So what we'll do is this problem here, which is let's calculate out what the wavelength of radiation n would be emitted from a hydrogen atom if we start at the n equals 3 level and we go down to the n equals 2 level.

我们来做这个问题,让我们来计算一下,从n等于3到,等于2能级氢原子辐射的波长是多少。

麻省理工公开课 - 化学原理课程节选

because I always have to cross the bridge. And we usually go to Baker Beach down there,

因为我上班的时候要过桥。我们也经常去贝克海滩，

美国的不动产市场 - SpeakingMax英语口语达人

So, if we look on the periodic table, comparing, for example, s to o, if we have s it's below o, what happens to ionization energy as we go down a table?

那么，如果我们看周期表上，比较，比如，硫和氧，硫在氧下面，当我们沿着表向下看的时候,电离能是怎么变化的？

麻省理工公开课 - 化学原理课程节选

Then finally, down we go to Sicily and there you have the east coast.

最后,我们来到,西西里岛东海岸

耶鲁公开课 - 古希腊历史简介课程节选

So, we know it's going to go up and turn around and come down.

我们知道物体会先上升然后调转方向下落

耶鲁公开课 - 基础物理课程节选

And all of those long notes are coming on the downbeat so that's how we start to hear that as a downbeat and that's how we know to make our hand go down at that point so that's one way.

所有的长音都出现在重拍上,这就是我们怎么判断出重拍,如何判断出该什么时候把手往下摆的,所以那是一条途径

耶鲁公开课 - 聆听音乐课程节选

We used to go to concerts and listen to rock music down there.

我们常去听演唱会，去那儿听摇滚乐。

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and we were going to go busking down on the South Bank.

我们去南海岸做街头表演。

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We're going to go down the whole list.

我们会顺全部的名单。

麻省理工公开课 - 固态化学导论课程节选

Similarly we see as we go down the table, so as we're going from one row to the next row, so, for example, between helium and lithium, we see a drop; the same with neon to sodium, we see a drop here.

同样地，我们来看看沿着周期表往下走，当我们从一行到下一行时，比如，从氦到锂，我们看到了一个下落;,从氖到钠也一样，我们看到这里有个下落。

麻省理工公开课 - 化学原理课程节选

We can go all the way down -- magnesium aluminum, all the way to this noble gas, 3s23p6 argon, which would be n e and then 3 s 2, 3 p 6.

我们可以继续，镁，铝,一直到惰性气体，氩它是Ne然后。

麻省理工公开课 - 化学原理课程节选

So as we go down we're now adding electrons to further and further away shells, so what we're going to see is that the atomic radius is going to increase as we're going down the periodic table.

当我们向下走时,我们会将电子加在越来越远的壳层上，因此我们将看到原子半径,将随我们沿周期表向下走而增大。

麻省理工公开课 - 化学原理课程节选

So this is not even thinking about the other electron shielding, just if we think of the fact, all we need to think about is that the effect of going to a further away n n as we go down the table.

到现在我们甚至还没有考虑,其它电子的屏蔽效果，即使我们要考虑这个因素，我们需要考虑也就是,沿着周期表的某一列往下走，距离会逐渐变远,将起最重要的作用，actually，dominates,这一结果所产生的影响。

麻省理工公开课 - 化学原理课程节选

So, as we go down a column, we see ionization energy's going to decrease.

总之，当我们沿着列往下走的时候，我们会看到电离能在降低。

麻省理工公开课 - 化学原理课程节选

What we've done is taken this pitch and played it all the way down an octave below it so we're actually getting back to this configuration of the pitch right next to it, and we could--then of course we could go down one more step and we would get the octave, which is a duplication of two-to-one.

我们所做的是固定一个音高，向下一路弹奏一个八度,所以事实上我们又回到了与这个固定音高相邻的音上，我们当然也可以向下再弹一组，然后得到这个八度，这其实就是两个八度对一个八度的重复。

耶鲁公开课 - 聆听音乐课程节选