巧用v-t图象解题

例1 一个物体做匀加速直线运动，依次经过4、B、C三个位置，B为4C的中点，物体在AB段加速度为α1，在BC段的加速度为α2，现测得物体经过B点时的即时速度为vB=1/2（vA+vC），比较α1和α2的大小有：

A Class of Nonlocal Boundary Value Problems for Elliptic Systems in Unbounded Domains

A class of nonlocal boundary value probl em s for elliptic systems in the unbounded domains are considered. Under suitable c onditions, the existence of solution and the comparison theorem for the boundary value problems are studied.