And for retrofitting older buildings to be more energy effcient, wood is a good insulator.

为使旧建筑更节能，木材是很好的绝缘体。

Since these are not connected to each other, the result is an insulator.

它彼互不连接，因成为了绝缘体。

And in an insulator, like rubber, electrons can't really flow at all.

而在橡一类的绝缘体中，电子实际上根本无法流动。

Aerogels are great for insulation, because the air inside doesn't transfer heat very well.

气凝是绝佳的绝缘体，因为其内部气体不太能导热。

President Trump, I think, is an equal opportunity insulter.

为，特朗普总统是一个机会均等的绝缘体。

It also turned out that gutta percha was a great insulator for undersea cables.

事实证明，杜仲是海底电缆的绝佳绝缘体。

Powdery or soft, the substance provides an excellent source of insulation.

粉末状或是柔软的这种物质能成为绝好的绝缘体。

Your body creates its own warm bubble of air just above the skin thanks to conduction.

由于传导，你的身体会在皮肤上方产生热气绝缘体。

A topological insulator acts like both at the same time, which we used to think was impossible!

一个拓扑绝缘体就像两个同时起作用，而这在过去被为是不可能的。

Myelin acts like insulation, just like on an electrical wire that helps the impulse travel more quickly.

髓鞘就像绝缘体，就像电线一样，帮助脉冲更快地传播。

All right, let's begin. Show of hands, who here is familiar with the concept of topological insulators?

好吧 开始上课 请举手告诉 在座的哪位对拓扑绝缘体的概念比较熟悉？

Most of the material is an insulator, but its surface can carry an electric current.

大部分这种材料都是一个绝缘体，但其表面仍可带一支电流。

The effects of high pressure can also work in reverse, causing some metals to lose conductivity or become insulators.

高压也能产生相反的效果，可能会使一些金属失去导电性或变成绝缘体。

The electrons in insulators, on the other hand, have a tough time getting enough energy to break free and flow.

另一方面，绝缘体的电子难以获得足够的能量去摆脱束缚进行流动。

We do a fair amount in tiles and in insulators for electrica appliances. But kitchenware and tableware are our mainlines.

经营相当数量的瓷砖，以及电器用品的绝缘体。但是厨房用具和餐具是本公司主要系列产品。

Now, while chemically pure water is an insulator, most water is impure.

现在， 虽然化学纯水是绝缘体，但大多数水都是不纯的。

Myelin is an insulator and speeds up the electrical signals zipping down the nerve fiber.

髓磷脂是一种绝缘体，可加快电信号在神经纤维中的传输速度。

One example is called a topological insulator.

一个例子叫做拓扑绝缘体。

So we’ve got insulators and conductors with free electrons moving around in them.

所以有绝缘体和导体， 其中有自由电子在其中移动。

And in an insulator, like rubber, electrons can’t really flow at all.

在橡等绝缘体中，电子根本无法流动。