向量Lienard型方程的多个调和解

存在多个(无穷多个)调和解的条件,其中x∈R~n,F∈C~2(R~n,R),G∈C~2(R~n,R),p∈C~0(R,R~n),且p(t+T)≡p(t),integral from n=1 to p(t)dt=0。 对高维非线性非自治系统调和解的讨论,通常都要给出条件,保证周期解只在一个有界集内存在,然后对包含上述有界集的有界凸域利用不动点原理证明调和解的存在性。这样的处理方法很难对调和解的个数问题作深入讨论。本文采用广义Lienard变换首     

一类具有时滞的Liénard方程的调和解

利用Mawhin的重合度理论讨论一类具有时滞的Liénard方程x″(t)+f(x(t))x′+g(x(t-τ(t)))=p(t)的调和解,推广和改进了现有的结果.     

微分方程x+g(x)=p(T)的调和解

通过估计方程x+g(x)=p(t)之解绕原点一周的时间,讨论了周期解存在的条件及调和解的存在唯一性。     

具时滞n维Liénard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 n维 L iénard型方程 x″+ ddtgradF( x) + grad G( x( t- τ) ) =p( t)调和解的存在性 ,在对阻尼项 ddtgrad F( s)没有任何限制的前提下 ,给出了存在调和解的条件 .     

n维Liénard型方程的调和解

本文讨论有周期扰动的n-维Liónard型方程 +■~2F(x)/■x~2■+G(x)=p(t)的调和解,给出了存在调和解的一系列充分性判据。当G(x)=x~TBx时,给出了存在唯一调和解的条件。     

微分方程 g(x)=p(T)的调和解

通过估计方程 g(x)=p(t)之解绕原点一周的时间,讨论了周期解存在的条件及调和解的存在唯一性。     

方程+f(x)■+g(x)=p(t)的调和解

本文不作假设integral from 0 to ±∞ (f(x)+|g(x)|dx=±∞),得到方程(?)+f(x)(?)+g(?)=p(t)调和解的存在性,以及当integral from 0 to ±∞(g(x)dx=+∞时,其解的正向有界性和当g(x)=x,f(x)>0时,其调和解的渐近稳定性、唯一性。     

一类非线性振动方程的小摄动

本文考虑一类非线性振动方程:x″ g(x)h(x′)=εcosωt,(1)当小参数ε的绝对值充分小时,其调和解的存在性问题.方程(1)等价于     

次线性Duffing系统的多重次调和解

本文证明了，次线性Ｄｕｆｆｉｎｇ系统存在无穷多个高阶次调和解及次调和解列是无界的。     

具有时滞的n维Liénard型方程的调和解

本文讨论具有周期扰动的n维时滞Liénard型方程()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.     

广义Davey-Stewartson方程组的整体解及自相似解

本文研究Dalvey-Stewartson方程组的整体解与自相似解的存在性.首先,运用Ba- nach不动点定理得到一个关于解整体存在性的一般性定理,然后把一类特殊的初始值用到该存在性结果上去从而得到自相似解存在的结论.     

Solutions of the generalized Lennard-Jones system

In this paper, we study solution structures of the following generalized Lennard-Jones system in R~n,x=(-α/|x|~(α+2)+β/|x|~(β+2))x,with 0 α β. Considering periodic solutions with zero angular momentum, we prove that the corresponding problem degenerates to 1-dimensional and possesses infinitely many periodic solutions which must be oscillating line solutions or constant solutions. Considering solutions with non-zero angular momentum, we compute Morse indices of the circular solutions first, and then apply the mountain pass theorem to show the existence of non-circular solutions with non-zero topological degrees. We further prove that besides circular solutions the system possesses in fact countably many periodic solutions with arbitrarily large topological degree, infinitely many quasi-periodic solutions, and infinitely many asymptotic solutions.     

AF—代数的闭的Jordan理想

讨论AF-代数的闭的Jordan理想。我们证明了AF-代灵敏的一个闭的子集是其一Jordan理想的充分必要条件是它是一个结合理想。     

一类半线性积分微分方程初边值问题的爆破解和全局解

本文研究初边值问题的爆破解和全局解，证明了在ｆ的凸性假设和一定的增长性假定下解在有限时刻爆破，而在ｆ的其他假设下证明了全局解的存在性。     

一类拟线性常微分方程的多解

说明一类拟线性特征值问题有两个正解;一个大解,一个小解。同时本也证明小解是一个山路解当参数大时发展成为尖解。     

关于运输问题最优解的进一步讨论

首先给出了运输问题最优解的相关概念,将最优解扩展到广义范畴,提出狭义多重最优解和广义多重最优解的概念及其区别.然后给出了惟一最优解、多重最优解、广义有限多重最优解、广义无限多重最优解的判定定理及其证明过程.最后推导出了狭义有限多重最优解个数下限和广义有限多重最优解个数上限的计算公式,并举例验证了结论的正确性.     

Generalized Maximin Solutions in Multicriteria Bargaining

In this paper we address bargaining games where the agents have to take into account different criteria to value the decisions. We propose the class of generalized maximin solutions, as the natural extension for these games of the maximin solutions in conventional bargaining. In order to refine this solution concept, we define a multicriteria lexicographic partial ordering and present the class of generalized leximin solutions as those that are nondominated with respect to this relation. We establish some properties of these solutions and characterize them as solutions of multicriteria problems. The research of the authors is partially supported by the Spanish Ministry of Science and Technology projects BFM2002-11282-E and BEC2003-03111.     

Affine-Periodic Solutions and Pseudo Affine-Periodic Solutions for Differential Equations with Exponential Dichotomy and Exponential Trichotomy

It is proved that every $(Q,T)$-affine-periodic differential equation has a $(Q,T)$-affine-periodic solution if the corresponding homogeneous linear equation admits exponential dichotomy or exponential trichotomy. This kind of ``periodic'' solutions might be usual periodic or quasi-periodic ones if $Q$ is an identity matrix or orthogonal matrix. Hence solutions also possess certain symmetry in geometry. The result is also extended to the case of pseudo affine-periodic solutions.     

On Efficient Solutions in Vector Optimization

A new characterization is obtained for the existence of an efficient solution of a vector optimization problem in terms of associated scalar optimization problems. The consequences for linear vector optimization problems are derived as a special case, Applications to convex vector optimization problems are also discussed.     

Sign-Changing Solutions and Multiple Solutions Theorems for Semilinear Elliptic Boundary Value Problems with a Reaction Term Nonzero at Zero

In this paper, we use the ordinary differential equation theory of Banach spaces and minimax theory, in particular, the local mountain pass lemma to study asymptotically linear and superlinear elliptic boundary value problems with a reaction term nonzero at zero, and get new multiple solutions and sign-changing solutions theorems. Moreover, the sign-changing solutions change sign exactly once under some conditions.