On the other hand, temperature, volume and pressure are variables that are much easier in the lab to keep constant.

另一方面，温度，体积和压强,在实验室中比较容易保持恒定。

麻省理工公开课 - 热力学与动力学课程节选

STUDENT: PROFESSOR: Yes, thank you. All right, it is constant. You keep sitting back there where I can't get to you. Thank you very much.

学生：【不解中】,教授：是的，是常数，如果，就是常数,你坐在那儿一动不动我没法找到你。

麻省理工公开课 - 计算机科学及编程导论课程节选

How do I keep p1 constant while I'm lowering the volume?

怎么保持压强不变,而减小体积？

麻省理工公开课 - 热力学与动力学课程节选

And when we make these comparisons, one thing I want to point out is that we need to keep the constant principle quantum number constant, so we're talking about a certain state, so we could talk about the n equals 2 state, or the n equals 3 state.

当我们做这些比较时，我想指出的一件事是,我们需要保持常量原则,保持量子数是常数，所以我们在讨论一个确定的态时，我们可以谈论n等于2的态，或者n等于3的态。

麻省理工公开课 - 化学原理课程节选

All right? It's now something that I can search in constant time. And that's what's going to allow me to keep this thing as being log.

在固定的时间内搜索,这样就可以让时间复杂度保持在对数级,好的，考虑过了这些。

麻省理工公开课 - 计算机科学及编程导论课程节选

But we'd like to relate it to what happens if we keep the temperature constant.

但是我们想知道如果保持温度不变的话,结果会怎么样。

麻省理工公开课 - 热力学与动力学课程节选

If I keep the pressure constant.

当我保持压强恒定。

麻省理工公开课 - 热力学与动力学课程节选

We can also do a similar thing, and I'll keep my distance from the board, but we can instead be holding x constant, for example, putting x to be equal to zero, and then all we're doing is considering the electric field as a function of t.

我们也可以做类似的事情,把x固定为一个常数,例如令x等于零，然后,考虑电场作为时间的函数,这种情况下，我们划掉。

麻省理工公开课 - 化学原理课程节选