So, we can actually kind of visualize what we would see if we were looking at a photoelectron spectrum.
实际上,我们可以在一定程度上想象出,我们在光电子谱上可以看到什么。
So hopefully you're convinced that your predictions worked well and you are able to predict what's going on when you're looking at the photoelectric effect.
希望你们确信,你们的预测都是对的,而且当你们考虑光电效应的问题时,你们可以预测。
These are photodetectors, band gap two electron volts, respond to visible light.
这是光电探测器,能带隙为2电子伏,当它反应于可见光。
What we're going to start with is discussing photoelectron spectroscopy, which is a spectroscopy technique that will give us some information about energy levels in multielectron atoms.
首先,我们将讨论,光电子能谱,通过这种技术,我们能够得到多电子原子的能级信息。
So once we cover it, it will then be fair game to ask these photoelectron spectroscopy or these photoelectric effect questions using the wavelength of the electron.
所以一旦我们涉及到它,问及光电子能谱或者,用电子的波长问及,光电效应是一样的。
In terms of talking about the electrons, I wanted to point out that in the book and other places you might see electrons referred to as photoelectrons.
在谈到电子方面,我想指出在这本书,或者其他地方你可能会看到,电子被称为光电子。
You should be able to maybe print out a blank copy of those notes from the website not for memorizing them, but now just understanding how the photoelectric effect works.
你们应该可以从网站上打印一份,这些笔记中的空白的纸张,不仅仅是为了记忆,而且现在要理解,光电效应是如何工作的。
This is the last question we'll see in class on the photoelectric effect, so hopefully we can have a very high success rate here to show we are all ready to move on with our lives here.
这是这个课上最后一个关于,光电效应的问题,所以希望,你们能有个高的通过率,来证明我们已经可以继续往下走。
This should all sound incredibly familiar, like I'm just repeating myself in terms of photoelectric effect, because essentially that's what I'm doing, and that's one reason we spent so much time and did so many problem-set problems on the photoelectric effect.
这应该听起来极其熟悉,就像我在重复自己在讲光电效应时所说的话,因为基本上我正是在这样做,这也是我们在光电效应这个问题上,花这么多时间,做这么多习题的原因之一。
So, it turns out that the photoelectric effect is not the only evidence for the fact that light has these particle-like characteristics.
所以,原来是光电效应,不是唯一的证明光具有,粒子特性的证据。
So, if we're going to go to the moon, we're going to go to Mars,we want to be able to produce oxygen, structural metals and photovoltaic materials from in situ resources.
如果我们要去月球上,我们要去火星上,我们则必须要制造,氧气,结构金属和光电材料,就在原地制造。
And, subsequently, we looked at photoelectron spectroscopy which is a technique that allows us to determine binding energies, ionization energies being just one example.
随后,我们看了光电子谱,这是一种只用一个样品,能够测量结合能,离子化能的技术。
What we had just done a clicker question on is discussing light as a particle and the photoelectric effect, so we're going to finish up with a few points about the photoelectric effect today.
我们刚才做得课堂表决器那个问题,是讨论光作为一个粒子以及光电效应,所以今天我们将以一些,关于光电效应的观点作为结束。
And the reason for this, and this is a very important point about the photoelectric effect, and the point here is that the electrons here are acting as particles, you can't just add those energies together.
这个现象的原因是,这是光电效应非常重要的一个论点,这个论点就是电子,在这里是粒子行为,你不能仅仅把这些能量加在一起。
Any one of these different elements could actually produce a photoelectron spectroscopy spectrum that has five distinct lines.
其中任何一种元素,都可能产生,有五条分立谱线的光电子能谱。
All right. So let's go ahead and try an example here in thinking about photoelectron spectroscopy.
好的,下面我们继续来看一个,关于理解光电子能谱的例子。
It's called this just because it's an electron that results when an electron absorbs a photon's worth of energy, so thus it's a photoelectron.
之所以这样称呼是因为,当一个电子吸收,一个光子的能量的结果,因此它是一个光电子。
Since that time, PES we've been able to actually measure these bond strengths by PES, photoelectron spectroscopy.
自从那时,我们就能够用,测量键的强度,光电子能谱。
And this is called photoelectron spectroscopy, and essentially what it is is very similar conceptually to what we were talking about way back in the first couple lectures when we were talking about the photoelectric effect.
也就是光电子能谱,从本质上来讲,这项技术,与我们在最开始的几节课上讲的,光电效应在概念上非常相似。
All right, so where we left off with the photoelectric effect was when we first introduced the effect, we were talking about it in terms of frequencies.
好,我们刚才停止光电效应这个话题,是当我们第一次用频率,来讨论这个效应的时候。
And if we have time today, we'll start in on the photo-electron spectroscopy, if not, that's where we'll start when we come back on Wednesday.
而且如果我们今天还有时间,我们将会开始光电子频谱,如果没有,我们将会在下周三回来时开始。
So, we do this here for the photoelectric effect, and in terms of the photoelectric effect, what we know the important point is that the incoming photon has to be equal or greater in energy then the work function of the metal.
所以,我们做这个是为了说明,光电效应,在光电效应方面,我们知道的最重要的事情,就是入射的光子能量必须等于,或者大于金属的功函数。
So, one difference between photoelectron spectroscopy and, for example, the photoelectric effect is that in this case, we're not just looking at one energy level, which is what we were looking at from the surface of a metal, now we're talking about this gaseous atom.
光电子能谱与光电效应的不同点在于,以这种情况为例,我们不只关心一个能级,就像原来在金属表面那样,现在我们研究的是气体原子,所以,我们可以从原子中。
They are made of organic matter:the same rules, the same laws of chemistry that apply to what makes this laser glow green apply to what makes these photodetectors work.
而是由有机物制作的,同样的规律,它与应用于让激光的光芒变绿,以及使这些光电探测器工作,的化学是一样的规律。
So, we'll take a little bit of a step back after we introduce quantum mechanics, and talk about light as a wave, and the characteristic of waves, and then light as a particle. And one example of this is in the photoelectric effect.
等我们介绍完量子力学后,我们要回过头来讨论下光,作为一种波和它的波动性特征,以及光作为一种粒子,其中的一个粒子就是光电效应。
All right. So let's test what we, in fact, know about the photoelectric effect, and before we do that actually, we're going to calculate what we would predict, so when we do the demo it will be meaningful and we can tell whether we're successful or not.
好的,我们来测试一些,我们实际上懂了,多少光电效应的东西,在我们做测试之前,我们先算一下我们能预知什么,这样我们做的测试会很有意义,并且也知道我们是否成功了。
So, let's start with talking about photoelectron spectroscopy.
那么,我们开始讲光电子能谱。
So we see that we do not eject electrons in the case of the laser pointer, even if we have this intensity, it is still not related to the energy of an individual photon, so we won't see an effect.
所以我们看到我们用激光笔,还是没有逐出电子,即使我们有这样的强度,它仍然与一个单个的光子能量无关,所以我们不会看到光电效应。
When we talked about the photoelectric effect, that was called the work function.
如果我们在研究光电效应,这被称为功函数。
Alright, so we'll pick up with photoelectron spectroscopy on Wednesday.
好的我们周三将会讲解,光电子能谱的专题。
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