SSS 2012-08-22
时间:2013-01-06 08:47:30
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(单词翻译)
This is scientific American sixty seconds science. I'm Christopher Intagliata. Got a minute?
Camouflage1 face paint can make a soldier invisible to enemy in eyes. But it won't shield him from the
shearing2 heat of a roadside bomb, a
lethal3 eleven hundred degrees
Fahrenheit4. And the greases and oils in the
makeup5 just add fuel to the fire,
essentially6 cooking the soldier's face. But researchers have come up with a safer, heat-blocking alternative, presented in this week at a meeting of the American Chemical Society.
Conventional camo paint has tiny nano particles of
pigment7, they are great at reflecting visible light which is why the paint looks green or black or tan. But the particles don't reflect longer
wavelengths8 like heat. To do that, you need larger globs of pigment. So researchers bundled together a bunch of those smaller particles into
chunks9 the size of grains of sand, large enough for heat rays to bounce right off. And it
swapped10 out the grease for silicone which adds smoothest and spreadability to
cosmetics11, but won't catch fire. Under a blowtorch, the new camo paint can block out heat for fifteen seconds, long enough to weather a bomb blast and keep soldiers cool in the heat battle.
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