简介:Inthispaper,aBoussinesqhierarchyinthebilinearformisproposed.ABacklundtransformationforthishierarchyispresentedandthenonlinearsuperpositionformulaisprovedrigorously.
简介:Ageneralnonlinearconstitutivemodelisproposedformagnetostrictivematerials,basedontheimportantphysicalfactthatanonlinearpartoftheelasticstrainproducedbyapre-stressisrelatedtothemagneticdomainrotationormovementandisresponsibleforthechangeofthemaximummagnetostrictivestrainwiththepre-stress.Toavoidthecomplicityofdeterminingthetensorfunctiondescribingthenonlinearelasticstrainpart,thispaperproposesasimplifiedmodelbymeansoflinearizingthenonlinearfunction.Fortheconvenienceofengineeringapplications,theexpressionsofthe3-D(bulk),2-D(film)and1-D(rod)modelsare,respectively,givenforanisotropicmaterialandtheirapplicablerangesarealsodiscussed.BycomparisonwiththeexperimentaldataofaTerfenol-Drod,itisfoundthattheproposedmodelcanaccuratelypredictthemagnetostrictivestraincurvesinlow,moderateandhighmagneticfieldregionsforvariouscompressivepre-stresslevels.Thenumericalsimulationfurtherillustratesthat,foreithermagnetostrictiverodsorthinfilms,theproposedmodelcaneffectivelydescribetheeffectsofthepre-stressorresidualstressonthemagnetizationandmagnetostrictivestraincurves,whilenoneoftheknownmodelscancaptureallofthem.Therefore,theproposedmodelenjoyshigherprecisionandwiderapplicabilitythanthepreviousmodels,especiallyintheregionofthehighfield.
简介:为非强迫的优化在方法上介绍研究。学习的假设;主要结果;在简化Armijo类型下面的方法的集中性质衬里搜索。
简介:Thedynamicresponseofthenon-linearelasticsimplysupportedbeamsubjectedtoaxialforcesandtransverseperiodicloadisstudied.Melnikovmethodisusedtoconsiderthedynamicbehav-iorofthesystemwhosepost-bucklingpathissteady.Theeffectofthehigherordertermsinthecon-trollingequationistakenintoaccount.Itisfoundthatthefifth-ordertermshaveagreatinfluenceonthedynamicbehaviorofthesystem.Theresultshowsthatthereexisteitherhomoclinicorbitsorhete-roclinicorbitsinthesystem.Inthispaper,thecriticalvaluesofthesystementeringchaoticstatesaregiven.Thediagramofanexampleisshown.
简介:Fromthegroupmovementofthebedloadwithinthebottomlayer,detailsofthenonlineardynamiccharacteristicsofbedloadmovementarediscussedinthispaper.Whetherthesedimentisinitiatedintomotioncorrespondstowhethertheconstanttermintheequationisequaltozero.Ifconstanttermiszeroandnodispersiveforceisconsidered,theequationrepresentsthetraditionalShieldsinitiationcurve,andifconstanttermiszerowithoutthedispersiveforcebeingconsidered,thenanewShieldscurvewhichismuchlowerthanthetraditionaloneisgot.Thefixedpointoftheequationcorrespondstotheequilibriumsedimenttransportofbedload.Inthemutationanalysis,wehavefoundthattheinflectionpointisthedemarcationpointofbreaking.Intheory,thebreakingpointcorrespondstothedividingboundaryline,acrosswhichthebedformchangesfromflatbedtosandrippleorsanddune.ComparedwiththeexperimentaldataofChatouHydraulicLabinFrance,theconclusionsareverified.
简介:Wededuceacompletewavepropagationequationthatincludesinhomogeneityofthedielectricconstantandpresentthispropagationequationincompactvectorform.Althoughsimilarequationsareknowninnarrowfieldssuchasradiowavepropagationintheionosphereandelectromagneticandacousticwavepropagationinstratifiedmedia,wedevelophereanovelapproachofusingsuchequationsinthemodelingoflaserbeampropagationinnonlinearmedia.Ourapproachsatisfiesthecorrespondenceprinciplesinceinthelimitofzero-lengthwavelengthitreducesfromphysicaltogeometricaloptics.
简介:Theconjugategradientmethodforunconstrainedoptimizationproblemsvarieswithascalar.Inthisnote,ageneralconditionconcerningthescalarisgiven,whichensurestheglobalconvergenceofthemethodinthecaseofstrongWolfelinesearches.ItisalsodiscussedhowtousetheresulttoobtaintheconvergenceofthefamousFletcher-Reeves,andPolak-Ribiere-Polyakconjugategradientmethods.Thattheconditioncannotberelaxedinsomesenseismentioned.
简介:Startingfromnonlinearequationsonthef-planecontainingfrictionaldissipationundertheBoussinesqapproximation,anewkindofgeneralizedenergyisproposedastheLyapunovfunction,andaveragesaretakenasanyfunctionsof(x,z)insteadofthecommonly-usedmeansofbilinearfunctionsof(x,z),therebyresultinginanewcriterionofgeneralizednonlinearsymmetricstability.Itshowsthatnotonlymustthedissipativecoefficientbegreaterthanacertaincriticalvaluebuttheinitialdisturbanceamplitudemustbesynchronouslysmallerthananothermarginalvalueaswell.Itfollowsthatthelatterimposesacrucialconstraintontheformer,thusleadingtothefactthatwhentheamplitudeisbiggercomparedtoanothercriticalvalue,generalizednonlinearsubcriticalsymmetricalinstabilitymayoccur.Thenewcriterioncontributesgreatlytotheimprovementofthepreviousresultsofitskind.
简介:Inanormalousdispersionofmonomodeopticalfiber,opticalsolitonsareevolvedfromopticalpulseswhenthedispersionisbalancedbythenonlinearity.Undistortedtransmissioncanberealizedbyusingopticalsolitons,whichcanoffermuchgreaterthetransmissioncapacityandextendtherepeaterspacingofthefibercommunicationsystem.Themechanismofthegenerationofopticalsolitonsisexpounded.Afewformsofnonlineartransmissionequationareobtainedbyusingaconcisemethod.Thegeneralcompleteexpressionofelementarysolitonsolutionofthenonlineartransmissionequationwithoutlossisgiven,andthedesignofthesolitontransmissionsystemisdiscussed.
简介:Someofthemathematicalpropertiesoftheinterfacebetweentwoincompressibleinviscidandimmisciblefluidswithdifferentdensitiesundertheinfluenceofaconstantgravityfieldgareinvestigated.ThepurposeofthispaperistoprovethatlinearlyunstablemodesforRayleigh-Taylorinstabilitiesgivebirthtononlinearinstabilitiesforthefullnonlinearsystem.Themainingredientisageneralinstabilitytheoreminananalyticframeworkwhichenablesustogofromlineartononlinearinstabilities.
简介:§1.IntroductionAssociatedwiththeeigenvalueproblem
简介:
简介:完美的改编描述一个生物系统的能力在被环境骚乱影响以后精确恢复它的生物函数到不安前水平。算术地,有完美的改编的一个生物系统能作为输入产量被建模产量的非线性的系统,通常决定生物函数,在担心的所有输入骚乱下面是asymptotically稳定的。在这份报纸,相当一般的输入产量数学模型被雇用并且生物功能(FBF)功能-产量Lyapunov功能-被探索调查它的完美的改编能力。足够的状况与FBF为系统被建立完成完美的改编。然后,一个足够、必要的条件被获得让线性系统拥有一个输出Lyapunov函数。而且,这被显示出受体功能活动在E的完美的改编模型存在。coli趋化性。与存在不同完美的改编,其大多数基于控制理论的立场,上的数学调查我们首先用非线性的系统分析的方法调查这个问题。
简介:交换非线性的系统的一个类的稳定在纸被调查。担心的系统具有(概括)交换了Byrnes-Isidori正规形式,它都交换了模型在(概括)Byrnes-Isidori正规形式。首先,交换系统的稳定性结果被获得。然后,解决交换非线性的控制系统的稳定问题被用来。另外,必要;足够的条件为是等价于的反馈的一个交换仿射的非线性的系统被获得(概括)交换Byrnes-Isidori正规系统被介绍。最后,作为一个应用程序,交换lorenz系统的稳定性被调查。