SSS 2008-09-01
时间:2019-01-08 作者:英语课 分类:Scientific American(九)月
This is Scientific American's 60-Second Science. I'm Steve Mirsky. Got a minute?.
[Spray sound.] Killing 1 bugs 2? No. [Spray sound.] Deodorizing the bathroom? No. [Spray sound.] Checking for explosives, yes. Because chemists at the University of California, San Diego have come up with a spray-on polymer film that can spot residue 3 from nitrogen-based explosives such as TNT. It works in as little as 30 seconds.
When ultraviolet light is shined on a safe, sprayed surface, it glows blue. But when the surface shows traces of a nitrogen-based explosive, it stays dark. Because the explosives soak up the electrons that would emit the blue glow. The researchers describe the synthesis and properties of their polymers in the Journal of Materials Chemistry.
A single layer of the polymer, about one-thousandth of a gram, is enough for the test. And the polymer is so sensitive, it can detect explosive residues 4 on the order of a few millionths of a gram. Often more than a thousand times that amount is left on surfaces. The method is so promising 5, it’s already been featured on an episode of CSI: Miami. Chemists know that’s a technology’s acid test.
Thanks for the minute for Scientific American's 60-Second Science. I'm Steve Mirsky .
- Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
- Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。
- All programs have bugs and need endless refinement. 所有的程序都有漏洞,都需要不断改进。 来自《简明英汉词典》
- The sacks of rice were swarming with bugs. 一袋袋的米里长满了虫子。 来自《简明英汉词典》
- Mary scraped the residue of food from the plates before putting them under water.玛丽在把盘子放入水之前先刮去上面的食物残渣。
- Pesticide persistence beyond the critical period for control leads to residue problems.农药一旦超过控制的临界期,就会导致残留问题。
- pesticide residues in fruit and vegetables 残留在水果和蔬菜中的杀虫剂
- All organic and metallic residues on the wafers must be removed. 片子上所有的有机和金属残留物均必须清除。 来自辞典例句