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時差N小時:蜘蛛絲是什么? What Is Spider Silk?

所屬教程:時差N小時

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2016年05月08日

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https://online2.tingclass.net/lesson/shi0529/0009/9697/488.mp3
https://image.tingclass.net/statics/js/2012
What's five times as strong as steel, twice as toughas Kevlar,and can be stretched over thirty percent inlength withoutbreaking?

什么東西的強度是鋼的5倍?什么東西的韌性是凱夫拉的2倍?什么東西能夠拉長到自身長度的30%卻不會斷裂?

The answer is spider silk.

答案是蜘蛛絲。

Spiders make at least six different types of silk whichthey use for locomotion, protecting eggs,wrappingprey, and gluing pieces of web together.

蜘蛛能生產(chǎn)至少6種不同類型的蛛絲用以移動、護(hù)卵、捕食和結(jié)網(wǎng)。

Silk is not only strong, it's biodegradable andproduced at low temperatures and pressures,unlike many man made polymer fibers.

蛛絲不僅結(jié)實,而且在低溫低壓下可生物降解和再生。這有別于許多人造纖維。

Why don't we use spider silk to make things?

為什么我們不利用蜘蛛絲來制作產(chǎn)品呢?Unlike silk worms, spiders can'tproduce much silk at a time.

蜘蛛無法像蠶那樣在短時間內(nèi)產(chǎn)生大量的絲。

It took eighty weavers and a milliongolden orb spiders five years to make a spider silk rug alittle over twelve feet square.

制作12平方英尺多點的蛛網(wǎng)地毯,需要80名織工,使用100萬只金球蜘蛛,花費5年時間才能完成。

Scientists decided to work on the silk quantity problem.

科學(xué)家們決定研究蛛絲的數(shù)量問題。

And, no, they didn't create giant spiders.

當(dāng)然他們不會去創(chuàng)造巨型蜘蛛。

First, they identified soft and crystalline components in the silk protein sequences that makeit bothstretchy and strong.

首先,他們在蛛網(wǎng)蛋白序列中識別出使蛛網(wǎng)具備延展性和強韌性的柔軟又透明的成份。

Once they identified these elements, they located the gene that codes forspider silk.

一旦科學(xué)家們成功識別出這些成份,他們就能鎖定形成蛛網(wǎng)的基因。

With the gene in hand, scientists decided to use a common intestinal bacteria namedEscherichiacoli to help them.

基因到手后,科學(xué)家們決定使用一種普遍的腸道細(xì)菌—大腸桿菌—作為輔助。

They inserted the spider gene into the bacteria.

他們要把蜘蛛基因嵌入大腸桿菌。

Because the protein was large,they had to do some metabolic engineering to enable thebacteria to produce it.

不過蜘蛛的蛋白很大,所以科學(xué)家們需要做一些代謝工程使得大腸桿菌能夠生產(chǎn)蜘蛛蛋白。

In the end, they made spider silk, but it wasn't as fine as the real thing.

最后,大腸桿菌產(chǎn)出蛛網(wǎng),但其質(zhì)量不如真正的蛛絲那么理想。

That's because spidersenhance the uniformity of their silk as they pull it from their spinnerets.

原因在于蜘蛛是從吐絲器官里把蛛絲拉出來的,這加強了蛛絲的均勻性。

The pulling process wasn't replicated in the lab until scientists developed a device to mimicthefiber-pulling step.

在科學(xué)家們開發(fā)出一種模擬拉出蛛絲的設(shè)備之前,這種拉絲過程無法在實驗室里復(fù)制。

They have now created a thread rivaling natural silk.

不過科學(xué)家們現(xiàn)已創(chuàng)造出一種與織線媲美的天然絲。

This great fiber could soon be used for violin strings as well as bullet proof vests.

這種優(yōu)質(zhì)的纖維預(yù)計很快就能用于小提琴琴弦或者防彈背心上了。

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