2025年四川大学化工专业考研复试英语面试题库及答案解析汇编

1.Whenafluidflowsthroughaductoroverasurface,thevelocityoveraplaceat

rightanglestothestreamisnotnormallyuniform.Thevariationofvelocitycanbeshov/nby

theuseofstreamlineswhicharelinessodrawnthatthevelocityvectorisalwaystangential

tothem.Theflowratebetweenanytwostreamlinesisalwaysthesame.Constantvelocity

overacross-sectionisshownbyequidistantstreamlinesandincreaseinvelocitybycloser

spacingofstreamlines.

2.Itisfoundtheheattransferrateperunitareaqisdependentonthosephysical

propertieswhichaffectflowpattern.Thethermalpropertiesofthefluidandthevelocityof

flowthefluidoverthesurface,thetemperaturedifferencetandafactordeternmingthe

naturalcirculationeffectcausebyexpansionofthefluidonheating.

3.Theoildistilledinaverylargesteeltower,thetechnicalnamesofwhichisthe

fractionatingtower.Thetoweristhirtytofiftymeterstallanditsdiameterisonetothree

meters.Itisdividedintochambers,eachofwhichcontainsalayeroftrays.Thereareholesin

thetrays.Thechanbersareatdifferentheights,andtemperatureateachheightisdifferent.

4.Agroupofoperationforseparatingthecomponentsofmixtureisbasedonthe

transferofmaterialfromonehomogeneousphasetoanther.Unlikepurelymechanical

separation,thesemethodsutilizedifferencesinvaporpressureorsolubility,notdensityor

particlesize.Thedrivingforcefortransferisaconoantrationdiffercetooraconcentration

gradient,muchasatemperaturedifferenceoratemperaturegradientprovidesthedriving

forceheattransfer.

5.Thethreemostimportantcharacteristicsofanindividualparticleareits

composition,itssizeanditsshape.Compositiondeterminesuchpropertiesasdensityand

conductivity,providedthattheparticleiscompletelyuniform.Aparticleshapemaybe

regularsuchassphericalorcubic,oritmaybeirregularas,forexample,withapieceof

brokenglass.

6.homogeneouscatalysisistheindustricaloxoprocessformanufacturingnormal

iosobuty（异丁醛）。Ahomogeneouscatalysispressinvolvemorethanonephase,usually

thecatalystisasolidandthereactantsandproductsareinliquidorgaseousform.

7.Whenthevaporsriseintothecoolerpartofthefractionatingtower;theylose

heat,thevaporsriseuntiltheyarejustbelowtheirownboilingtemperature.thenthey

condenseonatrayandturnintoaliquidagain.Theliquidoneachtrayflowsintoaseparate

smalltowerwheretheliquidbreaksdownintosmallerfractions.Theseparationofthe

hydrocarbonsismoreaccurate.

8.Thefunctionofdistillationistoseparate,byvaporization,aliquidmixtureof

miscible,andvolaulesubstancesintoindividualcomponentsor,insomecases,intogroups

ofcomponents,theseparationofamixtureofalcoholandwaterintoitscomponentofliquid

nitrogen,oxygenandargon,andofcrudepetroleumintogasoline,kerosence,fueloil,and

lubricationstockareexamplesofdistillation.

9.Forthepumpingofliquidsorgasesfromonevesseltoanotherorthroughlong

pipes,somefromofmechanicalpumpisusuallyemployed.Theenergyrequirebythepump

willcependontheheightthroughwhichtheliquidsraised,thepressurerequiredatdelivery

point,thelengthanddiameterofthepipe,therateofflow,togetherwiththephysical

propertiesoftheliquid,particularlyitsviscosityanddensity.

10.Inthemajorityofchemicalprocesses,heatiseithergivenoutorabsorbed,and

fluidsmustoftenbeheatedorcooleinawiderangeofplant,suchasfurnaces,evaporates,

distillationunits,dryers,andreactionvesselswhereoneofthemajorproblemsisthatof

transferringheatatthedesiredrate.Inaddition,itmaybenecessarytopreventthelossof

heatatthedesiresrateformsoneofthemostimportantareasofchemicalengineering.

11.membranesciencehasreachedmaturity,andtheseparationprocesses,whichare

basedonthetechnologiesthatithasspawned,arenowcommonplace.Theycoversuch

widerangingapplicationasmicrofiltration,reserveosmosis,gasseparation,theartificial

kidneyandcontrolled-releasepharmaceuticals,andtheyareusedextensivelyinindustry,

medicineandtoprotecttheenvironment

12.Theremovalofoneormoreselectedcomponentsfromamixtureofgasesby

absorptionintoasuitableliquidisthesecondmajoroperationofchemicalengineeringthat

isbasedoninterphasemasstransfercontrolledlargelybyratesofdiffusion.Thus,acetone

canberecoverdfromanacetone-airmixturebtpassingthegasstreamintowaterinwhich

theacetonedissolveswhiletheairpassesout.

13.Evaporationisachievedbyaddingheattothesolutiontovaporisethesolvent.

Theheatissuppliedprincipallytoprovidethelatentheatcfvaporization,and,byadopting

methodsforrecoveryofheatfrcmthevepor,ithasbeenpossibletoachievegreateconomy

inheatutilization.Whilstthenormalheatingmediumisgenerallylowpressureexhaust

steamfromturbines,specialheattransferfluidsorfluegasesarealsoused.

14.Manyorganicliquidarepurifiedbycrystallizationratherthanbydistillationsince

enthapiesofcrystallizationaregenerallymuchlowerthanenthalpiesofvaporizationand

caystallizationmaybecarrieoutclosertoambienttemperaturetherebyreducingenergy

requirements.Againstthis,crasrallizationisrarelythelaststageinaprocessandsolvent

separation,washinganddryingstagesareusuallyrequired.

15.Theseparationofliquidmixtureintotheirvariouscomponentisoneofthemajor

operationsintheprocessindustries,anddistillation,themostwidelyusedmethodof

achievingthisend,isthekeyoperatinginandoilrefinery.Inprocessing,thedemandfor

purerproduct,coupledwiththeneedforgreatereffiency,haspromotedcontinuedresearch

intothetechniquesofdistillation.

16.Thisistheclassicreatorusedbyorganicchemists.Thetypicalvolumein

glasswareisafewhundredmilliliters.Reactantsarechargestothesystem,rapidlymixed,and

repidlybroughtuptotemperaturesothatreactionconditionsarewelldefined.Heatingis

carriedoutwithanoilbathoranelectricheatingmantle.Mixingiscarriedoutwitha

magneticstirrerorasmallmechanicalagitator.Temperatureiscontrolledbyregulationthe

temperatureorbyallowingasolventtoreflux.

17.Inabatchreatorallmoleculesenterandleavetogether.ifthesystemsis

omermal,reactionyieldsdependonlyontheelapsedtimeandontheinitialcomposition,the

situationinflowsystemismorecomplicatebutnotimpossiblyso.Thecounterpartcfthe

batchreactiontimeistheageofamolecule.Agingbeginswhenamoleculeentersthe

reactorandceseswhenitleaves,thetotaltimespentwithintheboundariesofthereactionis

knownastheexitage,orresidencetime.

18.Severalpossiblemechanismshavebeensuggestedasthecauseofcrystal

nucleationfromasupersaturatedsolution.Threerecognizednucleationprocesses

are(l)homogeneousnucleation,whichoccursspontaneouslyanddoesnotrequirethe

presenceofsurfacesofanykind;(2)heterogeneousnuclestion,usuallypromptedbythe

presenceofacrystallinephaseofthesolutematerial.

19.Enzymesarenature1scatalysts.Forthemomentitissufficienttoconsideran

enzymeasalargeprotein,thestructureofwhichresultsinaveryshape-specificactivesite.

Havingshapethatareoptimallysuitedtoguidereactantmolecules(usuallyreferredtoas

substrates)intheoptimumconfigurationforreaction,enzymesarehighltspecialand

efficientcatalysts.

20.Environmentalcatalysisisprojectedtogrowfasterthananyothersegmentofthe

catalystmarketinthenext20years.Thisgrowthwillcomebothfromtraditionalareas,such

asemissionstreatment,andfromnewareasthatrangefromtheautomotiveindustryto

pharmaceuticals.Tosustainthisgrowthandtomeetmorestringentenvironmentdemands,

researcherswillrequireever-increasingcontrolandunderstandingofcatalyticmaterialand

processesatthemolecularlevel.

21.Processengineeringdesignistheappllicationofchemical,mechanical,petroleum,

gasandotherengineeringtalentstotheprocess-relateddevelopment,planning,designs

anddecisionsrequiresforeconomicalandeffectivecompletionofaprocessproject.

Although!processdesignengineersareorganizationallylocatedinresearch,technical

service,wconomicevaluation,theusualarrangementistohavethemavailabletothe

engineeringgroupsconcernedwithdevelopingtheengineeringdetailsofaproject.

22.Compressorsareusedforprovidinggaspressurerequiredtotransortgaswith

pipelinesandtoliftoilingas-liftoperations.Thecompressorsusedintoday'snaturalgas

productionindustyfallintotwodistincttypes:reciprocatingandrotarycompressors.

Reciprocatingcompressorsaremostcommonlyusedinthenaturalgasindustry.Theyare

builtforpracticallyallpressuresandvolumetriccapacities.

23.Hydrocarbonsconstitutetheessentialcomponentsofpetroleum,theirmolecules

containonlycarbonandhydrogen;theyaregroupedintomanychemicalfamiliesaccoringto

theirstructure.Allstruct