简介：ＴＨＥＩＮＩＴＩＡＬＦＬＯＷＳＴＡＴＥＯＦＡＢＲＯＫＥＮＤＡＭＣｈｅｎＹａｏ－ｓｏｎｇ；ＪｉａｎｇＴａｏ（ＰｅｋｉｎｇＵｎｉｖｅｒｓｉｔｙ，Ｂｅｉｊｉｎｇ１００８７１，Ｐ．Ｒ．Ｃｈｉｎａ）Ａｂｓｔｒａｃｔ：Ｔｈｉｓｐａｐｅｒｕｔｉｌｉｚｅｓｔｈｅｍａ...

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简介：Pertainingtodynamicsystemsingeneral,areviewisgivenofrelationsbetweenmathematicaldescriptionsinthefrequencydomainortimedomainandstate-spacedescriptions.Fortheanalysisofhydrodynamicproblemsinoceanengineeringwaveforcesmayberepresentedbyconvolutionintegrals.Thepaperpresentsamethodtoconstructafinite-orderstate-spacemodelwhichrepresentsagoodapproximationtosuchaconvolutionintegral.Themethodutilizesaparticularalgorithmtocomputethepartialderivativeoftheexponentialfunctionofa(state-space)matrixwithrespecttothematrixelements.Themethodisappliedtoanexampleoffittingastatespacemodeloforderfivetothefreeoscillationscorrespondingtowaveradiationinatransientexperimentwithanoscillatingwatercolumn.

简介：Convectioninahorizontalfluidlayerheatedfrombelowisoneofmodelsforstudyingpatternsofconvectioninbinaryfluidmixturesandhasbeenextensivelystudied.Inthisarticle,theconvectionstructuresinarectangularcellwereinvestigatedfortheaspect-ratioΓ=12andtheseparationratioψ=-0.47.SimulationswerepreformedbysolvingthehydrodynamicequationsusingtheSIMPLEmethod.ACounterPropagatingWave(CPW)statewasfoundinbinaryfluidconvectionwithaperiodicallyhorizontalmotionofdefects,andthepatterndynamicswasfurtherdiscuss.