资源描述:
《【精品】专业英语总结》由会员上传分享,免费在线阅读,更多相关内容在工程资料-天天文库。
1、Materialsareatthecoreofalltechnologicaladvancesandtheyareevolvingtodayfasterthanatanytimeinhistory.Industrialnationsregardthedevelopmentofnewandimprovedmaterialsasan”underpinningtechnologyaterialsareprobablymoredeep-seatedinourculturethanmostofourrealization.Transpor
2、tation,housing,clothing,communication,recreation,andfoodproduction—virtuallyeverysegmentofoureverydaylivesisinfluencedtoondegreeoranotherbymaterials.Historically,thedevelopmentandadvancementofsocietieshavebeenintimatelytiedtothemembers'abilitytoproduceandmanipulatema
3、terialstofilltheirneeds.Infact,earlycivilizationshavebeendesignatedbytheleveloftheirmaterialsdevelopment材料是所有技术前沿的核心,现在它们的发展比历史上任何一个时期都快。工业国家把发展新材料和改进材料视为“支柱技术”。材料对我们文化的影响比我们认识到的还要深远。运输业,住房,制衣业,通讯,娱乐产业和食品加工业——几乎我们生活的方方面面都或多或少受到材料的影响。历史上,社会的发展和进步和人类制造并使川材料来满足需求的能力紧密相关
4、。事实上,早期的文明就是按照他们材料的发展来区分的。Furthermore,environmentalqualitydependsonourabilitytocontrolairandwaterpollution.Pollutioncontroltechniquesemployvariousmaterials.Inaddition,materialsprocessingandrefinementmethodsneedtobeimprovedsothattheyproducelessenvironmentaldegradation
5、,thatis,lesspollutionandlessdespoilmentofthelandscapefromtheminingofrawmaterials・此外,环境质量决定于我们控制空气和水污染的能力。污染控制技术使用各种材料。除此Z外,材料加工和提纯技术需要得到改进,这样才能减轻环境质量的下降,也就是说,更少的污染和在开采原料吋对环境更少的掠夺。Significantquantitiesofenergyareinvolvedintransportation・Reducingtheweightoftransportati
6、onvehicles,aswellasincreasingengineoperatingtemperatures,willenhancefuelefficiency.Newhigh-strength,low-densitystructuralmaterialsremaintobedeveloped,aswellasmaterialsthathavehighertemperaturecapabilities,foruseinenginecomponents.运输业消耗了大量的能源。减轻交通工具的重量并提高引擎运行温度将会提高燃料使
7、用效率。新型轻质髙强结构材料和引擎部件用的耐热材料有待开发。OneearlyoutgrowthofquantummechanicswasthesimplifiedBohratomicmodel,inwhichelectronsareassumedtorevolvearoundtheatomicnucleusindiscreteorbital,andthepositionofanyparticularelectronismoreorlesswelldefinedintermsofitsorbital.Thismodelofthea
8、tomisrepresentedinFigure2.1•量子力学一个早期的分支是简化的波尔原子模型,这个模型中假设电子圉绕原子核以离散轨道转动,并且任意特定电子的位置都可以通过它的轨道很好地定义。这个原子模型如表2」所示。Asmaybenotedfromthep