简介：Inthispaper,withPoincare’sformalism,andanindirectmethod,thecanonicalformsofthegeneralizedequationsofmotionduetoNielsenandCenovofaholonomicdynamicalsysteminthevelocity-phasespaceandtheacenleration-phasespaceareobtainedintermsofthePoincareparameters.

简介：ThesolutionsofGreen'sfunctionaresignificantforsimplificationofproblemonatwo-phasesaturatedmedium.UsingtransformationofaxisymmetriccylindricalcoordinateandSommerfeld'sintegral,superpositionoftheinfluencefieldonafreesurface,authorsobtainedthesolutionsofatwo-phasesaturatedmediumsubjectedtoaconcentratedforceonthesemi-space.

简介：Thediscretizationsizeislimitedbythesamplingtheorem,andthelimitisonehalfofthewavelengthofthehighestfrequencyoftheproblem.However,onehalfofthewavelengthisanidealvalue.Ingeneral,thediscretizationsizethatcanensuretheaccuracyofthesimulationismuchsmallerthanthisvalueinthetraditionalfiniteelementmethod.Thepossiblereasonofthisphenomenonisanalyzedinthispaper,andanefficientmethodisgiventoimprovethesimulationaccuracy.

简介：介绍了捷联惯导系统中圆锥补偿算法与划船误差补偿算法之间的相似性;根据它们之间的相似性得出了一简单的公式,该公式能够将一种圆锥补偿算法转换成相应的划船误差补偿算法;此外还给出了该公式的推导过程及几种高精度补偿算法;最后进行了仿真.

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简介：Byusingthefundamentalequationsofaxisymmetricshallowshellsofrevolution,thenonlinearbendingofashallowcorrugatedshellwithtaperunderarbitraryloadhasbeeninvestigated.ThenonlinearboundaryvalueproblemofthecorrugatedshellwasreducedtothenonlinearintegralequationsbyusingthemethodofGreen'sfunction.Tosolvetheintegralequations,expansionmethodwasusedtoobtainGreen'sfunction.ThentheintegralequationswerereducedtotheformwithdegeneratecorebyexpandingGreen'sfunctionasseriesofcharacteristicfunction.Therefore,theintegralequationsbecomenonlinearalgebraicequations.Newton'siterativemethodwasutilizedtosolvethenonlinearalgebraicequations.Toguaranteetheconvergenceoftheiterativemethod,deflectionatcenterwastakenascontrolparameter.Correspondingloadswereobtainedbyincreasingdeflectiononebyone.Asanumericalexample,elasticcharacteristicofshallowcorrugatedshellswithsphericaltaperwasstudied.Calculationresultsshowthatcharacteristicofcorrugatedshellschangesremarkably.Thesnappinginstabilitywhichisanalogoustoshallowsphericalshellsoccurswithincreasingloadifthetaperisrelativelylarge.Thesolutionisclosetotheexperimentalresults.

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简介：采用Born近似的Maxwell方程组积分解形式较少应用于气动光学数值计算,其困难在于对该方程组的离散化数值计算.而结合GCV-FFT（GeneralizedconvolutionbyfastFouriertransform）方法,在自由空间传播的Rayleigh-Sommerfeld衍射方程数值计算可以达到比较高的精度.通过对Green函数及采样系数的修正,积分方法可以用于气动光学现象的数值模拟.通过在超声速湍流边界层中光束传输的数值计算,可以看到一些气动光学效应,如光束偏移破碎等,可以用修正GCV-FFT＋数值积分的方法得到良好的模拟.现有的方法可以给出更接近物理本质的定量结果.

简介：Liquid-solid(L-S)masstransfercoefficients(Ks)werecharacterizedinagas-liquid-solid(G-L-S)three-phasecountercurrentmagneticallystabilizedbed(MSB)usingamorphousalloySRNA-4asthesolidphase.Effectsofsuperficialliquidvelocity,superficialgasvelocity,magneticfieldstrength,liquidviscosityandsurfacetensionwereinvestigated.ExperimentalresultsindicatedthattheexternalmagneticfieldincreasedKsinthree-phaseMSB,ascomparedtothoseinconventionalG-L-Sfluidizedbeds;thatKsincreasedwithmagneticfieldstrength,superficialgasandliquidvelocitiesanddecreasedwithliquidviscosityandsurfacetension;andthatKsshoweduniformaxialandradialdistributionsexceptforsmallincreasesclosetothewall.DimensionlesscorrelationswereestablishedtoestimateKsoftheG-L-ScountercurrentMSBusingSRNA-4catalyst,withanaverageerrorof3.6%.

简介：BasedupontheHellinger-Reissner(H-R)mixedvariationalprincipleforthree-dimensionalelasticbodies,themodifiedH-Rmixedvariationaltheoremformagnetoelectroelasticbodieswasestablished.Thestate-vectorequationofmagnetoelectroelasticplateswasderivedfromtheproposedtheorembyperformingthevariationaloperations.Tolayatheoreticalbasisofthesemi-analyticalsolutionappliedwiththemagnetoelectroelasticplates,thestate-vectorequationforthediscreteelementinplanewasproposedthroughtheuseoftheproposedprinciple.Finally,itispointedoutthatthemodifiedH-Rmixedvariationalprincipleforpureelastic,singlepiezoelectricorsinglepiezomagneticbodiesarethespecialcasesofthepresentvariationaltheorem.

简介：BycombiningChapman-EnskogexpansionwiththeBGKapproximationtoBaltzmannequationandNavier-Stokesequationwasobtained.AndanexpressionofDarcy'slawwasobtainedthroughtakingvariableaverageoverNavier-Stokesequationonsomerepresentativespaceinporousmedia,andfinallyanexamplewastakentoproveitsreliability.

简介：TheconstitutiveequationforasemiconcentratedfibresuspensionintheOldroyd-Bfluidhasbeenderivedfromastatisticalmodelofsuchasuspensionbyemployingthemoleculartheoryforpolymericliquids.Tocircumventtheoreticaldifficultiesinviscoelasticfluidmechanics,severalsimplifiedmodelsareusedtoaccountfortheinteractionsoffibresandpolymermolecules.Someofmaterialfunctionsarecalculatedintermsoftheconstitutiveequation.

简介：ThispaperestablishesthevelocityfieldandtheadequateshearstresscorrespondingtothemotionofanOldroyd-BfluidbetweentwoinfinitecoaxialcircularcylindersbymeansoffiniteHankeltransforms.Theflowofthefluidisproducedbytheinnercylinderwhichappliesatime-dependentlongitudinalshearstresstothefluid.Theexactanalyticalsolutions,presentedinseriesformintermsofBesselfunctions,satisfyallimposedinitialandboundaryconditions.ThegeneralsolutionscanbeeasilyspecializedtogivesimilarsolutionsforMaxwell,secondgradeandNewtonianfluidsperformingthesamemotion.Finally,somecharacteristicsofthemotionaswellastheinfluenceofthematerialparametersonthebehaviorofthefluidmotionaregraphicallyillustrated.

简介：Acompositebeamissymmetricifboththematerialpropertyandsupportaresymmetricwithrespecttothemiddlepoint.Inordertostudythefreevibrationperformanceofthesymmetriccompositebeamswithdifferentcomplexnonsmooth/discontinuousinterfaces,wedevelopanR(x)-orthonormaltheory,whereR(x)isanintegrableflexuralrigidityfunction.TheR(x)-orthonormalbasesinthelinearspaceofboundaryfunctionsareconstructed,ofwhichthesecond-orderderivativesoftheboundaryfunctionsareaskedtobeorthonormalwithrespecttotheweightfunctionR(x).WhenthevibrationmodesofthesymmetriccompositebeamareexpressedintermsoftheR(x)-orthonormalbaseswecanderiveaneigenvalueproblemendowedwithaspecialstructureofthecoefficientmatrixA:=[aij],aij=0ifi+jisodd.Basedonthespecialstructurewecanprovetwonewtheorems,whichindicatethatthecharacteristicequationofAcanbedecomposedintotheproductofthecharacteristicequationsoftwosub-matriceswithdimensionshalflower.Hence,wecansequentiallysolvethenaturalfrequenciesinclosed-formowingtothespecialtyofA.Weusethispowerfulnewtheorytoanalyzethefreevibrationperformanceandthevibrationmodesofsymmetriccompositebeamswiththreedifferentinterfaces.

简介：部分地，聪明切割的过程，缺陷由尺寸描绘了的结合的效果和在切开前后的内部压力上的2纸被使用破裂力学模型学习。有大尺寸的结合的缺陷是容易的引起缺点生长的严重偏差，这被发现，当切开时，导致薄层的一个非转移的区域。在结合的缺陷的内部压力是很小的一个实际聪明切割的过程，大界面的缺点总是在切开的过程支持缺点生长。同时，增加结合的缺陷的内部压力减少在切开前的缺点生长和它的偏差。stiffener限制的松驰的机制被建议澄清结合的缺陷的效果。而且，当结合的缺陷是在场的时，切开的过程的进步被分析。在切开以后，有大尺寸和高内部的压力的那些结合的缺陷在高温度的退火期间为薄电影的blistering是脆弱的。

简介：用时域泰勒级数展开的方法分析了速率偏频激光陀螺惯导系统常用速度数值积分算法的误差。分析显示速率偏频陀螺本身的高速旋转使惯性导航系统时刻处于大角运动条件下。若其旋转轴与比力方向不平行,则常用速度算法的误差不可忽略。提出了速率偏频激光陀螺惯导系统速度算法的优化改进方法。对常用速度算法和提出的算法进行了仿真比较。仿真显示,用泰勒级数展开分析速度数值积分算法误差是可行的;提出的算法能够将速率偏频激光陀螺惯导系统以及其他惯性导航系统在大机动运动环境下的导航精度提高一阶。

简介：Thispaperaimstoinvestigatethehydrodynamicbehaviorofatensionlegplatform(TLP)whenthetendonconnectionanglesarevariedat90°,70°,50°,and30°.ThreedifferenttypesofloadingconditionsareappliedtotheTLP.Conditionsinclude100-yearhurricanestormperiod,regularwavesandnoloading.TheTLPdisplayedmajorresponseinthepitchdegreeoffreedom.Amaximumreductionof14%inpitchrotationisachievedwhen100-yearhurricanestormconditionsareappliedtotheTLP.Thisoccurredin0°loadingsat30°tendonconnectionangleascomparedto90°tendonconnectionangle.Reductioninpitchrotationisalsoachievedintheregularwaveloadings.Amaximumof9%inpitchrotationisachievedduring0°waveloadingat30°tendonconnectionangleascomparedto90°.Whenthetendonconnectionangleisreducedfrom90°to30°,thenaturalfrequencyoftheTLPincreasedbothinpitchandyawdegreesoffreedomby2.55%and2.40%,respectively.

简介：Astandardconservationformisderivedinthispaper.ThehyperbolicityofHelbing’sfluiddynamictrafficflowmodelisproved,whichisessentialtothegeneralanalyticalandnumericalstudyofthismodel.Onthebasisofthisconservationform,alocaldiscontinuousGalerkinschemeisdesignedtosolvetheresultingsystemefficiently.Theevolutionofanunstableequilibriumtrafficstateleadingtoastablestop-and-gotravelingwaveissimulated.Thissimulationalsoverifiesthatthemodelistrulyimprovedbytheintroductionofthemodifieddiffusioncoefficients,andthushelpstoprotectvehiclesfromcollisionsandavoidetheappearanceoftheextremelylargedensity.

简介：Weprovideanalyticalsolutionstotheproblemsofacircularbendingofabeaminplanestrainandthetorsionofanon-circularcross-sectionbeam,thebeamsobeyingasecond-gradientelasticitylawproposedbytheauthor,followingaprevioussuggestionofdell'Isolaetal.(2009).Themotivationwastofindbenchmarkanalyticalsolutionsthatcanservetograspthephysicalfoundationsofsecondgradientelasticitylawsforheterogeneousmaterials.TheanalyticalsolutionofthecircularbeamproblempresentstheadditionaladvantagetoestablishsomenicepropertiesontheunknownsecondgradientelasticmoduliintroducedbyEnakoutsa(2014)modelandtheclassicalelasticityconstantsforbothincompressibleandcompressibleheterogeneouselasticmaterials.Aframeworktofindtheelasticmoduliofthenewmodelisalsoproposed.