详细地介绍了fdtd在三维、二维、一维情况下的差分公式以及不同情况下PML边界层的设置情况-FDTD，introduced in 3D, 2D, 1D case difference formula and the setting of boundary layer PML

基于灰度CT 图像的岩石孔隙分形维数计算2，大家可以互相交流！！！(Calculation of fractal dimension of rock pore based on gray CT image)