Melnikov函数在中心处的可微性问题

本文证明（一阶）Melnikov函数在初等中心处关于Hamilton量至少为二次可微，井且得到二阶Melnikov函数为二次可微的充要条件，最后举例说明文[3,4]所讨论的一类扰动系统的后继函数在中心处不是二阶可微的．     

指数二分性与高阶Melnikov函数

本文利用指数二分性理论和Liapunov－Schmidt方法，研究了当Melnikov函数具有高阶零点时的横截同宿轨道的存在性，得到了一个所谓的高阶Melnikov函数     

Bogdanov-Takens系统的三次齐次扰动

对Bogdanov-Takens向量场的三次齐次扰动系统进行了讨论，得到了当其前二阶Melnikov函数恒为0时，则其后各阶Melnikov函数一定为0，且对于小的扰动参数，此系统为可积的或为Hamilton的；并对M1（h)≠0和M1(h)≡0，M2(h)≠0两种情形该系统的分岔结构给出了较全面的结论。     

PERTURBATIONS OF A KIND OF DEGENERATE QUADRATIC HAMILTONIAN SYSTEM WITH SADDLE－LOOP

61. IntroductionConsidcr a Hamiltonian system with smaIl perturbations{::leq:jix:<,\:>!>, (1l.)where X(x, y, e) and Y(I, y, ') are polynomia1s of T, y with coefficients depending analyti-cally on the small paramcter e, and the unperturbed s)ystern (1.l)() has at least onc cel1tersurrounded b}' the compact component r}, of algebraic curveH(x, g) = h, deg H(x, y) = m + 1, nlax{deg X(x. y, '). dog y(J. y. ')} = 7n.Tbe number of ]jm jt cyc]es of (1.1 ). whjcb emergp fIon) Th is equa] to tbe l1…     

EXPONENTIAL DICHOTOMIES,HOMOCLINIC ORBITS AND METHODS OF MELNIKOV

ＥＸＰＯＮＥＮＴＩＡＬＤＩＣＨＯＴＯＭＩＥＳ，ＨＯＭＯＣＬＩＮＩＣＯＲＢＩＴＳＡＮＤＭＥＴＨＯＤＳＯＦＭＥＬＮＩＫＯＶ（曾唯尧，钱祥征，王志成）￥ＺｅｎｇＷｅｉｙａｏ（Ｄｅｐｔ．ｏｆＭａｔｈ．，ＨｕｎａｎＬｉｇｈｔＩｎｄｕｓｔｒｉａｌＣｏｌｌｅｇｅ，...     

A CLASS OF QUADRATIC HAMILTONIAN SYSTEMS UNDER QUADRATIC PERTURBATION

1 IntroductionConsider a Hamiltonian system with small perturbationwhere E is a small parameter. H(x, y), P(x, y) and Q(x, y) are all real polynimials of x and ywith degH = n 1, degP degQ 5 n. We suppose there is a fandly of ovals r(h) C {H(x, y) = h}for h E (ho, h1).The nunther of limit cycles of (1.1). l which tend to some r(h) as e -- 0, is closely relatedto the number of isolated zeroes of Abelian integraJThe next problem is to determille the lowest bound of the isolated zeroes of M…     

扰动双中心Hamiltonian系统的分支

本文对一类具双中心的二次Ｈａｍｉｌｔｏｎｉａｎ扰动系统的Ｈｏｐｆ分支、Ｐｏｉｎｃａｒé分支进行了研究，并讨论了能否在双中心同时产生极限环的问题     

LIMIT CYCLES OF A QUADRATIC HAMILTONIAN SYSTEM BY CUBIC PERTURBATIONS

In this paper,we are concerned with a cubic near-Hamiltonian system,whose unperturbed system is quadratic and has a symmetric homoclinic loop.By using the method developed in [12],we find that the system can have 4 limit cycles with 3 of them being near the homoclinic loop.Further,we give a condition under which there exist 4 limit cycles.     

The third order Melnikov function of a quadratic center under quadratic perturbations

We study quadratic perturbations of the integrable system , where H=(x²+y²)/2. We prove that the first three Melnikov functions associated to the perturbed system give rise at most to three limit cycles.     

指数型二分性,Melnikov函数和异宿轨道

本文用不同于Ｐａｌｍｅｒ＾［２］的方法，讨论了非自治微分方程存在异宿轨道的条件。得到了已知文献中不同的一个Ｍｅｌｍｉｋｏｖ型的函数。     

BIFURCATIONS OF LIMIT CYCLES FROM A HETEROCLINIC CYCLE OF HAMILTONIAN SYSTEMS

§１．ＮｏｒｍａｌＦｏｒｍｓｏｆＤｉｓｐｌａｃｅｍｅｎｔＦｕｎｃｔｉｏｎｓＣｏｎｓｉｄｅｒａｐｌａｎａｒＣ∞ｓｙｓｔｅｍｏｆｔｈｅｆｏｒｍｘ＝ｆ（ｘ）＋λｆ０（ｘ，δ，λ）≡ｆ（ｘ，δ，λ），（１．１）ｗｈｅｒｅｘ∈Ｒ２，λ∈Ｒ，δ∈Ｒｍ，ａｎｄｔｒ...     

三维系统中一族闭轨在周期扰动下的分支

讨论一类三维系统在周期扰动下的分支问题.假设此三维系统有一族闭轨,利用 Poincar\'e映射及积分流形定理,得到了在周期扰动下由这族闭轨产生次调和解和不变环面的条件,并讨论了次调和解的鞍结点分支.     

具有星形结点的三次系统的极限环

本文研究具有星形结点的三次系统ｘ＝ｘ＋Ｐ２（ｘ，ｙ）＋Ｐ３（ｘ，ｙ），ｙ＝ｙ＋Ｑ２（ｘ，ｙ）＋Ｑ３（ｘ，ｙ），引入函数ｇ４（θ）见（１．６）和Ａ（θ）（见４．４）），得到下述结论；若ｇ４有零点，则不存在包围原点在其内部的闭轨，特别地，若ｇ４＝０，则全平面不存在闭轨；若ｇ４定号，Ａ常号，则至多存在一个闭轨，若存在，它必包含所有在其内部，且为星形的；若ｇ４定号而Ａ变号，则给出了极限环不唯一的例子。     

PERTURBATION EQUATION OF DLW HIERARCHY AND ITS HAMILTONIAN STRUCTURE

The first-order perturbation equation of DLW hierarchy is derived by virtue of zero-curvature equation. Then, Hamiltonian structure of the obtained system is given by means of component-trace identity.     

ON THE NUMBER OF LIMIT CYCLES OF A POLYNOMIAL DIFFERENTIAL SYSTEM

In this paper, we employ qualitative analysis and methods of bifurcation theory to study the maximum number of limit cycles for a polynomial system with center in global bifurcation.     

THE CALCULUS OF GENERATING FUNCTIONS AND THE FORMAL ENERGY FOR HAMILTONIAN ALGORITHMS

1.DarbouxTransformationConsidercotangentbundleT*R"acRZnwithnaturalsymplecticstructureandtheproductofcotangentbundles(T*R")x(T*R")=R4nwithnaturalproductsymplecticstructureCorrespondingly,weconsidertheproductspaceR"xR"rsRZn.ItscotangentbunT*(R"xR")=T*Rzn=R'nhasnaturalsymplecticstructure')PreparedbyQinMengzhaoChoosesymplecticcoordinatesz~(p,q)onthesymplecticmanifold,thenforsymplectictransformationg:T*R"~T*R",wehaveitisaLagrangiansubmanifoldofT*R"xT*RninR4n~(R'",J4.).NotethatonR4nth…     

THE LIMIT CYCLE OF A CLASS OF DYNAMICAL SYSTEM ABOUT CHEMICAL REACTION

1IntroductionInachemicalreaction'A-Al,itcanbeseenthatreactionspeedisapproximatelydirectratiototheconcentrationofreactant.Butreactionspeedisnotinfinitelyincreasingastheincreasingofconcentrationofreactant,thatis,ithasasaturatedreactionspeed.Oneoftherelation…     

奇摄动下的共振不变环面分支

本文研究高维退化系统在小扰动下的动力学行为,在共振的情况下,利用延拓的方法,讨论了扰动 系统不变环面的保存性,并利用推广的Melnikov函数、横截性理论讨论了同宿于不变环面的横截同宿 轨道存在的条件,推广和改进了一些文献的结果.     

周期参数扰动的T混沌系统周期轨道分析

本文研究了一类周期参数扰动的T混沌系统的周期轨道问题.利用次谐波Melnikov方法,获得了具有广义Hamilton结构的周期参数扰动的慢变系统的振荡周期轨道和旋转周期轨道.     

一类五次系统的赤道极限环问题

本文解决了一类五次系统赤道环的稳定性与极限环分枝问题,所得的结论与三次系统的若干结论形成有趣的对比.