自动化英语电子教案

Unit1ElectronicsElementsandLawsResistors,CapacitorsandInductorsResistors,capacitorsandinductorsareveryimportantelementsinelectroniccircuits.ResistorsandResistance Aresistorisatwo-terminalelement.Resistanceisthecapacityofmaterialstoimpedetheflowofcurrentor,morespecifically,theflowofelectriccharge.resistor n.[电]电阻器 capacitorn.(=capacitator)电容器inductor n.电感器 element n.元件electronica.电子的 circuit n.电路resistancen.电阻，阻抗 terminal n.终端capacity n.容量 impede v.阻止current n.电流 charge n.负荷，电荷，充电电阻器、电容器和电感器在电子电路中，电阻器、电容器和电感器是非常重要的元件。电阻器和电阻电阻器是二端口元件。电阻是阻止电流流动，更确切地说，是阻止电荷流动的能力。InSI,resistanceismeasuredinohms.TheGreekletteromega(Ω)isthestandardsymbolforanohm.Largeramountofresistancearecommonlyexpressedinkilo-ohm(kΩ)andinmega-ohm(MΩ).SI 国际单位制,英文:InternationalSystemofUnitsohm n.[物]欧姆在国际单位制中，电阻用欧姆来度量。希腊字母Ω是欧姆的标准符号。较大的电阻一般用千欧和兆欧来表示。Thecircuitelementusedtomodelthisbehavioristheresistor.Figure1.1showsthecircuitsymbolfortheresistor,withRdenotingtheresistancevalueoftheresistor.Figure1.1Thecircuitsymbolforaresistor模拟这种特性常用的电路元件是电阻器。图1.1表示电阻器的电路符号，R表示电阻器的电阻值。图1.1电阻器的电路符号Forpurposesofcircuitanalysis,wemustreferencethecurrentintheresistortotheterminalvoltage.Ifwechoosetheassociatedreferencedirection,therelationshipbetweenthevoltageandcurrentisv=iR(1.1)Wherevisthevoltageinvolts,iisthecurrentinamperes,andRistheresistanceinohms.voltage n.[电工]电压，伏特数associated a.联合的，关联的ampere n.安培为了进行电路分析，我们必须在电阻器中指明电流和电压的参考方向。如果我们选择关联参考方向，那么电压和电流之间的关系是：这里v是电压，其单位是伏特，i是电流，其单位是安培，R是电阻，其单位是欧姆。Ifwechoosenon-associatedreferencedirection,wemustwritev=-iR (1.2)ThealgebraicsignsusedinEqs(1.1)and(1.2)areknownasOhm’sLaw.Ohm’sLawexpressedthevoltageasafunctionofthecurrent.Howeverexpressingthecurrentasafunctionofthevoltageisalsoconvenient.Ohm’sLawisthealgebraicrelationshipbetweenvoltageandcurrentforaresistor.non-associated a.非联合的，非关联的algebraic a.代数的，关于代数学的Eq. 公式(equation)的缩写Ohm’sLaw 欧姆定律function n.[数]函数如果选择非关联参考方向，我们必须写成：v=-iR(1.2)用在公式（1.1）和（1.2）中的代数式就是著名的欧姆定律。欧姆定律表示了电压作为电流的函数。然而，要表示电流是电压的函数也是非常方便的。欧姆定律是电阻两端的电压和电流间的代数关系。CapacitorsandCapacitanceThedevicecapableofdoingthisiscalledacapacitor.Theabilityofacapacitortostoreelectricalenergyistermedcapacitance.1Electricalenergycanbestoredinanelectricfield.Figure1.2showsthecircuitsymbolforthecapacitor.capacitance n.容量，电容electricfield 电场电容器和电容电能可以存储在电场中，存储电能的装置叫电容器。电容器存储电能的能力叫做电容。图1.2表示电容器的电路符号。存储能量的装置叫电容器｡电容器存储电能的能力叫做电容｡句中“tostoreelectricalenergy”为不定式作定语｡两个句子都是被动语态,在科技英语中经常使用被动语态｡ThecircuitparameterofcapacitanceisrepresentedbytheletterC,ismeasuredinfarads(F).Becausethefaradisanextremelylargequantityofcapacitancepracticalcapacitorvaluesusuallylieinthepicofarad(pF)tomicrofarad(μF)range.Fig.1.2Thecircuitsymbolforacapacitorparametern.参数，参量faradfaradn.[电]法拉，电容单位picofaradn.[电]皮(可),法拉,微微法拉,百亿分之一法拉,符号为PF或pfmicrofaradn.[电]微法拉电容的电路参数用字母C表示，用法拉来度量。因为法拉是相当大的电容量，实际上电容值通常位于皮法和微法之间。图.1.2电容器的电路符号Asthevoltagevarieswithtime,thedisplacementofchargealsovarieswithtime,causingwhatisknownasthedisplacementcurrent.2Attheterminals,thedisplacementcurrentisindistinguishablefromaconductioncurrent.Whenthecurrentreferenceandthevoltagereferenceareassociated,thecurrentisproportionaltotherateatwhichthevoltageacrossthecapacitorvarieswithtime,or,mathematically,whereiismeasuredinamperes,Cinfarads,vinvolts,andtinseconds.当电压随时间变化时,电荷的位移也随时间变化,引起了众所周知的位移电流｡在“causingwhat...”中,causing是现在分词短语作结果状语,what引导宾语从句,作causing的宾语｡当电压随时间变化时，电荷的位移也随时间变化，引起了众所周知的位移电流。在终端，位移电流和传导电流没有区别。当电流参考方向和电压参考方向是关联参考方向时，电流正比于电容两端电压随时间的变化率，数学表达式为：这里i的单位是安培，C的单位是法拉，v的单位是伏特，t的单位是秒。InductorsandInductanceItiswellknownthatinductorsareoneofbuildingblocksinelectroniccircuits.Allcoilshaveinductance.Inductanceisthepropertyofopposinganychangeofacurrentflowingthroughacoil.InductanceissymbolizedbytheletterL,ismeasuredinhenrys(H).Figure1.3showsaninductor.Fig.1.3Thecircuitsymbolforaninductorinductance n.感应系数，自感应coil v.盘绕,卷,线圈henry n.henries亨利(电感单位)电感器和电感众所周知，电感是电子电路中的模块之一。所有的线圈都有电感。电感是抵抗流过线圈电流的任何变化的性质。电感用字母L表示，其单位是亨利。图1.3表示一个电感器。图1.3电感器的电路符号Whenthereferencedirectionsofthecurrentandvoltageareassociated,yieldswherevismeasuredinvolts,Linhenrys,iinamperes,andtinseconds.当电流和电压的参考方向关联时，有(1.4)这里v的单位是伏特，L的单位是亨利，i的单位是安培，t的单位是秒。NotefromEq.(1.4)thatthevoltageacrosstheterminalsofaninductorisproportionaltothetimerateofchangeofthecurrentintheinductor.Wecanmaketwoimportantobservationshere.First,ifthecurrentisconstant,thevoltageacrosstheidealinductoriszero.Thustheinductorbehavesasashortcircuitinthepresenceofaconstant,ordc.current.Second,acurrentcannotchangeinstantaneouslyinaninductor,thatis,thecurrentcannotchangebyafiniteamountinzerotime.Aninductor,likeacapacitor,storestheenergysuppliedtoit,butitstoresenergyintheformofamagneticratherthananelectricfield.3constant n.[数､物]常数，恒量finite a.有限的，[数]有穷的，限定的shortcircuit 短路dc.current 直流电流电感器和电容器一样,存储供给它的能量,但是它是以磁场的形式而不是以电场的形式存储能量｡句中“ratherthan”可作连词词组使用,连接两个并列成分,表示在两者中间进行选择,否定后者｡后面可以接名词､代词､形容词､副词､动词和动词不定式等｡Exercises1.two-terminalelement 2.associatedreferencedirection Ohm’sLaw4.electricfield .Chooseonewordfromthewordlistbelowtofillintheblankineachofthefollowingsentences.Changetheformofthewordwherenecessary.1.Theabilityofacapacitortostoreelectricalenergyistermed.2.Aisadevicedesignedtohavecapacitance.3.InSIismeasuredinohms.4.Ohm’sLawisthealgebraicrelationshipbetweenthevoltageandcurrentfora.5.isthepropertyofopposinganychangeofacurrentflowingthroughacoil.6.storesenergyintheformofamagneticratherthananelectricfield.III.PleasetranslatethefollowingparagraphintoChinese.Wecanmaketwoimportantobservationshere.First,ifthecurrentisconstant,thevoltageacrosstheidealinductoriszero.Thustheinductorbehavesasashortcircuitinthepresenceofaconstant,ordc.current.Second,acurrentcannotchangeinstantaneouslyinaninductor,thatis,thecurrentcannotchangebyafiniteamountinzerotime.在此，我们可以得到两条重要的结论：第一，如果电流是常数，理想电感器的端电压为0，这样电感器在恒量或直流中可以当作短路；第二，在电感器中电流不能瞬时变化，也就是说，在0时间内电流不能以有限量改变。科技英语的翻译标准及方法翻译是一种语言表达法,是译者根据原作者的思想,用本国语言表达出来｡这就要求译者必须确切理解和掌握原著的内容和意思,丝毫不可以离开它而主观地发挥译者个人的想法和推测｡在确切理解的基础上,译者必须很好地运用本国语言把原文通顺而流畅地表达出来｡1.翻译的标准科技英语的翻译标准可概括为“忠实､通顺”四个字｡忠实:首先指忠实于原文的内容,译者必须把原作的内容完整而准确地表达出来,不得任意增删､歪曲;忠实还指保持原作风格,尽可能还其本来面目｡通顺:指译文语言必须通顺易懂,符合汉语规范｡忠实与通顺是相辅相成的｡忠实而不通顺,读者看不懂,也就做不到忠实;通顺而不忠实,脱离原作的内容与风格,通顺也就失去了作用｡例如:1)Heknowssomethingaboutelectricity.错误译法:他知道有关电的某些东西｡正确译法:他懂点电｡2)Theelectricresistanceismeasuredinohms.错误译法:电的反抗是用欧姆测量的。正确译法:电阻的测量单位是欧姆｡3)Allmetalsdonotconductelectricityequallywell.错误译法:全部金属不导电得相等好。正确译法:并非所有的金属都同样好地导电｡4)Themomentthecircuitiscompleted,acurrentwillstartflowingtowardthecoil.错误译法:电路被完成的片刻,一个电流将开始流向这个线圈｡正确译法:电路一接通,电流就开始流向线圈｡从以上例句中可以清楚地看到:不要任意增删,并非是逐词死译;译文汉语规范化,并非是离开原文自由发挥｡在科技英语的翻译过程中,还应该注意通用术语的译法｡例如,例句2中“电阻”是术语,没有别的译法｡2.翻译的方法 翻译的方法大体说来有两种:直译(literaltranslation)和意译(freetranslation)｡直译,即指“既忠实于原文内容,又忠实于原文形式”的翻译,但决不是“死译”,不可望文生义｡意译,就是指忠实于原文的内容,不拘泥于原文的形式｡在翻译时,我们应灵活使用上述两种方法,能直译的就直译,能意译的就意译,因为对同一个句子有时并非只能用一种方法,有时两种方法可交替使用或同时并用｡总之,要遵循“忠实､通顺”的宗旨｡试看下面的例子:theMilkyWay银河(意译)(不可直译为:牛奶路)bull’seye靶心(意译)(不可直译为:牛眼睛)catchacold感冒(意译)(不可直译为:抓住一个冷)Newuseshavebeenfoundforoldmetals,andnewalloyshavebeenmadetosatisfynewdemands.老的金属有了新用途,新的合金被冶炼出来,以满足新的需要｡(本句前半部分用的是意译法,后半部分用的是直译法｡)TheIdealBasicCircuitElementandKirchhoff’sLawsTheidealbasiccircuitelementAnidealbasiccircuitelementhasthreeattributes:(1)ithasonlytwoterminals,whicharepointsofconnectiontoothercircuitcomponents:(2)itisdescribedmathematicallyintermsofcurrentsand/orvoltages,and(3)itcannotbesubdividedintootherelements.Weusetheword“ideal”toimplythatabasiccircuitelementdoesnotexistasarealizablephysicalcomponent.Weusethe“basic”toimplythatthecircuitelementcannotbefurtherreducedorsubdividedintootherelements.Thusthebasiccircuitelementsformthebuildingblocksforconstructingcircuitmodels,buttheythemselvescannotbemodeledwithanyothertypeofelements.Therearefiveidealbasiccircuitelements:voltagesources,currentsources,resistors,inductors,andcapacitors.Kirchhoff’sLawsAcircuitissaidtobesolvedwhenthevoltageacrossandthecurrentineveryelementhavebeendetermined.Ohm’sLawisanimportantequationforderivingsuchsolutions.Insimplecircuitstructures,Ohm’sLawissufficientforsolvingforthevoltagesacrossandthecurrentsineveryelement.However,formorecomplexinterconnectionsweneedtousetwomoreimportantalgebraicrelationshipsknownasKirchhoff’sLaws,tosolveforallthevoltagesandcurrents.ThereareKirchhoff’sCurrentLawandKirchhoff’sVoltageLaw.Kirchhoff’sCurrentLawcanbestated,thealgebraicsumofallthecurrentsatanynodeinacircuitequalszero.TouseKirchhoff’sCurrentLaw,analgebraicsigncorrespondingtoareferencedirectionmustbeassignedtoeverycurrentatthenode.Assigningapositivesigntoacurrentleavinganoderequiresassigninganegativesigntoacurrententeringanode.Conversely,givinganegativesigntoacurrentleavinganoderequiresgivingapositivesigntoacurrententeringanode.BeforewecanstateKirchhoff’sVoltageLaw,wemustdefineaclosedpathorloop.Startingatanarbitrarilyselectednode,wetraceaclosedpathinacircuitthroughselectedbasiccircuitelementsandreturntotheoriginalnodewithoutpassingthroughanyintermediatenodemorethanonce.WecannowstateKirchhoff’sVoltageLaw,Thealgebraicsumofallthevoltagesaroundanyclosedpathinacircuitequalszero.TouseKirchhoff’sVoltageLaw,wemustassignanalgebraicsign,referencedirection,toeachvoltageintheloop.Aswetraceaclosedpath,avoltagewillappearaseitherariseoradropinthetracingdirection,assigningapositivesigntoavoltageriserequiresgivinganegativesigntoavoltagedrop.Conversely,givinganegativesigntoavoltageriserequiresgivingapositivesigntoavoltagedrop.TechnicalWordsandExpressionsKirchhoff’sLaws 基尔霍夫定律component n.元件subdivide v.细分node n.节点positive a.正的negative a.负的Unit2DigitalCamerasDigitalCamerasDigitalcamerasaresimpletouseandofferamazingqualitypictures.Adigitalcameratakespicturesusinganelectronicphotosensitivesensor.Theimagesarestoredinthecamera’sdigitalmemoryandcanbetransferredtoacomputerorstoragedevice.Whereastraditional35mmcamerasrelyonmechanicalandchemicalprocessestocreateaphoto,digitalcamerashaveasmallcomputerinsidethemtorecordadigitalimage.photosensitive a.对光敏感的,感光的whereas conj.然而,反之,鉴于,尽管,但是数码相机使用简单并可提供惊人的高质量图像。数码相机是利用电子感光传感器拍摄照片，图像储存在相机的数字存储卡中，并可传到计算机或存储设备。传统的35毫米照相机依靠机械和化学过程来生成一个照片，而数码相机内部有一个小型计算机来记录数字图像。ApertureAnadjustableirisoropeningthroughwhichlightentersacamera’slens.Thelargertheapertureis,thegreaterthecamera’sphotosensitivityis.Asmalleraperture,however,givesgreaterdepthoffieldtoapicture.Theaperturesettingiscalledthef-stop.Asmallaperturehasarelativelyhighf-number,suchasf8orf11,andalargeraperturehasasmallernumber,suchasf2.8.aperture n.孔,穴,缝隙,(照相机,望远镜等的)光圈,孔径iris n.希神,彩虹之女神,虹,虹彩photosensitivity n.[物]光敏性,感光性;感光灵敏度光圈控制光线进入相机镜头的一个可调的虹膜或孔。光圈越大，相机的感光灵敏度越大。然而较小的光圈会使照片有更大的景深。光圈设置被称做f-stop(光圈级数)，小光圈有相对较高的f值，比如f8或f11；较大的光圈是较小的值，如为f2.8。光圈越大,相机的感光灵敏度越大｡themore...themore...,越……就越……Theharderyouwork,thegreaterprogressyou’llmake.你越努力工作,你取得的进步就越大｡然而,较小的光圈值会使照片有更大的景深｡句子中间的however是副词插入语,把句子的主谓语分开了｡插入语一般对一句话做一些附加的说明｡通常与句中其它部分没有语法上的联系,将它删掉之后,句子结构仍然完整｡插入语在句中有时是对一句话的一些附加解释､说明或总结;有时表达说话者的态度和看法;有时起强调的作用;有时是为了引起对方的注意;还可以起转移话题或说明事由的作用;也可以承上启下,使句子衔接得更紧密一些｡Theaperturesettingmustbebalancedagainsttheshutterspeed.Thefastertheshutterspeed,thelargertheaperturemustbe,andviceversa,toadmittherightamountoflighttotheimagesensorforproperexposure.CompressionAprocessthatreducestheamountofdatarepresentinganimagesothatthefiletakesuplessspaceinyourcamera,memorycard,andcomputer.shutterspeed 快门速度viceversa ad.反之亦然compression n.浓缩,压缩,压榨,密集光圈设置必须兼顾快门速度，快门速度越快，光圈必须越大，反之亦然，允许适量的光线进入以使图像传感器正确曝光。压缩压缩是减少代表图像数据量的一种过程，以使文件在您的相机、记忆卡和电脑中占用较少的空间。Compressingandsavinganimageactuallytakeslesstimethansavinganuncompressedimage.Smallerfilesarequickertousefore-mailandontheWeb.Whenafileisovercompressed,however,imagequalitycanbeseriouslydegraded.degraded a.被降级的,退化的,堕落的其实压缩并保存图像比保存非压缩图像所花的时间更少。较小的文件在电子邮件和在网络上更快。不过当一个文件被过度压缩时，图像质量可能严重退化。DepthoffieldAnindicationofhowmuchofascenewillbesharpandinfocus.Agreaterdepthoffieldimpliesanincreaseddistancebetweenwell-focusedbackgroundandforeground,witheverythinginbetweenproperlyfocused.Anarrowdepthoffieldconcentratesitsareaoffocuswithinasmallrange,basedonthecentralsubject’sdistancefromthecamera.depthoffield 景深infocus 焦点对准,清晰景深景深是景象的清晰程度和对焦的指标。越大的景深意味着背景和前景之间更大的距离，在两者之间的一切都可正确聚焦。根据镜头中央的对象与相机之间的距离，狭窄的景深把聚集面积集中在一个小范围内。Forinstance,ifyoursubjectisstandingaloneinaballpark,usinganarrowdepthoffieldwillmakemostoftheballparklookblurry,onlythesubjectwillbefocused.Agreaterdepthoffieldmightkeepmostoftheballparkinfocusblurrya.模糊的,不清楚的例如，如果你的目标是独自站在一个球场，狭窄的景深会令大部分的球场看起来模模糊糊的，只有目标被对焦，更大的景深可能保持球场的大部分都能被对焦。ImagesensorThesemiconductorchipinadigitalcamerathatreplacesfilm.Itcapturesthelightofasceneorasubject,whichitturnsintoelectricalsignalsthatthecameracanunderstandanduse.Thecamerainturnconvertsthesesignalsintodigitaldatathatyourcomputercanunderstandanduse.图像传感器图像传感器是数码相机里可以取代胶卷的半导体芯片。它捕捉到一个场景或对象的光线，并把它变成相机可以识别和使用的电信号。相机依次把这些信号转换为计算机可以识别和使用的数字信息。ThemostcommonimagesensortypesareCCD(charge-coupleddevice)andCMOS(complementarymetal-oxidesemiconductor).Bothtypesofimagersconvertlightintoelectricchargeandprocessitintoelectronicsignals.CCDsensorshavebeenusedincamerasformorethan20yearsandpresentmanyadvantageousqualities,amongthem,betterlightsensitivitythanCMOSsensors.advantageous a.有利的,有益的最常见的图像传感器类型有CCD（电荷耦合器件）和CMOS（互补金属氧化物半导体）。这两种类型的传感器都是把光线转换成电荷并处理成为电信号。CCD传感器在照相机中的应用已超过20年了，它有许多优良性能，其中之一就是：其光敏性优于CMOS传感器。LCDviewfinderAsmallelectronicscreenonthebackofadigitalcamerathatdisplayswhatthelenssees.Youwoulduseittocomposeyourpicture,chooseyoursettingsfocusandframeanimageinmacromode,andviewjust-shotphotos.viewfindern.取景器LCD取景器数码相机背面的小电子屏幕会显示镜头看到的东西。你可以用它来调整图片、选择你的设置、在微距模式对焦并框定一帧图像、查看刚刚拍摄的照片。MemorycardAsmallremovablestoragedevicethatsavestheimagesadigitalcameracaptures.Whenitisfull,youcanswaponememorycardforanotherandcontinueshooting.Acardreadercanbeattachedtoyourcomputerforopeningandsavingimagefilesoutsideofyourcamera.Memorycardscomeinvariousdensities,asdoanyotherdrivesorstoragedevices.存储卡一种可以保存数码相机所拍摄图像的小巧、可移动存储设备。当它存满时，你可以更换另一个存储卡，并继续拍摄。读卡器可以连到你的电脑上用来打开和保存你相机中的图像文件。存储卡有各种密度，任何其他的驱动器或存储设备也是同样的，ThemostcommontypesofmemorycardsareCompactFlash,SmartMedia,andSecureData(SD).Youmustusetherighttypeandvolumeofcardforyourdigitalcamera.Ascameramegapixelcountsgrow,highercapacitymemorycardsbecomenecessary.最常见类型的记忆卡有CF卡、SM卡和SD卡。必须使用适合你数码相机的适当型号和容量的存储卡。随着照相机像素的不断增加，更大容量的存储卡已成为必备。像素数字图像中的一个数据点，这个词是图像元素的简称。数码相机的分辨率是衡量图像传感器能够捕捉到的像素数量的指标。每一个像素含有一系列的描绘颜色或亮度的数字，一个像素可以表示的精度被称作“位（bit）”或“色彩深度”。图像所包含的像素越多，它就有越多的细节描述能力。ShutterspeedAmeasureofhowlongacameraallowslighttofallontheactiveimagesensor(expressedasafractionofasecond).Intraditionalfilmcameras,thereisaphysical,mechanicalshutterinthelensthatopensandclosestoregulatehowlongthefilmisexposedtolight.Thoughmanydigitalcamerashavebothelectronicandmechanicalshutters,inexpensivemodelsrelysolelyonelectronicshuttersthatturnoffthephotosensitivityoftheimagesensors.快门速度衡量允许光线落在图像传感器的时间长度（表示为一秒钟的若干分之一）的参数。传统的胶片相机，在镜头上有一个物理机械快门，用快门的打开或关闭来调节胶卷曝光时间。虽然许多数码相机都有电子和机械两种快门，但廉价的相机单靠电子快门来关闭图像传感器的感光性。ExercisesI.MarkthefollowingstatementswithT(true)orF(false)accordingtothetext.1. Adigitalcameratakespictures,andthensavestheminadigitalmemory.2.Thereisasmallcomputerinsidethedigitalcamera.3.Thelargertheapertureis,thesmallernumberoff-stopis.4. Theslowertheshutterspeed,thelargertheaperturemustbe.5.Digitalcameracannotworkwellwithoutfilm.6. Compressingtheimagefilepurposestosavetheimagefilesinlessspace.7. Acompressedimagemaylosssomeinformation.8.Themorepixelsanimagecontainsthelessdetailitcanpresent.9.Theaperturesettingandtheshutterspeedmustbematchedwell.(TTTFFTTFT)II.TranslatethefollowingphrasesintoEnglish.1.数码相机2.电子光学传感器3.景深4.快门速度5.存储卡6.胶片照相机7.电子快门8.光圈9.液晶取景器10.电荷耦合器件(CCD)1.digitalcamera2.electronicphotosensitivesensor3.depthoffield4.shutterspeed5.memorycard6.filmcamera7.electronicshutter8.aperture9.LCDviewfinder10.charge-coupleddeviceIII.TranslatethefollowingphrasesintoChinese.1.convertlightsignalsintodigitaldata2.imagesensor3.lightsensitivity4.electronicscreen5.macromode6.removablestoragedevice7.acardreader8.digitalimage9.pictureelement10.colordepth1.把光信号转换成数字信息2.图像传感器3.光敏性4.电子屏幕5.微距模式6.可移动存储装置7.读卡器8.数字图像9.图像元素10.色彩深度IV.TranslatethefollowingparagraphsintoChinese.Thedigitalcamerasoffermorethanjusttheinstantgratificationofpreviewingpicturesonsmallcolorscreens,thuseliminationthecostofrepetitiveshots.Theycanstoredozenssometimeshundredsofimagesthatcanbeprintedeasilyathomeorsentbye-mail.Althoughthereareextracostsinvolvedingoingdigital,thecostofmemorycardsforstorage,andthespecialpaperforprinting,manybuyershavebeenwillingtomaketheswitch.Digitalcamerasarecapturingagrowingshareoftheconsumermarket,andthenumberofdigital-camerahouseholdsiscertaintogrow.Thepriceshavecomedownandthequalityhasgoneup.Withalargememorycardtostorepictures,youcanshootandshootandneverhavetoworryaboutchangingaroll.数码相机除了可以在其小彩色屏上立刻预览照片是否令人满意，省去了重复拍摄的开支之外，还可以存储几十张、甚至是数百张照片，这些照片可以在家里打印出来或用电子邮件发送出去。尽管走向数字化也需要额外的花费，如存储卡、打印用特殊纸张的开支，但许多购买者还是愿意换用（数码相机）。数码相机占有的市场份额正在增长中，拥有数码相机家庭的数量当然也在增长。数码相机的价格已经下降，而质量却在上升。有一张大容量的保存照片的存储卡，你就可以不停地拍照而不必担心更换胶卷。Grammar:省略和插入语英语的句子中除主､谓､宾､定､状､补及补足语外,常有同位语､插入语及独立定语,这些句子的附加成分在语法中虽然不处于重要的地位,但对阅读科技专业书刊往往会起一些干扰作用,妨碍我们对句子中主要成分的理解和分析｡1.省略:英语句子中常省略一些成分使语言精练,但有时这种省略会给我们的阅读和翻译带来一些困难,现在我们来看一下在科技英语中常见的省略情况｡1)并列结构中某些相同成分的省略在and,but,or,while,so等词连起来的并列句中,常省去与前面相同的成分｡Stoneandglassconductheatpoorlycomparedtometals,butwellcomparedtowoodandpaper.石头和玻璃与金属相比导热性能很差,但是与木头和纸相比则导热性很好｡But后面省略了theyconductheat｡2)状语从句中省略在一些状语从句中,如果其主语与主句中的主语相同,且谓语中含有动词be,则从句中的主语和be常常可以省略｡Potentialenergy,thoughnotsoobviousaskineticenergy,existsinmanythings.势能虽不如动能那样明显,但很多物体都具有势能｡Though后面省略了itis｡3)常用省略有些省略已成为习惯用法,如ifpossible(如果可能),ifnecessary(如有必要),ifany(如果主句中含有否定的意思,译成:即使有,也很少;如果主句是肯定的,译成:若有……)｡Innon-conductors(insulators)therearefewifanyfreeelectrons.在绝缘体中几乎没有自由电子,即使有,也极少｡这里ifany也可不译｡Thereareveryfewmistakesinhiswork,ifany.他工作极少出错｡4)比较句中的省略Thehotterthegas,thefasterdothemoleculesmove.气体越热,分子就运动得越快｡gas后面省略了is｡Inaseriescircuitthetotalresistanceisthesumoftheindividualresistances.Thecurrentineachunitisthesameasinallotherunits.在串联电路中,总电阻等于各个电阻的总和,通过每一个元件的电流与通过其他元件的电流相同｡as后面省略了thecurrentis｡2.插入语插入语也是英语中常有的现象,它也能造成句子的分离现象,在阅读和翻译时把它先放在一边,免得对句子的主要意思产生干扰｡一般插入语会用逗号断开,所以还是比较好判断的｡1)插入语中见到最多的是同位语,如果名词后面有另一名词(或代词)､词组或句子对该名词作进一步的说明,而这两者在语法上又处于同等的位置,则称为同位语｡同位语和前面的(特别是),including(包括)等引出同位语｡Colortelevisionsbreakdownthepicturesintothreecolors—red,green,andblue.彩色电视把图像分解为三种颜色——红､绿､蓝｡OnOctober17,1831,Faradaysucceededinmakingoneofthegreatestdiscoveriesinthefieldofelectricity—theelectromagneticinduction.法拉第于1831年10月17日成功地做出了电学领域中的一项最伟大的发现——电磁感应｡Their(electrons)orbits,orpaths,formconcentricshells,orlayers,somewhatlikethelayersofanonion. 电子的轨道(即轨迹)形成一些同心的外壳(即同心层),有点像洋葱的表皮｡2)插入语中常见的还有一些表示语气､态度､承上启下或转折的短语,这样的插入语有许多,典型的如:therefore所以,forexample(例如),forinstance(例如),inaconclusion(作为结论),inshort(简言之)等｡但也有的插入语没有用逗号分开,要注意区分｡Thearea-delaytrade-offinvolvedhereisinessence,theproblemoftransistorsizeoptimization.这里所涉及的面积-延迟平衡(问题)本质上就是晶体管规模设计优化问题｡ClassroomReadingPropertyofDigitalCamerasAdvantagesofDigitalCamerasIfyouwanttobuyadigitalcamera,considerthefollowingadvantages,instantimagechecking,noscanning,nofilmcost,andpromotingacleanerenvironment.Forjustaminimalinvestment,youcanenhanceyourpicturesusingdigitaltechnology.Allyouneedisadigitalcamera,abasiccomputer,aphoto-qualityprintermaybesomeadditionalmemory,andaremovablemediaexternaldrive.You’llalsoneedsomeimagingprograms.You’llbeabletocropandgetridofdustmarksandscratches,bleach,sharpen,soften,splittoneretouchcolor,andperformdozensofotherfunctionincludingcorrectingperspective.Anddoitsoquicklyandeasilythatyourresultwillsoonsurpassthoseofconventionalphotographerswhotookyearstolearntheircraft.BasicrequirementsofdigitalcamerasLet’stalkaboutbasicrequirementsofadigitalcamera.Anydigitalcamerathathasa640by480pixelsresolutionwouldbeagoodstartifyoudon’tneedprintslargerthan4by6inches.Youneedapersonalcomputeralso,themonitorisoneofthemostimportantelementsinthedigitalchain.Youmayneedsomeextrastoragespacefortheimagesyouworkon.Theirfilesizescangobbleupanywherefrom1MB~5MBperpictureandthey’llfillupyourdrivefast.Finally,I’mgoingtosuggestyoubuyacolorink-jetprinter.ResolutionResolutionistheabilityofadevicetorecordfinedetailsinanimage.Imagesfromdigitalcamerasaremadeupoflittlesquares(sometimesrectangles)calledpixels.Apixelisshortfora“picturecell”.Adigitalcamera’simagingsurfaceismadeupofrowsoftinyindividuallightsensorsthatcapturecolorandlightinformationthatisthenelectricallyconvertedintodigitaldata—thecellsorpixelsthatmakeuptheimage.Themorepixelsthatcanbepackedintoagivenarea,thehighertheresolution.Thehighertheresolution,thelargerthefilessize—eventhoughmostimagesarecompressedinthecamerausingJPEGencoding.Yourfilesizeswilldependonthespecificimageanddegreeofcompression.Manycamerasallowyoutoselectthedegreeofcompressiondependingontheultimatepicturequalityyourequire.Ifahighdegreeofcompressionisacceptable,itallowsyoutostoremoreimagesinthecameraoronitsmemorycard.Whenanuncompressedimageisopened,itwillberoughlyfivetotwentytimeslargerthanitscompressedsize.JPEGisalosscompressionmethod.Thismeansthattoreducefilesize,someoftheimageinformationislost,oncegone,youcan’tgetthosepixelsbackwithoutstartingoverfromyouroriginalimage.SosaveimagesinTIFF,losslesscompression,ifavailable,tosavespace.TechnicalWordsandExpressionsenhance v.提高,增强scratch v.乱涂,勾抹掉,擦,刮bleach v.漂白sharpen v.锐化surpass v.胜过,超越conventional a.传统的,惯例的resolution n.分辨率lightsensor 光传感器JPEG abbr.联合图像专家组一种压缩标准degreeofcompression 压缩程度losscompressionmethod 有损压缩方式losslesscompression 无损压缩TIFF 标签图像文件格式Unit3MicrocontrollersTheAT89C51isalow-power,high-performanceCMOS8-bitmicrocontrollerwith4KbytesofFlashprogrammableanderasablereadonlymemory(PEROM).Bycombiningaversatile8-bitCPUwithFlashonamonolithicchip,theAtmelAT89C51isapowerfulmicrocontrollerwhichprovidesahighly-flexibleandcost-effectivesolutiontomanyembeddedcontrolapplications.microcontroller n.微处理器(在本文中可以译成单片机)CMOS是ComplementaryMetalOxideSemiconductor缩写,指互补金属氧化物(PMOS管和NMOS管)半导体共同构成的互补型MOS集成电路制造工艺,它的特点是低功耗programmablea.可设计的,可编程的 erasablea.可消除的,可抹去的versatile a.多用途的,多功能的 monolithicn.单片电路,单块集成电路flexible a.柔韧性,易曲的,可通融的cost-effectivea.有成本效益的,划算的embeddeda.植入的,深入的,内含的微处理器AT89C51是一种低功耗、高性能的带有4KB可编程和可擦除的只读存储器(PEROM)。CMOS8位微控制器，通过把通用的8位CPU与Flash内存集成在一块单芯片上，AT89C51是一种功能强大的微控制器，它为许多嵌入式控制应用提供了具有高度灵活性且价格低廉的解决方案。TheAT89C51providesthefollowingstandardfeatures,4KbytesofFlash128bytesofRAM,32I/Olines,two16-bittimer/counters,afive-vectortwo-levelinterruptarchitecture,afullduplexserialport,on-chiposcillatorandclockcircuitry.Inaddition,theAT89C51isdesignedwithstaticlogicforoperationdowntozerofrequencyandsupportstwosoftwareselectablepowersavingmodes.interrupt n.发给电脑的中断信号duplex a.双倍的,复式的<电信､计>双工的,双向的circuitry n.电路,线路AT89C51具有以下标准特点：4KB闪存、128字节RAM、32个I/O、2个16位定时器/计数器、五个2级中断结构、全双工串行端口、片内振荡器和时钟电路。此外，AT89C51具有降到零频率的静态逻辑，以及支持两种软件可选的省电模式。Port0isan8-bitopen-drainbi-directionalI/Oport.Asanoutputport,eachpincansinkeightTTLinputs.When1sarewrittentoPort0pins,thepinscanbeusedashighimpedanceinputs.Port0mayalsobeconfiguredtobethemultiplexedloworderaddress/databusduringaccessestoexternalprogrammemoryanddatamemory.1highimpe