高维非自治系统的周期解

本文利用指数型二分性理论和不动点方法考虑系统Ｘ＝ｆ（ｔ,ｘ）,Ｘ＝Ａ（ｔ,ｘ）ｘ＋ｂ（ｔ,ｘ）的周期解的存在性问题,其中Ａ（ｔ,ｘ）是ｎ×ｎ连续矩阵函数,ｆ（ｔ,ｘ）,ｂ（ｔ,ｘ）是ｎ维连续向量函数,且关于ｔ以ｗ＞０为周期,所得结果推广了王联和曾唯尧的结果．     

一类微分差分方程的周期解

本文研究微分差分方程ｘ＇（ｔ）＝－ｆ（ｘ（ｔ），ｘ（ｔ－τ１））－ｆ（ｘ（ｔ），ｘ（ｔ－τ２））－．．．－ｆ（ｘ（ｔ），ｘ（ｔ－τｎ））非平凡周期解的存在性问题，得到了一些判别准则，推广和改进了文［１－４］的工作。     

高阶亚线性Duffing方程的周期解

在本文中，二阶亚线性Ｄｕｆｆｉｎｇ方程周期解存在的结果被推广到高阶Ｄｕｆｆｉｎｇ方：ｘ＾（２ｎ）＋ｇ（ｘ）＝ｐ（ｔ）＝ｐ（ｔ＋２π）（ｎ≥１）和ｘ＾（２ｎ＋１）＋ｇ（ｘ）－ｐ（ｔ）＝ｐ（ｔ＋２π）。     

一类沿曲面的奇异积分算子的（L^∞,BMO）—有界性

设ｎ≥３，定义Ｔｆ（ｘ，ｘｎ）＝Ｐ．Ｖ．∫Ｒ＾ｎ－１ｂ（ｔ）Ｋ（ｔ）ｆ（ｘ＝ｔ，ｘｎ－Г（│ｔ│））ｄｔ，其中ｘ∈Ｒ＾ｎ－１，ｂ（ｔ）为Ｒ＾ｎ－１上的有界函数，Ｋ（ｔ）为Ｒ＾ｎ－１上满足Ｈｏｒｍａｎｄｅｒ条件的函数，且Г（ｓ）为〔０，∞）上的任意函数。本文给出了Ｔ为（Ｌ∞（Ｒ＾ｎ），ＢＭＯ（Ｒ＾ｎ））一型，或等价地（Ｈ＾１（Ｒ＾ｎ），Ｌ＾１（Ｒ＾ｎ））一型时，ｂ所应满足的充分必要条件。     

一个高阶三点边值问题的可解性

本文考虑以下三点边值问题：ｘ＾（ｎ）＝ｆ（ｔ，ｘ，．．．，ｘ＾ｎ－１）（０≤ｔ≤１），ｘ（０）＝ξ１，ｘ＾（ｉ）（ｃ）＝ξｉ＋１（０≤ｉ≤ｎ－３），ｘ（１）＝ξｎ，其中ｃ∈（０，１）ｇｎ ξｉ∈Ｒ＾ｋ是给定的，利用基于度理论的一定不动点定理，得到了关于以上边值问题的某些存在唯一性结果。     

一类高维时滞微分方程的周期解

本文考虑高维时滞微分方程ｘ′（ｔ）＝Ａ（ｔ,ｘ（ｔ））ｘ（ｔ）＋ｆ（ｔ,ｘ（ｔ－ｒ（ｔ）））其中（ｔ,ｘ）∈Ｒ^ｎ,Ａ（ｔ,ｘ）是ｎ×ｎ连续矩阵,ｆ（ｔ,ｘ）是ｎ维连续向量,ｒ（ｔ）是时间依赖的滞量,应用不动点定理,在确定的条件下,证明了该系统的周期解的存在性与唯一性     

一个反应扩散过程的门槛结果

本文讨论反应扩散方程Ｃａｕｃｈｙ问题（ｕｔ－△ｕ＝ｕ＾ｐ－ｕ＾ｐ－ｕ，Ｘ∈Ｒ＾ｎ，ｔ∈（０，Ｔ），ｕ（ｘ，０）＝ｕ０（ｘ）≥０，Ｘ∈Ｒ＾ｎ，解的整体存在性，渐近性质和Ｂｌｏｗ－ｕｐ问题，其中１＜ｑ＜ｐ＜ｎ＋２／ｎ－２，ｎ≥３或者１＜ｑ＜ｐ＋∞，ｎ＝２．得到门槛结果。     

△^2u=λu＋N＋4／N—4＋μf（x）的多解存在性

讨论了非齐次双调和方程边值问题｛△＾２ｕ＝λｕ＋Ｎ＋４／ｕＮ－４＋ｕｆ（ｘ）,ｘ∈Ωｎ＝△ｕ｜ｎ＝０,的两个正解的存在性和非存在性,这里Ω是Ｒ＾Ｎ内有界光滑区域,Ｎ〉４,λ∈Ｒ＾１,μΠ０,ｆ（ｘ）是非负连续函数。     

变系数高阶中立型泛函数分方程的振动性与渐近性

考虑变系数高阶中立型泛函微分方程ｄ＾ｎ／ｄｔ＾ｎ（ｘ（ｔ）＋ｐ（ｔ）ｘ（ｔ－τ（ｔ））＋ｍ∑ｉ＝１Ｐｉ（ｔ）ｘ（ｔ－τｉ（ｔ）＝０，在－１＜ｐ（ｔ）≤０情形下解的振动性与渐近性，取消了Ｐｉ（ｔ）≥ｑｉ＞０的限制，改进以往的相应结果，本文结果时高阶泛函方程Ｘ＾（ｎ）（ｔ）＋ｍ∑ｉ＝１ｐｉ（ｔ）ｘ（ｔ－τｉ（ｔ））＝０也是适用的。     

高维非自治系统非平凡周期解的存在性

本文利用非线性泛函分析中锥的理论，讨论了ｎ维非自治系统ｘ＝Ａ（ｔ）ｘ＋ｇ（ｔ，ｘ）ｘ∈Ｒ＾ｎ产工得到了系统（１）存在非平凡ω周期解的充分条件。     

ON THE ALMOST PERIODIC SOLUTIONS OF HIGHER DIMENSIONAL NONAUTONOMOUS SYSTEMS

By means of the properties of almost periodic system and Lyapunov function, we give some criteria which guarantee the existence and uniqueness and stability of almost periodic solutions of higher dimensional nonautonomous system. The result is more convenient and effective than the related result in[1].     

高维时滞周期的Kolmogorov型系统的正周期解

本文应用Ｂａｎａｃｈ空间中的Ｈｏｒｎ不动点得到了高维时滞的周期Ｋｏｌｍｏｇｏｒｏｖ型生态系统的正周期解存在性定理,作为这个定理的应用,讨论了几类时滞的周期ＬｏｔｋａＶｏｌｔｅｒｒａ型系统的正周期解的存在性问题,建立了新的实用的判别准则。     

PERIODIC AND ALMOST PERIODIC SOLUTIONS OF A CERTAIN INFINITE DELAY INTEGRAL EQUATION

In this paper,by using successive approximation method and fixed-point theorem,we discuss a class of infinite delay integral equation and obtain some sufficient conditions which guarantee the existence and uniqueness of the peri- odic and almost periodic solutions of the system.     

THE EXISTENCE AND STABILITY OF ALMOST PERIODIC SOLUTION

By using the ordinary dichotomy and theory of stability,we study the nonli- near differential equation and obtain some sufficient conditions which guarantee the existence and stability of almost periodic solution for the nonlinear diffe- rential equation.     

POSITIVE PERIODIC SOLUTION TO A CLASS OF NONLINEAR PERIODIC DIFFERENTIAL EQUATION WITH IMPULSES AND DELAY

In this paper, by using a fixed point theorem of Krasnoselskii, we study the positive periodic solution for a class of nonlinear periodic differential equation with impulses and delay. Firstly, definition of periodic solution and some lemmas are stated. Then some results of the existence of positive periodic solution about the equation are obtained.     

EXISTENCE AND UNIQUENESS OF PERIODIC SOLUTIONS TO A HIGHER DIMENSIONAL PERIODIC SYSTEM WITH DELAY

In this paper, using fixed point theorem, we discuss a higher dimensional nonautonomous periodic system with delay and give some suffcient criteria for the existence and uniqueness of periodic solution. Our results extend and improve some results in previous researches.     

广义 Liénard方程周期解的存在性和不存在性

研究了广义 Ｌｉéｎａｒｄ方程ｘ＋ｆ（ｘ,ｘ）ｘ＋ｇ（ｘ）＝ ０周期解的存在性和不存在性,在一定条件下,我们得到了非零周期解的存在与不存在的一些充分条件．     

FORCED ALMOST PERIODIC OSCILLATION OF SECOND ORDER NONLINEAR EQUATION

1 IntroductionConsider equation of the Duffing fOrmX" cx' g(x) = p(t) (1)where c is a constant, p and g are continuous functions defined on (--oo, oc).In the early years of the l990's, some authors investigated the existence andstability of periodic solution of system (1), when p(t) is a periodic function(see [1],[2]).In this paper, we consider the situation in where p(t) is an almost periodicfunction. Under some conditions, we prove the existence and uniqueness ofalmost periodic soluti…     

EXISTENCE AND UNIQUENESS OF ALMOST PERIODIC SOLUTIONS FOR FORCED RAYLEIGH EQUATIONS

1 IntroductionEquationor its nonhomogeneous formwhere p, q) r and w are constants, originated with the study of aerodinamica.And then as its generalization, forced Rayleigh equationespecially its periodic solution has been studied by many authors. For example,R.Reissig [1], proved equation (1.1) has at least one w-periodic solution underthe following conditionsi) F(v), g(x) and e(t) are continuous functions;n) Suppose that m 5 0 5 M, and that there exists a positive number V,such that when …     

奇次周期Riccati型微分系统的周期解

本文讨论的是一类奇次周期Riccati型方程的周期解问题,利用数学归纳法,得到了奇次周期Riccati型方程周期多个周期解存在的充分条件,并且给出了定理实现的例子。