简介：linear-springdashpot(迷幻药)和接触建模的非线性的Hertzian-springdashpot(HSD)通常在小粒的系统的分离元素方法(DEM)模拟为接触力量的计算被使用。尽管有这些模型，为象僵硬那样的模仿的粒子的接触参数的合适的值的决心，抑制系数，归还的系数，和模拟的流行，预定步，不完全是明显的。在这个工作，在这些之间的关系为一座公寓上的影响基于的一个粒子被检验的一个模型系统联系参数。建议在DEM模拟为使用有关这些接触参数的决心被做。

简介：本文介绍航海－ⅢＧ型陀螺罗经用大功率三相正弦波脉宽调制中频静止电源，它由Ｅ－ＰＲＯＭ构成的可编程正弦波脉宽调制信号发生器、Ａ／Ｄ转换器组成的幅度调节器以及场效应管功率放大器等电路组成，输出频率、幅度、相位稳定的纯三相正弦波，具有效率高、负载能力强等优点，该电源还设置了多种故障检测、报警和多重过载保护电路，整机性能稳定，工作可靠。它不仅适用于航海型陀螺罗经的供电，对于其他功率较大的中频供电场合也是适宜的

简介：ThepreconditionedGauss-Seideltypeiterativemethodforsolvinglinearsystems,withtheproperchoiceofthepreconditioner,ispresented.ConvergenceofthepreconditionedmethodappliedtoZ-matricesisdiscussed.Alsotheoptimalparameterispresented.NumericalresultsshowthattheproperchoiceofthepreconditionercanleadtoeffectivebythepreconditionedGauss-Seideltypeiterativemethodsforsolvinglinearsystems.

简介：Non-singularfictitiousboundaryintegralequationsfororthotropicelasticplaneproblemswerededucedaccordingtoboundaryconditionsbythetechniquesofsingularpoints-outside-domain.Thentheunknownfictitiousloadfunctionsalongthefictitiousboundarywereexpressedintermsofbasicsplinefunctions,andtheboundary-segment-leastsquaresmethodwasproposedtoeliminatetheboundaryresiduesobtained.Bytheabovesteps,numericalsolutionstotheintegralequationscanbeachieved.Numericalexamplesaregiventoshowtheaccuracyandefficiencyoftheproposedmethod.

简介：Afinitedifferencemethodispresentedtosimulatetransversevibrationsofanaxiallymovingstring.Bydiscretizingthegoverningequationandtheequationofstress-strainrelationatdifferentfrictionalknots,twolinearsparsefinitedifferenceequationsystemsareobtained.Thetwoexplicitdifferenceschemescanbecalculatedalternatively,whichmakethecomputationmuchmoreefficient.Thenumericalmethodmakesthenonlinearmodeleasiertodealwithandoftruncationerrors,O(Δt~2+Δx~2).Italsoshowsquitegoodstabilityforsmallinitialvalues.Numericalexamplesarepresentedtodemonstratetheefficiencyandthestabilityofthealgorithm,anddynamicanalysisofaviscoelasticstringisgivenbyusingthenumericalresults.

简介：AVU-decompositionmethodforsolvingasecond-orderconeproblemispresentedinthispaper.Itisfirsttransformedintoanonlinearprogrammingproblem.Then,thestructureoftheClarkesubdifferentialcorrespondingtothepenaltyfunctionandsomeresultsofitsVU-decompositionaregiven.Underacertaincondition,atwicecontinuouslydifferentiabletrajectoryiscomputedtoproduceasecond-orderexpansionoftheobjectivefunction.Aconceptualalgorithmforsolvingthisproblemwithasuperlinearconvergencerateisgiven.

简介：Basedonthefundamentaldynamicequationsoffunctionallygradedmaterial(FGM)cylindricalshell,thispaperinvestigatesthesoundradiationofvibrationalFGMshellinwaterbymobilitymethod.ThismodeltakesintoaccounttheexteriorfluidloadingduetothesoundpressradiatedbytheFGMshell.TheFGMcylindricalshellwasexcitedbyaharmoniclineradialforceuniformlydistributingalongthegenerator.TheFGMshellequationsofmotion,theHelmholtzequationintheexteriorfluidmediumandth...

简介：TheresultsofplaneturbulentwakegivenbyChouPeiyuanareconsideredasthefirstorderap-proximationandputintotheequationsofturbulentfluctuation.Theequationsaresolvednumericallywithintherangeofmicro-scalebymeansofspectrummethod.Thedouble,tripleandquadruplefluctuatingvelocitycorrelationsareobtainedbycomputation.Theyareingoodagreementwithexperimentalresults.

简介：Themethodofnonlinearparabolizedstabilityequations(PSE)isappliedinthesimulationofvortexstructuresincompressiblemixinglayer.Thespatially-evolvingunstablewaves,whichdominatethevortexstructure,areinvestigatedthroughspatialmarchingmethod.Theinstantaneousflowfieldisobtainedbyaddingtheharmonicwavestobasicflow.TheresultsshowthatT-Swavesdonotkeepgrowingexponentiallyasthelinearevolution,theenergytransfertohighorderharmonicmodes,andthatfinallyallharmonicmodesgetsaturatedduetononlinearinteraction.Themeanflowdistortioninducedbythenonlinearinteractionbetweentheharmonicmodesandtheirconjugateharmonicones,makesgreatchangeoftheaverageflowandincreasesthethicknessofmixinglayer.PSEmethodscanwellcapturethetwo-andthree-dimensionallargescalenonlinearvortexstructuresinmixinglayerssuchasvortexroll-up,vortexpairing,andAvortex.

简介：Thispaperfirstanalyzesthefeaturesoftwoclassesofnumericalmethodsforglobalanalysisofnonlineardynamicalsystems,whichregardstatespacerespectivelyascontinuousanddiscreteones.Onbasisofthisunderstandingitthenpointsoutthatthepreviouslyproposedmethodofpointmappingundercellreference(PMUCR),haslaidaframeworkforthedevelopmentofatwoscalednumericalmethodsuitablefortheglobalanalysisofhighdimensionalnonlinearsystems,whichmaytaketheadvantagesofb...

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简介：Inthispaper,anewmethodoftopologicalcleanupforquadrilateralmeshispresented.Themethodfirstselectsapatchofmesharoundanirregularnode.Itthenseeksthebestconnectionoftheselectedpatchaccordingtoitsirregularvalenceusinganewtopologicaloperation:smallpolygonreconnection(SPR).Byreplacingtheoriginalpatchwithanoptimalonethathaslessirregularvalence,meshqualitycanbeimproved.Threeapplicationsbasedontheproposedapproachareenumerated:(1)improvingthequalityofaquadrilateralmesh,(2)convertingatriangularmeshtoaquadrilateralone,and(3)adaptingatrianglegeneratortoaquadrilateralone.Thepresentedmethodishighlyeffectiveinallthreeapplications.

简介：Ageneralizedhyperbolicperturbationmethodispresentedforhomoclinicsolutionsofstronglynonlinearautonomousoscillators,inwhichtheperturbationprocedureisimprovedforthosesystemswhoseexacthomoclinicgeneratingsolutionscannotbeexplicitlyderived.Thegeneralizedhyperbolicfunctionsareemployedasthebasisfunctionsinthepresentproceduretoextendthevalidityofthehyperbolicperturbationmethod.Severalstronglynonlinearoscillatorswithquadratic,cubic,andquarticnonlinearityarestudiedindetailtoillustratetheefficiencyandaccuracyofthepresentmethod.

简介：Asetofparameterscalledrelativeorbitalelementsweredefinedtodescribetherelativemotionofthesatellitesintheformationflying.Withthehelpoftheseparameters,theeffectoftheperturbationsontherelativeorbittrajectoryandgeometricpropertiesofsatelliteformationcanbeeasilyanalyzed.First,therelativeorbitalelementsarederived,andpointedout:iftheeccentricityoftheleadingsatelliteisasmallvalue,therelativeorbittrajectoryisdeterminedbytheintersectionbetweenanellipticcylinderandaplaneintheleadingsatelliteorbitframereference;andtheparametersthatdescribetheellipticcylinderandtheplanecanbeusedtoobtaintherelativeorbittrajectoryandtherelativeorbitalelements.Second,byanalyzingtheeffectsofgravitationalperturbationsontherelativeorbitusingtherelativeorbitalelements,itisfoundthatthepropagationofarelativeorbitconsistsoftwoparts:oneisthedriftoftheellipticcylinder;andtheotheristherotationoftheplaneresultedfromtherotationofthenormaloftheplane.Meanwhile,theanalyticformulaeforthedriftandrotationratesofarelativetrajectoryundergravitationalperturbationsarepresented.Finally,therelativeorbittrajectoryandthecorrespondingchangeswereanalyzedwithrespecttotheJ2perturbation.

简介：产生交通的逃亡者灰尘是在北京的城市的大气的微粒污染的来源。这篇论文介绍暂停方法，在AP-42文件由USEPA推荐了，为收集北京道路表面灰尘。分析为道路表面灰尘的集体尺寸分发在数字尺寸分发和一个双山峰模式显示出单个山峰的分布。一条高级道路上的道路灰尘的集体集中分发的中部的直径在一条低档道路上比那高。到PM10的PM2.5的比率与那为香港在类似的研究获得了一致。为二件选择道路样品，尺寸分发的平均相对偏差是10.9%和11.9%。所有结果显示有效地在这个论文罐头介绍的方法从交通决定逃亡者灰尘的尺寸分发。

简介：ThestabilitydegreeofperiodicsolutionofnonlinearnonautonomoussystemwasdefinedbymeansoftheFloquettheory.Amethodevaluatingthestabilitydegreeofperiodicsolutionbasedontransientresponsewaspresentedbytheaidoftheconceptofdynamicsystemsorflows.Thecriticalvalueofasystemwasdeterminedbythecondition,i.e.,itsstabilitydegreeequalszero.Stableregionsofrotorsystemswithbalancedandunbalanceddisksupportedonlubricatedbearingswerecalculated.Thestudyshowsthatstableregiondecreaseswiththeincreaseofspeedforabalancedrotorsystemanddecreaseswiththeincreaseofunbalanceforanunbalancedrotorsystem.Stableregionsofperiodicsolutionsarelessthanthatofequilibriumpointsunderthesamesystematicconditions.

简介：Theexactanalyticmethodwasgivenby[1].Itcanbeusedforarbitraryvariablecoefficientdifferentialequationsandthesolutionobtainedcanhavethesecondorderconvergentprecision.Inthispaper,anewhighprecisionalgorithmisgivenbasedon[1],throughabendingproblemofvariablecross-sectionbeams.Itcanhavethefourthconvergentprecisionwithoutincreasingcomputationwork.Thepresentcomputationmethodisnotonlysimplebutalsofast.Thenumericalexamplesaregivenattheendofthispaperwhichindicatethatthehighconvergentprecisioncanbeobtainedusingonlyafewelements.Thecorrectnessofthetheoryinthispaperisconfirmed.

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简介：纸论述改进没有元素的Galerkin(IEFG)为三维的波浪繁殖的方法。改进移动最少平方(IMLS)近似被采用构造形状函数，它与一个重量函数把一个直角的函数系统用作基础函数。与常规移动相比最少平方(MLS)近似，在IMLS的代数学的方程系统近似不是性恶的，并且没有导出反的矩阵，能直接被解决。因为比在MLS近似在IMLS有更少系数，更少节点比在没有元素的Galerkin方法在IEFG方法被选择。因此，IEFG方法有更高的计算速度。在IEFG方法，Galerkin弱形式被采用获得一个discretized系统方程，并且惩罚方法被使用强加必要边界条件。为二点的边界价值问题的传统的差别方法为时间discretization被选择。当波浪方程和边界起始的条件取决于时间，可伸缩的参数，节点的数字和时间，步长度为集中学习被考虑。

简介：Theformulaswhicharesuitabletobirefringentmediumwithsymmetricplanearederivedbymeansofphaseretardintegration.Wehaveadoptedthisconcepttotheaxisymmetricproblemsanddeducedsomeusefulformulasforthesecases.Asapracticalapplication,thestrainrateanalysisofflowinadivergingoraconvergingvesselisillustratedattheendofthispaper.