简介：基于Si的多层的结构广泛地在当前的微电子学被使用。在他们的准备期间，一些不同类的剩余应力被导致，导致在接口错配和表面精力和平导致结构失败之间的竞争。这个工作在多层的半导体heterostructure在剩余应力的测量上介绍方法学的研究。扫描电子显微镜学(SEM)，micro-Raman光谱学(太太)，和传播电子显微镜学(TEM)被使用测量多层的结构的几何参数。在拉曼光谱和压力/紧张在上之间的关系[100]并且[110]水晶取向被决定分别地启用表面和剖面图剩余压力分析。基于印射结果的拉曼，沿着多层的heterostructure的深度的剩余应力的分发成功地被获得。

简介：ThispaperstudiesMulti-modescontrolmethodforlibrationpointsformationestablishmentandreconfiguration.Firstly,relationsbetweenoptimalimpulsecontrolandFloquetmodesareinvestigated.Methodofgeneratingmodesisproposed.Characteristicsofthemodecoefficientsstimulatedatdifferenttimearealsogiven.Studiesshowthatcoefficientsofcontrolledmodescanbeclassifiedintofourtypes,andformationestablishmentandreconfigurationcanbeachievedbymulti-impulsecontrolwiththepresentedmethodofgeneratingmodes.Then,sincelibrationpointsformationisgenerallyunstable,mutli-modeskeepingcontrolmethodwhichcanstabilizefiveFloquetmodessimultaneouslyisproposed.Finally,simulationonformationestablishmentandreconfigurationarecarriedoutbyusingmethodofgeneratingmodesandmutli-modeskeepingcontrolmethod.Resultsshowthattheproposedcontrolmethodiseffectiveandpractical.

简介：Thedynamicsformulti-linkspatialflexiblemanipulatorarmsisinvestigated.ThesystemconsideredhereisanN-flexible-linkmanipulatordrivenbyNDC-motorsthroughNrevoluteflexiblejoints.Theflexibilityofeachflexiblejointismodeledasalinearlyelastictorsionalspring,andthemassofthejointisalsoconsidered.Fortheflexibilityofthelink,allofthestretchingdeformation,bendingdeformationandthetorsionaldeformationareincluded.ThecompletegoverningequationsofmotionofthesystemarederivedviatheLagrangeequations.Thenonlineardescriptionofthedeformationfieldoftheflexiblelinkisadoptedinthedynamicmodeling,andthusthedynamicstiffeningeffectsarecaptured.Basedonthismodel,ageneral-purposesoftwarepackagefordynamicsimulationofmulti-linkspatialflexiblemanipulatorarmsisdeveloped.Severalillustrativeexamplesaregiventovalidatethealgorithmpresentedinthispaperandtoindicatethatnotonlydynamicstiffeningeffectsbutalsotheflexibilityofthestructurehassignificantinfluenceonthedynamicperformanceofthemanipulator.

简介：Theefficiencyandaccuracyaretwomostconcernedissuesinthemodelingandsimulationofmulti-bodysystemsinvolvingcontactandimpact.Thispaperproposedaformulationbasedonthecomponentmodesynthesismethodforplanarcontactproblemsofflexiblemulti-bodysystems.Aflexiblebodyisdividedintotwoparts:acontactzoneandanun-contactzone.Fortheun-contactzone,byusingthefixed-interfacesubstructuremethodasreference,afewlow-ordermodalcoordinatesareusedtoreplacethenodalcoordinatesofthenodes,andmeanwhile,thenodalcoordinatesofthelocalimpactregionarekeptunchanged,thereforethetotaldegreesoffreedom(DOFs)aregreatlycutdownandthecomputationalcostofthesimulationissignificantlyreduced.Byusingadditionalconstraintmethod,theimpactconstraintequationsandkinematicconstraintequationsarederived,andtheLagrangeequationsofthefirstkindofflexiblemulti-bodysystemareobtained.Theimpactofanelasticbeamwithafixedhalfdiskissimulatedtoverifytheefficiencyandaccuracyofthismethod.

简介：在现在的纸，包含三个任意的函数为的一个一般解决方案概括(2+1)维的KdV-mKdV方程，它被导出从概括(1+1)维的KdV-mKdV方程，首先借助于Wiess被介绍，小鼓，Carnevale(WTC)截断方法。然后有考虑的几条能量守恒定律的multisymplectic明确的表达被介绍为概括(2+1)维的KdV-mKdV方程基于桥的multisymplectic理论。随后，源于以便以Jacobi椭圆形的功能的合理功能模仿周期的波浪答案一般答案，一个半含蓄的multi-symplectic计划被构造那等价于Preissmann计划。从数字实验的结果，我们能断定multi-symplectic计划能精确地模仿周期的波浪答案概括(2+1)维的KdV-mKdV方程当时近似保存能量守恒定律。

简介：Wepresentadesignmethodforcalculatingandoptimizingsoundabsorptioncoefficientofmulti-layeredporousfibrousmetals(PFM)inthelowfrequencyrange.PFMissimplifiedasanequivalentidealizedsheetwithallmetallicfibersalignedinonedirectionanddistributedinperiodichexagonalpatterns.Weuseaphenomenologicalmodelintheliteraturetoinvestigatetheeffectsofporegeometricalparameters(fiberdiameterandgap)onsoundabsorptionperformance.ThesoundabsorptioncoefficientofmultilayeredPFMsiscalculatedusingimpedancetranslationtheorem.Todemonstratethevalidityofthepresentmodel,wecomparethepredictedresultswiththeexperimentaldata.Withtheaveragesoundabsorption(lowfrequencyrange)astheobjectivefunctionandthefibergapsasthedesignvariables,anoptimizationmethodformulti-layeredfibrousmetalsisproposed.Anewfibrouslayoutwithgivenporosityofmulti-layeredfibrousmetalsissuggestedtoachieveoptimallowfrequencysoundabsorption.Thesoundabsorptioncoefficientoftheoptimalmulti-layeredfibrousmetalishigherthanthesinglelayeredfibrousmetal,andasignificanteffectofthefibrousmaterialonsoundabsorptionisfoundduetothesurfaceporosityofthemulti-layeredfibrous.

简介：Astrictproofofthehyperbolicityofthemulti-classLWR(Lighthill-Whitham-Richards)trafficflowmodel,aswellasthedescriptionsonthosenonlinearwavescharacterizedinthetrafficflowproblemsweregiven.Theyweremainlyaboutthemonotonicityofdensitiesacrossshocksandinrarefactions.Asthesystemhadnocharacteristicdecompositionexplicitly,ahighresolutionandhigherorderaccuracyWENO(weightedessentiallynon-oscillatory)schemewasintroducedtothenumericalsimulation,whichcoincideswiththeanalyticaldescription.

简介：Anewhigh-ordermulti-jointfiniteelementforthin-walledbarwasderivedfromtheHermiteinterpolationpolynomialandminimumpotentialenergyprinciple.Thiselement'scharacteristicsarethatitisofhighaccuracyandcanbeusedinfinitemethodanalysisofbridge,tallmega-structurebuilding.

简介：Theeffectofthefacethicknesstocoreheightratioondifferentmulti-layerpyramidalcoresandwichcolumnsunderin-planecompressionisinvestigatedtheoreticallyandnumerically.Numericalsimulationisingoodagreementwiththeory.Resultsindicatethatonespecifiedfacethicknesstocoreheightratiocorrespondstooneoptimumlayernumberofmulti-layerpyramidalcoresandwichcolumnsinconsiderationofengineeringapplication.Thisresultcanguidethesandwichstructuredesign.

简介：Inthepresentstudy,theconceptoftheoutputfrequencyresponsefunctionisappliedtotheoreticallyinvestigatetheforcetransmissibilityofmulti-degreeoffreedom(MDOF)structureswithanonlinearanti-symmetricviscousdamping.Theresultsrevealthatananti-symmetricnonlinearviscousdampingcansignificantlyreducethetransmissibilityoverallresonanceregionsforMDOFstructureswhileithasalmostnoeffectonthetransmissibilityovernon-resonantandisolationregions.Theresultsindicat...

简介：Dispersionofmulti-walledcarbonnanotubesinpoly(p-phenylene)compositeexposedtotoluenewasexperimentallyinvestigated.3mgofmulti-walledcarbonnanotubeswithnominalsizeof20nmwascompoundedwith30mgofpoly(p-phenylene)withthepresenceofterpineolasbindinginitiator.Toinvestigateanoptimalconditionforhomogenizingallconstituents,ultrasonicationwithanoutputpowerof750Wwasemployedwithcompoundingtimeof3,10,20and30min.WithFTIRanalyses,itcouldbeconfirmedthathomogeneouscompositeofmulti-walledcarbonnanotubesandpoly(p-phenylene)couldbeprepared.SEManalyseswerealsoconductedtoexaminethedispersionofmulti-walledcarbonnanotubesinthepolymermatrix.Thenintrinsicelectricalresistanceofthecompositesafterbeingexposedtotoluenewasalsoinvestigated.Itwasfoundthatthecompositefilmpreparedwithultrasonicationfor20mincouldprovidesufficientlysensitiveresponsewithrespecttovariedconcentrationoftoluene.

简介：Ammoniumsulfateresidueisaparticulatesolidandisproducedduringthemanufactureofammoniumsulfatefertilizer.Theresidueusedinthisstudycontainedalargeportionofcalciumcarbonate,fromwhichactivelime（CaO）wasrecoveredviathermaldecomposition.Weusedapurpose-builtdevicetodecomposetheresidueinasemi-suspensionstate.WefoundthatCaOhadthehighestactivitywhenresiduewasdecomposedat850-900℃.OurexperimentsindicatedthatammoniumsulfateresidueshouldbedecomposedinasuspensionstatetoproduceactiveCaO.Basedonourlaboratorytestfindings,anindustrial-scaleproductionlinewithahighsolid/gasratioinasuspensionstatewasdevised.TheoptimaloperatingconditionsforthedecompositionoftheammoniumsulfateresiduetoproducehighqualityCaOwerealsoinvestigated.WefoundthattheCaCO3decompositionratewashighandtheCaOproductwashighlyactive,averaging170sbythecitricacidmethod.MorphologymeasurementsshowedthattheCaOproducthadaporousstructureandalargespecificsurfaceensuringhighactivity.

简介：Symplecticapproachhasemergedapopulartoolindealingwithelasticityproblemsespeciallyforthosewithstresssingularities.However,anisotropicmaterialproblemunderpolarcoordinatesystemisstillabottleneck.Thispaperpresentsasubfieldmethodcoupledwiththesymplecticapproachtostudytheanisotropicmaterialunderantiplanesheardeformation.Anisotropicmaterialaroundwedgetipisconsideredtobeconsistedofmanysubfieldswithconstantmaterialpropertieswhichcanbehandledbyth...

简介：Globalbifurcationsandmulti-pulsechaoticdynamicsforasimplysupportedrectangularthinplatearestudiedbytheextendedMelnikovmethod.Therectangularthinplateissubjecttotransversalandin-planeexcitation.Atwo-degree-of-freedomnonlinearnonautonomoussystemgoverningequationsofmotionfortherectangularthinplateisderivedbythevonKarmantypeequationandtheGalerkinapproach.Aone-tooneinternalresonanceisconsidered.Anaveragedequationisobtainedwithamulti-scalemethod.Aftertransformingtheaveragedequationintoastandardform,theextendedMelnikovmethodisusedtoshowtheexistenceofmulti-pulsechaoticdynamics,whichcanbeusedtoexplainthemechanismofmodalinteractionsofthinplates.AmethodforcalculatingtheMelnikovfunctionisgivenwithoutanexplicitanalyticalexpressionofhomoclinicorbits.Furthermore,restrictionsonthedamping,excitation,anddetuningparametersareobtained,underwhichthemulti-pulsechaoticdynamicsisexpected.Theresultsofnumericalsimulationsarealsogiventoindicatetheexistenceofsmallamplitudemulti-pulsechaoticresponsesfortherectangularthinplate.

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

简介：Fastsolvinglarge-scalelinearequationsinthefiniteelementanalysisisaclassicalsubjectincomputationalmechanics.Itisakeytechniqueincomputeraidedengineering(CAE)andcomputeraidedmanufacturing(CAM).Thispaperpresentsahigh-efciencyimprovedsymmetricsuccessiveover-relaxation(ISSOR)preconditionedconjugategradient(PCG)method,whichmaintainstheconvergenceandinherentparallelismconsistentwiththeoriginalform.Ideally,thecomputationcanbereducednearlyby50%ascomparedwiththeoriginalalgorithm.Itissuitableforhigh-performancecomputingwithitsinherentbasichigh-efciencyoperations.Bycomparingwiththenumericalresults,itisshownthattheproposedmethodhasthebestperformance.

简介：Harmonic,subharmonic,superharmonic,simultaneoussub/superharmonic,andcombinationresonancesoftheadditivetypeofself-excitedtwocoupled-secondordersystemstomulti-frequencyexcitationareinvestigated.Thetheoreticalresultsareobtainedbythemultiple-scalesmethod.Thesteadystateamplitudesforeachresonanceareplotted,showingtheinfluenceofthedifferentparameters.Analysisforeachfigureisgiven.Approximatesolutioncorrespondingtoeachtypeofresonanceisdetermined.Stabilityanalysesarecarriedoutforeachcase.