He said his plan would balance the need for energy with the need to protect natural resources.

VOA: special.2010.05.01

The second piece of information we need to know is what actually the kinetic energy is of the ejected electron, and that's something we can just measure by measuring its velocity.

其次，我们需要知道的信息是,出射电子的动能，这可以通过,测量它们的速度得到。

麻省理工公开课 - 化学原理课程节选

We didn't just need that n, not just the principle quantum number that we needed to discuss the energy, but we also need to talk about l and m, as we did in our clicker question up here.

我们不仅需要ｎ,不仅要这个可以,决定能量的主量子数，还需要ｍ和ｌ,就像我们做这道题这样。

麻省理工公开课 - 化学原理课程节选

He says these "virtual desktops" lower costs,reduce energy use and lessen the need for technical support.

VOA: special.2010.04.12

You need energy to move your arms around and move around mechanical systems, obviously, cars, boats, etcetera.

你需要能量,来移动胳膊和走动,机械系统，汽车，船等等。

麻省理工公开课 - 热力学与动力学课程节选

Economic empowerment, education,health care, access to energy and to credit these are the basics that all communities need to thrive.

VOA: standard.2009.11.03

With the United States quite isolated, not reaching out to Canada and Mexico, which is one thing we need to be doing for energy and economic reasons.

而美国则被孤立了，不和加拿大，墨西哥打交道，事实上这是我们现在该做的,为了能源问题和经济发展。

普林斯顿公开课 - 国际座谈会课程节选

Why do we need energy efficiency experts? Introducing them means hitting the energy monopolist over the head.

VOA: standard.2010.02.03

Because you see, also motivation and energy-- you don't need research for that, you know that when you are feeling good, you have more motivation, you have more energy-- of course, there is a lot of research to back that up.

因为动力和精力-,不需要研究就能明白，你知道感觉好时，动力和精力更充沛-,当然有很多研究支持这一点。

哈佛公开课 - 幸福课课程节选

"One lesson we need to work together toward is a more secure energy future.

VOA: standard.2009.10.23

We don't know the intended recipient of this letter, and we actually have no idea whether Milton actually sent the letter; but a couple of drafts of this letter actually exist in Milton's own hand, and the letter is clearly a document that Milton had devoted some energy and some time to. We need to look at it.

我们不知道收件人是谁，我们也不清楚弥尔顿到底有没有寄这封信;,但这份信的草稿确实在弥尔顿那里，弥尔顿显然对这封信投入了不少,时间和精力，我们来看看。

耶鲁公开课 - 弥尔顿课程节选

We need sustainable energy security that includes diversification of supplies and transit routes,".

VOA: standard.2009.10.23

If we have a higher z effective, it's pulled in tighter, we have to put in more energy in order to eject an electron, so it turns out that that's why case 2 is actually the lowest energy that we need to put in.

而如果有效核电量更高，原子核的束缚也就更紧，我们不得不输入更多的能量来打出一个电子，这就是第二种情况,所需要输入的,能量更少的原因。

麻省理工公开课 - 化学原理课程节选

We need your daring and your enthusiasm and your energy."

VOA: standard.2009.05.14

The first that we need to know the energy of the photon that's incident on our gaseous atom.

首先，我们需要知道,入射到气体原子的光子的能量。

麻省理工公开课 - 化学原理课程节选

adaptations,coastal protections Among a host of necessary need to be built, crops threatened by drought need to be modified, health care needs to be stepped up, and new clean energy solutions need to put in place.

VOA: standard.2009.12.11

So that means we're going to need to figure out what is the energy per photon that's emitted by that UV light.

所以那意味着我们将需要,计算出从紫外光源发射出的,每个光子的能量。

麻省理工公开课 - 化学原理课程节选

So how do you feed a city like, for example, Nairobi or many other very large mega-cities with desperately poor people in them where food simply cannot be provided in cities without access to diesel and so on?" Taylor says governments need to start investing in safe and sustainable energy alternatives.

VOA: standard.2009.10.20

So, this one can be tricky because oxygen looks like it's in the middle because of the way it's written, but we need to start by looking at the lowest ionization energy.

这个例子可能有些狡猾,因为氧看起来是在中间的,因为它是这样写的，但是我们需要从寻找最低的电离能开始。

麻省理工公开课 - 化学原理课程节选

We start at this lower energy state and go up that means we need to absorb a photon, we have to take in energy.

我们从一个低能级开始，到一个高能级去,这意味着需要吸收一个光子，我们要获得能量。

麻省理工公开课 - 化学原理课程节选

So, if we want to go from that stable state to that less stable state, we need to put in a certain amount of energy to our system, that difference between the free electron and the electron bound to the metal.

所以，如果我们想使电子,从稳态到达不够稳定的状态，我们需要引入一定数量的,能量到系统中，即自由电子和束缚于金属的,电子的能量差。

麻省理工公开课 - 化学原理课程节选

So that's just a little bit of a check for yourself, and it should make sense because what you're doing is you're calculating the difference between energy levels, so you just need to flip around which you put first to end up with a positive number here, and that's a little bit of a check that you can do what yourself.

所以你们总要确保括号，离得这项是正的，这是你们自己,可以做的检查，这事很有道理的，因为你们做的是计算能量差,所以你需要调整顺序来保证一个正数，这是你们自己可以做的检查。

麻省理工公开课 - 化学原理课程节选

So you don't want to put in a negative energy, that's not going to help you out, you need to put in positive energy to get an electron out of the system. So that's why you'll find binding energies are always negative, and ionization energies are always going to be positive, or you could look at the equation and see it from there as well.

因为这对电离没有帮助,你需要一个正的能量,使得电子脱离这个系统,这就是为什么你会发现,结合能总是负的而电离能总是正的,或者你们看这个方程也可以发现这一点。

麻省理工公开课 - 化学原理课程节选

So, the take-home message is whether you have three photons or 3,000,000 photons that you're shooting at your metal, if you're not at that minimum frequency or that minimum energy that you need, nothing is going to happen.

所以，这里表明的信息是,无论是向金属发射3个光子,还是300万个光子,如果没有达到所需的最低频率,或者最小能量,什么事情都不会发生。

麻省理工公开课 - 化学原理课程节选

I don't care how you do it on exams or on problem sets, but you do need to be aware that the 3 d once filled is lower in energy than the 4 s, and the reason you need to be aware of that is if you're asked for the electron configuration now of the titanium ion.

我不关心你们在考试或者,问题集中如何做它，但是你们的确需要知道3d一旦被填充,它的能量是小于4s的，你们需要知道这个的原因,是如果你现在被要求,写出钛离子的电子构型。

麻省理工公开课 - 化学原理课程节选