高中英语 Unit 3 Life in the future Reading素材 新人教版必修5.doc

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1、MaglevTrain磁悬浮列车Q:Whatdoesmaglevmean?A:Maglevisshortformagneticlevitation(漂浮）,whichmeansthatthesetrainswillfloatoveraguideway(导轨）usingthebasicprinciplesofmagnetstoreplacetheoldsteelwheelandtracktrains.Q:Whatisguidewayandhowdoesitwork?A:Themagnetizedcoil([电]线圈)runningalongthetrack,call

2、edaguideway,repelsthelargemagnetsonthetrain'sundercarriage(车盘),allowingthetraintolevitate(飘浮)between0.39and3.93inches(1to10cm)abovetheguideway.Oncethetrainislevitated,powerissuppliedtothecoilswithintheguidewaywallstocreateauniquesystemofmagneticfieldsthatpullandpushthetrainalongthegui

3、deway.Theelectriccurrentsuppliedtothecoilsintheguidewaywallsisconstantlyalternatingtochangethepolarity(极性)ofthemagnetizedcoils.Thischangeinpolaritycausesthemagneticfield（磁场）infrontofthetraintopullthevehicleforward,whilethemagneticfieldbehindthetrainaddsmoreforwardthrust(推力).Q:Howmanyc

4、omponentsaretheretoamaglevtrainrailsystem?A:Themagneticfieldcreatedinthiswire-and-batteryexperimentisthesimpleideabehindamaglevtrainrailsystem.Therearethreecomponentstothissystem:AlargeelectricalpowersourceMetalcoilsliningaguidewayortrackLargeguidancemagnetsattachedtotheundersideofthe

5、train.Q:Whatisthedifferencebetweenamaglevtrainandaconventional(常规的，传统的)train?A:Thebigdifferencebetweenamaglevtrainandaconventionaltrainisthatmaglevtrainsdonothaveanengine?nbsp;atleastnotthekindofengineusedtopulltypicaltraincarsalongsteeltracks.Theengineformaglevtrainsisratherinconspic

6、uous（不显眼的，不引人注意的).Insteadofusingfossilfuels(矿物燃料),themagneticfieldcreatedbytheelectrifiedcoilsintheguidewaywallsandthetrackcombinetopropel(推进)thetrain.Q:Howfastcanmaglevtrainstravel?A:Maglevtrainsfloatonacushionofair(气垫),eliminatingfriction(摩擦).Thislackoffrictionandthetrains'aerodynam

7、ic(空气动力学的)designsallowthesetrainstoreachunprecedented(空前的)groundtransportationspeedsofmorethan500kph.Incomparison,aBoeing-777commercialairplaneusedforlong-rangeflightscanreachatopspeedofabout789kph.Oncemanufacturerscanprovethatmaglevtrainscantransportpassengerssafelyatsuchhighspeeds,m

8、aglev