英語(yǔ)聽(tīng)力文摘497 像霧一樣的固體物質(zhì)

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https://online2.tingclass.net/lesson/shi0529/0007/7643/497.mp3

https://image.tingclass.net/statics/js/2012

固體煙

Male: What's as light as smoke but strong as a brick?

Female: I'm gonna take a while guess and say... aerogel?

Male: Sorry,yaoyao,the answer is... Wait a second! Did you say aerogel? How did you know?

F:Yeap! Did you know that aerogel is the lightest solid on earth?

M: I was going to tell you that.

F: Another cool thing is that it starts out as a kind of chemical Jello. Then the gel is dried in a powerful pressure cooker and emerges as a very lightweight, dry, sponge- like material that looks like frozen smoke.

M: OK! Did you know that aerogel is ninety-nine-point-eight percent air?

F: Sure.That was in your notes.And it’s incredibly light–one thousand times less dense than glass. But it's also really strong and an excellent insulator.

M: Is there anything you don't know about aerogel? For instance,scientists are using it to try to capture dust particles from the tail of a comet. When the particlesslam into an aerogelpanel aboard a space probe, they'll bury themselves inside and leave visible trails. Since aerogel is mostly air, it won't damage the particles.

F: Actually, I know that too.

男：什么東西既可以跟煙一樣輕，又可以跟磚塊一樣重?

女：讓我想會(huì)兒... 氣凝膠?

男：瑤瑤，不好意思，答案是... 等等!你說(shuō)的是氣凝膠嗎?你是怎么知道的?

女：是的!你知道氣凝膠是地球上最輕的固體嗎?

男：我剛剛正要告訴你呢!

女：了不起的是，氣凝膠開(kāi)始是作為一種化學(xué)凝膠物的。然后膠體在壓力很強(qiáng)的鍋里變干，成為了一種重量很輕、很干燥、類似海綿狀，看起來(lái)像固體煙霧的物體。

男：是的!那你知道氣凝膠中99.8%都是空氣嗎?

女：知道啊!你的筆記中有的!氣凝膠相當(dāng)?shù)妮p，輕到密度只有玻璃的千分之一。但它也很結(jié)實(shí)，是幾號(hào)的絕緣體。

男：關(guān)于氣凝膠，你還有什么不知道的嗎?比如說(shuō)，科學(xué)家正在試圖用它捕捉彗星經(jīng)過(guò)的微塵。當(dāng)(微塵)顆粒猛烈撞擊到航空探測(cè)器上的氣凝膠板時(shí)，它們將會(huì)自然，從而留下可見(jiàn)的痕跡。因?yàn)闅饽z差不多等同于空氣，并不會(huì)破壞(微塵)顆粒。

女：其實(shí)這個(gè)我也知道!

【W(wǎng)ords & Expressions】

aerogel：氣凝膠，又稱為干凝膠。是一種固體物質(zhì)形態(tài)，世界上密度最小的固體。當(dāng)凝膠脫去大部分溶劑，使凝膠中液體含量比固體含量少得多，或凝膠的空間網(wǎng)狀結(jié)構(gòu)中充滿的介質(zhì)是氣體，外表呈固體狀，這即為干凝膠，也稱為氣凝膠。

slam into：猛烈撞擊

space probe：航空探測(cè)器