左端温度已知（假设100),右端为自然对流散热，h=10(T-Tf)^0.25，采用外点法（1,2,3）计算每一个节点温度（一部分条件在程序中指明）-The left end of the known temperature (assuming 100), on the right for natural convection, h = 10 (T-Tf) ^ 0.25, external point method (1,2,3) calculate each node temperature (part of the conditions specified in the program)