This is the equivalent to ray optics, isn't it?

这与X射线是等价的，是不是？

麻省理工公开课 - 固态化学导论课程节选

I've been teaching long enough to know that doing derivations in class is equivalent to pouring ice water on the proceedings, so I do this sparingly.

我已经教了这么长时间书,所以我知道在课堂上讲推导,就好像泼冰水一样，所以我在讲这个的时候很小心。

麻省理工公开课 - 固态化学导论课程节选

And what this is, is that if you want to take the section in French, you should have about an equivalent of 130, and the discussion's in French and a couple of the books-- I'll talk about them in a minute-- you can read in French, the others you read in English.

这个就是说,你要是想用法语授课,你的法语得有130分左右的水平,课堂讨论是用法语还有一些书,我马上要说到那些书 你可以看法语版的,其他人可以看英语版的

耶鲁公开课 - 1871年后的法国课程节选

And this is equivalent to modeling the wave fronts as particles.

这和把波端,当成粒子是一样的。

麻省理工公开课 - 固态化学导论课程节选