『新东方在线托福听力』为托福考生准备了ETS托福TPO/Official 44 Lec 1听力练习：What is the main purpose of the lecture?原文题目答案解析，TPO/Official 44 Lec 1听力原文范文音频翻译。

托福TPO/Official 44 Lec 1听力原文What is the main purpose of the lecture?【新东方在线】

旁白：请听一段材料科学的讲座。

Narrator: Listen to part of a lecture in a materials science class.

教授：好。上次，我们完成了纳米技术一些基本概念的学习，纳米技术是一门交叉科学，是在分子甚至原子的数量级上利用或控制极小的物质单位。

Professor: OK. Last time we finished going over some of the fundamental concepts of nanotechnology, the multi-disciplinary science of manipulating or controlling extremely small units of matter on the scale of molecules or even atoms.

今天，我想谈谈纳米技术是如何被使用的。

So, I want to talk about how nanotechnology is being used today.

为了让大家对此有所了解，我们将看一看纳米技术的一个特殊用途。

And just to give you an idea, we'll look at one particular application.

马萨诸塞州的一个材料科学家团队一直致力于一种新的超薄涂层的研究，他们在研究可应用于浴室镜子、车窗和眼镜等物体的防雾纳米涂层。

A team of material scientists in Massachusetts has been working on a new ultra-thin coating, a nano coating that might be applied to objects like bathroom mirrors, car windows, and eye glasses to prevent fogging.

与目前市场上的各种防雾喷剂不同，纳米涂层具有永久性解决雾化的潜力。

And the coating has the potential to be a permanent solution, unlike the kinds of anti-fogging spray-on liquids that are on the market today.

当冰冷的表面与温暖、潮湿的空气接触时，经常会发生雾化，例如洗热水浴时，玻璃浴室门或镜子会起雾。

Now, fogging often occurs when a cold surface comes into contact with warm moist air, such as when a glass shower door or mirror fogs up during a warm shower.

实际发生的是——雾是什么——是数千个微小的球形水滴凝结在玻璃表面上。

Now, what's actually happening is, what the fog is, is thousands of tiny spherical water droplets condensing on the surface of the glass.

光线照射在水滴上，并且在任意方向上散射，导致雾化效应。

Light hits the water droplets and is scattered in random directions, causing the fogging effect.

刚才提到的那种防雾喷剂的除雾方法，

Now, the kind of spray-on treatments I mentioned,

使用这种方法除雾时所发生的是：当防雾喷剂用于浴室门、 浴室镜、或任何其它物体为它们除雾时，防雾喷剂会在这些物体表面冷凝，并且压平这些物体表面上的微小水滴。

What happens is they cause the tiny water droplets to flatten when they condense on the surface of the shower door or bathroom mirror or whatever object it is, it's been applied to.

因为水滴被压平，当光线照射它们时，光不散射。

Because the droplets are flattened, when light hits them, the light doesn't scatter.

但是，正如我之前所说，除雾效果不持久。

But, as I said, those kinds of treatments don't last very long.

The new coating has two important components.

一： 带负电的硅纳米颗粒，这些基本上是极小的玻璃颗粒。

One, negatively charged silicon nano particles, these are basically tiny particles of glass.

二： 一个带正电荷的聚合物，你们知道的，聚合物是一种化合物。

And two, a positively charged polymer, which you already know, a polymer is a chemical compound.

聚合物、硅纳米颗粒、聚合物、硅纳米颗粒，懂了吧。

the polymer, then the silicon nano particles, the polymer, then the silicon nano particles, you see.

它们以这样的方式分层，于是硅纳米颗粒就不能紧密地聚集在一起。

They're layered in such a way that the silicon nano particles don't pack together tightly.

换句话说，该结构有孔或洞，微小的小洞遍布其中。

In other words, the structure has pores, or holes, little tiny pockets throughout it.

纳米涂层能防止雾的形成，因为它喜欢水。

The coating prevents fog from developing, because it loves water.

它吸收水滴，把水滴吸入自己微小的孔中。

It attracts the water droplets, sucking them into the tiny pores.

And that alters the shape of the droplets.

水滴被迫变平并且聚集在一起成为一层水，而不再是能让光线在多个方向散射的、一滴滴单独的球状水滴。

The droplets are forced to flatten and to join together into a single sheet of water, rather than remaining as single droplets, each of which is a sphere that scatters light in different directions.

所以，光线不再散开，而是穿过薄薄的水层。

Ok, so, instead of being scattered, the light passes through the thin sheet of water.

超薄涂层可以更耐用，方法是将涂层和要用涂层的物体加热到极高的温度 —— 500摄氏度。

The ultra-thin coating can be made more durable by heating it, and of course the object it's applied to, to an extremely hot temperature, 500 degree Celsius.

这种方法所做的是：燃烧聚合物，把硅纳米粒子融合在一起，并且同时保持孔结构。

What that does, is burn the polymer away, and fuse the silicon nano particles together, while maintaining the structure of pores.

但是，这种方法只能用于可以承受高热的材料上。

But that's possible only on materials that can withstand high heat.

不过，他们正在努力解决这个问题，尝试找出一种方法为塑料和其它材料做出持久、有效的涂层。

But they're working on solving that problem, trying to come up with a way to coat plastics and other materials, durably and effectively.

有趣的是，正是荷花这种植物激发了纳米涂层的灵感，

Interestingly, it was a plant—the lotus plant—that inspired this work.

我想你可以说它以一种间接的方式激发了灵感。

I guess you could say inspired it in an indirect sort of way.

这种植物的叶子是我们所说的超疏水的。

The leaves of this plant are what we call superhydrophobic.

Lotus leaves, being superhydrophobic, don't attract water.

当雨滴落在莲叶上时，雨滴保持球形。

When raindrops fall on lotus leaves, they remain spherical.

很长一段时间，马萨诸塞州的科学家们试图做出一种涂层，可以像莲叶一样超疏水。

So for a long time, the Massachusetts scientists tried to create a coating that acted like these lotus leaves, a coating that was superhydrophobic.

But then they began to think about the opposite extreme.

是否能通过制作一种不排斥水，而是吸收水的涂层来实现自己的目标呢？

Could they accomplish their goal by making a coating that, instead of repelling water, actually, attracted water?

他们用这种方法似乎已经取得了很大的进展。

Well, they seem to have gotten quite far with this approach.

这真是一项强大的研究成果，具有广泛、有趣的商业应用。

It's really strong work, with a range of interesting consumer applications.

It's not costly to manufacture the coating.

一些汽车制造商对这种方法很感兴趣，想将它用于挡风玻璃上。

Some car-makers are interested in applying it to their wind shields.

在未来几年，我们有可能在市场上看到用它所生产的日常用品。

Looks like we'll probably see it on the markets in everyday products in the next few years.

How does the professor organize the information he presents to the class?

According to the professor, how does the new nanocoating work?

According to the information in the lecture, why does the new nanocoating not last as long on plastic as it does on glass?

What inspired the team of scientists in developing the new coating?

What is the professor's opinion about the approach inventors took to the development of the new nanocoating?

Listen to part of the lecture in a material science class
OK, last time we finished going over some of the fundamental concept of nanotechnology. The multi-disciplinary science that manipulating or controlling extremely small unites of matter, on the scale of molecules or even atoms. So I wanted to talk about nanotechnologies being used today. And just give you an idea, we’ll give you a particular application. 
A team of material scientists in Massachusetts has been working on a new ultra-thin coating, a nano-coating that might be applied to objects like bathroom mirrors, car windows and eye glasses, to prevent fogging. And the coating has the potential to be permanent solution unlike the kinds of anti-fogging spray-on liquids that were on the market today. 
Now, fogging often occurs when cold surface came into contact with warm moist air. Such when a glass shower door or mirror fogs up during a warm shower. Now, what’s actually happening is, what the fog is, is thousands of tiny spherical water droplets condensing on the surface of the glass. Light hits the water droplets and is scatted into random directions, causing the fogging effect. Now the kind of spray-on treatments I mentioned, they wear off. What happens is they cause the tiny water droplets to flatten when they condense on the surface of the shower door or bathroom mirror or whatever object it is, that it’s been applied to. Because the droplets are flattened, when light hits them, the light doesn’t scattered. But as I said, those kinds of treatments, don’t last very long.
The new coating has two important components. One negatively charged silicon nano-particles. These are basically tiny particles of glass. Two, positively charged Polymer which you already know a Polymer is a chemical compound. They are layered over each other. The Polymer, then the silicon nano-particles, the Polymer, then the silicon nano-particles, you see. They are layered in such a way, that the silicon nano-particles don’t packed together tightly. In other words, the structure has pores or holes, little tiny pockets throughout it. The coating prevents fog from developing because it loves water. It attracts the water droplets sucking them into the tiny pores, and that alters the shape of the droplets. The droplets are forced to flatten and join together into a single sheet of water rather than remaining a single droplets each of which that sphere and scattered light into different directions. Ok, so, instead of being scattered, the light passes through the thin sheet of water. So, there’s no fogging effect. The ulter-thin coating can be made more durable by heating it, and of course the object that it applied to, to an extremely high temperature, 500 degree Celsius. What that does, is burn the polymer away, and fuse the silicon nano-parts together while maintain the structure of pores. But, that’s possible only on materials that can withstand high heat. Glass? Yes. Plastic? No. But they are working on solving that problem, trying to come up with a way to coat plastics and other materials durably and effectively. Interestingly, it was a plant, the lotus plant, that inspire this work. I guess you could say inspired it in an indirect sort of way. The leaves of this plant are what we call the “superhydrophobic”. Lotus leaves, being superhydrophobic, don’t attract water, they repel it, in a big way. When rain drop fall on lotus leaves, they remain spherical. They roll right off. So, for a long time, the Massachusetts scientist try to create a coating that acted like these lotus leaves. A coating that was superhydrophobic. Then, they began to think the opposite extreme. Could they accomplish their goal by making a coating that, instead of repelling water, actually, attracted water. Well, they seem to get quite far with this approach. It’s really strong work with a range of interesting consumer applications. It’s not costly to manufacture the coating, some car makers are interested in applying to wind shields. Looks like we’ll probably see it on the market in everyday products in the next few years.

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