2001 CV model to achieve a better procedure, which contains the second

代码说明：

2001年C-V模型的一个较好的实现程序，其中含有齐次第二边值条件（Numann边值条件）处理，这里呈现给大家-2001 CV model to achieve a better procedure, which contains the second-homogeneous boundary conditions (Numann boundary conditions) treatment here presented to the U.S.