We can make some substitutions here using some of the derivation on the previous board which will give us the Planck constant divided by 2 pi mass of the electron times the Bohr radius.

在这里我们也可以,用我以前在黑板上写过的一些词来取代它,得到的是普朗克常数除以2π电子质量,再乘以波尔半径。

麻省理工公开课 - 固态化学导论课程节选

So we're to assume we can get to any piece of data, any instruction in constant time, and the second assumption we're going to make is that the basic primitive steps take constant time, same amount of time to compute. Again, not completely true, but it's a good model, so arithmetic operations, comparisons, things of that sort, we're all going to assume are basically in that in that particular model.

因此如果我们假设在恒定的时间内,我们可以取得任何一块数据,任何一种数据结构的话,我们要做的第二个假设就是,基本的原始操作计算花费的时间是恒定的,这个假设也不是完全正确的，但这个模型其实挺不错的，因此算法操作，比较，这一类的事情，我们在这个特定的模型中都假设是基本的,操作，花费的时间是恒定相同的。

麻省理工公开课 - 计算机科学及编程导论课程节选

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

What we need to do is get rid of the Coulomb tag that we have - that's how we measure our electron charges - charge, and so we use this epsilon nought quite often, this permativity constant of a vacuum to make that conversion.

怎么量度电子电荷,所以我们会经常用到,这个epsilon，nought记号,这是真空中的介电常数,我们还要指出,这个介电常数。

麻省理工公开课 - 化学原理课程节选

So, sometimes you'll find the Rydberg constant in different forms, but just make sure you pay attention to units because then you won't mess them up, because this is in inverse seconds here, the other Rydberg constant is in joules, so you'll be able to use what you need depending on how you're using that constant.

有时候你们会发现Rydberg常数,会写成不同的形式，但你们要注意,它的单位就不会弄错了，因为这里是秒的倒数，而另一个Rydberg常数是焦耳，所有你可以根据你要怎么使用,这个常数来选择你需要的常数。

麻省理工公开课 - 化学原理课程节选