约束物体运动过程中的物理量有许多,其中势垒就是一个最重要的方面,而且许多时候,势垒的存在是隐形的,我们很难一下子发现,本文从不同的角度阐述了几种不同的势垒或者类势垒,以便阐明势垒的重要功用。 There are many physical quantities in the process of constraining objects. Among them, barriers are one of the most important aspects, and many times, the existence of barriers is invisible. We find it difficult to find them all at once. This article describes several different aspects from different perspectives. Barriers or class barriers to clarify the important function of barriers.