SSS 2009-03-13
时间：2019-01-08 作者：英语课 分类：Scientific American(三)月
This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute.
If you get a scratch, your skin can heal itself. But if your car gets scratched, it stays scratched. Scientists at the University of Southern Mississippi think they may have solved that problem. They’ve developed a new material that can self-heal scratches when exposed to sunlight. They published this research in the March 13th edition of the journal Science.
The new technology first takes polyurethane—the coating on many cars. Then researchers added chitosan—that’s a key polymer in crab 1 and shrimp 2 shells. The final bit thrown into the mix are minute amounts of oxetane rings, with three atoms of carbon and one of oxygen.
The researchers are trying to mimic 3 natural processes. Here’s how it works. When there’s a scratch, damaging the molecule 4, the oxetane ring opens. It has two reactive ends. In sunlight, chitosan breaks into two chains and generates free radicals 5. Then those chitosan chains link up with the reactive ends of the oxetane, filling in the scratch.
Researchers say this technique is much simpler and more cost-efficient than other attempts at self-healing. So maybe in the future, when your car gets scraped, it’ll be all healed up before you have to spend any of your hard earned scratch.
Thanks for the minute for Scientific American's 60-Second Science. I'm Cynthia Graber.
- I can't remember when I last had crab.我不记得上次吃蟹是什么时候了。
- The skin on my face felt as hard as a crab's back.我脸上的皮仿佛僵硬了，就象螃蟹的壳似的。
- When the shrimp farm is built it will block the stream.一旦养虾场建起来，将会截断这条河流。
- When it comes to seafood,I like shrimp the best.说到海鲜，我最喜欢虾。
- A parrot can mimic a person's voice.鹦鹉能学人的声音。
- He used to mimic speech peculiarities of another.他过去总是模仿别人讲话的特点。
- A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
- This gives us the structural formula of the molecule.这种方式给出了分子的结构式。