简介:这研究向动人的表面为三维的麦克斯韦液体集中于热和集体流动的Cattaneo-Christov理论。有可变热电导率的不可压缩的laminar流动被考虑。流动产生由于表的双向拉长。热和集体运输的联合现象被说明。热和集体散开的Cattaneo-Christov模型被用来开发精力和集体种类的表情。在集体种类方程的一阶的化学反应术语被考虑。边界层假设导致管理数学模型。homotopic模拟被采用设想无尺寸的流动方程的结果。速度,温度,和集中的图显示出不同产生参数的效果。一个数字基准被介绍设想计算结果的会聚的价值。结果证明集中和温度地为热和集体散开的Cattaneo-Christov理论被腐烂。
简介:Anewefficientmeshlessmethodbasedontheelement-freeGalerkinmethodisproposedtoanalyzethestaticdeformationofthinandthickplatestructuresinthispaper.Usingthenew3Dshell-likekinematicsinanalogytothesolid-shellconceptofthefiniteelementmethod,discretizationiscarriedoutbythenodeslocatedontheupperandlowersurfacesofthestructures.Theapproximationofallunknownfieldvariablesiscarriedoutbyusingthemovingleastsquares(MLS)approximationschemeinthein-planedirections,whilethelinearinterpolationisappliedthroughthethicknessdirection.Thus,differentboundaryconditionsaredefinedonlyusingdisplacementsandpenaltymethodisusedtoenforcetheessentialboundaryconditions.TheconstrainedGalerkinweakform,whichincorporatesonlydisplacementdegreesoffreedom(d.o.f.s),isderived.Amodified3Dconstitutiverelationshipisadoptedinordertoavoidoreliminatesomeself-lockingeffects.Thenumericefficiencyoftheproposedmeshlessformulationisillustratedbythenumericexamples.
简介:软事被观察异常粘性行为经常在声学的波浪繁殖由幂定律频率依赖者变细描绘了。最近的十年在为如此的异常粘性行为,礼品,作者们经由积极部分衍生物在哪个之中建议了修改Szabo的波浪方程开发各种各样的模型上见证快成长研究。学习是使用修改Szabo的波浪方程模仿一种最近的超声的成像技术的这的目的把临床的amplitudevelocity重建称为具有典型软织物事的胸肿瘤的成像(CARI)。调查在超声的医药成像的质量上在尺寸的效果和肿瘤的位置上被做了。它从数字结果被观察沿着思考的线的健全压力,它显示察觉结果,与尺寸和肿瘤的侧面的位置显然变化,但是几乎仍然是为不同轴的位置的一样。
简介:Inthispaper,weinvestigatetheglobalexistenceandlongtimebehaviorofstrongsolutionsforcompressiblenematicliquidcrystalflowsinthreedimensionalwholespace.TheglobalexistenceofstrongsolutionsisobtainedbythestandardenergymethodundertheconditionthattheinitialdataareclosetotheconstantequilibriumstateinH~2-framework.IftheinitialdatasinL~1-normarefiniteadditionally,theoptimaltimedecayratesofstrongsolutionsareestablished.WiththehelpofFouriersplittingmethod,onealsoestablishesoptimaltimedecayratesforthehigherorderspatialderivativesofdirector.
简介:Theboundaryelementmethodforthemodalanalysisoffreevibrationfor3-Danisotropicstructuresusingparticularsolutionshasbeendeveloped.Thecompletepolynomialsofordertwoareusedtoconstructtheparticularsolutionsforgeneralanisotropicmaterials.Thenumericalresultsfor3-Dfreevibra-tionanalysisofanisotropiecantileverbeambythemethodpresentedisingoodagreementwiththeresultsus-ingtheRitztechnique.Foranisotropicmaterials,thenumericalresultscalculatedfromtheproposedmethodareingoodagreementwiththeresultsfromMSC.NASTRAN.
简介:Amorphouscarbonandgrapheneco-modifiedLiFePO4nanocompositehasbeensynthesizedviaafacilepolyolprocessinconnectionwithafollowingthermaltreatment.Variouscharacterizationtechniques,includingXRD.Mossbauerspectra,Ramanspectra,SEM,TEM,BET,O2-TPO,galvanocharge-discharge,CVandEISwereappliedtoinvestigatethephasecomposition,carboncontent,morphologicalstructureandelectrochemicalperformanceofthesynthesizedsamples.TheeffectofintroducingwayofcarbonsourcesonthepropertiesandperformanceofLiFePO4/C/graphenecompositewaspaidspecialattention.Underoptimizedsyntheticconditions,highlycrystalizedolivine-typeLiFePO4wassuccessfullyobtainedwithelectronconductiveFe2PandFePasthemainimpurityphases.SEMandTEManalysesdemonstratedthegraphenesheetswererandomlydistributedinsidethesampletocreateanopenstructuredLiFePO4withrespecttographene,whiletheglucosederivedcarbonmainlycoatedoverLiFeP04particleswhicheffectivelyconnectedthegraphenesheetsandLiFePO4particlestoresultinamoreefficientchargetransferprocess.Asaresult,favorableelectrochemicalperformancewasachieved.Theperformanceoftheamorphouscarbon-grapheneco-modifiedLiFePO4wasfurtherprogressivelyimproveduponcyclinginthefirst200cyclestoreachareversiblespecificcapacityashighas97mAh·g-1at10Crate.
简介:Reactionsofthe6-hydroxy-thiopyrano[3,4-c]pyridine-5-carbonitrilederivative1withα-halo-carbonylcompoundsgavetheortho-substitutedintermediates2a-cwhichwereconvertedintofuro[2,3-b]thiopyrano[4,3-d]pyridines3a-cbyfusionofafuranmoietyunderbasicconditions.Furthercyclizationof3a-cledtoafusionofapyrimidinering,yieldingthetetracyclicproducts6,7and8.Inaddition,condensationof6withvariousaromaticaldehydesaffordedthecorrespondingimines9a,b.Mannichreactionof7gaveproducts10a,b.
简介:A3-DnonlinearproblemofsupercavitatingflowpastanaxisymmetricbodyatasmallangleofattackisinvestigatedbymeansoftheperturbationmethodandFourier-cosine-expansionmethod.Thefirstthreeorderperturbationequationsarederivedindetailandsolvednumericallyusingtheboundaryintegralequationmethodanditerativetechniques.Computationalresultsofthehydrodynamiccharacteristicsandcavityshapesofeachorderarepresentedfornonaxisymmetricsupercavitatingflowpastconeswithvariousapex-anglesatdiffer-entcavitationnumbers.Thenumericalresultsarefoundingoodagreementwithexperimentaldata.
简介:Uptothisdate,researchersarestillfacingdifficultiestoexpandthetechnologyofdirectmethanolfuelcells(DMFCs)becauseofthehighoverpotentialrequiredtooxidizethemethanolanditsrelativelypoorperformanceduetoCOpoisoningoftheleading-highcostanodecatalyst.Inlinewiththis,wehavesuccessfullymodifiedthemorphologicalstructureandcompositionoflowcostcobaltbased-metaloxides,MCo2O4(M=ZnandNi),withthesimpleandnobleuseofpolyvinylpyrrolidone(PVP)asgrowthmodifierandsurfacestabilizerduringthesynthesisofnanoparticlesinourpreviousreports,whichshownhighelectrocatalyticactivityandstrongstability.DuetothegoodperformanceofourPVPmodifiedMCo2O4towardspseudocapacitorandoxygenevolutionreactionapplications,wedecidedtoextendourresearchstudytomethanoloxidationreaction.Remarkably,PVPmodifiedNiCo2O4electrodedirectlygrownonnickelfoamsubstrateviaasimplehydrothermalprocessexhibitedbetterperformancecomparedwithPVPmodifiedZnCo2O4andNiCo2O4withoutPVP.Ithadobtainedaremarkablylowonsetpotentialof0.285Vandhighcurrentdensityof280mAcm-2,andshowngreatstabilityandhighpoisontoleranceduringacontinuousCVcyclingandChronoamperometrytest,whichattainedhighefficiencyof86.86%and98.52%,respectively.ThesepositiveresultsofPVPmodifiedNiCo2O4electrodetowardsMORmightbeattributedtoitshierarchical3Dnanostructureswithhighlymesoporoussurfaceandlargesurfaceareawhichmayhaveprovidednumerouselectroactivesites,andtheexceptionalcorrosionstabilityofNiCo2O4electrodeinalkalinesolution.
简介:这篇文章与库仑潜在的x考虑3D-Hartree-type方程的一个家庭(?1),其起始的数据震荡以便一苛性出现。在线性几何光学盒子中,由使用Lagrangian积分,对答案在外面的一致描述苛性、近苛性被获得。给词调音:Hartree方程;几何光学;Lagrangian积分
简介:Atopologymethodispresentedinthispapertorevealflowtructureoccurringinsieturbomachinery,inwhichnearwallflowstructureisrevealedbyusingwalllimitingstreamilinesandspaceflowfeatureisrevealedbyusingspacestreamilinesandcross-sectionstreamlines,Asanexample,acomputationalthree-dimensionalviscousflowfieldinsideatransonicturbinecascadeisstudied.Throughtheanalysis,theformandevolutionofvortexsystemandthewholeprocessofseparationoccurringwithinthiscascadearerevealed.Theapplicationoftopologymethodforanalyzeflowstructureinsideturbomachinmeryisveryimportantforunderstandingflowfeaturesandmechanismofflowlossevenforimprovingthedesignofturbomachineryandincreasingitsefficiency.