During this part, when you're doing a quarter of a circle, this is supposed to be a quarter of a circle.

在这部分,当你沿着四分之一圆运动,这就是个一个圆的四分之一

耶鲁公开课 - 基础物理课程节选

In other words, you don't have to be moving actually in a circle to have the acceleration.

也就是说,你不必真的在一个圆上运动以获得相应的加速度

耶鲁公开课 - 基础物理课程节选

Every time you see a square bracket, put a paren in. All right?

每次你看到一个方括弧，你就得在此添加一个圆括弧，明白了吗？

麻省理工公开课 - 计算机科学及编程导论课程节选

So in hydrogen atom a, I'll depict that here where the nucleus is this dot, and then the circle is what I'm depicting as the wave function.

在氢原子A里，我在这里把原子核画成一个点，这圆就是波函数。

麻省理工公开课 - 化学原理课程节选

That means, it can only be rattling around in a circle of radius R.

也就是说它只能,限制在一个半径为 R 的圆上运动

耶鲁公开课 - 基础物理课程节选