学科分类
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7 个结果
  • 简介:Becauseoflimitedresourceofembeddedplatforms,thecomputationalcomplexityofadvancedcontrolalgorithmsraisessignificantchallengesfortheuseofembeddedsystemsincomplexcontrolfield.AScilab/Scicosbasedembeddedcontrollerisdevelopedonwhichvariouscontrolsoftwarecanbeeasilymodeled,simulated,implemented,andevaluatedtomeettheever-expandingrequirementsofindustrialcontrolapplications.BuiltontheCirrusLogicEP9315ARMsystems-on-chipboard,thisembeddedcontrollerispossibletodevelopcomplexembeddedcontrolsystemsthatemployadvancedcontrolstrategiesinarapidandcost-efficientfashion.Duetothefreeandopensourcenatureofthesoftwarepackagesused,thecostoftheembeddedcontrollerisminimized.

  • 标签: 嵌入式控制器 嵌入式控制系统 低成本 SCILAB Scicos CIRRUS
  • 简介:在这研究,为评估自然频率和模式的准确解决方案的分析关系与嵌入的形状存储器横梁塑造合金(SMA)电线被介绍。横梁根据Euler-Bernoulli,Timoshenko和第三根顺序横梁(瑞迪)理论被建模。一种关系为决定预先拉紧的SMA电线的恢复行动产生的轴的负担的效果被获得。由定义一些无尺寸的数量,频率和系统的模式形状上的不同机械性质的效果小心地被检验。轴的负担的效果与弄弯由SMA电线产生了负担和频率跳精确地被学习。

  • 标签: 形状记忆合金丝 嵌入式 振动分析 光束 模态振型 自然频率
  • 简介:Horizontalimpedancefunctionsofinclinedsinglepilesaremeasuredexperimentallyformodelsoil-pilesystemswithboththeeffectsoflocalsoilnonlinearityandresonantcharacteristics.Twopracticalpileinclinationsof5掳and10掳inadditiontoaverticalpileembeddedincohesionlesssoilandsubjectedtolateralharmonicpileheadloadingsforawiderangeoffrequenciesareconsidered.Resultsobtainedwithlow-to-highamplitudeoflateralloadingsonmodelsoil-pilesystemsencasedinalaminarshearboxshowthatthelocalnonlinearitieshaveaprofoundimpactonthehorizontalimpedancefunctionsofpiles.Horizontalimpedancefunctionsofinclinedpilesarefoundtobesmallerthantheverticalpileandthevaluesdecreaseastheangleofpileinclinationincreases.Distinctvaluesofhorizontalimpedancefunctionsareobtainedforthe'positive'and'negative'cyclesofharmonicloadings,leadingtoasymmetricforce-displacementrelationshipsfortheinclinedpiles.Validationoftheseexperimentalresultsiscarriedoutthroughthree-dimensionalnonlinearfiniteelementanalyses,andtheresultsfromthenumericalmodelsareingoodagreementwiththeexperimentaldata.Sensitivityanalysesconductedonthenumericalmodelssuggestthattheconsiderationoflocalnonlinearityatthevicinityofthesoil-pileinterfaceinfluencetheresponseofthesoil-pilesystems.

  • 标签: 阻抗函数 模型试验 粘性土 三维非线性有限元分析 单桩 数值分析
  • 简介:Aseriesof3wt%Ruembeddedonorderedmesoporouscarbon(OMC)catalystswithdifferentporesizeswerepreparedbyautoreductionbetweenrutheniumprecursorsandcarbonsourcesat1123K.RunanoparticleswereembeddedonthecarbonwallsofOMC.CharacterizationtechnologiesincludingpowerX-raydiffraction(XRD),nitrogenadsorption-desorption,transmissionelectronmicroscopy(TEM),andhydrogentemperature-programmedreduction(H2-TPR)wereusedtoscrutinizethecatalysts.ThecatalystactivityforFischer-Tropschsynthesis(FTS)wasmeasuredinafixedbedreactor.Itwasrevealedthat3wt%Ru-OMCcatalystsexhibitedhighlyorderedmesoporousstructureandlargesurfacearea.Comparedwiththecatalystswithsmallerpores,thecatalystswithlargerporeswereinclinedtoformlargerRuparticles.These3wt%Ru-OMCcatalystswithdifferentporesizesweremorestablethan3wt%Ru/ACcatalystduringtheFTSreactionsbecauseRuparticleswereembeddedonthecarbonwalls,suppressingparticlesaggregation,movementandoxidation.ThecatalyticactivityandC5+selectivitywerefoundtoincreasewiththeincreasingporesize,however,CH4selectivityshowedtheoppositetrend.ThesechangesmaybeexplainedintermsofthespecialenvironmentoftheactiveRusitesandthediffusionofproductsintheporesofthecatalysts,suggestingthattheactivityandhydrocarbonselectivityaremoredependentontheporesizeofOMCthanontheRuparticlesize.

  • 标签: 碳纳米粒子 合成孔径 有序介孔 嵌入式 催化性能 固定床反应器
  • 简介:Anumericalstudyofanon-Darcymixedconvectiveheatandmasstransferflowoveraverticalsurfaceembeddedinaporousmediumundertheefectsofdoubledispersion,melting,andthermalradiationisinvestigated.Thesetofgoverningboundarylayerequationsandtheboundaryconditionsistransformedintoasetofcouplednonlinearordinarydiferentialequationswiththerelevantboundaryconditions.ThetransformedequationsaresolvednumericallybyusingtheChebyshevpseudospectralmethod.Comparisonsofthepresentresultswiththeexistingresultsintheliteraturearemade,andgoodagreementisfound.Numericalresultsforthevelocity,temperature,concentrationprofiles,andlocalNusseltandSherwoodnumbersarediscussedforvariousvaluesofphysicalparameters.

  • 标签: 混合对流 多孔介质 分散液 表面 垂直 非线性常微分方程
  • 简介:Theinfluenceofinitialstrainstateonthedynamicresponseofanendbearingpileembeddedinisotropicsaturatedsoilisinvestigatedthroughthelinearizedtheoryofsmallelasticperturbationsuperposedonlargelystressedbodies.Thegoverningequationsforsoil,basedonBiot’sporoelasticitytheory,arederivedinthecylindricalcoordinates,andthepileismodeledbyusingtheone-dimensionalelastictheory.Theanalyticalsolutionsofpileimpedance,frequencyresponseofbothtwistangleandtimehistoryofvelocityresponseareobtainedbyusingofseparationofvariablestechnique.Finally,aparametricstudyoftheinfluenceofinitialstrainsonthetorsionalimpedance,twistangle,andvelocityresponseatthetopofthepileiscarriedout.

  • 标签: 力学 流体力学 粘性流体力学 边界层