通过有限差分对平行板电容器进行差分，然后求解泊松方程，求出空间电荷在平行板电容器中电场分布情况-Through the finite-difference differential pairs of parallel-plate capacitor, and then solving Poisson' s equation of space charge in a parallel plate capacitor in the electric field distribution

计算平行板电容器电场分布，比较初级，需要者自取(Parallel plate capacitor electric field distribution, the primary need to self.)