The number that you choose to rotate your letters by is what we call in cryptography, a key.

你选择的旋转字母的数量,就是所谓的加密学，一个密钥。

哈佛公开课 - 计算机科学课程节选

So in order to rotate a double bond, you have to actually break the pi bond, so essentially what you're doing is breaking the double bond.

为了能够旋转双键，你必须打破一个π键，本质上我们要做的就是打破双键。

麻省理工公开课 - 化学原理课程节选

As I mentioned, we'll rotate the teaching fellows through different parts of the alphabet, so every teaching fellow will have equal opportunity to grade work from each person in the class.

如我所说,我们会根据字母顺序,来更换助教,因此,每一位助教都有相同的机会,为班上每个人的作业评分

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

So if I try to rotate my 2 atoms, you see that I have to break that pi bond, because they need to be lined up so that the electron density can overlap.

如果我要试着转动两个原子，你会看到我必须要打破一个π键，因为他们需要连接起来,让那些电子能够重叠。

麻省理工公开课 - 化学原理课程节选

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

So that's the important take-away message from this slide. If we think about these different types of lights, microwave light, if it's absorbed by a molecule, is a sufficient amount of frequency and energy to get those molecules to rotate. That, of course, generates heat, so that's how your microwaves work.

重要的信息，如果我们看看,这些不同种类的光，微波,如果被分子吸收，它的频率和能量可以,使分子转动,这当然的，会产生热量,这就是你们微波炉的工作原理。

麻省理工公开课 - 化学原理课程节选