模拟带电粒子在有界磁场中的运行规律，是物理教学辅助工具。有界磁场能在方形、圆形、三角形间进行切换。把题目用WORD编辑后存放到程序同一目录下，能自动调用。-Simulation of charged particles in a bounded laws governing the operation of the magnetic field is physics teaching aids. Bounded magnetic field can switch between a square