GRE阅读笔记no63Word格式文档下载.docx
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GRE阅读笔记no63Word格式文档下载.docx
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condenser,whichtransfersheatfrom
(20)therefrigeranttoabodyofair.Now
therefrigerant,asahigh-pressure,
cooledliquid,confrontsaflowrestriction
whichcausesthepressuretodrop.As
thepressurefalls,therefrigerant
(25)expandsandpartiallyvaporizes,
becomingchilled.Itthenpasses
throughasecondheatexchanger,the
evaporator,whichtransfersheatfrom
theairtotherefrigerant,reducing
(30)thetemperatureofthissecondbodyof
air.Ofthetwoheatexchangers,oneis指示词
locatedinside,andtheotherone
outsidethehouse,soeachisincontact
withadifferentbodyofair:
roomair≠
(35)andoutsideair,respectively.
Theflowdirectionofrefrigerant
throughaheatpumpiscontrolledby
valves.Whentherefrigerantflowis
reversed,theheatexchangersswitch
(40)function.Thisflow-reversalcapability
allowsheatpumpseithertoheator
coolroomair.
Now,ifundercertainconditionsa
heatpumpputsoutmorethermalenergy>
(45)thanitconsumesinelectricalenergy,
hasthelawofenergyconservationbeen
challenged?
No,notevenremotely:
theTS
additionalinputofthermalenergyinto
thecirculatingrefrigerantviathe
(50)evaporatoraccountsforthedifference特殊短语、≠
intheenergyequation.
Unfortunately,thereisonereal∨、SE、—
problem.Theheatingcapacityofa
heatpumpdecreasesastheoutdoor
(55)temperaturefalls.Thedropincapacity
iscausedbythelesseningamountof
refrigerantmassmovedthroughthe
compressoratonetime.Theheating
capacityisproportionaltothismass关系
(60)flowrate:
thelessthemassof关系
refrigerantbeingcompressed,theless
thethermalloaditcantransferthrough
theheat-pumpcycle.Thevolumeflow
rateofrefrigerantvaporthroughthe
(65)single-speedrotarycompressorusedin
heatpumpsisapproximatelyconstant.
Butcoldrefrigerantvaporenteringa
compressorisatlowerpressurethan<
warmervapor.Therefore,themassof
(70)coldrefrigerant—andthusthethermal
energyitcarries—islessthanifthe<
refrigerantvaporwerewarmerbefore
compression.
Here,then,liesagenuinedrawbackofSE、∨
(75)heatpumps:
inextremelycoldclimates—
wherethemostheatisneeded—heat
pumpsareleastabletosupplyenough⊙
heat.
文章结构类型:
现象解释型,首段先提出一个疑问,后文给出解释。
Theuseofheatpumpshasbeenheldbacklargelybyskepticismaboutadvertisers'
claimsthatheatpumpscanprovideasmanyastwounitsofthermalenergyforeachunitofelectricalenergyused,thusapparentlycontradictingtheprincipleofenergyconservation.
TS:
theadditionalinputofthermalenergyintothecirculatingrefrigerantviatheevaporatoraccountsforthedifferenceintheenergyequation.
热泵(heatpump)的使用受到阻遏,这在很大程度上由于人们对广告商的声音心存疑虑,广告商称,对于所被消耗的每个单位的电能来说,热泵可产生多达两个单位的热能,因此显然与能量守恒定理相背悖。
热泵将一液体致冷剂加予循环流动,该致冷剂在一封闭的环道内从其液体阶段至气体阶段交替地作循环运动。
致冷剂初启动时作为一低温低压的气体,进入由电动马达驱动有压缩机。
在离开压缩机时,致冷剂已变作高温、稠密的气体,流经一个被称为冷凝器的热交换器,将热量从致冷剂转换作一团气体。
现在,该致冷剂作为一高压、冷却的液体,面临一流量限制,致使压力下降。
随着压力的下降,致冷剂膨胀且部分蒸发,变得冷却下来。
接着,它流经第二个热交换器,即蒸发机,将热量从气体转换为致冷剂,从而将这第二团气体的压力加以降低。
在这两个热交换器之间,一个位于室内,另一个位于室外,这样,每个热交换器所接触的是一团不同的气体,分别为室内空气和室外空气。
致冷剂在热泵内的流向由阀门控制。
当致冷剂的流向被逆转时,两个热交换器便互相转换其功能。
这种流向逆转能力致使热泵可将房间空气加热或冷却。
现在,如果在某些条件下,热泵所产生的热能超出了它所消耗的电能,能量守恒定律即已遭到质疑了吗?
不,丝毫没有:
通过蒸发机而额外输入到循环流动的致冷剂中的热能足以解释能量平衡方面的这一差异。
不幸的是,存在着一个真的问题。
热泵的加热功能会随着室外温度的下降而减弱。
加热能力的降低是由压缩机中一次流过的致冷剂质量的减少所致。
加热能力与此致冷剂质量流率成正比:
受到压缩的致冷剂质量越少,它通过热泵循环所能转换的热负载就越低。
流经单速旋转压缩机的致冷剂气体,其体积流率是大致稳定不变的。
但是,进入压缩机的冷致冷剂气体的压力要低于较暖气体的压力。
因此,冷致冷剂的质量——以及因此它所运载的热能——要低于另一种情形下的质量,即假如致冷剂气体在被压缩之前温度较高的话。
如此看来,这里存在着热泵的一个真正的障碍:
在极寒冷的气候条件中——亦即最需要热量之时——热泵却最不能提供充分的热量。
17.Theprimarypurposeofthepassageisto(全文主旨题,从TS、SE上看,首先提出一个问题,然后解释heatpumps的工作原理,再给出其缺陷)
A.explainthedifferencesintheworkingofaheatpumpwhentheoutdoortemperaturechanges(片面)
B.contrasttheheatingandthecoolingmodesofheatpumps(文章未提)
C.describeheatpumps,theiruse,andfactorsaffectingtheiruse
D.advocatethemorewidespreaduseofheatpumps(文章未提)
E.exposeextravagantclaimsaboutheatpumpsasfalse(与原文相反)
答案:
(C)
18.Theauthorresolvesthequestionofwhetherheatpumpsruncountertotheprincipleofenergyconservationby(细节题)
A.carefullyqualifyingthemeaningofthatprinciple(文章未提)
B.pointingoutafactualerrorinthestatementthatgivesrisetothisquestion(文章未提)
C.supplyingadditionalrelevantfacts(文章第二段解释heatpumps的工作原理)
D.denyingtherelevanceofthatprincipletoheatpumps(文章未提)
E.explainingthatheatpumpscancool,aswellasheat,roomair(片面)
19.Itcanbeinferredfromthepassagethat,inthecourseofaheatingseason,theheatingcapacityofaheatpumpisgreatestwhen(推理题,定位L53~55:
Theheatingcapacityofaheatpumpdecreasesastheoutdoortemperaturefalls.室外温度下降,热泵能力下降,因此,室外温度上升,热泵能力也上升;
热泵能力最高也就是室外温度最高的时候,即最不需要热量的时候。
定位L74~78取非,Here,then,liesagenuinedrawbackofheatpumps:
inextremelycoldclimates—wherethemostheatisneeded—heatpumpsareleastabletosupplyenoughheat.)
A.heatingisleastessential
B.electricityratesarelowest
C.itscompressorrunsthefastest
D.outdoortemperaturesholdsteady
E.theheatingdemandsurges
(A)
20.Iftheauthor'
sassessmentoftheuseofheatpumps(lines1-8)iscorrect,whichofthefollowingbestexpressesthelessonthatadvertisersshouldlearnfromthiscase?
(推理题,定位L47~51,No,notevenremotely:
theadditionalinputofthermalenergyintothecirculatingrefrigerantviatheevaporatoraccountsforthedifferenceintheenergyequation.顾客之所以怀疑,是因为对heatpump的工作机理不了解)
A.Donotmakeexaggeratedclaimsabouttheproductsyouaretryingtopromote.(没有夸大)
B.Focusyouradvertisingcampaignonvagueanalogiesandveiledimplicationsinsteadofonfacts.(不是问题的根源)
C.Donotusefactsinyouradvertisingthatwillstraintheprospectiveclient'
sabilitytobelieve.
D.Donotassumeinyouradvertisingthattheprospectiveclientsknoweventhemostelementaryscientificprinciples.(本文的顾客虽然知道能量守恒,但不知道heatpump的具体工作机理,从而导致的怀疑)
E.Concentrateyouradvertisingfirmlyonfinanciallyrelevantissuessuchaspricediscountsandefficiencyofoperation.(文章未提)
21.Thepassagesuggeststhatheatpumpswouldbeusedmorewidelyif(缺陷题,定位L47~51,No,notevenremotely:
theadditionalinputofthermalenergyintothecirculatingrefrigerantviatheevaporatoraccountsforthedifferenceintheenergyequation.正是因为顾客不了解evaporator的作用,所以怀疑这个广告)
A.theycouldalsobeusedasairconditioners(文章未提)
B.theycouldbemovedaroundtosupplyheatwhereitismostneeded(问题的关键不是heatpumps的缺陷,而是人们怀疑广告)
C.theirheatoutputcouldbethermostaticallycontrolled(问题的关键不是heatpumps的缺陷,而是人们怀疑广告)
D.modelswithtrulysuperiorcoolingcapacitywereadvertisedmoreeffectively(文章未提)
E.peopleappreciatedtheroleoftheevaporatorintheenergyequation
(E)
22.Accordingtothepassage,theroleoftheflowrestriction(line22)inaheatpumpisto(给定行数题,定位L20~26,Nowtherefrigerant,asahigh-pressure,cooledliquid,confrontsaflowrestrictionwhichcausesthepressuretodrop.Asthepressurefalls,therefrigerantexpandsandpartiallyvaporizes,becomingchilled.)
A.measureaccuratelytheflowrateoftherefrigerantmassatthatpoint(文章未提)
B.compressandheattherefrigerantvapor
C.bringabouttheevaporationandcoolingofrefrigerant
D.exchangeheatbetweentherefrigerantandtheairatthatpoint(定位L26~29,Itthenpassesthroughasecondheat
exchanger,theevaporator,whichtransfersheatfromtheairtotherefrigerant,不是flowrestriction的作用)
E.reversethedirectionofrefrigerantflowwhenneeded(定位L36~40,Theflowdirectionofrefrigerant
throughaheatpumpiscontrolledbyvalves.Whentherefrigerantflowisreversed,theheatexchangersswitchfunction.)
(C)
23.Theauthorregardsthenotionthatheatpumpshaveagenuinedrawbackasa(态度题,定位L52~53,Unfortunately,thereisonerealproblem.)
A.causeforregret
B.signofprematuredefeatism
C.welcomechallenge
D.caseofsloppythinking
E.focusforaneducationalcampaign
(A)
AllofFrancoiseDupare'
ssurvivingSE、F-D
paintingsblendportraitureandgenre.
Hersubjectsappeartobeacquaintances
whomshehasaskedtopose;
shehas
(5)capturedboththeirself-consciousness
andthespontaneityoftheireveryday
activities,thedepictionofwhich
characterizesgenrepainting.ButgenreSE、转折
painting,especiallywhenitportrayed
(10)membersofthehumblestclasses,was⊙
neverpopularineighteenth-centuryFran-18-c-F
ce.TheLeNainbrothersandGeorgesL=G
deLaTour,whoalsochosesuchthemes,
werelargelyignored.Theirpresent
(15)highstandingisduetoadifferent,moreSE、特殊短语,≠,>
democraticpoliticalclimateandto
differentaestheticvalues:
wenolonger≠
requireartiststoprovideidealimages
ofhumanityforourmoraledification
(20)butratherregardsuchidealizationasa﹥﹤
falsificationofthetruth.Duparcgives
noimprovingmessageanddiscreetly
refrainsfromjudginghersubjects.In
brief,herworksneithereleva
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