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时间:2019-01-07
《高中英语导学案与练习2012高考英语阅读理解课堂练学案(5)_设计》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、2012高考英语:阅读理解课堂练学案(5)PassageEleven(SuperconductingMaterials)Thestoneage,TheIronAge.Entireepochshavebeennamedformaterials.Sowhattocallthedecadesahead?Thechoicewillbetough.Welcometotheageofsuperstuff.Materialscience--oncetheleastsexytechnology–isburstingwithnew,practicaldiscoveries
2、ledbysuperconductingceramicsthatmayrevolutionizeelectronics.Butsuperconductorsarejustpartofthepicture:fromhouseandcarstocookpotsandartificialteeth,theworldwillsomedaybemadeofdifferentstuff.Exoticplastics,glassandceramicswillshapethefuturejustassurelyashavegeneticengineeringandcom
3、puterscience.Thekeytothenewmaterialsisresearchers’increasingabilitytomanipulatesubstancesatthemolecularlevel.Ceramics,forexample,havelongbeenlimitedbytheirbrittleness.Butbyminimizingthemicroscopicimperfectionsthatcauseit,scientistsaremakingfarstrongerceramicsthatstillretainsuchqu
4、alitiesashardnessandheatresistance.FordMotorCo.nowusesceramictoolstocutsteel.AfirmcalledKyocerahascreatedalineofceramicscissorsandknivesthatstaysharpforyearsandneverrustorcorrode.Asimilartransformationhasovertakenplastics.High-strengthpolymersnowformbridges,ice-skatingrinksandhel
5、icopterrotors.Andonenewplasticthatgenerateselectricitywhenvibratedorpushedisusedinelectricguitars,touchsensorsforrobothandsandkaratejacketsthatautomaticallyrecordeachpunchandchop.Evenplasticlitter,whichoncethreatenedtopermanentlyblotthelandscape,hasprovedamenabletomoleculartinker
6、ing.Severalmanufacturersnowmakebiodegradableforms;someplasticsix-packringsforexample,graduallydecomposewhenexposedtosunlight.Researchersaredevelopingwaystomakeplasticsasrecyclableasmetalorglass.Besides,composites–plasticreinforcedwithfibersofgraphiteorothercompounds–madetheround-
7、the-worldflightofthevoyagerpossibleandhaveevenbeenprovedincombat:ahelmetsavedaninfantryman’slifebydeflectingtwobulletsintheGrenadainvasion.Someadvancedmaterialsareoldstandardwithanewtwist.Thenewestfiberopticcablethatcarrytelephonecallscross-countryaremadeofglasssotransparentthata
8、pieceof100milesthickisclearerthanastanda
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