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53 个结果
  • 简介:DYNAMICALBEHAVIORSFORATHREE-DIMENSIONALDIFFERENTIALEQUATIONINCHEMICALSYSTEMLINYIPING(SectionofMathematics,KunmingInstituteofT...

  • 标签: Local stability HOPF BIFURCATION multiple HOPF
  • 简介:Inthispaper,weconsiderexistenceanduniquenessofpositivesolutionstothreecouplednonlinearSchrdingerequationswhichappearinnonlinearoptics.Weusethebehaviorsofminimizingsequencesforaboundtoobtaintheexistenceofpositivesolutionsforthreecoupledsystem.Toprovetheuniquenessofpositivesolutions,weusetheradialsymmetryofpositivesolutionstotransformthesystemintoanordinarydifferentialsystem,andthenintegratethesystem.Inparticular,forN=1,weprovetheuniquenessofpositivesolutionswhen0≤β=μ1=μ2=μ3orβ>max{μ1,μ2,μ3}.

  • 标签: 非线性SCHRODINGER方程 正解的存在性 非线性耦合 耦合系统 非线性光学 径向对称性
  • 简介:Considerasystemofnonlinearwaveequations(e)2t-c2i△xui=Fi(u,(e)u,(e)x(e)u)in(0,∞)×(R)3fori=1,┈,m,whereFi(i=1,┈,m)aresmoothfunctionsofdegree2neartheoriginoftheirarguments,andu=(u1,┈,um),while(e)uand(e)x(e)urepresentthefirstand(secondderivativesofu,respectively.Inthispaper,theauthorpresentsanewclassofnonlinearityforwhichtheglobalexistenceofsmallsolutionsisensured.Forexample,globalexistenceofsmallsolutionsfor((e)2t-c21Δx)u1=u2((e)tu2)+arbitrarycubicterms,((e)2t-c22Δx)u2=u1((e)tu2)+((e)tu1)u2+arbitrarycubictermswillbeestablished,providedthatc21≠c22.

  • 标签: 波动方程 倍数 处处存在 偏微分方程 非线性
  • 简介:这份报纸的目的是为任何特定的热比率在3证明稳定的可压缩的isentropicMHD方程的一个空间地周期的弱答案的存在>1。证明为导致弱集中的密度,和方法的某更高的integrability的近似系统基于压力和动能的加权的估计。根据作者知识,是第一结果在三种尺寸对待稳定的可压缩的MHD方程的弱答案的存在与>1。

  • 标签: 磁流体动力学方程 可压缩 解的存在性 流体力学方程组 稳态 三维
  • 简介:在这篇文章,我们认为非线性的秒顺序的二个积极答案的存在是三点的单个边界价值问题:?u(t)=f(t,u(t))为,使=0和u()=u(1)遭到到u(0)的所有t(0,1)0,1),[0,1),并且是一个积极参数。非线性的术语f(t,u)是nonnegative,并且可能在t=0,t=1,和u=0单个。由固定的点索引理论和近似方法,我们证实那在那里存在*(0,+]以便上述问题为任何东西有至少二个积极答案(0,*)在非线性的条款f上的某些条件下面。

  • 标签: 奇异边值问题 正解的存在性 非线性项 近似方法 固定点 二阶
  • 简介:ThediscreteSobolev’sinequalitiesinL_pnormareprovedforthree-dimensionalsphericalandcylindricalcoordinates,byusingdiscreteHolderinequality.propertyofthetrianglefunctionsandcomplicateddeduction.

  • 标签: COORDINATES INEQUALITY TRIANGLE SPHERICAL HOLDER milar
  • 简介:Thepurposeofthispaperistoinvestigatesomesufficientandnecessaryconditionsforthree-stepIshikawaiterativesequenceswitherrortermsforuniformlyquasi-Lipschitzianmappingstoconvergetofixedpoints.OurresultsextendandimprovetherecentonesannouncedbyLiu[3,4],XuandNoor[5],andmanyothers.

  • 标签: 均一准Lipschitzian映射 三阶Ishikawa迭代 固定点 必要条件
  • 简介:Inthispaperwediscusstheexistenceofatleastthreesolutionsforaclassofgradientmixedboundaryvaluesystems.TheapproachisfullybasedonarecentthreecriticalpointstheoremofB.Ricceri[Athreecriticalpointstheoremrevisited,NonlinearAnal.,70:9(2009),3084-3089].

  • 标签: 应用数学 数学分析 数学理论 数学研究
  • 简介:Weusetheincrementalunknownsmethodinconjunctionwiththeiterativemethodstoapproximatethesolutionofthenonsymmetricandpositive-definitelinearsystemsgeneratedfromamultileveldiscretizationofthree-dimensionalconvection-diffusionequations.Theconditionnumbersofincrementalunknownsmatricesassociatedwiththeconvection-diffusionequationsandthenumberofiterationsneededtoattainanacceptableaccuracyareestimated.Numericalresultsarepresentedwithtwo-levelapproximations,whichdemonstratethattheincrementalunknownsmethodwhencombinedwithsomeiter-ativemethodsisveryeffcient.

  • 标签: 逻辑积 扩散方程 离散化 迭代法
  • 简介:InthepresentpaperweintroducearandomiterationschemeforthreerandomoperatorsdefinedonaclosedandconvexsubsetofauniformlyconvexBanachspaceandproveitsconvergencetoacommonfixedpointofthreerandomoperators.Theresultisalsoanextensionofaknowntheoreminthecorrespondingnon-randomcase.

  • 标签: 巴拿赫空间 线形算子 收敛 不动点 随机迭代
  • 简介:Thesoftwareforoil-gastransportandaccumulationistodescribethehistoryofoil-gastransportandaccumulationinbasinevolution.Itisofgreatvalueinrationalevaluationofprospectingandexploitingoil-gasresources.Themathematicalmodelcanbediscribedasacoupledsystemofnonlinearpartialdifferentialequationswithmovingboundaryvalueproblem.Foragenericcaseofthethree-demensionalboundedregion,bithisthesis,theeffectsofgravitation、buoyancyandcapillarypressureareconsidered,weputforwardakindofcharacteristicfinitedifferenceschemesandmakeusethickandthingridstoformacompleteset,andofcalculusofvaviations,thechangeofvariable,thetheoryofpriorestimatesandtechniques,Optimalorderestimatesinl~2normarederivedfortheerrorinapproximateassumption,Thuswehavecompletelysolvedthewell-knowntheoreticalproblemproposedbyJ.Douglas,Jr.

  • 标签: THREE-DIMENSIONAL MOVING boundary GRAVITATION BUOYANCY and
  • 简介:Thispaperpresentsalternatingdirectionfinitevolumeelementmethodsforthree-dimensionalparabolicpartialdifferentialequationsandgivesfourcomputationalschemes,oneisanalogoustoDouglasfinitedifferenceschemewithsecond-ordersplittingerror,theothertwoschemeshavethird-ordersplittingerror,andthelastoneisanextendedLODscheme.TheL2normandH1semi-normerrorestimatesareobtainedforthefirstschemeandsecondone,respectively.Finally,twonumericalexamplesareprovidedtoillustratetheefficiencyandaccuracyofthemethods.

  • 标签: Parabolic EQUATIONS METHODS for FINITE VOLUME
  • 简介:FOURIER-CHEBYSHEVSPECTRALMETHODFORSOLVINGTHREE-DIMENSIONALVORTICITYEQUATIONGUOBENYU(郭本瑜);LIJIAN(李健);MAHEPING(马和平)(Departmento...

  • 标签: THREE-DIMENSIONAL VORTICITY EQUATION Fourier-Chebyshev METHOD error
  • 简介:Inthispaper,bifurcationofsmallamplitudelimitcyclesfromthedegenerateequilibriumofathree-dimensionalsystemisinvestigated.Firstly,themethodtocalculatethefocalvaluesatnilpotentcriticalpointoncentermanifoldisdiscussed.Thenanexampleisstudied,bycomputingthequasi-Lyapunovconstants,theexistenceofatleast4limitcyclesonthecentermanifoldisproved.Intermsofdegeneratesingularityinhigh-dimensionalsystems,ourworkisnew.

  • 标签: 极限环分支 三维系统 Lyapunov 复性 中心流形 高维系统
  • 简介:Inthispaper,Chebyshevpseudospectral-finiteelementschemesareproposedforsolvingthreedimensionalvorticityequation.SomeapproximationresultsinnonisotropicSobolevspacesaregiven.Thegeneralizedstabilityandtheconvergenceareprovedstrictly.Thenumericalresultsshowtheadvantagesofthismethod.Thetechniqueinthispaperisalsoapplicabletootherthree-dimensionalnonlinearproblemsinfluiddynamics.

  • 标签: THREE-DIMENSIONAL VORTICITY EQUATION CHEBYSHEV pseudospectral-hybrid finite