1B?4N?4???U0????U0?3????3155
?1?????D?????3
S计算略
高温近似,
T??, ????0
?D?D??3??1?2B??ln??????d?????0??0B?ln????d??3?? ????lnZ????0??0
?D??3?ab1????0?B?ln?????0???2d??
30?3?3?D3?D????0?3Bln??????9B
????0?3Nln??????N解:参照9.17关于玻耳兹曼体系配分函数的处理
(计算略)
习题9.14用巨正则分布导出单原子分子理想气体的物态方程,内能,熵和化学势。
ln??ln??l??ln?l??e?????ll?0ll?0??
过渡到连续能量分布得:
ln??Vh3?????e????p2m?222x?py?pz?dpxdpydpz?V???e??e3h???3????2mp2?dp??3
???????V????3ee???0h???p?2m???2????d??2m?.???2m?????32
V???2m????2?m?? ??e??eV?32????h?????h?3利用热力学式可求得pV?NkT, U?NkT等 (略)
2
?3232注:?l--------单粒子处于l能级的能量。
习题9.17利用巨正则分布导出玻耳兹曼分布。 解:
????eNS??N??Es;由于玻耳兹曼系,粒子可分辨,从而
??????El?alN ???el?al?a1!a2!a3!?????a?!为简单起见,考虑无简并(有简并情况完全可类似处理)
??????El?al1???el?al?a1!a2!a3!?????a?!1?????El?al???ealal!l
???1?????El?al?????al?le?Cxpeal?0al!??expel?0????
于是:???????al?l?
?ale?????al?al?al!al?1?????am?am?e????a!m?l?amm?1?????al?ale??alal!lal?1??N?aleS???N??ES?
al?????al?ale?1?alal!????l
11?????al?al???e??alal!alal!??1?expe?????al??e??????l?
?l??
??即对无简并情况
al?e??????l?
al??le??????l? (略)
对有简并者,类似处理可得
?l——简并度
热力学与统计物理答案



