讨论： (1).T→0K,体系的温度极低时： x=hye/kT→oo T-0K lim 3Rx2 [e*/(ex-1)2] X→00 3R lim (x2/e*) X→00 =3Rim(2x/e)(罗必塔法则) X00 =3Rlim(2/e→0 (罗必塔法则 X→00 .Cy.m=3R.x2 [ex/(ex-1)2]0 (T→0K时)讨论： ⑴.T →0K, 体系的温度极低时: x=hE/kT → ∞ ∵ T=0K lim 3Rx2 [e x /(ex－1) 2 ] X→∞ = 3R lim (x2 /e x ) X→∞ =3R lim (2x/e x ) (罗必塔法则) X→∞ = 3R lim (2/e X) →0 (罗必塔法则) X→∞ ∴CV.m =3R·x2 [e x /(ex－1) 2 ] →0 ( T →0K时)