简介：

简介：usedto是英语中一个常见的短语,用于表示过去存在而今不复存在的习惯行为或状态,意为:“过去常常”。它在应用中具有以下特点:一,usedto只有一种形式即过去式,且可用于所有人称(包括存在句或无人称句)。例如:

简介：would与usedto都可用来表示过去经常发生的动作，常常可以互相换用。例如：

简介：Aseriesofmodifiedpoly(methylmethacrylate,PMMA)resinswerepreparedandcomparedtheiradsorptionabilitiestoendotoxin.Theresultsshowedthatadsorbents,whichweregraftedwithtertiaryamineandlongspacingarms,hadthebestadsorptioncapacitiesandgoodbloodcompatibility,Itishopefultobeusedasadsorbentinhemoperfusionforclinicalclearanceofendotoxin.Theinfluenceoforiginalconcentrationofendotoxinonadsorptionandtheadsorptionmechanismwerealsoinvestigated.

简介：1、usedto读作／ju：stu／，它后接动词原型，表示过去习惯的动作或经常出现的状态，常常用来对比过去或现在，说明过去的动作或状态现已不再继续存在了，它只能用于一般过去的，可用于所有的人称。

简介：“used”一词各词典的注音不尽相同,笔者据所见各例,大致归纳如下:1.used的基本读音为[ju:zd]如:Ahammerisusd[ju:zd]fordrivinginnails。锤用以敲钉子。Whenpersuasionfailedtheyusd[ju:zd]force。劝说失败时,他们就动武力。Hehasused[iu:zd]up-allhisstrength。他已经把所有的体力都耗尽了。

简介：一、would和usedto在提及过去一种习惯性动作时讲到具体时间,而这种习惯性动作在句子中没有显示与现在有直接或暗示的关系,那么would与usedto可互换。例如:OnSundayswhenIwasachildIwould/usedtogetupearlyandgofishing。Intheeveningtheoldmanwould/usedtogossipabouthisyouth。二、would和usedto主要区别在于:

简介：

简介：Inthepresentstudythemembranefoulinginmicrofiltrationusedforcellharvestinginadeadendsystemhasbeeninvestigated.experimentalresultswereanalysedintermsofexitingmembranefiltrationmodelsandmembraneresistances.Thecakefiltrationmodel(CFM)andstandardblockingmodel(SBM)havebeenconsideredinthisstudy.Variousmembraneresistancesweredeterminedatdifferentprocessingtime,feedconcentrationandstirringspeed.Resistancestopermeationinthissystemincludefiltermedium,poreblocking,adsorption,cakelayerandconcentrationpolarization.

简介：

简介：此篇有关比较usedto和would的用法的文章首先展示了含有“usedto+verb”和“would+verb”结构的语言材料，并提出了思考问题。然后是简结的归纳及巩固练习。建议老师把它作为一个课堂教学材料，那样会收到更好的教学效果。

简介：Thepropertiesandlowandmediumtem-peraturebondingmechanismsofvariedtypesofSiO2ultrafinepowderusedinceramicandrefractoryandthetemperatureatwhichSiO2ultrafinepowderbegantoreactwithAl2O3werestudied,AndinitialresearchesoneffectsofultrafinepowdersofAl2O3,SiC,3Al2o3·2SiO2,MgO·Al2O3andZrSiO4onpromotingsinteringweremade.TheresultsindicatedthatamongvarioustypesofSiO2ultrafinepowder,non-crystalsil-icaultrafinepowderwacharacterizedbyitsstructureandproperties,Itcouldyieldconsid-erablesilicagelonitssurfaceatlowtempera-ture,whichthendehydratedandformedSi-O-Sibond,therebydevelopinganettystructurethatcausedhigherbondstrengthatlowandmediumtemperaturesincethenettystructurebasicallyremperaturesincethenettystructurebasicallyreainedastermperturerising.SiO2ultrafinepowderbegantoreactwithAl2O3at700℃,Allofothertypesofultrafinepowderhadeffectsonstimulatingsintering,buttheeffectsweresignificantonlywhentheparticlesizeofultrafinepowderwaslessthan5μm。

简介：Non-destructivediagnosticmethodsareveryimportantforbeamadjustmentsandmonitors,especiallywhenthebeamintensityislessthan10~8ppsduringtheheavy-iontreatmentofcancer.NowthediagnosticdevicesofHIFRLcan’tsatisfytherequests,sowedecidetoconstructadetectingsystemoftheresidual-gasbeamprofile~([1,2]).ThesystemusesthePositionSensitiveDetector(PSD)~([3,4])basedonmicrochannelplate(MCP)to

简介：

简介：Inthispaper,theefficiencyof6kindsoffiltermaterials(polyesterfiber,cottonwool,celluloseacetate,polyvinylalcoholfiber,vinylonfiberandco-wovenfiber)spe-cificforleukocytedepletionfromredbloodcellswasevaluatedrespectively.Thedatademonstratedthatco-wovenfilterwasmosteffectiveintheremovalofleukocyte,fol-lowedbyvinylonfiber.Theleukocytedepletioncapacityandproprietyofco-wovenfibersdesignedforremovingleukocytefromwholebloodorredbloodcellconcen-

简介：Afixedlink(tunnelandbridge,intotal16km)wasconstructedbetweenSwedenandDenmarkduring1995-2000.Aspartofthework,approximately16milliontonnesofseabedmaterials(limestoneandclaytill)weredredged,andabout0.6milliontonnesofthesewerespilledinthewater.Modellingofthespreadingandsedimentationofthespilledsedimentstookplaceaspartoftheenvironmentalmonitoringoftheconstructionactivities.Inordertoverifytheresultsofthenumericalmodellingofsedimentspreadingandsedimentation,anewmethodwiththepurposeofdistinguishingbetweenthespilledsedimentsandthenaturallyoccurringsedimentswasdeveloped.Becausethespilledsedimentstendtoaccumulateattheseabedinareaswithnaturalsedimentsofthesamesize,itisdifficulttoseparatethesebasedpurelyonthephysicalproperties.Thenewmethodisbasedonthegeo-chemicaldifferencesbetweenthenaturalsedimentintheareaandthespill.ThebasicpropertiesusedarethehighercontentofcalciumcarbonatematerialinthespillascomparedtothenaturalsedimentsandthehigherCa/Srratiointhespillcomparedtoshellfragmentsdominatingthenaturalcalciumcarbonatedepositioninthearea.ThereasonforthesedifferencesisthatcarbonatederivedfromrecentshelldebriscanbediscriminatedfromDanienlimestone,whichisthematerialinwhichthemajorityofthedredgingtookplace,onthebasisoftheCa/Srratiobeing488inDanienLimestoneand237inshelldebris.Thegeochemicalrecognitionoftheoriginofthesedimentsprovedusefulinseparatingthespilledfromthenaturallyoccurringsediments.Withoutthisseparation,validationofthemodellingofaccumulationofspilledsedimentswouldnothavebeenpossible.Themethodhasgeneralvalidityandcanbeusedinmanysituationswheretheoriginoragivensedimentissought.

简介：Aclearlight-yellowsilversolwhichhasthevisiblespectralabsorptionat390nm,whenadsorbedphenylmercaptotetrazole(PMT)ormercaptobenzothiazole(MBT),hasanewabsorptionat510-550nm.ItwasfoundthattheadsorptionofhalideionscompeteswithPMTandMBT.However,halideionshaveacompletelydifferentinfluencefromPMTandMBTonthespectralabsorptionofthesilversol.Thedifferencesmayresultfromthechangeofthepropertiesofthesurfaceofthesilversubcolloidalparticlesandfromthebondformscombiningadsorbateswiththesubstrates.

简介：FUNCTIONSOFCELLSSCAFFOLDINTHETISSUEENGINEERINGCell,cellsscaffoldandtheconstructionoftissueandorganarethreemainfactorsfortheTissueEngineering.Amainfunctionofcellsscaffoldintissueengineeringistoprovideanenvironmentforcellspropagation.

简介：Inthispaper,severalmixtruerulesofsoundvelocityandtheirusefulnessincharacterizingthecomponentsofbiomediumareanalysed.Itispointedoutthatforcharacterizingthecomponentsofbiomedium,therulesarecompatiblewitheachotherundercertainconditions,andtheerrorsbetweeneachruleandrealsoundvelocityarediffferent.Itconcludesthatthereisnogeneralrulesuitableforvariousmediaamongabovementionedrules.

简介：AnelectroncyclotronresonanceheatingsystemwillbeconstructedinthenearfutureforECHandECCDinvestigationonHL-2Atokamak.ThenewECRHsystemwillprovideHL-2Awithapowercapabilityof1MWfor1satfrequencyof70GHz.Consequently,itisveryimportanttochooseasuitablegyrotronandsomecomponentsforHL-2AECRHsystem.