《電子信息類專業(yè)英語》課件-第5章

Unit5IntegratedCircuit科技英語中的定語從句

Firstly,let’sseethedevelopmentofIntegratedCircuit(IC).

Before1947,theheartoftheelectroniccircuitwasvacuumtubeinventedin1904byaBritishengineer,thoughthisdeviceunderwentconstantimprovement,inrealityforitscomplexdesign,thevacuumtubeisinherentlyunstable,power-hungry,andsubjecttoburnoutsandinternalshortcircuits.Italsotakesupalotofspace.TheseareamongtheshortcomingsofthevacuumtubethatledtothedevelopmentofthetransistorbyBellTelephoneLaboratoriesengineers.

Thekeytothetransistor’srapiddevelopmentwastheuseofsiliconinsteadofwireasthebasicconductivematerial.Thiselement,whichcomprises28percentoftheearth’scrust,isnotonlystableoverawiderangeoftemperatures,butalsooffersdependablemanufacturingcontrol.

Then,whatisIC?

Integratedcircuits,orICisacombinationofafewinterconnectedcircuitelementssuchastransistors,diodes,capacitors,andresistorsproducedinasinglemanufacturingprocessononeandthesamebearingstructure,calledthesubstrate,andintendedtoperformdefinitefunctioninvolvedinconvertinginformation.

TheelectricallyinterconnectedcomponentsthatmakeupanICarecalledintegratedelements.Ifanintegratedcircuitincludesonlyonetypeofcomponents,suchasonlydiodeorresistors,itissaidtobeanassemblyorsetofcomponents.

Theprincipleofintegratedcircuitelementsliesinthefollowing.Agreatnumberof“set”areproducedsimultaneouslyonawafer.Eachsetcontainsallthecomponentssuchastransistors,diodes,andresistorswhichareinterconnectedwithshortfinemetallicstripesdepositedonthewafersurface.Theymakeupafunctionalblock.EachICsofcomponentsisareadyintegratedcircuit.AllICsareregularlydistributedonthewafersurface.

ICscanbeclassifiedbyfunctionintotwo:circuitstobeappliedindigitalsystemsandthosetobeappliedinlinearsystems.ThedigitalICsareemployedmostlyincomputers,electroniccounters,frequencysynthesizersanddigitalinstruments.AndtheanalogorlinearICsoperateoveracontinuousrange,andincludesuchdevicesasoperationalamplifiers.

科技英語中的定語從句

定語從句一直是科技英語閱讀中經(jīng)常遇到卻又難以把握的問題。定語從句一般位于所修飾的名詞(先行詞)后，緊跟先行詞,或與先行詞有一定的間隔。定語從句究竟修飾文中的哪個先行詞,一要靠語言知識理解，二要根據(jù)上下文進行邏輯判斷。

定語從句有限定性和非限定性之分。前者是主句意義中不可缺少的部分，而后者主要對主句起附加說明作用，一般與主句用逗號隔開。

定語從句的一般結(jié)構(gòu)：

先行詞?+?引導(dǎo)詞(包括關(guān)系代詞who、that、which、whom、whose和關(guān)系副詞when、where、why)+?從句

例如：

①Atransformeriscomposedofsomecoilsthatarecoupledtogetherbymagneticinduction.

變壓器由磁感應(yīng)耦合線圈組成。

②ISDNisanewserviceofferedbymanytelephonecompaniesthatprovidesfast,high-capacitydigitaltransmissionofvoice,data,stillimagesandfull-motionvideoovertheworldwidetelephonenetwork.

綜合業(yè)務(wù)數(shù)據(jù)網(wǎng)(ISDN)是由電話公司提供的一項新型業(yè)務(wù)，這項業(yè)務(wù)可以在世界范圍內(nèi)的電話網(wǎng)上進行語言、數(shù)據(jù)、靜止圖像和運動視頻的快速、大容量的數(shù)字傳輸。

③Whenthepointerstopsmoving,thereadinggivenbytheohmmeteristheinsulationresistance,whichisnormallyhighifthecapacitorisingoodcondition.(非限制性定語從句)

指針停止移動時的讀數(shù)就是電容器的絕緣電阻值,假如電容器正常工作,絕緣電阻值通常很高。

注意：

1.在限定性定語從句中,引導(dǎo)詞指代先行詞,定語從句的引導(dǎo)詞在從句中充當(dāng)某個成分，有時可將其省略。例如：

TheGPSreceivercomparesthetimeasignalwastransmittedbyasatellitewiththetimeitwasreceived.

GPS接收機把衛(wèi)星發(fā)送信號的時間和接收信號的時間相比較。

2.在非限定性定語從句中不能使用that為關(guān)系代詞，而只能who,whom,whose等指人，用which指物或事。

3.在非限定性定語從句中，定語從句的引導(dǎo)詞不僅可以指代先行詞，有時還可指代前面的整個句子。

例如：