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Turn a Person’s Clothing into a Shield

2018-12-20 06:29:36
中學(xué)科技 2018年11期
關(guān)鍵詞:化學(xué)

In April,2017, bombs fell on a village in the Middle Eastern country of Syria. The explosions released toxic chemicals that killed or injured hundreds of people. On battlefields and in war-torn countries, protection against attacks by skin exposure to chemical weapons is a life-or-death need. And a new technology may help them. It would put such protection in a person's clothing.

Scientists recently showed how to coat fabric with a light layer of a certain chemical mix. This coating can absorb and neutralize chemical weapons in minutes. They described their new coating in Chemistry of Materials.

The coatings secret ingredient is a chemical known as a Metal-Organic Framework, or MOF. Such materials are composed of carbon-containing molecules attached to clusters of metal atoms. These materials have tiny holes, or pores, that can trap other chemicals. An MOF can interact with the trapped chemicals to break them down into harmless pieces. In the last few years, scientists have identified many different MOFs.

“This light material can absorb the nasty chemicals or harmful agents, and at the same time deactivate them,” explains Omar Farha. He is a chemist at Northwestern University in Evanston, Ill. Farha did not work on the fabric coating. But he knows all about it. His research focuses on materials that can hold chemicals and break them into less toxic substances. Those materials include MOFs. In the past, his lab identified MOFs that could be used to store and break down toxic chemicals on clothing.

2017年4月,多顆炸彈落在了中東國家敘利亞的一個村子里,爆炸釋放的有毒化學(xué)物質(zhì)導(dǎo)致數(shù)百人喪生或受傷。在戰(zhàn)場上和飽受戰(zhàn)爭摧殘的國家里,保護自己,不讓自己的皮膚暴露于化學(xué)武器而受到傷害,是一種生死攸關(guān)的需要。一項新技術(shù)可能會對那里的人們有幫助,它把這種保護托付給人們的衣服。

最近一些科學(xué)家展示了如何在衣服涂覆一層很輕的某種化學(xué)混合物。這樣的涂層能夠在幾分鐘內(nèi)將化學(xué)武器吸收并使之無效。他們在《材料化學(xué)》雜志上描述了他們的新型涂層。

這種涂層的秘密成分是一種被稱作“金屬有機骨架”的化學(xué)物質(zhì),簡稱MOF。該物質(zhì)由附在金屬原子簇上的含碳分子組成。這些材料有極小的空洞,即小孔,它們能夠困住其他化學(xué)物質(zhì)。有一種MOF會與被困住的化學(xué)物質(zhì)發(fā)生相互作用從而將它們分解成無害的碎片。在過去幾年,科學(xué)家已經(jīng)識別了很多不同的MOF。

“這種輕型材料能夠吸收危險的化學(xué)物質(zhì)或者有害制劑,同時使它們失活。”奧馬爾·法哈解釋道。他是美國伊利諾伊州埃文斯通鎮(zhèn)的西北大學(xué)的化學(xué)家。法哈沒有從事該項衣服涂層的研究,但他知曉詳情。他專注于研究能夠攫住化學(xué)物質(zhì)并將其分解成毒性較小物質(zhì)的材料。這些材料包括各種MOF。他的實驗室過去識別了多種能夠用來儲存和分解衣服上有毒化學(xué)物質(zhì)的MOF。

(注意磚紅色文字的譯法)

Our smartphones are our constant companions. We hunch over their screens, gaze at their blue-tinted light, and sacrifice human companionship for digital company. Over time, all these habits can wreak havoc on our (A)h________ .

Luckily, you can avoid some of these negative (1)e___________ ?without entirely relinquishing your pocket computers company. Heres how to protect your health from your (B)s________.

As we gaze down at our phones for hours every day, were reversing the typical backward curve of the neck. Unfortunately, this unnatural (2)p________ ?could be causing an increasing number of neck and spine injuries. To avoid that, you should keep your phone at eye level when texting, (C)e________, or social networking. This habit lets you hold your head up and your shoulders back when youre trying to sit ergonomically at your (D)c________. In addition, while standing, you keep your arms close to your body. When youre sitting, lean forward—again with your phone at eye level—with your elbows supported on your knees.

Cutting down on prolonged smartphone sessions will also help improve your posture and prevent other potential (3)p_______ like eye strain. If you must use your phone for hours, break up the time with small stretches, such as rolling your neck.

The sun and your digital (4)d_________ ?both emit short-wavelength high-energy blue light. Recent (E)r_________ has identified a process through which too much blue light can significantly damage cells in the eye. So you should protect your eyes by reducing the time of using your phone.

One of the best (F)m________ to protect your health from your phone is to use the gadget less frequently. To help with this goal, both iOS and Android are introducing so-called “digital wellness” tools that help you limit your smartphone use. Perhaps you need to have these tools to help you.

(A, B, C, D, E, F FOR CROSS, 1, 2, 3, 4 FOR DOWN. The first letters of the absents were given.)

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