So, if you look at all of these, we have full octets for all of them, and if we count up all of the valence electrons, it's going to be equal to our number 26 here.

那么，如果大家看看所有的这些，它们的“八隅体“都填满了，而如果我们来数一数价电子的总个数，它应该就等于我们这里的二十六。

麻省理工公开课 - 化学原理课程节选

As I said, what we want to do is, we want to count the number of basic steps it takes to compute a computation as a function of input size.

我刚才提到了，我们要建立，一个根据输入大小的方法来计算,一个计算过程需要的时间,建立这个方法需要几步呢？

麻省理工公开课 - 计算机科学及编程导论课程节选

So, the number of nuclei, 119 if we were to sit and count these as well, is 119. So, we'll multiply that by just pi, r squared, to get that cross-section, and divide all of that by 1 . 39 meters squared.

如果你们数的话，原子核的数是，我们用它乘以πr的平方，得到横截面积，除以1。39平方米。

麻省理工公开课 - 化学原理课程节选