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  • 简介:Nanoparticulate流动发生在大量自然现象和工程应用程序并且因此,吸引了许多注意。现在的论文的目的是提供在最后十年进行的研究的评论。盖住的研究在管子和隧道中由于凝结联系粒子,时刻的Taylor系列扩大方法,和nanoparticle分布到monodisperse和polydisperse的Brownian凝结流动,喷气流动,和混合的层并且在火焰合成和免职的过程。

  • 标签: 纳米颗粒 凝固 流动 综述 泰勒级数展开 自然现象
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  • 简介:TheEffectofWeakShear-inducedMotiononBrownianCoagulationofAerosolParticlesWinjingsons(C.S.Win)(温景嵩)(Departmentofphysics,Nankai...

  • 标签: AEROSOL dynamics COAGULATION Peclet number
  • 简介:TheevolutionequationsofmomentsfortheBrowniancoagulationofnanoparticlesinbothcontinuumandfreemoleculeregimesareanalyticallystudied.TheseequationsarederivedusingaTaylor-expansiontechnique.Theself-preservingsizedistributionisinvestigatedusinganewlydefineddimensionlessparameter,andtheasymptoticvaluesforthisparameteraretheoreticallydetermined.Thedimensionlesstimerequiredforaninitialsizedistributiontoachieveself-preservationisalsoderivedinbothregimes.Oncethesizedistributionbecomesself-preserving,thetimeevolutionofthezerothandsecondmomentscanbetheoreticallyobtained,anditisfoundthatthesecondmomentvarieslinearlywithtimeinthecontinuumregime.Equivalentequations,ratherthantheoriginalonesfromwhichtheyarederived,canbeemployedtoimprovetheaccuracyoftheresultsandreducethecomputationalcostforBrowniancoagulationinthecontinuumregimeaswellasthefreemoleculeregime.

  • 标签: 泰勒展开法 布朗粒子 凝聚方程 渐近行为 瞬间 无量纲参数
  • 简介:ACFDsimulationisperformedforaparticle-ladenplanarjetflow.TheReynoldsnumberis8300,andtheinitialparticlediameteris1μm.LargeEddySimulation(LES)isemployedtocalculatetheflowfield,andtheTaylor-seriesexpansionmomentmethod(TEMOM)isadoptedtodealwiththebalanceequationofparticlecoagulationandbreakage.Theshear-inducedcoagulationkernel,power-lawbreakagekernelandsymmetricfragmentdistributionfunctionareinvolved.Thepredictionofthedistributionofthemeanstreamwisevelocityofthejetisingoodagreementwithexperimentaldata.Theevolutionofparticlenumberconcentration,volumeconcentration,polydispersity,particlediameterandstandardgeometricdeviationisdiscussedindetail.Theresultsshowthatasthejettravelsdownstream,theparticlenumberconcentrationandvolumeconcentrationdecrease,whiletheirspansbecomewider.Thepolydispersityandparticlediameterareverylargeintheshearlayersattheupstreamandinthecoreofvortexstructuresatthedownstream.Theparticlestandardgeometricdeviationchangeswithintherangeof1.32≤σg≤1.96,andincreasessharplyintheshearlayers.Allvariablesapproachthesteady-stateastimeprogresses.

  • 标签: 粒子数浓度 射流流量 平面射流 剪切层 大小分布 破损
  • 简介:Theroleofpulseparametersonnanoparticlepropertyisinvestigatedself-consistentlybasedonacoupleoffluidmodelandaerosoldynamicsmodelinacapacitivelycoupledparallel-plateacetylene(C2H2)discharge.Inthismodel,themasscontinuityequation,momentumbalanceequation,andenergybalanceequationforneutralgasaretakenintoaccount.Thus,thethermophoreticforceariseswhenagastemperaturegradientexists.Thetypicalresultsofthismodelarepositiveandnegativeiondensities,electronimpactcollisionsrates,nanoparticledensity,andchargedistributions.Thesimulationisperformedfordutyratio0.4/0.7/1.0,aswellaspulsemodulationfrequencyfrom40kHzto2.7MHzforpureC2H2dischargesatapressureof500mTorr.Wefindthatthepulseparameters,especiallythedutyratio,haveagreataffectonthedissociativeattachmentcoefficientandthenegativedensity.Moreimportantly,bydecreasingthedutyratio,nanoparticlesstarttodiffusetothewall.Undertheactionofgasflow,nanoparticledensitypeakiscreatedinfrontofthepulseelectrode,wherethegastemperatureissmaller.

  • 标签: 脉冲参数 C2H2 纳米颗粒 凝固模拟 电容耦合 自放电
  • 简介:BackgroundAdvancedpracticenursetransitionalcarehasbeenproofedtobeimportantforolderadultswithchronicconditions.However,sucheffectivenesshasneverbeenstudiedinthemanagementofappropriateWarfarinuseinclinicalpractice.MethodsAtotalof97patientswererandomlydistributedintocontrolgroupwhoreceivedusualcare,andinterventionalgroupwhoreceivedtransitionalcareprovidedbyAPNs.A12-monthobservationofbothgroupswererecordedbyphysiciansandAPNsandtheimpactofAPNsonthemanagingofWarfarintherapywasalsoevaluatedbasedontimeinthetherapeuticrange(TTR).ResultsAPNstransitionalcaresignificantly(P<0.01)improvedpatients’adherence,increasedTTRandhighTTRratiocomparedwithcontrolgroup.Re-admissionduetostrokewassignificantly(P<0.01)reducedbyAPNstransitionalcare.ConclusionAPNstransitionalcareimprovespatients’knowledgeonAFandreducesstrokerisk.ThecurrentresearchstronglysuggestthenecessityofAPNstransitionalinterventionalinmanaginganticoagulationtherapyinAFpatientsinChina.

  • 标签: 中国南方 过渡性 治疗 患者 抗凝 房颤