But de Broglie has told us that the wavelength is related to the instant velocity through this formula.

但德布罗意曾说过,波长是和瞬时速度相联系的,通过这个公式。

麻省理工公开课 - 固态化学导论课程节选

So we can use an equation to relate the incident energy and the kinetic energy to the ionization energy, or the energy that's required to eject an electron.

因此我们可以用一个公式将入射能量,与动能和电离能，就是发射出一个电子所需要的能量关联起来。

麻省理工公开课 - 化学原理课程节选

Then, once we did that we could plug that into the formula that I gave you last time and get the standard deviation of the portfolio and the expected return on the portfolio.

再将估算出的数值代入到,上节课给你们的公式中,就能得到资产投资组合的标准差,和该投资组合的预期收益率

耶鲁公开课 - 金融市场课程节选

So we came up with two formulas, which are similar to the two that I'm showing here.

所以我们得到了两个公式，它们和我展示这两个,很类似。

麻省理工公开课 - 化学原理课程节选

if you don't want to use that, you can also derive it as we did every time, it should intuitively make sense how we got there. But the exams are pretty short, so we don't want you doing that every time, so we'll save the 2 minutes and give you the equations directly, but it's still important to know how to use them.

吸收的和发射的，如果你不想用公式,你也可以每次都向我们这样推导它,很直观的就能得到结果，但考试时间很短，我们不希望你们每次都推导,所以我们会直告诉你，让你节省2分钟，但知道如何应用它十分重要。

麻省理工公开课 - 化学原理课程节选