So if we want to talk about the volume of that, we just talk about the surface area, which is 4 pi r squared, and we multiply that by the thickness d r.

如果我们要讨论它的体积，我们要用的是表面面积，也就是４πｒ的平方，乘以厚度ｄｒ

麻省理工公开课 - 化学原理课程节选

r And what that is the probability of finding an electron in some shell where we define the thickness as d r, some distance, r, from the nucleus.

在某个位置为,厚度为dr的壳层内,找到原子,的概率，我们来考虑下我们这里所说的。

麻省理工公开课 - 化学原理课程节选

a perfectly spherical shell dr at some distance, thickness, d r, dr we talk about it as 4 pi r squared d r, so we just multiply that by the probability density.

在某个地方的完美球型壳层,厚度，我们把它叫做4πr平方，我们仅仅是把它,乘以概率密度。

麻省理工公开课 - 化学原理课程节选