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65 个结果
  • 简介:Bifurcationswithconstraintsareopenproblemsappearedinresearchonperiodicbifurcationsofnonlineardynamicalsystems,butthepresentsingularitytheorydoesn'tcontainanyanalyticalmethodsandresultsaboutit.Asthecomplementtosingularitytheoryandthefirststeptostudyonconstrainedbifurcations,herearegiventhetransitionsetsandpersistentperturbedbifurcationdiagramsof10elementarybifurcationofcodimensionnomorethanthree.

  • 标签: CONSTRAINT SINGULARITY theory BIFURCATION
  • 简介:The3-Dspiralstructureresultingfromthebalancebetweenthepressuregradientforce,Coriolisforce,andviscousforceisacommonatmosphericmotionpattern.Ifthenonlinearadvectivetermsareconsidered,thistypicalpatterncanbebifurcated.Itisshownthatthesurfacelowpressurewithconvergentcyclonicvorticityandsurfacehighpressurewithdivergentanticyclonicvorticityareallstableundercertainconditions.Theanomalousstructurewithconvergentanticyclonicvorticityisalwaysunstable.Buttheanomalousweakhighpressurestructurewithconvergentcyclonicvorticitycanexist,andthisdenotesthecyclone'sdyingout.

  • 标签: 水平分布 垂直旋涡状态 大气空间结构 分支 非线性动力方程
  • 简介:On △I=4 Bifurcation PhenomenaOn△I=4BifurcationPhenomena¥ZhangJingye;YangSunandMikeGuidryTheexperiments-bythenew7--raydetector...

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  • 简介:Inthispaper,westudytheperturbationofcertainofcubicsystem.Byusingthemethodofmulti-parameterperturbationtheoryandqualitativeanalysis,weinferthatthesystemunderconsiderationcanhavefivelimitcycles.

  • 标签: 扰动 分叉 立方系统 极限循环 环论
  • 简介:Theeffectsoftheconstantexcitationonthelocalbifurcationoftheperiodicsolutionsinthe1:2internalresonantsystemswereanalyzedbasedonthesingularitytheory.Itisshownthattheconstantexcitationmakeinfluenceonlywhenthereexistsomenonlinearterms,intheoscillatorwithlowerfrequency.Besidesactingasmainbifurcationparameter,theconstantexcitation,togetherwithcoefficientsofsomenonlinearterms,maychangethevaluesofunfoldingparametersandthetypeofthebifurcation.Underthenon-degeneratecases,theeffectofthethirdordertermscanbeneglected.

  • 标签: 固定激励 局部分歧 内部谐振 奇点理论
  • 简介:我们与处理描述并且分析一个简单SIS模型。特别地,我们借助于asymptotically自治的系统的理论给完全质的分析。如果足够的接触率或能力是小的,向后的分叉发生,这被发现。在那里存在,也被发现双稳态地方性的equilibria。在导致疾病的死亡的情况中,向后的分叉也发生,这被显示出。而且,在一些条件,和潜水艇下面没有限制周期批评Hopf分叉发生在另外一个下面条件。

  • 标签: 优选模型 SIS模型 传染病模型 应用数学
  • 简介:Thispaperdealswiththebifurcationproblemsofmultiparameterandmultibranchandtheirapproximations.Itderivesgeneralapproximationresultsofsolutionbranchesintheneighbourhoodofasingular(limit,turningormultibranch)point,andshowsthatturningandmultibranchpointsarebifurcationpoints.TheabstracttheoriesareappliedtoamixedfiniteelementapproximationofstationaryNavier-Stokesequation.

  • 标签: BIFURCATION TURNING stationary STOKES BRANCHES NAVIER
  • 简介:AnSMIBmodelinthepowersystems,especiallythatconceringtheeffectsofhardlimitsonbifurcations,chaosandstabilityisstudied.Parameterconditionsforbifurcationsandchaosintheabsenceofhardlimitsarecomparedwiththoseinthepresenceofhardlimits.Ithasbeenprovedthathardlimitscanaffectsystemstability.Wefindthat(1)hardlimitscanchangeunstableequilibriumintostableone;(2)hardlimitscanchangestabilityoflimitcyclesinducedbyHopfbifurcation;(3)persistenceofhardlimitscanstabilizedivergenttrajectorytoastableequilibriumorlimitcycle;(4)HopfbifurcationoccursbeforeSNbifurcation,sothesystemcollapsecanbecontrolledbeforeHopfbifurcationoccurs.Wealsofindthatsuitablelimitingvaluesofhardlimitscanenlargethefeasibilityregion.Theseresultsarebasedontheoreticalanalysisandnumericalsimulations,suchasconditionforSNBandHopfbifurcation,bifurcationdiagram,trajectories,Lyapunovexponent,Floquetmultipliers,dimensionofattractorandsoon.

  • 标签: SMIB 分枝 模糊 稳定性 可能性域 微分方程
  • 简介:Theeffectofmaterialanisotropyonthebifurcationforvoidtormationinanisotropiccompressiblehyperelasticmaterialsisexamined.Numericalsolutionsareobtainedinananisotropicsphere,whosematerialistransverselyisotropicintheradialdirection.Itisshownthatthebifurcationmayoccureithertotherightortotheleft,dependingonthedegreeofmaterialanisotropy.Thedeformationandstresscontributioninthespherebeforecavitationaredifferentfromthoseaftercavitation.Thestabilityofsolutionsisdiscussedthroughacomparisonofenergy.

  • 标签: 各向异性材料 空穴分支 能量对比 压缩超弹性材料 材料力学 数值分析
  • 简介:有二个参数的动态系统的分叉性质在这份报纸被调查。设置的转变的定义被建议,并且开发的途径被用来与非线性的反馈控制器调查非线性的强迫的未击中的系统的动态特征。整个参量的飞机被转变集合划分成几个坚持的区域,然后在不同坚持的区域的分叉图被获得。关键词二个参数-分叉-单个分析工程被中国(10632040)的国家自然科学基础支持。

  • 标签: 动力系统 分岔 奇异 反馈控制系统 动态特性 参数平面
  • 简介:Thispaperpresentstheexperimentalresultsonthedistributionofsedimentsatchannelbifurcation.Theexperimentshavebeenconductedinaphysicalmodelofchannelbifurcation.Itconsistsofastraightmainchannelwhichbifurcatesintotwobranchchannelsofdifferentwidths.Thetestrigisamobilebedwithfixedbank.Fourdifferentnoseshavebeenusedtostudythephenomenon.Foreachnose,threeupstreamdischargesviz.20l/s,30l/sand40l/shavebeenemployed.Fromthemeasureddata,dischargesandsedimenttransportratiosperunitwidtharecalculatedinthedownstreambranches.Thesedatahavebeensettothegeneralnodalpointrelationandasetofequationshasbeendevelopedtodescribethedistributionofsedimentstothedownstreambranchesfordifferentnoseangles.

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  • 简介:点火的分叉分析和催化燃烧在的扑灭一突然微隧道被执行,laminar模型作为流动模型合并了。横向的Thiele模量和滞留时间的平方被用作分叉参数。点火和扑灭行为上的不同参数的影响被调查。所有这些参数在点火和扑灭的分叉行为上有大效果在,这被显示出突然微隧道。燃烧的分叉行为上的流动模型的效果也被分析。结果证明与扁平的速度侧面模型比较,为laminar模型的案例,点火的温度和燃烧的扑灭更高,不稳定的多重答案区域更大。

  • 标签: 催化燃烧 分叉理论 热学 热处理
  • 简介:Inthispaper,westudythelocalbifurcationofcriticalperiodsnearthenondegeneratecenter(theorigin)ofaclassofLiénardequationswithdegree2n,andprovethatatmost2n-2criticalperiods(takenintoaccountmultiplicity)canbeproducedfromaweakcenteroffiniteorder.Wealsoprovethatitcanhaveexactly2n-2criticalperiodsneartheorigin.

  • 标签: LIÉNARD方程 局部分岔 局部分歧 非退化 有限阶 多重性
  • 简介:ANEWDETECTINGMETHODFORCONDITIONSOFEXISTENCEOFHOPFBIFURCATIONSHENJIAQI(沈家骐);JINGZHUJUN(井竹君)(DepartmentofMathematics,ShandongUn...

  • 标签: HURWITZ DETERMINANT matrix theory detecting method
  • 简介:FlowfieldsaroundarotatingcircularcylinderinauniformstreamarecomputedusingalowdimensionalGalerkinmethod.ResultsshowthattheformationofaFopplevortexpairbehindastationarycircularcylinderiscausedbythestructuralinstabilityinthevicinityofthesaddlelocatedattherearofthecylinder.Forrotatingcylinderabifurcationdiagramwiththeconsiderationoftwoparameters,ReynoldsnumberReandrotationparameterα,isbuiltbyakinematicanalysisofthesteadyflowfields.

  • 标签: TOPOLOGICAL BIFURCATION GALERKIN method circular cylinder