FC-空间上的鞍点定理及应用

在不具有任何凸性结构和线性结构的有限连续空间(简称FC-空间)中给出了一个鞍点定理.并应用此定理,在很弱的条件下证明了一些非空交定理及截口定理,推广了近期文献中的一些相关的结果.     

发现法讲授中值定理的一种尝试

微分学中值定理通常包括费尔马定理、罗尔定理、拉格朗日定理、柯西定理、泰勒定理。用启发式讲授这些定理的方案很多。笔者设计一种用发现法讲述这组定理的一种方案。最近的教法研讨会上,笔者介绍这种方案,同行们希     

G-凸空间中的KKM定理，匹配定理和截口定理

在G-凸空间中证明了一些新的KKM型定理．作为应用,在G-凸空间中得到了一些新的匹配定理和截口定理,所得结果改进和推广了[2,3,7]中的相关结果．     

$\varOmega$-凸集的组合与结构性质[英文]

本文研究$\varOmega$-凸集的组合性质和结构性质. 在一定条件下, 证明关于$\varOmega$-凸集的Randon型定理, Helly型定理. Caratheodory型定理以及Minkowski型定理, 并举例说明对一般的$\varOmega$-凸集这些定理不一定成立. 文中所得结果是关于凸集的这些类型定理的推广, 同时也为有关$\varOmega$-凸函数的研究提供了理论工具.     

一类新的Gale型定理及其应用

本文利用局部凸拓扑向量空间中的分离定理,得到一类很一般的Ｇａｌｅ型定理,由此导出某些新的Ｍｉｎｉｍａｘ定理,这些结果是己知文献结果的实质性推广．     

四阶椭圆方程的弱解(英文)

本文研究了一个四阶椭圆方程解的存在性问题.利用山路定理和喷泉定理,结合变分方法,获得了该问题弱解的几个存在性定理,推广了现有的一些结果.     

几乎凸多值映射的逼近选择及对平衡存在性与不动点定理的应用

在局部凸拓扑向量空间中确立了新的非空几乎凸几乎下半连续多值映射的逼近选择定理.作为应用,我们还给出了一个平衡存在性定理及不动点定理.这些结果推广和改进了文献中已有的相关结论.     

一类新的KKM定理及其应用*

本文得到一类新的KKM定理,统一和改进了[2,3,0,7,11]中的结果。作为应用,我们得到了几个匹配定理、重合定理、不动点定理、极大极小不等式定理及截口定理。     

FC-空间上的选择定理与应用

在FC-空间中给出了选择定理,证明了一些非空交定理,推广了近期文献中的一些相关的结果.     

H-空间的截口定理重合定理相交定理及其应用*

本文的目的是在H-空间上得出几个截口定理、相交定理和重合定理.作为这些结果的应用,我们研究了H-空间中的极大极小不等式和变分不等式解的存在性问题.本文结果改进和发展了引文[1,3,5,6,8,9,12,14,15,17]中的相应结果.     

Gradient Estimates for p-Laplacian Lichnerowicz Equation on Noncompact Metric Measure Space

Abstract In this paper,the authors obtain the gradient estimates for positive solutions to the weighted p-Laplacian Lichnerowicz equation■on noncompact smooth metric measure space,where c is a nonnegative constant,and p,σ(1p≤2,σ≤p-1)are real constants.Moreover,by the gradient estimate,they can get the corresponding Liouville theorem and Harnack inequality.     

Multiple sign-changing solutions for a class of semilinear elliptic equations in $\mathbb{R}^{N}$

In this paper, we study the following semilinear elliptic equations $$-\triangle u+V(x)u=f(x,u), \ \ x\in \mathbb{R}^{N},$$ where $V\in C(\mathbb{R}^{N}, \mathbb{R})$ and $f\in C(\mathbb{R}^{N}\times\mathbb{R}, \mathbb{R})$. Under some suitable conditions, we prove that the equation has three solutions of mountain pass type: one positive, one negative, and sign-changing. Furthermore, if $f$ is odd with respect to its second variable, this problem has infinitely many sign-changing solutions.     

f-Laplace非线性方程的梯度估计和Liouville定理

设(M,g,e~(-f)dv_g)是n维完备光滑的度量测度空间.考虑以下非线性椭圆方程△_f~u+hu~α=0,1α(n+m)/(n+m-2)(n+m≥4)和非线性抛物方程(△_f-?/?t)u+hu~α=0,α0正解的梯度估计.对于经典的Laplace情形,Li (Li J. Gradient estimates and harnack inequalities for nonlinear parabolic and nonlinear elliptic equations on Riemannian manifolds [J]. J Funct Anal,1991, 100:233-256.)证明了正解的梯度估计和Liouville定理.在本文中,对于上述的f-Laplace方程,作者将推导出相应的结果.     

Positive Ground State Solutions for Schrödinger-Poisson System with General Nonlinearity and Critical Exponent

In this paper, we consider the following Schrödinger-Poisson system \begin{equation*}\begin{cases} -\Delta u + \eta\phi u = f(x,u) + u^5,& x\in\Omega,\\ -\Delta\phi=u^2,& x\in\Omega,\\u = \phi =0,& x\in \partial\Omega, \end{cases}\end{equation*} where $\Omega$ is a smooth bounded domain in $R^3$, $\eta=\pm1$ and the continuous function $f$ satisfies some suitable conditions. Based on the Mountain pass theorem, we prove the existence of positive ground state solutions.     

奇异非线性$p-$调和方程的一类正整体解

设p>1,β≥0是常数, n是自然数, 是一个连续函数.本文研究形如的奇异非线性p-调和方程的正整体解,给出了该类方程具有无穷多个其渐近阶刚好为|x|(2n-2)(当|x|→∞时)的径向对称的正整体解的若干充分条件.     

MULTIPLICITY OF PERIODIC SOLUTIONS OF DUFFING’S EQUATIONS WITH LIPSCHITZIAN CONDITION

This paper deals with the existence and multiplicity of periodic solutions of Duffing equations $\ddot{x}+g(x)=p(t)$. The author proves an infinity of periodic solutions to the periodically forced nonlinear Duffing equations provided that g(x) satisfies the globally lipschitzian condition and the time-mapping satisfies the weaker oscillating property.     

Triple positive periodic solutions of nonlinear singular second-order boundary value problems

This paper studies the positive solutions of the nonlinear second-order periodic boundary value problem u″(t) + λ(t)u(t) = f(t,u(t)),a.e.t ∈ [0,2π],u(0) = u(2π),u′(0) = u′(2π),where f(t,u) is a local Carath′eodory function.This shows that the problem is singular with respect to both the time variable t and space variable u.By applying the Leggett–Williams and Krasnosel'skii fixed point theorems on cones,an existence theorem of triple positive solutions is established.In order to use these theorems,the exact a priori estimations for the bound of solution are given,and some proper height functions are introduced by the estimations.     

Existence of Nonoscillatory Solutions for a Rational Difference Equation of Higher Order

In this paper, we investigate a rational difference equation of higher order for the existence of nonoscillatory solutions. To prove our main results, we use an inclusion theorem stated and proved in \cite{L1}. In this way, we give an answer of an open problem formulated in \cite{FPB}.     

一类奇异三阶三点边值问题的正解

In this paper,we study the existence of positive solutions for the nonlinear singular third-order three-point boundary value problemu （t） = λa（t）f（t,u（t））,u（0） = u （1） = u （η） = 0,where λ is a positive parameter and 0 ≤ η 1 2 .By using the classical Krasnosel’skii’s fixed point theorem in cone,we obtain various new results on the existence of positive solution,and the solution is strictly increasing.Finally we give an example.     

Landau-Type Theorems for Solutions of a Quasilinear Differential Equation

In this paper, we study solutions of the quasilinear differential equation $\bar{z}\partial_{\bar{z}}f(z)+z\partial_{z}f(z)+(1-|z|^2)\partial_{z}\partial_{\bar{z}}f(z)=f(z)$. We utilize harmonic mappings to obtain an explicit representation of solutions of this equation. By this result, we give two versions of Landau-type theorem under proper normalization conditions.