Periodic boundary value problems for impulsive fuzzy differential equations

The peculiarity of the Hukuhara derivative makes it impossible to find periodic solutions for fuzzy differential equations with the exception of very restrictive situations. In this work, we consider a boundary value problem associated with an impulsive fuzzy differential equation and approximate the extremal solutions in a fuzzy functional interval using the monotone method. Fuzzy comparison results are useful in our procedure and the expression of the solution for some impulsive periodic ‘linear’ differential problems is also provided.     

Vortex analysis of the periodic Ginzburg–Landau model

We study the vortices of energy minimizers in the London limit for the Ginzburg–Landau model with periodic boundary conditions. For applied fields well below the second critical field we are able to describe the location and number of vortices. Many of the results presented appeared in [H. Aydi, Doctoral Dissertation, Université Paris-XII, 2004], others are new.     

2阶抽象微分方程的周期解

本文考虑Banach空间中形如x″=A(t)x f(t,x,x′)的2阶微分方程,利用基于度理论的一定不动点定理得到了以上方程存在周期解的若干充分条件。     

Eigenfunctions and optimal orbits

For the algebraic structure ($\text{R}$, max, +) we study the continuous analogue of the eigenvector-eigenvalue problem and relate it to a minimal-cost orbit problem. An explicit solution is given for the concave-quadratic case.     

具变时滞的细胞神经网络的周期解

本文研究了一类具变时滞细胞神经网络系统,利用重合度理论中的延拓定理、不等式的分析原理、矩阵理论和Lyapunov泛函方法,得到了该系统周期解的存在唯一性及全局指数稳定性的结论,不仅在一些应用领域上是可行的且易检验,而且为神经网络系统周期解的存在性论证,提供了一个新的有效方法.     

Problems in homoclinic bifurcation with higher dimensions

In this paper, a suitable local coordinate system is constructed by using exponential dichotomies and generalizing the Floquet method from periodic systems to nonperiodic systems. Then the Poincaré map is established to solve various problems in homoclinic bifurcations with codimension one or two. Bifurcation diagrams and bifurcation curves are given. Project 19771037, supported by NSFC     

On the finiteness of the number of orbits on quasihomogeneous (ℂ*)k × SL 2(ℂ)-manifolds

We obtain an effective criterion for the finiteness of the number of orbits contained in the closure of a given G-orbit for the case of a rational linear action of the group G: = (?*)^k × SL ₂(?) on a finite-dimensional linear space as well as on the projectivization of such a space.     

基于响应矩阵和SVD算法的输运线束流轨道校正

在输运线中, 磁铁的加工及安装误差所产生的二极磁场分量会导致束流运动轨道偏离理想轨道. 采用基于Matlab的AT程序, 利用响应矩阵和SVD算法, 对SSRF高能输运线磁铁布局方案进行了轨道畸变校正, 对不同的校正子和BPM放置方案作了比较研究, 并对SVD算法中截断阈值的选取对输运线束流轨道畸变校正的效果作了比较研究.     

Periodic solutions for discrete predator–prey systems with the Beddington–DeAngelis functional response

Sufficient criteria are established for the existence of positive periodic solutions of discrete nonautonomous predator–prey systems with the Beddington–DeAngelis functional response using a continuation theorem.