简介:Theeffectsofisothermalholdingprocessonthemicrostructureevolutionofsemi-solid7075strengthaluminumalloyproducedbytherecrystallisationandpartialremelting(RAP)processwereinvestigated.Tensilemechanicalpropertiesofas-receivedandthixoformedalloysatroomtemperaturewereexamined.Theresultsshowthatthemicrostructureofas-receivedalloyexhibitsremarkableorientationalongthedeformationdirection.Withtheincreaseofisothermalholdingtime,thesolidparticlegrainsizecontinuouslyincreasesandthedegreeofspheroidizationalsoimproves.Coalescencemechanismisdominantwhenreheatedat595°CandOstwaldripeningmechanismisdominantwhenreheatedat615°Cinthesemi-solidstate.Alowercoarseningrateisobservedfor615°C(coarseningrateK=391μm3s-1)comparedwiththecoarseningratefor595°C(coarseningrateK=501μm3s-1).TheRAP7075aluminumalloycanbesuccessfullythixoformedandthefillingofcomponentsisgoodafterthixoforming.Thethixoformedcomponentsexhibitfavoritemechanicalproperties.
简介:CSIR-RCS的灵活性,与使过程凉下来的同时的空气激动人心的正式就职,在有高压力的联合死扔被在广告2024,6082和7075上执行的盘子的半固体rheocasting成功地表明做铝合金。张力的性质为在T6的铝合金调节的做的上述提及的rheocast被测量。结果证明张力的性质接近了或甚至在一些情况中超过了最小的说明。rheocast2024-T6的收益力量和延伸超过了最小的要求做处于T6条件的合金但是因为开始的合金的Mg内容在商业合金说明下面,最终的张力的力量仅仅完成了90%说明。rheocast6082-T6的力量超过了所有做合金T6力量目标但是延伸仅仅由于孔管理了36%要求的最小,由在好金属间化合的针的答案热处理,和存在期间的早期的融化在引起了最容易溶解。7075超过了的rheocast的收益力量要求的和最终的张力的力量也管理了97%说明;当延伸仅仅由于在解决方案热处理进程期间引起的早期的融化的孔也到达了46%最小的要求时。
简介:Dynamicfluid-solidinteractionsarewidelyfoundinchemicalengineering,suchasinparticle-ladenflows,whichusuallycontaincomplexmovingboundaries.Theimmersedboundarymethod(IBM)isaconvenientapproachtohandlefluid-solidinteractionswithcomplexgeometries.Inthiswork,Uhlmann’sdirect-forcingIBMisimprovedandimplementedonasupercomputerwithCPU-GPUhybridarchitecture.Thedirect-forcingIBMismodifiedasfollows:thePoisson’sequationforpressureissolvedbeforeevaluationofthebodyforce,andtheforceisonlydistributedtotheCartesiangridsinsidetheimmersedboundary.Amultidirectforcingschemeisusedtoevaluatethebodyforce.Thesemodificationsresultinadivergence-freeflowfieldinthefluiddomainandtheno-slipboundaryconditionattheimmersedboundarysimultaneously.Thismethodisimplementedinanexplicitfinite-differencefractional-stepscheme,andvalidatedby2Dsimulationsoflid-drivencavityflow,Couetteflowbetweentwoconcentriccylindersandflowoveracircularcylinder.Finally,themethodisusedtosimulatethesedimentationoftwocircularparticlesinachannel.Theresultsagreeverywellwithpreviousexperimentalandnumericaldata,andaremoreaccuratethantheconventionaldirect-forcingmethod,especiallyinthevicinityofamovingboundary.
简介:扔的near-liquidus准备的6061件半固体铝合金化工物品借助于Gleeble-3500热机械的模拟器处于半固体状态被压缩。在在不同温度和紧张率的真压力和真紧张之间的关系与70%的变丑度被学习。微观结构在变丑过程期间被描绘。半固体合金的变丑机制和形成thixo性质被分析。结果证明同类并且6061Al合金由扔技术的near-liquidus生产了的半固体的非树突微观结构能与对与通过再热的最容易溶解的作文在球形附近的谷物和液体阶段镇静的形成thixo合适的微观结构被转变成半固体状态过程。变丑温度和紧张率显著地影响山峰压力而非稳定流动应力。到处于半固体状态的变丑的抵抗随变丑温度的增加和紧张率的减少减少。在稳定的thixotropic变丑舞台,thixotropic性质是一致的,并且主要变丑机制是在稳固的粒子和稳固的粒子的塑料变丑之间旋转或滑动。
简介:Thewaterintakeheadinstalledwithinclinedboardingsiscalledlaminatesedimentprecipitation,whichseparatesliquidandsolidparticlesintwo-phaseflowbygravity.ThepaperpresentstheequationsforcalculatingthedistanceHbetweentwoincllinedboardings,indicatingthatHhasakeyeffectontheparticleprecipitationvelocityV2.Thepaperfocusesalsoonthecal-culationofhydraulicsimilarityofmodelwiththetheoreticmodel.
简介:【摘 要】非标自动化设备定制是一种需要根据用户需求定制设备的供应模式,该模式往往没有既有的模型和数据作为基础支持,需要根据用户的需求不断调整设计数据,双方不断达成沟通,最终完成设计生产。非标自动化设备供应涉及到大量的数据交互和责权划分等问题,传统的信息交互模式存在较多的弊端,对此,在非标自动化设备行业中应用SOLID WORKS PDM系统便有了很好的基础空间。
简介:Densegas-particleflowsareencounteredinavarietyofindustriallyimportantprocessesforlargescaleproductionoffuels,fertilizersandbasechemicals.Thescale-upoftheseprocessesisoftenproblematicandisrelatedtotheintrinsiccomplexitiesoftheseflowswhichareunfortunatelynotyetfullyunderstooddespitesignificanteffortsmadeinbothacademicandindustrialresearchlaboratories.Indensegas-particleflowsboth(effective)fluid-particleand(dissipative)particle-particleinteractionsneedtobeaccountedforbecausethesephenomenatoalargeextentgoverntheprevailingflowphenomena,i.e.theformationandevolutionofheterogeneousstructures.Thesestructureshavesignificantimpactonthequalityofthegas-solidcontactandasadirectconsequencethereofstronglyaffecttheperformanceoftheprocess.Duetotheinherentcomplexityofdensegas-particlesflows,wehaveadoptedamulti-scalemodelingapproachinwhichbothfluid-particleandparticle-particleinteractionscanbeproperlyaccountedfor.Theideaisessentiallythatfundamentalmodels,takingintoaccounttherelevantdetailsoffluid-particle(latticeBoltzmannmodel)andparticle-particle(discreteparticlemodel)interactions,areusedtodevelopclosurelawstofeedcontinuummodelswhichcanbeusedtocomputetheflowstructuresonamuchlarger(industrial)scale.Ourmulti-scaleapproach(seeFig.1)involvesthelatticeBoltzmannmodel,thediscreteparticlemodel,thecontinuummodelbasedonthekinetictheoryofgranularflowandthediscretebubblemodel.Inthispaperwegiveanoverviewofthemulti-scalemodelingstrategy,accompaniedbyillustrativecomputationalresultsforbubbleformation.Inaddition,areaswhichneedsubstantialfurtherattentionwillbehighlighted.
简介:Endoscopicultrasonography-guidedfine-needleaspiration(EUS-FNA)hasbeenappliedtopancreaticobiliarylesionssincethe1990sandisinwidespreadusethroughouttheworldtoday.Weusedthismethodtoconfirmthepathologicalevidenceofthepancreaticobiliarylesionsandtoperformsuitabletherapies.ComplicationsofEUS-FNAarequiterare,butsomeofthemaresevere.OperatorsshouldmasterconventionalEUSobservationandexperienceaminimumof20-30casesofsupervisedEUS-FNAonnon-pancreaticandpancreaticlesionsbeforeattemptingsoloEUSFNA.StudiesconductedonpancreaticobiliaryEUSFNAhavefocusedonselectionofsuitableinstruments(e.g.,needleselection)andsamplingtechniques(e.g.,fanningmethod,suctionlevel,withorwithoutastylet,optimumnumberofpasses).Today,thediagnosticabilityofEUS-FNAisstillimproving;thedetectionofpancreaticcancer(PC)currentlyhasasensitivityof90%-95%andspecificityof95%-100%.InadditiontoPC,avarietyofrarepancreatictumorscanbediscriminatedbyconductingimmunohistochemistryontheFNAmaterials.Aflexible,largecaliberneedlehasbeenusedtoobtainalargepieceoftissue,whichcanprovidesufficienthistologicalinformationtobehelpfulinclassifyingbenignpancreaticlesions.EUSFNAcansupplyhighdiagnosticyieldsevenforbiliarylesionsorperi-pancreaticobiliarylymphnodes.ThisreviewfocusesontheclinicalaspectsofEUS-FNAinthepancreaticobiliaryfield,withtheaimofprovidinginformationthatcanenablemoreaccurateandefficientdiagnosis.
简介:Experimentswereconductedtoinvestigatetheeffectofaddingfinesonthetribo-chargingofcoarseglassbeads.Fourtypesoffines,i.e.,copper,stainlesssteel,uncoatedandsilver-coatedfineglassbeads,mixedw让h240-830μmglassbeadswereconveyedbyairthroughastainless-steelspiralpipeactingasatribo-charger.Regardlessofthetypeorelectricalconductivityofthefineparticlestested,addingsmallamountsoffines(upto10wt%)tocoarseglassbeadsresultedinasharpincreaseinthemassandsurfacechargedensitiesoftheparticles.Ingeneral,theprofilesofthemassandsurfacechargedensidesofthefine-coarseparticlemixturesasafunctionofthemixturecompositionweredeterminedbytherelativemagnitudeofcontactpotentialdifferencesandthetotalsurfaceareasofallthecomponents.Thedominantparticletribo-electrificationmechanismswitchedfromcoarseparticle-wallcontactstofineparticle-wallcontactswhenthefinesweightpercentageinthemixtureexceeded10%.Amodelwasdevelopedtopredictthemasschargedensityofbinarymixturesasafunctionofthemixturecomposition.
简介:EthylN-cyanomethytbenzenecarboximidatereactedwithaliphaticaldehydesunderthesolid-liquidPTCconditiontogirea-ethoxyphenylmethylene-aminoacrylonitrilederivativesandoxazolinederivatives.Itisaconvenientandnewmethodforsynthesisofβ,β’-dihyroxy-a-aminoacidsbyhydrolysisoftheoxazolinederivatives.
简介:Thepresentpaperdescribesthestatisticalmodelingandoptimizationofamultistagegas-solidfluidizedbedreactorforthecontrolofhazardouspollutantsinfluegas.Inthiswork,westudythehydrodynamicsofthepressuredropandminimumfluidizationvelocity.Thehydrodynamicsofathree-stagefluidizedbedarethencomparedwiththoseforasingle-stageunit.Itisobservedthatthetotalpressuredropoverallstagesofthethree-stagefluidizedbedislessthanthatofanidenticalsingle-stagesystem.However,theminimumfluidizationvelocityishigherinthesingle-stageunit.Underidenticalconditions,theminimumfluidizationvelocityishighestinthetopbed,andlowestinthebottombed.Thissignifiesthatthebehaviorofsolidschangesfromawell-mixedflowtoaplug-flow,withintermediatebehaviorinthemiddlebed.
简介:Wedevelopatheoreticalmodelforpredictingtheultrasonicattenuationintheliquid-solidsystemcontainingmixedparticles.Theultrasonicattenuationcoefficientisobtainedbycountingthenumberofphononsthatreachthereceiver.UsingtheMonteCarlomethod(MCM),numericalsimulationswereperformedtopredicttheultrasonicattenuationswithnotonlyasingleparticletypebutalsomonodisperseandpolydispersemixedparticles.Thesimulationresultsforthesystemswithasingleparticletypewerecomparedwithvariousstandardmodels.Theresultsshowthattheyagreewellatrelativelylowparticlevolumeconcentrations(within10%).Forsystemswithmixedparticles,theparticlevolumeconcentrationwasfoundtoincreasetoaround10%,andthevariationoftheultrasonicattenuationagainstthemixingratioyieldsanonlineartrend.Moreover,theultrasonicattenuationissignificantlyaffectedbyparticleproperties.Thenumericalresultsalsoshowthatboththeparticletypeandparticlesizedistributionshouldbecarefullytakenintoaccountinthedispersionswithpolydispersemixedparticles,wheretheMCMcangiveamoredirectdescriptionofthephysicsofsoundpropagationcomparedwiththeconventionalmodels.
简介:Quasi-solid-statedye-sensitizedsolarcells(DSCs)werepreparedusinggelelectrolytegelatedbypoly(ethylene-oxide)(PEO)withdifferentmolecularweight.WiththeincreaseinPEOmolecularweight,theshortcircuitcurrentdensities(Jsc)increasesignificantly,whichisrelatedtotheincreaseinI-diffusionduetotheincreaseinfreevolumeofgelelectrolyte.However,onlyaslightincreaseinopenvoltage(Voc)isobserved,whichisexplainedbythedecreaseindarkcurrentarisingfromthereductionoftriiodide(I3-)byconductionbandelectrons.
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简介:Wepresentthesolidmodeleditdistance(SMED),apowerfulandflexibleparadigmforexploitingshapesimilaritiesamongstCADmodels.ItisdesignedtomeasurethemagnitudeofdistortionsbetweentwoCADmodelsinboundaryrepresentation(B-rep).Wegivetheformaldefinitionbyanalogywithgrapheditdistance,oneofthemostpopulargraphmatchingmethods.Toavoidtheexpensivecomputationalcostpotentiallycausedbyexactcomputation,anapproximateprocedurebasedonthealignmentoflocalstructuresetsisprovidedinaddition.Inordertoverifytheflexibility,wemakeintensiveinvestigationsonthreetypicalapplicationsinmanufacturingindustry,anddescribehowourmethodcanbeadaptedtomeetthevariousrequirements.Furthermore,amultilevelmethodisproposedtomakefurtherimprovementsofthepresentedalgorithmonbotheffectivenessandefficiency,inwhichthemodelsarehierarchicallysegmentedintotheconfigurationsoffeatures.ExperimentresultsshowthatSMEDservesasareasonablemeasurementofshapesimilarityforCADmodels,andtheproposedapproachprovidesremarkableperformanceonareal-worldCADmodeldatabase.