简介:Bifurcationswithconstraintsareopenproblemsappearedinresearchonperiodicbifurcationsofnonlineardynamicalsystems,butthepresentsingularitytheorydoesn'tcontainanyanalyticalmethodsandresultsaboutit.Asthecomplementtosingularitytheoryandthefirststeptostudyonconstrainedbifurcations,herearegiventhetransitionsetsandpersistentperturbedbifurcationdiagramsof10elementarybifurcationofcodimensionnomorethanthree.
简介:The3-Dspiralstructureresultingfromthebalancebetweenthepressuregradientforce,Coriolisforce,andviscousforceisacommonatmosphericmotionpattern.Ifthenonlinearadvectivetermsareconsidered,thistypicalpatterncanbebifurcated.Itisshownthatthesurfacelowpressurewithconvergentcyclonicvorticityandsurfacehighpressurewithdivergentanticyclonicvorticityareallstableundercertainconditions.Theanomalousstructurewithconvergentanticyclonicvorticityisalwaysunstable.Buttheanomalousweakhighpressurestructurewithconvergentcyclonicvorticitycanexist,andthisdenotesthecyclone'sdyingout.
简介:On △I=4 Bifurcation PhenomenaOn△I=4BifurcationPhenomena¥ZhangJingye;YangSunandMikeGuidryTheexperiments-bythenew7--raydetector...
简介:Theeffectsoftheconstantexcitationonthelocalbifurcationoftheperiodicsolutionsinthe1:2internalresonantsystemswereanalyzedbasedonthesingularitytheory.Itisshownthattheconstantexcitationmakeinfluenceonlywhenthereexistsomenonlinearterms,intheoscillatorwithlowerfrequency.Besidesactingasmainbifurcationparameter,theconstantexcitation,togetherwithcoefficientsofsomenonlinearterms,maychangethevaluesofunfoldingparametersandthetypeofthebifurcation.Underthenon-degeneratecases,theeffectofthethirdordertermscanbeneglected.
简介:Thispaperdealswiththebifurcationproblemsofmultiparameterandmultibranchandtheirapproximations.Itderivesgeneralapproximationresultsofsolutionbranchesintheneighbourhoodofasingular(limit,turningormultibranch)point,andshowsthatturningandmultibranchpointsarebifurcationpoints.TheabstracttheoriesareappliedtoamixedfiniteelementapproximationofstationaryNavier-Stokesequation.
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.
简介:Theeffectofmaterialanisotropyonthebifurcationforvoidtormationinanisotropiccompressiblehyperelasticmaterialsisexamined.Numericalsolutionsareobtainedinananisotropicsphere,whosematerialistransverselyisotropicintheradialdirection.Itisshownthatthebifurcationmayoccureithertotherightortotheleft,dependingonthedegreeofmaterialanisotropy.Thedeformationandstresscontributioninthespherebeforecavitationaredifferentfromthoseaftercavitation.Thestabilityofsolutionsisdiscussedthroughacomparisonofenergy.
简介:Thispaperpresentstheexperimentalresultsonthedistributionofsedimentsatchannelbifurcation.Theexperimentshavebeenconductedinaphysicalmodelofchannelbifurcation.Itconsistsofastraightmainchannelwhichbifurcatesintotwobranchchannelsofdifferentwidths.Thetestrigisamobilebedwithfixedbank.Fourdifferentnoseshavebeenusedtostudythephenomenon.Foreachnose,threeupstreamdischargesviz.20l/s,30l/sand40l/shavebeenemployed.Fromthemeasureddata,dischargesandsedimenttransportratiosperunitwidtharecalculatedinthedownstreambranches.Thesedatahavebeensettothegeneralnodalpointrelationandasetofequationshasbeendevelopedtodescribethedistributionofsedimentstothedownstreambranchesfordifferentnoseangles.
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简介:Inthispaper,westudythelocalbifurcationofcriticalperiodsnearthenondegeneratecenter(theorigin)ofaclassofLiénardequationswithdegree2n,andprovethatatmost2n-2criticalperiods(takenintoaccountmultiplicity)canbeproducedfromaweakcenteroffiniteorder.Wealsoprovethatitcanhaveexactly2n-2criticalperiodsneartheorigin.
简介:FlowfieldsaroundarotatingcircularcylinderinauniformstreamarecomputedusingalowdimensionalGalerkinmethod.ResultsshowthattheformationofaFopplevortexpairbehindastationarycircularcylinderiscausedbythestructuralinstabilityinthevicinityofthesaddlelocatedattherearofthecylinder.Forrotatingcylinderabifurcationdiagramwiththeconsiderationoftwoparameters,ReynoldsnumberReandrotationparameterα,isbuiltbyakinematicanalysisofthesteadyflowfields.