One thing that I want to mention that is really important is once you have double bonds, what happens between those two atoms in the molecule is they can no longer rotate in relation to each other.

我要提醒你们的非常重要的一点事,一旦有了双键，分子中的两个原子,就不能相对旋转了。

麻省理工公开课 - 化学原理课程节选

And something that we'll see later on is that triple bonds, for example, are going to be stronger than a corresponding double bond or a corresponding single bond.

而我们以后还会看到三键，举例来说，应该更强，相较于相应的双键,或者相应的单键来说。

麻省理工公开课 - 化学原理课程节选

That tells you something about the physical chemistry of the molecule; that it's these hydrogen bonds that hold the double strands and I can break those down under certain conditions.

我们从中可以知道一些,DNA分子的理化特点,双链是由氢键连接在一起,在一定条件下这些氢键可以断裂

耶鲁公开课 - 生物医学工程探索课程节选

So let's think about how we can classify single and double and triple bonds, which is what we're really used to dealing with in terms of these sigma bonds and these pi bonds.

让我们想想怎么来分类单键双键,和三键，这在我们在考虑sigma键,和π键是很有用的。

麻省理工公开课 - 化学原理课程节选

So that's two of our types of bonds in benzene, and we have one type left, that's going to actually be the double bond or the pi bond that So we can have one bond here between this carbon's p orbital and this carbon's p orbital.

这就是苯环里的两种键，我们还剩一种，那就是这些p轨道之间，形成的双键或者π键,我们可以在这个碳的p轨道,和这个碳的p轨道之间有个键。

麻省理工公开课 - 化学原理课程节选