简介：Tochangethecurrentphenomenonof'Beinganarmchairstrategist'intheresearchofasteppingmotor,thevirtualsimulationsystemofsteppingmotorwasdevelopedusingvirtualrealitytechnique.Thebasicprincipleofsteppingmotorwasexpounded.Thedevelopmentstrategyofthesimulationsoftwareisintroduced.Somekeyproblemsandtheirsolutions,includingcoordinatetransformationofrotorandorderofon-offelectricityforstator,wereputforwardinsystemdevelopment.Finally,therearethreevirtualsimulationexamplesoftheon-offelectricitywayinthispaper.Thisworkprovidesavaluableauxiliarytoolforthestudyofthesteppingmotor.

简介：由di-(2,4,4-trimethylpentyl)的L本氨基丙酸的抽取行为phosphinic酸，di-(2,4,4-trimethylpentyl)-monothiophosphinic酸和di-(2-ethylhexyl)磷的酸分别地在二阶段、三阶段的系统被学习。为这些抽取反应的平衡常数是计算的。

简介：Thebandgap,animportantcharacteristicoftheperiodicstructure,isdispersionrelated,whichcanbedesignedbytailoringthelayoutofmaterialswithintheperiodicmicrostructures.Atypicalexampleofaperiodicstructureisphononiccrystals(PnCs),whicharetraditionallyfabricatedfromtwo-phasematerials.Herein,weinvestigatethetopologiesofperiodicthree-phasePnCs.Themicrostructuresofthethree-phasePnCsareoptimizedusingatwo-stagegeneticalgorithm,andthreecasestudiesareproposedtoobtainthefollowing:(1)themaximumrelativebandgapwidth,(2)themaximumabsolutebandgapwidth,and(3)themax-imumbandgapataspecifiedfrequency.Moreimportantly,thethree-phasematerialprovidessignificantadvantagescomparedtothetypicaltwo-phasematerials,suchasalow-frequencybandgap.Thisresearchisexpectedtocontributehighlytovibrationandnoiseisolation,elasticwavefilters,andacousticdevices.

简介：Theeffectivethermalconductivityofmatrix-inclusion-microcrackthree-phaseheterogeneousmaterialsisinvestigatedwithaself-consistentmicromechanicalmethod（SCM）andarandommicrostructurefiniteelementmethod（RMFEM）,IntheSCM,microcracksareassumedtoberandomlydistributedandpen-ny-shapedandinclusionstobespherical,thecrackeffectisaccountedforbyintroducingacrackdensitypa-rameter,theeffectivethermalconductivityisderivedwhichrelatesthemacroscopicbehaviortothecrackdensityparameter.IntheRMFEM,thehighlyirregularmicrostructureoftheheterogeneousmediaisaccu-ratelydescribed,theinteractionamongthematrix-inclusion-microcracksisexactlytreated,theinclusionshapeeffectandcracksizeeffectareconsidered.ANi/ZrO2particulatecompositematerialcontainingran-domlydistributed,penny-shapedcracksisexaminedasanexample.Themainresultsobtainedare:（1）theeffectivethermalconductivityissensitivetothecrackdensityandexhibitsessentiallyalinearrelationshipwiththedensityparameter;（2）theinclusionshapehasasignificanteffectontheeffectivethermalconductiv-ityandapolygon-shapedinclusionismoreeffectiveinincreasingordecreasingtheeffectivethermalconduc-tivitythanasphere-shapedone;and（3）theSCMandRMFEMarecomparedandthetwomethodsgivethesameeffectivepropertyinthecaseinwhichthematrixthermalconductivityλ,isgreaterthantheinclusiononeλ2.Intheinversecaseofλ1<λ2,thetwomethodsagreeastheinclusionvolumefractionandcrackdensityarelowanddifferastheyarehigh.Areasonableexplanationfortheagreementanddeviationbetweenthetwomethodsinthecaseofλ1<λ2ismade.

简介：Inphaseunwrapping,howtocontroltheresiduesandcut-linesiscriticaltounwrapill-statewrappedphasemapsuccessfully.Somenewconceptsinphaseunwrappingfieldareproposed.Firstly,theresiduesinthreetypes,I.e.,singularresidues,normalresiduesandvirtualresidues,areclassified,whichleadstosomerationalunwrappingpaths.Secondly,somedifferencesbetweencut-lineandcurved-lineareanalyzed.Andfinally,experimentiscarriedouttocompareournewenhancedGoldsteinalgorithmwiththeoriginalGoldsteinalgorithm.

简介：OnNovember18,2001,thesecondphasecofferdamofThreeGorgesProjectwasstartedtodismantle.Thedismantlementofcofferdamwithheightof80oddm,weircrestwidthof15mandoveralllengthof2.4km,marksthebeginningofthesecondtimecutoffofThreeGorgesProject—thecutoffofdiversion

简介：Theelectromechanicalbehaviorofpoly(vinylidenefluoride-trifluoroethylene)[P(VDF-TrFE)]ferroelectricthinfilmwasinvestigatedusingthethreedimensional(3D)phase-fieldmethod.Variousenergeticcontributions,includingelastic,electrostatic,anddomainwallenergyweretakenintoaccountinthevariationalfunctionalofthephasefieldmodel.EvolutionofthemicroscopicdomainstructuresofP(VDF-TrFE)polymerfilmwassimulated.Effectsofthein-planeresidualstress,thefilmthicknessandexterna...

简介：Bystudyingthethermal-inducedphaseshiftmechanismofaninterferometricfiber-opticgyroscope(IFOG)sensingcoil,anovelgeneralizedexpressionbasedonathree-dimensional(3D)modelisproposed.ComparedwiththetraditionalpureShupeeffectmodel,thesimulationresultsshowthatthenew3Dmodel,includingelasticstrainandtheelasto-opticaleffect,candescribethethermaleffectofthecoilsmoreaccurately.Experimentswithtemperaturechangeratesbetween-40°Cand70°Careperformedtoverifytheeffectivenessoftheproposedgeneralizedexpression.Theresultsofourworkcanguideresearchersinidentifyingcountermeasurestoreducethethermal-inducedbiaserrorinIFOG.

简介：Basedonthetensoranalysisofwater-sedimenttwo-phaseflow,thebasicmodelequationsforclearwaterflowandsediment-ladenflowarededucedinthegeneralcurvecoordinatesfornaturalwatervariable-densityturbulentflow.Fur-thermore,correspondingboundaryconditionsarealsopresentedinconnectionwiththecompositionandmovementofnon-uniformbedmaterial.Thetheoreticalresultsareappliedtothecalculationofthefloatopencaissonintheconstructionperiodandgoodresultsareobtained.

简介：Inaspectofthescaleofworks,theThreeNorthShelterbeltProgramisuptonowthemostmagnificentprojectofforestryecologicalconstructionintheworld.Attheendof2000,the1st,2nd,and3rdperiodsofconstructioninthe1stphase(1978-2000)hadbeencompleted.Basedonfuzzycomprehensiveevaluationmethod,thepaperisabouttheresearchesonpost-evaluationinthe1stphaseaimsoftheThreeNorthShelterbeltProgram.Theconclusionobtainedisthattheaimsarepartlysuccessful.

简介：ThisArticlepresentsathreedimensionalnumericalmodelinvestigatingthermalperformanceandhydrodynamicsfeaturesoftheconfinedslotjetimpingementusingslurryofNanoEncapsulatedPhaseChangeMaterial(NEPCM)asacoolant.Theslurryiscomposedofwaterasabasefluidandn-octadecaneNEPCMparticleswithmeandiameterof100nmsuspendedinit.AsinglephasefluidapproachisemployedtomodeltheNEPCMslurry.ThethermophysicalpropertiesoftheNEPCMslurryarecomputedusingmodernapproachesbeingproposedrecentlyandgoverningequationsaresolvedwithacommercialFiniteVolumebasedcode.TheeffectsofjetReynoldsnumbervaryingfrom100to600andparticlevolumefractionrangingfrom0%to28%areconsidered.ThecomputedresultsarevalidatedbycomparingNusseltnumbervaluesatstagnationpointwiththepreviouslypublishedresultswithwaterasworkingfluid.ItwasfoundthataddingNEPCMtothebasefluidresultswithconsiderableamountofheattransferenhancement.ThehighestvaluesofheattransfercoefficientsareobservedatH/W=4andC_m=0.28.However,duetothehigherviscosityofslurrycomparedwiththebasefluid,theslurrycanproducedrasticincreaseinpressuredropofthesystemthatincreaseswithNEPCMparticleloadingandjetReynoldsnumber.

简介：Thisstudypresentsathree-dimensionalnumericalstudyofthemixingandsegregationofbinaryparticlemixturesinatwo-jetspoutfluidizedbedbasedonanEulerian-Eulerianthree-fluidmodel.Initially,theparticlemixtureswerepremixedandpackedinarectangularfluidizedbed.Asthecalculationbegan,thegasstreamwasinjectedintothebedfromthedistributorandjetnozzles.Themodelwasvalidatedbycomparingthesimulatedjetpenetrationdepthswithcorrespondingexperimentaldata.Themainfeaturesofthecomplexgas-solidflowbehaviorsandthemechanismofmixingandsegregationofthebinarymixtureswereanalyzed.Moreover,furthersimulationswerecarriedouttoevaluatetheeffectsofoperatingconditionsonthemixingandsegregationofbinaryparticlemixtures.Theresultsillustratethatmixingcanbeenhancedbyincreasingthejetvelocityorenlargingthedifferenceofinitialproportionsofbinaryparticlemixtures.

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简介：Notfarfromtheedge[1]ofapleasantwoodthereoncelivedthreeBears.Theywerekind,goodBears,notrude,wildfellows[2]likethosethatlivenow;andtheyhadbuiltforthemselvesacomfortablelittlehouse.

简介：母亲：汤姆，快起床，快起床，公鸡已经叫过了。

简介：ＴＨＲＥＥＳＴＲＥＳＳＥＳＴＨＲＥＥＳＴＲＥＳＳＥＳＴｈｅ＂ｔｈｒｅｅｓｔｒｅｓｓｅｓ＂ｒｅｆｅｒｓｔｏａｐｒｉｎｃｉｐｌｅｏｆｆａｍｉｌｙｐｌａｎｎｉｎｇｉｍｐｌｅｍｅｎｔａｔｉｏｎｗｈｉｃｈｏｒｉｇｉｎａｔｅｄｉｎＲｏｎｇｃｈｅｎｇＣｉｔｙ，Ｓｈ...

简介：看了上一期的故事之后，你一定对这一期很期待吧？故事的结尾一定是“主人公从此过上了幸福、快乐的生活。”那其间又发生了什么？他们是如何战胜了恶龙呢？接着看本期的故事……

简介：ResultsofinelasticneutronscatteringexperinientsandabinitiomoleculardynamicssimulationsforGeTe一theparentcompoundofphase-changematerialsarereported.TheinelasticneutronspectraofGeTepowdersampleshavebeendeterminedinthetemperaturerangeextendingfrom300to700K.Thephononpeaksundergothermalshiftsresultingfromanharmoniceffectsbeingweakerforacousticthanopticmodes.AsmallconcentrationoffreechargecarriesarisingfromthepresenceofGe-vacancieswasfoundnottoaffectsignificantlytheneutronweightedphonondensitiesofstatesofGeTe.Thespectralpatternchangesqualitativelyacrossthestructuralphasetransition,butthelocalstructureofGeTeremainshardlyaffected,asconfirmedbytheanalysisoftemperaturedependenceofthepairdistributionfunctionobtainedfromabinitiomoleculardynamicsinvestigations.Thepresenttheoreticalstudiessupportinawideextentourexperimentalobservationsandalsothoseprovidedbylocalprobemethods.

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