本程序实现了一维稳态无源项的对流-扩散方程的数值解法，采用的离散格式包括中心差分，一阶迎风，混合格式与QUICK格式。并画出其与精确解的比较。-This program implements a one-dimensional steady-state convection passive items- diffusion equations numerical solution, a discrete format used include center differential, the f