentiation, tissue morphogenesis, and organ formation. Understanding the processes involved in development is crucial for fields such as medicine, agriculture, and evolutionary biology.One of the fundamental concepts in developmental biology is the idea of cell differentiation. During development, cells become specialized to perform specific functions in the organism. This process is controlled by a combination of genetic and environmental factors. Cells receive signals that instruct them to adopt a particular fate and differentiate into specific cell types. This process leads to the formation of tissues and organs with distinct functions.Another important aspect of developmental biology is tissue morphogenesis, which involves the shaping and structuring oftissues and organs. This process is highly regulated and involves complex interactions between cells, extracellular matrix, and signaling molecules. For example, during embryonic development, cells migrate, divide, and change shape to form the basic body plan of the organism.Organ formation is the final stage of development and involves the assembly of different tissues into functional organs. This process requires precise coordination between different cell types and involves the remodeling of existing tissues to create complex structures. For example, the development of the heart involves the formation of specialized muscle cells, blood vessels, and connective tissue to create a functional pump.Studying developmental biology has numerous practical applications. In medicine, understanding how organs develop can provide insights into birth defects and genetic diseases. By elucidating the molecular mechanisms underlying development, researchers can design therapies to correct these abnormalities. In agriculture, developmental biology can be used to improve crop yields and increase resistance to pests and diseases. By manipulating the developmental processes of plants, scientists can create new varieties with desirable traits.Developmental biology also plays a crucial role in evolutionary biology. By studying the similarities and differences in developmental processes among different species, researchers can uncover the genetic changes that drive evolution. For example, the evolution of complex structures such as eyes or limbs can be traced back to changes in developmental pathways that control their formation.In conclusion, developmental biology is a fascinating and diverse field that explores the processes that shape living organisms. By unraveling the mysteries of development, researchers can unlock the secrets of life itself. The insights gained from studying developmental biology have far-reaching implications for medicine, agriculture, and our understanding of the natural world.。
房间空调用压缩机标准制修订沿革及修订建议
Articles论文房间空调用压缩机标准制修订沿革及修订建议Evolution and suggestions on the revision of compressor standard forroom air-condition沙露孙民阚安福SHALu SUN Min KAN Anfu西安庆安制冷设备股份有限公司陕西西安710075Xi'an Qingan Refrigeration Equipment Co.,Ltd.Xi'an7100751|』丨言空调压缩机是房间空调器的关键重要部件，在制 冷剂回路中起到压缩驱动制冷剂的作用。
早期的空调器 生产配套以活塞式压缩机为主，转子式压缩机于上世纪 八十年代开始，在20年的时间内迅速取代了活塞式压缩 机。
近年来，随着压缩机变频技术的发展，转子式压缩 机在3h p以上范围开始挤占涡旋式压缩机的空间，并取得 长足进步，涡旋式压缩机则在更大冷量范围内拓展了小 轻商空调系统的应用领域。
中国家用空调压缩机行业在“零部件强，主机才能 强”、“做家电强国必须拥有高水平的家用电器关键零部 件及原材料”的思想主导下，G B/T 15765标准于1993年开 始起草，并于1995年首次正式发布，此后又进行了两次修 订（2006版、2014版）。
为规范、引导中国空调压缩机行 业健康、快速发展，G B/T 15765在保障安全、节能环保、提高舒适性、适应行业发展等思路的指导下，提出空调压 缩机各项技术要求，并持续进行更新、完善。
2 GB/T 15765制修订持续跟踪行业和技术 发展2.1 G B/T15765基本内容上世纪八十年代末，我国家用空调生产企业只有组 装能力，不具备空调压缩机的生产能力，少部分企业引 进日本空调压缩机技术，基本形成了我国空调生产产业 链。
我国空调压缩机行业发展之初，产品供不应求，但是 市场中存在多种类型企业，一类是引进、消化国外的技 术的国有企业，一类是合资或外商独资企业，同时存在 一些作坊式的工厂，各企业产品技术规范不统一，不利 于压缩机行业的健康发展，因此非常有必要制定国家标摘要对GB/T 15765《房间空气调f器用全封闭型电动机一压缩机》制修订沿革进行M宄，阐述了该标准持续跟踪行业和技术发展的过程，从而保持标准的先进性。
演变后的生物英语作文200字
演变后的生物英语作文200字英文回答：Evolutionary biology has its roots in the Darwinian theory of evolution, which proposes that species evolve over time through natural selection. This process involves the differential survival and reproduction of individuals within a population, leading to changes in the genetic composition of the population over generations. Evolutionary biology seeks to understand the mechanisms driving these changes and how they shape the diversity of life on Earth. It encompasses a wide range of scientific disciplines, including genetics, molecular biology, paleontology, ecology, and developmental biology.Over the last century, evolutionary biology has made significant contributions to our understanding of the natural world. For instance, studies on genetic variation and inheritance have revealed the underlying mechanisms of evolution at the molecular level. Research on populationgenetics has shown how genetic diversity can be maintained within populations, while ecological studies have examined how environmental pressures influence the evolution of species. Comparative analyses of species across different taxonomic groups have provided insights into the phylogenetic relationships between organisms and the evolutionary history of life.中文回答：进化生物学植根于达尔文的进化论，后者提出物种通过自然选择随着时间的推移而进化。
我敬佩的达尔文英语作文
我敬佩的达尔文英语作文The Remarkable Legacy of Charles DarwinCharles Darwin, the renowned British naturalist, is widely regarded as one of the most influential figures in the history of science. His groundbreaking work on the theory of evolution has profoundly shaped our understanding of the natural world and our place within it. As we delve into the life and achievements of this remarkable individual, it becomes clear why he is so deserving of our admiration and respect.Born in 1809 in the small town of Shrewsbury, England, Darwin's early years were marked by a keen interest in the natural world. From a young age, he was fascinated by the diverse array of flora and fauna that surrounded him, and he spent countless hours exploring the countryside, collecting and cataloging his findings. This insatiable curiosity would ultimately lead him on a journey of discovery that would change the course of scientific thought forever.After completing his studies at the University of Cambridge, Darwin was offered the opportunity to join the crew of the HMS Beagle, a British surveying ship embarking on a five-year voyage around theworld. This expedition, which took him to various corners of the globe, including the Galapagos Islands, would prove to be a pivotal moment in his life. It was during this time that Darwin began to formulate the ideas that would eventually culminate in his groundbreaking theory of evolution by natural selection.Throughout his voyage, Darwin observed the remarkable adaptations of various species to their respective environments. He noted how the finches on the Galapagos Islands, for example, had developed distinct beak shapes that allowed them to exploit different food sources, a phenomenon that would later become known as "Darwin's finches." This observation, coupled with his extensive research and analysis, led him to the conclusion that species were not static entities, but rather, dynamic and ever-evolving organisms.Upon his return to England, Darwin began the arduous task of organizing and synthesizing the wealth of information he had gathered during his travels. It was during this time that he developed his theory of evolution by natural selection, which postulated that species evolve through a process of gradual change, driven by the survival and reproduction of individuals with favorable traits. This revolutionary idea challenged the prevailing belief that species were immutable and had been created in their present form by a divine being.Darwin's theory of evolution was met with fierce opposition from religious and scientific establishments, who were deeply uncomfortable with the implications of his work. Nonetheless, he persisted in his research and the meticulous documentation of his findings, eventually publishing his seminal work, "On the Origin of Species," in 1859. This groundbreaking book not only established the foundation for our understanding of the mechanisms of evolution but also sparked a paradigm shift in scientific thought that continues to reverberate to this day.Beyond his scientific contributions, Darwin's life and work were marked by a deep commitment to intellectual honesty and a unwavering pursuit of the truth. He was a tireless researcher, meticulously collecting and analyzing data, and he was never afraid to challenge the prevailing orthodoxies of his time. This dedication to the scientific method and his willingness to question long-held beliefs have made him a true role model for aspiring scientists and thinkers alike.Moreover, Darwin's impact extends far beyond the realm of biology and into the realm of philosophy and social thought. His ideas on the origins of species and the mechanisms of evolution have profoundly influenced our understanding of ourselves and our place in the natural world. They have also challenged our notions of human exceptionalism and the idea that we are separate from the rest of thenatural world.In the decades since the publication of "On the Origin of Species," Darwin's work has been subjected to rigorous scrutiny and has withstood the test of time. Modern scientific research has not only confirmed the validity of his core ideas but has also expanded upon them, deepening our understanding of the evolutionary process and its far-reaching implications.Today, Charles Darwin is widely regarded as one of the most influential and revered figures in the history of science. His legacy continues to inspire and inform our understanding of the natural world, and his commitment to intellectual honesty and the pursuit of truth remains a shining example for all who seek to expand the boundaries of human knowledge.As we reflect on the life and work of this remarkable individual, we cannot help but be in awe of his intellectual prowess, his dedication to scientific inquiry, and his unwavering commitment to the pursuit of truth. Charles Darwin's legacy will continue to shape our understanding of the natural world for generations to come, and his enduring impact on the course of human thought and discovery is a testament to the power of the scientific mind.。
推动近代自然科学产生的方法论原则
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从传统秋千的演进看哈尼族体育文化的变迁
Value Engineering1哈尼族传统秋千概述哈尼族的传统秋千分为荡秋、磨秋和转秋三种，荡秋绳是牛皮条结扎或用藤条扭扎而成，可单人荡，也可双人荡。
磨秋是横架在一条竖木顶端的长杆，杆的两端可上下升降，又能循环旋转，在人数方面，两端坐骑需要相等，其中，一端的人猛力用脚蹬地进而使磨秋腾空升起，另一方则下降，同时双脚着地，又蹬地腾空而起，秋杆便不断地起落飞旋。
民俗村哈尼寨的秋千是转秋，形状像巨型纺车，安在轴心上的四对飞叶之间的横木上架设着四个小荡秋，每个荡秋乘坐一人，随着轴心和飞叶的旋转而旋转。
———————————————————————作者简介:曹正学（1982-），男，云南金平人，毕业于红河学院。
从传统秋千的演进看哈尼族体育文化的变迁Seeing the Changes of Sport Culture in Hani Nationality from the Evolution of Traditional Swings曹正学CAO Zheng-xue（云南卫生职业学院，蒙自661100）（Yunnan Health Vocational College ，Mengzi 661100，China ）摘要:通过对哈尼族传统秋千演进过程进行调研，研究分析哈尼族传统体育文化的思想,进而在一定程度上反映不同历史时期哈尼族的社会发展情况。
研究这一传统体育项目流变过程并在其渐变的现实中寻找哈尼族社会前进的文化动因，这对促进和保护哈尼族传统体育项目，丰富哈尼族的精神文化生活具有非常重要的历史和现实意义。
Abstract:Through the research on the evolution process of Hani traditional swing,the paper studies the thought of traditional sports culture in the Hani nationality,then reflects the social development of Hani in the different historical period to a certain extent,researches the process of the traditional sport project and finds the culture motivation of the social advancement in gradually varied reality in Hani,all these have very important historical and realistic significance for the promotion and protection of traditional sports and enriching the spiritual and cultural life in Hani nationality.关键词:哈尼族；传统秋千；演进；变迁Key words:Hani nationality ；traditional swing ；evolution ；change 中图分类号:G812.47文献标识码:A 文章编号:1006-4311（2014）03-0321-02作人员加以区别对待：①在应用激光测距仪对起重机跨度指标进行测定的过程当中，以两跨侧，一对车轮为例，需要以其中一个车轮的外端面作为基准，将激光测距仪测底座与基准端面保持在对齐状态，另一跨侧车轮的外端面需要延伸出遮挡板（实际工作中主要以硬纸板作为遮挡），启动激光测距仪，将光束点集中在遮挡板当中，进而对激光测距仪在此状态下所显示的数据进行读取，该数值作为一次跨度数值进行保存。
你对动物研究的理解英语作文
你对动物研究的理解英语作文It seems clear that there is something to be learned about human behavior through the observation of animal behavior,especially behavior of our close relatives on the evolution charts.Studies about aggression,sexual behavior,grief,etc.in animals have helped explain such aspects in humans and led to effective treatments and better understanding of the problem.The observational work of the famous scientist Jane Goodall is an example.She has shown that animal behavior is very similar to ours;understanding theirs in their basic animal status with far fewer“intellectual”factors helps us better see the fundamental basis for our own behavior.The more controversial question of trying to understand human nature by the study of animals in terms of using drugs,chemicals or certain treatments raises questions of ethics and potential cruelty to animals.Nevertheless, the genetic closeness of some animals to humans does,in fact,make these experiments very useful for the study of human behavior.Examples of these studies are the effects of certain chemicals,drugs and treatments,on animals trying to induce or reduce such emotions as depression,a serious problem in many humans.Other animal studies related to human behavior have involved important human behavior issues such as fear,joy,off-spring rejection,etc.The fact that these studies have been so prevalent shows that they are considered by the scientific community as helpful in understanding human behavior.Can these observations and studies help us understand human behavior?It seems that the answer is“Yes”。
浅谈非洲刚果(金)加丹加成矿带及找矿方向
加丹加地区区域主要由两大区别明显的地层系统组成 ： 一是由太古代基底杂岩与元古代加丹加超群组成的古老基 底（其中基底杂岩由片岩、片麻岩、花岗岩、石英岩及砾岩 等变质岩系组成，加丹加超群由罗安群、恩古巴群及孔德龙 古群组成），是加丹加弧形构造带的重要组成部分 ；二是盖 层，由第三系和近代冲积层、残积层、坡积层组成，主要分 布于成矿带的西部和东北部，以及科卢韦齐、利卡西及卢菲 拉河谷一带，面积不足全区的 15%。
形 成 了 卢 菲 利 安 弧 的 外 部 褶 皱 推 覆 带 和 穹 隆 区。如 图 2，区域褶皱大多为不对称的构造，并向北辐合，南翼地层通 常与北翼地层冲抵，表现为无顶或向北翻转的形式。逆冲断
2021年 3月下 世界有色金属 61
P 找矿技术 rospecting technology
图 1 中非铜带主要矿床分布图（引自《The Central Africa Copperbelt in Southeastern DRC》）
控制，层控型铜矿床是成矿带的主要特征，主要分布在穹窿部边缘，含矿岩石主要为罗安群地层中的白云岩及白云质页
岩。
关键词 ：刚果（金）；卢菲利安弧 ；层控型铜钴矿床 ；含矿岩石
中图分类号 ：１００２－５０６５（２０２１）０６－００６１－３
Discussion on the Katanga metallogenic belt in Congo (DRC) and its prospecting direction in Africa
Urbanization The Evolution of Cities
Urbanization The Evolution of CitiesUrbanization, the process of population concentration in urban areas, has been a significant phenomenon throughout human history. As societies evolve, citiesgrow and transform, becoming centers of culture, commerce, and innovation. This evolution of cities has been shaped by various factors, including technological advancements, economic drivers, social dynamics, and political influences. Understanding the evolution of cities is crucial in comprehending the complexities of urban life and planning for sustainable urban development in the future. Historically, urbanization can be traced back to ancient civilizations such as Mesopotamia, Egypt, and Indus Valley, where urban centers emerged as hubs of trade, governance, and cultural exchange. The rise of industrialization in the 18th and19th centuries further accelerated urban growth, as people migrated from rural areas to cities in search of employment opportunities in factories and industries. This period marked a significant shift in the urban landscape, with the development of infrastructure, transportation networks, and public services to support the expanding urban population. The evolution of cities has been asubject of debate among scholars, policymakers, and urban planners. Some view urbanization as a positive force, driving economic growth, technological innovation, and cultural exchange. Cities are seen as engines of prosperity, offering opportunities for social mobility, education, and cultural enrichment. However, others raise concerns about the negative impacts of urbanization, such as environmental degradation, social inequality, and overcrowding. Rapid urbanization can lead to urban sprawl, traffic congestion, and inadequate infrastructure,posing challenges for sustainable urban development. Case studies from around the world highlight the diverse experiences of urbanization and its impact on cities. For example, the rapid urbanization of cities like Beijing and Shanghai in China has led to significant economic growth but also environmental pollution and social disparities. In contrast, cities like Copenhagen and Singapore have adopted sustainable urban planning strategies, promoting green spaces, public transportation, and affordable housing to create livable and resilient urban environments. These examples demonstrate the importance of holistic urban planning approaches that balance economic growth with social equity and environmentalsustainability. A critical evaluation of the evolution of cities reveals both benefits and drawbacks associated with urbanization. On the one hand, cities offer opportunities for economic development, cultural diversity, and social interaction. Urban centers attract talent, investment, and innovation, driving productivity and competitiveness on a global scale. On the other hand, rapid urbanization can lead to social exclusion, spatial segregation, and environmental degradation. Inadequate housing, transportation, and public services can exacerbateinequalities and undermine the quality of life for urban residents. Looking ahead, the future implications of urbanization call for integrated and inclusive urban planning strategies that prioritize sustainability, resilience, and social equity. As the world continues to urbanize at a rapid pace, cities must adapt to the challenges of climate change, population growth, and technological disruption. Investing in green infrastructure, affordable housing, and public transportation can help create more livable and sustainable cities for future generations. By fostering collaboration between government, businesses, and communities, citiescan harness the power of urbanization to build a more inclusive and prosperous society. In conclusion, the evolution of cities reflects the dynamic interplay of social, economic, and environmental forces shaping urban life. By understandingthe historical background, analyzing different perspectives, and evaluating the benefits and drawbacks of urbanization, we can gain insights into the complexities of urban development. Through case studies and examples, we can learn from the experiences of cities around the world and draw lessons for sustainable urban planning in the future. Ultimately, the future of cities lies in our ability to embrace innovation, collaboration, and inclusivity in building resilient andvibrant urban environments for generations to come.。
托福TPO30阅读Passage2原文文本+题目+答案解析
托福TPO30阅读Passage2原文文本+题目+答案解析为了帮助大家高效备考托福，为大家带来托福TPO30阅读Passage2原文文本+题目+答案解析，希望对大家备考有所帮助。
The Pace of Evolutionary ChangeA heated debate has enlivened recent studiesof evolution.Darwin's original thesis,and theviewpoint supported by evolutionary gradualists,isthat species change continuously but slowly and insmall increments.Such changes are all but invisible over the short time scale of modernobservations,and,it is argued,they are usually obscured by innumerable gaps in theimperfect fossil record.Gradualism,with its stress on the slow pace of change,is a comfortingposition,repeated over and over again in generations of textbooks.By the early twentiethcentury,the question about the rate of evolution had been answered in favor of gradualism tomost biologists'satisfaction.最近的一个关于进化的研究引发了激烈的争论。
达尔文的原始论点和进化渐进主义者支持的观点是物种会持续地改变，但非常缓慢，增量也很小。
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However, a lot of issues associated with rockburst are still to be addressed. The first key issue is that the occurrence of rockbursts is an evolving process, lasting from one to several days (short-term), or from two to four weeks (long-term). Another key issue is that there are several types of rockbursts based on different rockburst classification systems. Basically, there are strain rockbursts, strain-structure slip rockbursts, fault slip rockbursts in terms of mechanism classification, immediate rockbursts, and time-delayed rockbursts associated with evolution time of rockbursts after excavation (see Fig. 1). Therefore, understanding the features and mechanisms of rockburst evolution processes is imperative, especially the differences of key features and mechanisms of different types of rockbursts.
In order to assess rockbursts proneness and the risks of rockburst, some criteria have been proposed (Bolstad, 1990; Kaiser et al., 1992; Essrich, 1997; Beck and Brady, 2002). Feng (1994) and Feng et al. (1996, 1998) employed neural networks in combination of fuzzy systems to describe the nonlinear relationship between the main factors and intensities of rockbursts. For application of expert knowledge and experiences to assess rockburst risks, Feng et al. (1996) established expert systems that are further enriched by data mining methods. In addition, concerning the practical earlywarning measures associated with rockbursts, various handbooks have been published in South Africa and Canada. The progress on risk prediction of rockbursts in China is also made, and the rockburst classification for hydropower engineering projects has also been established, in which support design under rockburstprone conditions has also been considered.
Deep rock excavation will induce rockbursts, and some key factors associated with excavation methods (TBM or D&B), section size and shape, advancing rate, etc., have considerable influence on the rockburst evolution process. Thus, in-situ tests and monitoring during tunneling or mining processes are helpful in investigating those key features and in understanding the mechanisms of rockbursts evolution processes of different types. Nevertheless, real-time warning system is also needed to predict the intensity of rockburst and potential failure depth of rockbursts. Because of difficulties in investigating the geological conditions, dynamic design method can be employed to reduce and/or avoid the occurrence of rockbursts, according to the predicted intensity and potential failure depth of rockbursts. In practice, the proposed methods have been successfully applied to warning and preventing rockbursts in the headrace tunnels of Jinping II hydropower project in China. This paper will summarize the progress of these studies.
Abstract: This paper focuses on the evolution processes of different types of rockbursts occurring in deep tunnels. A series of laboratory tests and in-situ monitoring in deep tunnels excavated by tunnel boring machine (TBM) and drill-and-blast (D&B) method have been conducted to understand the mechanisms and processes of the evolution of different types of rockbursts, including strain rockburst, strain-structure slip rockburst, immediate rockburst and time-delayed rockburst. Three different risk assessment methods are proposed to evaluate the intensity and potential failure depth of rockbursts. These methods can be applied before excavation and the results can be updated according to the real-time information during excavation. Two micro-seismicity based real-time warning systems have been established for predicting various intensities of rockbursts, such as slight, moderate, intensive and extremely intensive rockbursts. Meanwhile, the probability and intensity of the rockburst are also given. The strategy for excavation and support design has been suggested for various intensities of rockbursts before excavation. The strategy for dynamic control of the rockburst evolution process is also proposed according to the monitoring results. The methodology has been successfully applied to rockburst risk reduction for deep tunnels at Jinping II hydropower project. The results have illustrated the applicability of the proposed methodology and techniques concerning rockbursts. Key words: rockburst; risk assessment; tunnel boring machine (TBM); drill-and-blast (D&B) method