Using the solution, the key parameters controlling the variation trend from LTNE to LTE were analyzed, and a quantitative criterion to evaluate the LTE assumption was suggested.

• 利用解析解，讨论了热平衡与非热平衡的变化趋势以及影响热平衡的关键参数，并在此基础上，提出一个定量的热平衡假设使用准则。