一类带变号权函数的p-Kirchhoff方程正解的存在性与多解性

利用变分方法,通过对Nehari流形进行分解,证明了一类带变号权函数的pKirchhoff方程正解的存在性与多解性.     

TWO POSITIVE SOLUTIONS TO THREE-POINT SINGULAR BOUNDARY VALUE PROBLEMS

In this article, we consider the existence of two positive solutions to nonlinear second order three-point singular boundary value problem: -u′′(t) = λf(t, u(t)) for all t ∈ (0, 1) subjecting to u(0) = 0 and αu(η) = u(1), where η∈ (0, 1), α∈ [0, 1), and λ is a positive parameter. The nonlinear term f(t, u) is nonnegative, and may be singular at t = 0, t = 1, and u = 0. By the fixed point index theory and approximation method, we establish that there exists λ* ∈ (0, +∞], such that the above problem has at least two positive solutions for any λ∈ (0, λ*) under certain conditions on the nonlinear term f.     

基于S7-300PLC的蒸发器液位控制系统设计

为了实现对蒸发器液位的实时控制,设计了一种基于S7-300PLC的液位控制系统,并利用组态王软件制作人机对话界面,实现对整个系统的远程实时监控.用户可以在监控界面中对液位高度和PID参数进行设定,还可以在上位机中浏览到液位的历史变化曲线及数据,实现良好的人机界面交流.