具有时滞的n维Liénard型方程调和解的存在性

本文利用迭合度理论研究了具有时滞的n维Lienard型方程调和解的存在性,在对阻尼项不作限制的前提下,给出了存在调和解的条件．     

一类带有界回复力非线性Hill型方程的周期解

该文研究了一类带有界回复力的Hill方程的周期解问题.针对权函数为正数的情形,证明了无穷多个次调和解的存在性.当权函数关于时间是偶函数时,证明了无穷多个偶次调和解的存在性和偶次调和解的稠密性分布.     

双曲极限环在周期扰动下次调和解的分支

研究了一给定平面自治系统的双曲极限环在周期扰动下m阶次调和解的分支问题,用Poincar啨映射,通过变尺度方法,获得了判别m阶次调和解的存在条件,最后给出了一个实例。     

时间映射和跨共振点的Duffing方程

本文在较弱的条件下证明了跨共振点的Duffing方程至少存在一个调和解和无穷多个次调和解,并在对称情况下给出了对称次调和解的一个稠密性分布定理。主要的讨论建立在对时间映射的分析,并利用由丁伟岳推广的Poincare-Birkhoff 扭转定理。     

具有时滞的n维Lienard型方程的调和解

本文讨论具有周期扰动的ｎ维时滞Ｌｉｅｎａｒｄ型方程ｐ（ｔ）的调和解．给出了存在调和解的若干充分条件,推广了ＧｅＷｅｉｇａｏ（１９９１）文中的相关结果．     

具有时滞的$n$维Li\''{e}nard型方程调和解的存在性

本文利用迭合度理论研究了具有时滞的$n$维Li\'{e}nard型方程调和解的存在性,在对阻尼项不作限制的前提下,给出了存在调和解的条件.     

具时滞n维Lienard型方程调和解的存在性

该文利用重合度理论和一些分析技巧讨论了具时滞狀维Ｌｉéｎａｒｄ 型方程狓″＋ｄｄ狋ｇｒａｄ犉（狓）＋ｇｒａｄ犌（狓（狋－τ））＝狆（狋）调和解的存在性，在对阻尼项ｄｄ狋ｇｒａｄ犉（狊）没有任何限制的前提下，给出了存在调和解的条件．     

一类一阶Hamilton系统的次调和解

运用临界点理论中的极小极大方法得到一类一阶Hamilton系统的次调和解的存在性定理.     

偏差变元的二阶n-维p-Laplacian方程调和解的存在性

本文研究了一类具偏差变元的二阶n-维p-Laplacian方程调和解的存在性,在对阻尼项不作限制的前提下,利用拓扑度理论得到了存在调和解的新条件,改进了一些已有的结果.     

一类局部非二次Hamilton系统的次调和解的存在性

运用极小极大方法得到一类局部非二次的Hamilton系统的次调和解的存在性定理.     

Existence of positive solutions for fourth-order m-point boundary value problem with variable parameters

In this paper, we investigate the existence of positive solutions for a class of nonlinear fourth-order m-point boundary value problem with two variable parameters. By using the fixed point index theory, we give some new existence results.     

Non-zero solutions for a class of generalized variational inequalities in reflexive Banach spaces

In this paper, we study the existence of nonzero solutions for a class of generalized variational inequalities involving set-contractive mappings by using the fixed point index approach in reflexive Banach spaces. Under some suitable assumptions, we show some new existence theorems of nonzero solutions for this class of generalized variational inequalities in reflexive Banach spaces.     

Positive and Nontrivial Solutions for the Urysohn Integral Equation

We establish new criteria for the existence of either positive or nonzero solutions of the Urysohn integral equation. We also discuss the existence of an interval of positive eigenvalues and sufficient conditions for the existence of at least a positive eigenvalue with a nonzero or positive eigenfunction for the Urysohn integral operator. Among others, we employ techniques based on fixed point index theory for compact maps, which are new for this type of equation.     

Positive solutions for systems of a nonlinear fourth-order singular semipositone boundary value problems

In this paper, we study the existence of positive solutions of a two-point boundary value problem for a system of fourth-order nonlinear singular semipositone differential equations by the fixed point index theorem. Some new existence results are established, and an example is given to demonstrate the application of our main results.     

MULTIPLE POSITIVE SOLUTIONS TO A SYSTEM OF NONLINEAR HAMMERSTEIN TYPE INTEGRAL EQUATIONS

In this paper, we use cone theory and a new method of computation of fixed point index to study a system of nonlinear Hammerstein type integral equations, and the existence of multiple positive solutions to the system is discussed.     

Nested sequences of index filtrations and continuation of the connection matrix

In this paper, we prove the existence of nested sequences of index filtrations for convergent sequences of (admissible) semiflows on a metric space. This result is new even in the context of flows on a locally compact space. The nested index filtration theorem implies the continuation of homology index braids which, in turn, implies the continuation of connection matrices in the infinite-dimensional Conley index theory.     

2m阶Dirichlet边值问题的多解(英文)

本文讨论了非线性2m阶Dirichlet边值问题多解的存在性.在非线性项满足一定条件时,通过有效地利用锥中的不动点指数理论和解的反对称延拓法,得到关于变号解的一些新的存在结果.确切地说,得到该2m阶边值问题至少存在两个正解,两个负解和多个变号解.     

Triple Positive Solutions of Boundary Value Problems for High-order Fractional Differential Equation at Resonance with Singularities

In this paper, we investigate the existence of triple positive solutions of boundary value problems for high-order fractional differential equation at resonance with singularities by using the fixed point index theory and the Leggett-Williams theorem. The spectral theory and some new height functions are also employed to establish the existence of triple positive solutions. The nonlinearity involved is arbitrary fractional derivative, and permits singularity.     

Existence of Mild Solutions to Stochastic Delay Evolution Equations with a Fractional Brownian Motion and Impulses

In this article, we study the existence of mild solutions to stochastic impulsive evolution equations with time delays, driven by fractional Brownian motion with the Hurst index H > 1/2 via a new fixed point analysis approach.     

New results for the Liebau phenomenon via fixed point index

We prove new results regarding the existence of positive solutions for a nonlinear periodic boundary value problem related to the Liebau phenomenon. As a consequence we obtain new sufficient conditions for the existence of a pump in a simple model. Our methodology relies on the use of classical fixed point index. Some examples are provided to illustrate our theory. We improve and complement previous results in the literature.