学物理气体运动理论中讲授的一个难点，其公式抽象、繁难，学生不易理解. 本文根据速度空间概念，给出速度球的表面积相

当于气体分子微观状态数的观点，利用拉郎格日函数，推导理想气体平衡态下气体分子的速率分布函数. 这种推导方法相对

比较简单、易学，便于学生理解和培养学生的空间想象力.

A basic point in college physics teaching is to cultivate students' spatial imagination. Maxwell's rate

distribution law is a central content of the gas molecule kinetic theory，which is difficult for students to learn and

professors to teach during the teaching process of gas dynamics theory. Its formula is abstract，complicated and difficult

for students to understand. Based on the concept of velocity space， it is presented the surface area of the velocity

sphere is equivalent to the number of microscopic states of a single gas molecule，and the Langerian function is used

to derive the velocity distribution function of gas molecules in the ideal gas equilibrium state. This method is relatively

simple and easy for students to understand is helpful to cultivate their spatial imagination.