使用FORTRAN编写的三个程序，程序一和二可以计算二维平板的导热，程序一给定温度条件，程序二给定边界热流，程序三维方形管内流体对流换热。-Use three programs written in FORTRAN, the program I and II can calculate the thermal conductivity of two-dimensional flat, procedures, conditions for a given temperature, the prog