论文网
理工类类论文范文素材,与电力工程师职文成人相关论文范文
本论文是一篇理工类类论文范文,关于电力工程师职文成人相关研究生毕业论文开题报告范文。免费优秀的关于理工类及答案及学术期刊方面论文范文资料,适合理工类论文写作的大学硕士及本科毕业论文开题报告范文和学术职称论文参考文献下载。
CD播放机3.asyouwoulddowithafloppydisk:就象你使用软磁盘一样4.CD-ROMstandsforCompactDisc-ReadOnlyMemory:CD-ROM是CompactDisc-ReadOnlyMemory这五个词首字母的组成的缩写词.5.Itmaynotbemanymoreyearsbeforeapletelynewtechnologyisinvented:过不了几年,说不定又会发明一种全新的技术等.manymoreyears是"再过许多年".6."thereisnodoubtyouwillcontinuetoenjoylisteningtoyourfavoritemusiconCDs"语法上可以理解为"thereisnodoubt(aboutthefactthat)youwillcontinuetoenjoylisteningtoyourfavoritemusiconCDs".练习:
1.Paragraphs1&,2ADigitalcodehaswideapplications.2.Paragraph3BFloppydisksareoutdated.3.Paragraph4CCDsaredurable.4.Paragraph5DCD'sworkingprincipleisexplained.ECD-RWsplaybetterthanCD-ROMs.FCDsareofmanyformats.
5.OneadvantageofCD-RWsisthattheycan__________likefloppydisks.6.Theauthorpredictsitwillnot__________beforeanewtechnologyisinventedformusicrecording.7.Thelaserbeam-emittingdeviceandthereceiverareconsideredto__________ofaCDplayer.8.Spaceprobescouldnot__________withoutusingdigitalcodes.
AshineonbumpsBtakemanymoreyearsCbethekeypartsDrestoretheoriginalcodeEbewrittenonandrewrittenonFkeepcontactwiththeirgroundstationefficiently
答案与题解:
1.D第一,二段介绍了CD的工作原理.声音以数码的形式刻录到CD碟片上.要回听声音,就得用CD放音机,CD机用激光照射CD,接收器收和分析从CD反射回来的激光波,还原为原来的数码,再转换为原来的声音.所以,D是答案.2.A第三段第一句{"Digitalcodesareusedwithmanytechnologies.")是主题句.本段其它句子提供例证,即应用领域.作者例举了5个领域:电邮,航天通讯,条码,手机和天气预报.选项A的"Digitalcodehaswideapplications"与主题句的意思完全吻合,所以是答案.3.F第四段第一句("Therearemanytypesofpactdisks"}是主题句.本段其它句子列举了两种常用的CD格式(format),一种是CD-RW,另一种是CD-ROM.选项F的"CDsareofmanyformats"概括了本段的大意,是答案.4.C第五段说的是CD碟片经久耐用,1982年上市的CD碟片至今还能使用,其音质依旧.现在上市的CD,更加耐用,如果使用得当,其寿命可达70-200年.选项C用了durable予以概括是很恰当的,所以,C是答案.5.E第四段中出现CD-RW这个词,介绍了"Theycanberecordedonandre-recordedon(rewrittenon).这就是选E的依据.6.B第六段能找到与答案有关的句子,即Itmaynotbemanymoreyearsbeforeapletelynewtechnologyisinventedandintroducedtothepublicformusicrecording.7.C第二段说到在CD机上还原数码时依靠的是激光发射装置和接收器.由此我们可以推论出激光发射器和接收器是CD机的主要部件.所以C是答案.8.F第三段第三句("Spaceprobesmunicatewiththeirgroundstationonearthusingdigitalcodes")是选F的依据.
第十一篇TheTiniestElectricMotorintheWorld
1.Scientistsrecentlymadepublicthetiniestelectricmotorever1built.Youcouldstuffhundredsofthemintotheperiodattheendofthissentence.Onedayasimilarenginemightpoweratinymechanicaldoctorthatwouldtravelthroughyourbodytoremoveyourdisease.
2.Themotorworksbyshufflingatomsbetweentwomoltenmetaldropletsinacarbonnanotube.Onedropletisevensmallerthantheother.Whenasmallelectriccurrentisappliedtothedroplets,atomsslowlygetoutofthelargerdropletandjointhesmallerone.Thesmalldropletgrows–butnevergetsasbigastheotherdroplet–andeventuallybumpsintothelargedroplet.Astheytouch,thelargedropletrapidlysopsuptheatomsithadpreviouslylost.Thisquickshiftinenergyproducesapowerstroke2.
3.Thetechniqueexploitsthefactthatsurfacetension--thetendencyofatomsormoleculestoresistseparating--beesmoreimportantatsmallscales3.Surfacetensionisthesamethingthatallowssomeinsectstowalkonwater.
4.Althoughtheamountofenergyproducedissmall--20microwatts--itisquiteimpressiveinrelationtothetinyscaleofthemotor4.Thewholesetup5islessthan200nanometersonaside,orhundredsoftimessmallerthanthewidthofahumanhair.Ifitcouldbescaleduptothesizeofanautomobileengine6,itwouldbe100milliontimesmorepowerfulthanaToyotaCamry's225horsepowerV6engine.
5.In1988,ProfessorRichardMullerandcolleaguesmadethefirstoperatingmicromotor,whichwas100micronsacross7,oraboutthethicknessofahumanhair.In2003,Zettl'sgroupcreatedthefirstnanoscalemotor.In2006,theybuiltananoconveyor,whichmovestinyparticlesalonglikecarsinafactory.
6.Nanotechnologyengineerstrytomimicnature,buildingthingsatom-by-atom.Amongotherthings,nanomotorscouldbeusedinopticalcircuitstoredirectlight,aprocesscalledopticalswitching.Futuristsenvisionaday
理工类类论文范文素材,与电力工程师职文成人相关论文范文参考文献资料：