信息科学与电子工程专业英语课后答案--王朔中

1、信息科学与电子工程专业英语课后答案-王朔中科技英语课件ExercisesUnit1ExercisesUnit1Exercises(1) TranslatethefollowingsentencesintoChinese.(1)TranslatethefollowingsentencesintoChinese.1. Aswithseriesresonance,thegreatertheresistanceinthecircuitthelowertheQand,accordingly,theflatterandbroadertheresonancecurveofeitherlinecurrento

2、rcircuitimpedance.对于串联谐振，电路中的电阻愈大Q值就愈低，相应地线路电流或电路阻抗的谐振曲线也就愈平、愈宽。2. Awirecarryingacurrentlooksexactlythesameandweighsexactlythesameasitdoeswhenitisnotcarryingacurrent.一根带电的导线其外表与重量都与不带电导线完全一样。3. Clickmouseonthewaveformanddragittochangethepulserepetitionrate,ordirectlyenteranewvalueoftheperiodinthepro

3、videddialoguebox,whilekeepingthepulsewidthunchanged.在波形上点击鼠标并拖动来改变脉冲重复频率，或者在提供的对话框中直接输入新的周期值，而保持脉冲宽度1HMILYYLIMH科技英语课件Exercises/、变。4. Electronicsisthescienceandthetechnologyofthepassageofchargedparticlesinagas,inavacuum,orinasemiconductor.Pleasenotethatparticlemotionconfinedwithinametalonlyisnotconsi

4、deredelectronics.电子学是一门有关带电粒子在气体、真空或半导体中运动的科学技术。注意，在本书中粒子运动仅限于金属的情况不属于电子学。5. Hardwaretechnologieshaveplayedvitalrolesinourabilitytouseelectronicpropertiestoprocessinformation,butsoftwareanddataprocessingaspectshavenotdevelopedatthesamespeed.硬件技术在我们使用电子特性来处理信息的能力中一直起着重要作用，而软件及数字处理方面却没能与硬件同步发展。6. Howe

5、ver,inaproperlydesignedDCamplifiertheeffectoftransistorparametervariation,otherthanIco,maybepracticallyeliminatediftheoperationpointofeachstageisadjustedsothatitremainsinthelinearoperationrange2HMILYYLIMH科技英语课件Exercisesofthetransistorastemperaturevaries.然而在设计得当的直流放大器中，若调节每一级的工作点使之在温度变化时保持在晶体管线性区，就能在

6、实际上消除Ico以外的晶体管参数变化所造成的影响。(2) Fillintheblankswiththemostappropriatechoice.(2)Fillintheblankswiththemostappropriatechoice.1. Amessagesignalcananyamplitudevaluebetween0andAvolts.A.assumeB.useC.receiveD.accept2. Eachtimeapositiveclockedgeoccurs,theflip-flopchangesstate,leadingtohalfasmanypulsesattheoutp

7、uttotheclockinput.A.asB.comparedC.dueD.soas3. Intheprevioussectionwediscussedsine-waveorCWmodulationsystemsinwhichthemodulatingsignalofadigitalpulsetrain.A.madeB.consistedC.containedD.got4. Inthisbookweshallemphasizethelimitationsimposedontheinformationtransmittedbythesystemthroughwhichitwasandshall

8、attemptsomecomparison3HMILYYLIMH科技英语课件Exercisesofdifferentsystems.A.putB.traveledC.passedD.viewed5. Thissignaleitherdoesnotchange,oritchangesbyanamountequivalenttooneormorequantumsteps.A.interruptedlyB.rudelyC.abruptlyD.absolutely6. Weshallonlybewithlogicalrepresentations,notabsolutevaluesA.interest

9、edB.caringC.referredD.concerned(3) Choosethephrasethatisclosestinmeaningtothe(3)Choosethephrasethatisclosestinmeaningtotheunderlinedpart.underlinedpart.1. Itisalltooeasywithlinearcircuits,whichappearrelativelysimplewhencomparedwithtodayscomplexlogicarrangements,toignoredetailedperformanceparametersw

10、hichcandrasticallyreducetheexpectedperformance.A. whichhasbadinfluenceuponthesystemperformanceB. whichisimportanttoensurecircuitlinearityC. whichispossibletoenhancethesystemperformance4HMILYYLIMH科技英语课件ExercisesD. whichiscrucialformaintainingthedesiredperformance2. Thereforetherewillbeaslighttimedela

11、y,duetothepropagationdelayoftheflip-flopsbetweenthetimeoneflip-flopchangesstateandthetimethenextonechangesstate,i.e.,thechangeofstateripplesthroughthecounter,andthesecountersarethereforecalledripplecounters.A.thestatechangeispropagatedthroughthecounterlikeripplesB.thestatechangescauseripplesinthecou

12、nterC.passingthroughthecounter,thestateripplechangesD.thestateofthecounterchangesduetoripples3. Insteadoftriggeringoneachpulse,aphaselocktechniqueexaminestherelativephasebetweeneachosc川atorandmanyofitssyncpulsesandadjustsoscillatorfrequencysothattheaveragephasediscrepancyissmall.A.checkseachoscillat

13、orformanysyncpulsesB.checksthephaserelationshipbetweenindividualoscillatorsandacollectionofsyncpulsesC.looksattherelationsbetweenthephaseandthesyncpulsesD.examineswhetherthephaseisrelativetotheoscillator5HMILYYLIMH科技英语课件Exercisesandthesyncpulses4.Bykeepingtheoffstateslightlybelowthreshold,thedelaybe

14、tweentheappliedelectricalpulseandtheresultingopticaloutputpulseisminimized;thisdelaymustindeednotbemorethanthebitintervalsothattheopticalpulsecanaccuratelyreproducetheinputsignal.A. ensuringthatthesystemisoffthethresholdbyasmallmarginB. maintainingthesystemsshut-downstatesomewhatbelowaprescribedleve

15、lC. makingsurethesystemisbelowitsthresholdsothatthestateiskeptoffD. keepingthesysteminashut-downstatethatisunderagivenlevelwithatinytoleranceS. Iftheoriginalsignaliswellbehaved,thelocaloscillatorwillneedverylittleinformationtobeabletotrack,andthatinformationcanbeobtainedbyaveragingforalongperiodofti

16、me,therebyeliminatingnoisethatcouldbeverylarge.A. theLOwillnotrequireanyinformationinordertokeeptrackingB. theLOwillmakeuseoftrackinginformationthatis6HMILYYLIMH科技英语课件ExercisesscarceinthesystemC. theLOwillrequiresomeinformation,butnotmuch,sothatthesystemcantrackD. theLOwillusenoinformationotherthans

17、omelittleonetomaintaintracking6.Thethirdsectiondescribesquantizationschemesthattakeaccountofthecharacteristicsofspeech.A. takemeasureofthespeechcharacteristicsB. takethespeechcharacteristicsintoconsiderationC.countthespeechcharacteristicsD.makeuseofthespeechcharacteristics7. InaproperlydesignedDCamp

18、lifiertheeffectoftransistorparametervariationmaybepracticallyeliminatediftheoperatingpointofeachstageisadjustedsothatitremainsinthelinearoperationrangeofthetransistorastemperaturevaries.A.theeffectivevariationofthetransistorparametersB.theefforttochangetransistorparametersC.thetransistorparametersth

19、ateffectivelychangeD.theresultscausedbytransistorparameterchanges8. Stabilityandrepeatabilityarefundamentalattributesofdigitalcircuits,however,andthenecessaryaccuracycan7HMILYYLIMH科技英语课件Exercisesbeobtainedinadigitalversionofthemodulatorbyanappropriatechoiceofwordlengthtorepresentthesignals.A.byexpre

20、ssingthesignalswithasuitablewordlengthB.byusingawordlongenoughtodescribethesignalsC.bychoosetocharacterizethesignalsintermsofwordlengthappropriatelyD.byappropriatelyrepresentingthesignalstochoosealengthofwordsUnit2ExercisesUnit2Exercises(1) TranslatethefollowingsentencesintoChinese.(1)Translatethefo

21、llowingsentencesintoChinese.1. Ifanalogsignalsaretobetransmitteddigitally,theyfirsthavetobesampledataspecifiedrateandfurtherconvertedtodiscreteamplitudesamplesbyquantization.如果要以数字方式传输模拟信号，首先必须以一定的频率对信号进行采样，然后通过量化进一步将它们转换为离散的幅度样本。2. Linearfiltersamplifyorattenuateselectedspatialfrequencies,canachiev

22、esucheffectsassmoothingandsharpening,andusuallyformthebasisofre-samplingand8HMILYYLIMH科技英语课件Exercisesboundarydetectionalgorithms.线性滤波器放大或衰减选择的空间频率，能够实现像平滑和锐化这些效果，通常是重采样和边缘检测算法的基础。3. Stabilityandrepeatabilityarefundamentalattributesofdigitalcircuits,however,andthenecessaryaccuracycanbeobtainedinadigi

23、talversionofthemodulatorbyanappropriatechoiceofwordlengthtorepresentthesignals.不过稳定性和可重复性是数字电路的基本性质，在数字式调制器中必要的精度可通过适当地选择代表信号的字长而获得。4. Thefirstobservationismadeonthefundamentalrelationshipbetweenthenatureofsystemandtheperiodicityofitsfrequencyresponse:acontinuoussystemhasanaperiodicfrequencyresponse

24、,whileadiscretesystemhasaperiodicfrequencyresponse.从系统性质和它频率响应的周期性之间的基本关系中首先可以看到：连续系统有非周期性的频率响应，而离散系统有周期性的频率响应。9HMILYYLIMH科技英语课件Exercises5. Themainfunctionofthereceiveristoextracttheinputmessagesignalfromthedegradedversionofthetransmittedsignalcomingfromthechannel.接收器的主要功能是从由信道传输来的退化了的信号中提取出输入消息。(2)

25、 Choosethewordorphrasethatisclosestinmeaningto(2)Choosethewordorphrasethatisclosestinmeaningtotheunderlinedpart.theunderlinedpart.1. Roughlyspeaking,thetransistorcanbelikenedtoanelectronicallycontrolledvalvewherebyenergyappliedtooneconnectionofthevalveenablesenergytoflowbetweentwootherconnections.A.

26、 relatedB. linkedC. analogizedD. viewed2. Whilethirdpartydesigntoolswereavailable,therewasnotaneffectivelinkfromthethirdpartydesigntoolstothelayoutandactualsemiconductorprocessperformancecharacteristicsofthevariousASICmanufacturers.A. WhenB. Although10HMILYYLIMH科技英语课件ExercisesC. AsD. Since3. Thesest

27、eps,implementedwithalevelofskillcommonintheindustry,almostalwaysproduceafinaldevicethatcorrectlyimplementstheoriginaldesign,unlessflawsarelaterintroducedbythephysicalfabricationprocess.A.practicedusingskillsgenerallyavailableintheindustryB.commonlyperformedatlevelsofskilledpersonnelintheindustryC.re

28、alizedwiththeskillfulcommonlevelintheindustryD.carriedoutbyskillscommonlyusedintheindustry4. Asecondmajorstepwouldbetodevelopdesignspecificationsthatconsiderthefunctionalityofthehumanwiththesamedegreeofcarethathasbeengiventotherestofthesystem.A. developdesignprocedurestoaccountforthehumanbehaviorand

29、activitiesB. promotedesignarrangementsandtakethehumanfactorsintoconsiderationC. makeusedofdesignstepsthatrespectthehumanfunctionalityD. draftandeffectdesignrequirementsthattakeinto11HMILYYLIMH科技英语课件Exercisesaccountthehumanfunctionality5. Clickmouseonthewaveformanddragittochangethepulserepetitionrate

30、ordirectlyenteranewvalueoftheperiodintheprovideddialoguebox,keepingthepulsewidthunchanged.A. simplytypeanewperiodvalueinthegivendialogueboxB. directanentryforthenewperiodvaluetothedialogueboxC. pointastraightforwardnewperiodvaluetothedialogueboxprovidedD. enteradirectionofanewperiodvaluetoprovideadi

31、aloguebox6. ComparedwithmostofthetextbooksattheintroductorylevelofRFanalogdesign,thisbookpresentssomehands-onexperiencesonthedesignissuesthatreallyworkandhasbeenprovedbymanufacturedchips.A. thisbookprovidessomeexperiencesathandontheissuesencounteredindesignB. thisbookprovidessomeactuallyworkingexper

32、iencesaboutthedesignproblemsC. thisbookpresentssomeavailableexperiencesoverthe12HMILYYLIMH科技英语课件ExercisesdesignproblemsD. thisbookpresentssomeissuesconcerningdesignexperiencesthatarehandedover7. Foradecadetherehasbeenasearchforaprogrammableprocessorwhich,giventhecostandvolumeconstraints,isgeneraleno

33、ughtobeprogrammedwithdifferentalgorithms.A. withcontrolledmeasuresofpriceandmagnitudeB.giventheconditionofriskandnumberC. giventheconstantsofchargeandweightD. giventhelimitsofpriceandsize8. InaproperlydesignedDCamplifiertheeffectoftransistorparametervariation,otherthanIco,maybepracticallyeliminatedi

34、ftheoperatingpointofeachstageisadjustedsothatitremainsinthelinearoperationrangeofthetransistorastemperaturevaries.A. transistorB. amplifierC. IcoD. parameter13HMILYYLIMH科技英语课件ExercisesUnit3Exercises(1) TranslatethefollowingsentencesintoChinese.(1)TranslatethefollowingsentencesintoChinese.1. Averycom

35、monlyusedmethodofmicrowavemeasurementsisbasedonthestudyofastandingwavepatternformedalongthelinebecauseoftheinterferenceofincidentandreflectedwaves.一个很常用的微波测量方法是基于对驻波图型的研究，这种驻波是由入射波和反射波之间的干涉而沿着传输线形成的。2. Computationsshowareductionof6dBintheEMfieldintensitywiththedistancedoubled,andanincreaseof3dBinthe

36、intensitywiththetransmittedpowerdoubled.Thisresultprovidesverificationtothealgorithmused.计算表明，当距离增大一倍时，电磁场强度减小6分贝；而发射功率增大一倍时，场强则增加3分贝。这一结果验证了所用算法的正确性。3. Liketransferofheatbyconduction,convectionandradiation,microwaveheatingcanbeconsideredasanothermodeofheattransfer,inwhichheatisproduceddirectlyat14H

37、MILYYLIMH科技英语课件Exercisesthelocationofthedielectriclosses.就像通过传导、对流、辐射来传递热量一样，微波加热可以看作热传递的另一种方式，即热量直接产生于发生介电损耗的地方。4. Operationoftheradarisbasedonthemeasurementofthetimeittakesforapulsetransmittedfromanantennatogetreflectedbytheobjecttobedetectedandtoreturnattheantennaandthereceiver.雷达的工作是基于对天线发出的脉冲被所

38、要探测的目标反射，（然后）回到天线和接收机所需时间的测量。5. OthermotivationsforusingCADincircuitdesignincludesthewishtoacquireconfidenceinadesignthatwasaccomplishedbyothermeans,and,notleastinimportance,asenseofcuriosityorperhapsadesiretodiscovertheunexpected.在电路设计中使用CAD勺其它动机包括：想要验证用别的方法设计出来的电路；满足好奇心或者可能是想发现预想不到的现象。后一个动机并非是最不重要

39、的。（取得信心，并非最不重要，意料之外的事）15HMILYYLIMH科技英语课件Exercises6. Thespacingbetweentherepeatingamplifiersisafunctionofthecableattenuationandthesystembandwidthsothatthegainprovidedbytheseamplifierscompensatesforthelossintroducedbythecable.中继放大器之间的间距是电缆衰减和系统带宽的函数，以便这些放大器提供的增益补偿电缆引起的损耗。7. Whenthecut-offfrequencyisno

40、lessthanthemaximalfrequencyoftheoriginalsignal,norisitgreaterthanthedifferencebetweenthesamplingfrequencyandthemaximalfrequency,theoriginalsignalmaybecompletelyrebuilt.当截止频率不小于原始信号的最高频率，也不大于采样频率和最高频率之差，原始信号可以完整地重建。8. WhilethepoliticsofthelastonehundredyearscenteredaroundIndustrialAgetechnology,thepo

41、liticsofthefuturewillbebasedonInformationAgeconcernsorientedtowardsthestorage,protectionandexchangeofinformation.尽管近百年来的政治活动是以工业时代的技术为中心的，未来的政治活动将基于信息时代的事物，面向信息16HMILYYLIMH科技英语课件Exercises的存储、保护和交换。(2) Choosethewordorphrasethatisclosestinmeaningto(2)Choosethewordorphrasethatisclosestinmeaningtotheund

42、erlinedpart.theunderlinedpart.1. Iftheseotherchargesandcurrentsarecomparableinsizetothesourcesproducingtheaboveelectromagneticfield,thenanewnetelectromagneticfieldwillbeproduced.A. makecomparisonwiththesizeofthesourcesB. arecomparedwiththesizeofthesourcesC. havesimilarsizetothesourcesD. takeacommons

43、izeofthesources2. Thisrangeofwavelengthshasledmanytoquestionthenamingconventionusedformicrowavesasthenamesuggestsamicrometerwavelength.A. hasraisedmanyquestionsaboutthenaminghabitB. hascausedmanypeopletochallengethenamingrulesC. hasledmanyquestionsofthenamingconventionD. hasresultedinmanyproblemsint

44、henamingtradition3.NASAworkedinthe1970sandearly1980storesearchthepossibilitiesofusingSolarPowerSatellite(SPS)systemswithlargesolararraysthatwouldbeampowerdowntothe17HMILYYLIMH科技英语课件ExercisesEarthssurfaceviamicrowaves.A. shedsolarenergytotheEarthssurfacefromthesatelliteB. setthesatellitedowntotheEart

45、hssurfacewithpowerssurfacefromC. shutdownthepoweron(to)theEarththesatelliteD. switchoffpowertotheEarthssurfacefromthesatellite4. AsDoDurgentlywantedmilitarycommandandcontrolnetworksthatcouldsurviveanuclearwar,ARPAwaschargedwithinventingatechnologythatcouldgetdatatoitsdestinationreliablyevenifarbitra

46、rypartsofthenetworkdisappearedwithoutwarningasaresultofanuclearattack.A. winanuclearwarB. beusedinpreparationofanuclearwarC.avoidanuclearwarD. bestilloperationalafteranuclearwar5. Atthepresent,stateoftheartmicrowaveamplifiersandoscillatortubescanoperateinafrequencyrangeupto40GHzandsolid-statemicrowa

47、vedevicesupto100GHz.A.recentandmostadvancedB. hightechrelated18HMILYYLIMH科技英语课件ExercisesC. sophisticatedD. artisticallymanufactured6. Insuchafiberraystravelingatlargerangleswithrespecttotheaxishavetotraversealongerpathandhencetakealongertimethanthoserayswhichpropagatewithsmalleranglestotheaxis.A. ha

48、vetransmittedoveralongerdistanceB. areboundtotreatalongerwayC. musttravelthroughalongerrouteD. mustdealwithalongertrace7. Bykeepingtheoffstateslightlybelowthreshold,thedelaybetweentheappliedelectricalpulseandtheresultingopticaloutputpulseisminimized;thisdelaymustindeednotbemorethanthebitintervalsoth

49、attheopticalpulsecanaccuratelyreproducetheinputsignal.A.thisdelaymustindeedbenomorethanoneinternalbitB.indeed,thisdelaymustexceedthebitofintervalC.asamatteroffact,thisdelayintervalmustbealittlebitlessD.thisdelaymustindeedbekeptlessthanthespacingbetweendatabits8. Computationsshowareductionof6dBintheE

50、Mfield19HMILYYLIMH科技英语课件Exercisesintensitywiththedistancedoubled,andanincreaseof3dBintheintensitywiththetransmittedpowerdoubled.Thisresultprovidesverificationtothealgorithmused.A.that,witha6dBreduction,theEMfieldintensityistwiceasstrongB. thattheEMfieldintensityisdecreasedby6dBastherangeisdoubledC.

51、that,intheEMfield,intensitywithdoubledistanceleadstoa6dBreductionD. a6dBintensityreductioncausesadoubledistanceintheEMfieldUnit4ExercisesUnit4Exercises(1) TranslatethefollowingpassagesintoChinese.(1)TranslatethefollowingpassagesintoChinese.1. Communicationmaybebroadlydefinedasthetransferofinformatio

52、nfromonepointtoanother.Whentheinformationistobeconveyedoveranydistanceacommunicationsystemisusuallyrequired.Withinacommunicationsystemtheinformationtransferisfrequentlyachievedbysuperimposingormodulatingtheinformationontoanelectromagneticwavewhichactsasa20HMILYYLIMH科技英语课件Exercisescarrierfortheinform

53、ationsignal.Thismodulatedcarrieristhentransmittedtotherequireddestinationwhereitisreceivedandtheoriginalinformationsignalisobtainedbydemodulation.Sophisticatedtechniqueshavebeendevelopedforthisprocessbyusingelectromagneticcarrierwavesoperatingatradiofrequenciesaswellasmicrowaveandmillimeterwavefrequ

54、encies.However,communicationmayalsobeachievedbyusinganelectromagneticcarrierthatisselectedfromtheopticalrangeoffrequencies.通信可以广义地定义为从一处到另一处的信息传递。当要将信息传输到任何距离以外时就需要有一个通信系统。在通信系统内部，信息的传输经常通过将信息叠加或调制到作为信号载体的电磁波上来实现。经调制的载波然后被传送到要求的目的地，在那里被接收，原始信号通过解调被恢复出来。为了实现这一过程，已经利用工作在射频、微波以及毫米波频率上的电磁载波开发了复杂的技术。不过通信

55、也可以用光波频段上的电磁载波来实现。2. Electroniccommunicationsisthetransferandmovementofdatabetweenlocationsthroughtheuseofcomputers.An21HMILYYLIMH科技英语课件Exerciseselectroniccommunicationsystemincludestheequipmentneededtosupportthemovementofinformation,thecommunicationlinesandmediatocarrytheinformation,thecomputersoft

56、wareandprogramstocontroltheflowofinformation,thepersonneltoplan,implement,andoperatecommunications,andthemanagementofalltheseresources.Electroniccommunicationsestablisheslinksbetweenpeopleaswellascomputers.电子通信就是通过使用计算机在不同的地点之间传输数据。一个电子通信系统包括：支持信息流动所需要的设备，承载信息的通信线路和媒介，控制信息流的计算机软件和程序，计划、实施、操作通信系统的人员，

57、以及对所有这些资源的管理。电子通信建立起人和人、计算机和计算机之间的联系。3. Firstgenerationcommunicationssystemscanbecharacterizedbytheuseofanalogtransmissiontechniques,andtheuseofsimplemultiplexaccesstechniquessuchasfrequencydivisionmultipleaccess(FDMA).Theysufferedfromalowusercapacity,andsecurityproblemsduetothesimpleradiointerfaceused.Secondgenerationsystemswereintroducedintheearly1990s,andallusedigital22HMILYYLIMH科技英语课件Exercisestechnology.Thisprovidedanincreaseintheusercapacityofaroundthreetimes,achievedbycompressingthevoicewaveformsbeforetransmission.Thirdgenerationsystemsareanextensiononthec