chapter 3 Free electrons in solid - 3.2 量子自由电子理论对一些现象的解释T>0K, total energy of free electrons: E = ∫ E d N = 3 5 N e E F 0 [ 1 + 5 12 π 2 ( k B T E F 0 ) 2 ] E= \int EdN = \frac{3}{5} N_e E_F^0 [1+\frac{5}{12}\pi^2 (\frac{k_B T}{E_F^0})^2] E=∫EdN=53NeEF0[1+125π2(EF0kBT)2]