An inverse problem for Sturm–Liouville differential operators with deviating argument

We consider second-order functional differential operators with a constant delay. Properties of their spectral characteristics are obtained and a nonlinear inverse problem is studied, which consists in recovering the operators from their spectra. We establish the uniqueness and develop a constructive algorithm for solution of the inverse problem.     

Generalized Logan’s Problem for Entire Functions of Exponential Type and Optimal Argument in Jackson’s Inequality in <Emphasis Type="Italic">L</Emphasis><Subscript>2</Subscript>(ℝ<Superscript>3</Superscript>)

We study Jackson's inequality between the best approximation of a function f ∈ L₂(R³) by entire functions of exponential spherical type and its generalized modulus of continuity. We prove Jackson's inequality with the exact constant and the optimal argument in the modulus of continuity. In particular, Jackson's inequality with the optimal parameters is obtained for classical modulus of continuity of order r and Thue-Morse modulus of continuity of order r ∈ N. These results are based on the solution of the generalized Logan problem for entire functions of exponential type. For it we construct a new quadrature formulas for entire functions of exponential type.     

带逐段常变量的二阶中立型延迟微分方程的概周期解

本文讨论了带逐段常变量的二阶中立型延迟微分方程(x(t)+px(t-1))″=qx(2[(t+1)/2])+f(t)的概周期解的存在性,此处[.]表示取整函数,p,q是非零实数,|p|=1,q≠-4,f(t)是一个概周期函数.     

多时滞三种群系统的Hopf分支

讨论了具有两个时滞的3种群模型,分析了系统正平衡点的稳定性和Hopf分支的存在性;然后利用中心流形定理和规范型方法,给出了确定分支周期解的分支方向与稳定性的计算公式,利用数值模拟验证了所得结论.     

生态马克思主义:产生、论域与趋势——近百年来某一个维度的综述

“生态马克思主义”是当今西方马克思主义的一个主要流派。面对凸显的现代生态危机,“生态马克思主义”提出了自己的见解。本文综述了近100年来“生态马克思主义”的产生和论域,且描述了“生态马克思主义”的现阶段的研究维度、层次、存在的问题与发展趋势。     

2×n同顺序排序问题的最优值计算

文中对２×ｎ同顺序排序问题进行了探讨并给出其求最优值的算法。     

中立型双曲方程解的强迫振动性

本文获得了中立型双曲方程解振动的充分条件。其中是具有逐片光滑边界的有界区域，△是拉普拉斯算符。