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23 Nano-tech 语音文本同步播放 00:02.12]23 Nano-technique --- Episode 20_ October 2, 2006 - Scientific American邱岩反复翻听制作一定要用卡拉ok播放方式,反复调了速度。0 x! e! y0 x! V0 ~
[00:02.44]This is scientific Americans, 60 second science, I'm Krealer Rull. Got a minute!
) F- N, ~" h" h. Y2 M. o[00:07.32]Nano technology has become a hot field of research in recent years. But nanotech may have made its début thousands years ago, in ancient Greece., L* r% I6 c2 y, ]7 y
[00:15.58]That’s according to a team of French researchers' publishing in the September issue of the Journal Nano Letters.
6 y# v! f1 e% D[00:21.95]The researchers replicated the formula for black hair dye used by the Greco-Romans. It was a paste, whose main ingradient was lead oxide.4 ]) B/ i' s0 l# B+ D. C
[00:30.19]On the paste, it slides down onto hair, the lead oxide reacts with the hair sulphur-rich proteins, creating crystals of lead sulphide. Those crystals accumulate in the hair, gradually turning it black. S* k. d4 c% m& p
[00:41.61]Now that chemistry has been understood for a while, in fact, it’s the secret behind a Grecian formula., D- |- ]) ~8 B% h8 a
[00:47.53]But the scientists went a bit further and looked at the dyed strands of hair under the microscope. s# l& Z! ?6 k E
[00:52.37]The lead sulphide crystals they saw, were just 5 nm in size, much smaller than the natural pigments in the hair away real brunette./ H F$ l2 Q: F
[01:00.23]By studying this ancient technique, the scientists hope to know how to better nano-particles, for more than just getting back in black.
# z& F0 H; l4 q: J' Q[01:07.55]Thanks for the minute for Scientific American’s 60-Second Science. I'm Krealer Rull./ u+ o k! W! P: y3 u/ \$ n! u; f: u
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其中至少10处地方每处复听10遍。此篇超难。有时听出内容,语法不对,又要重来。如要练习,最好不先看答案。这是个练习好机会。祝大家愉快 (发帖重复,抱歉,下次更正)9 A: j. H3 F8 z# n
7 O& S/ d! G* u) C! U9 S& r. [[ 本帖最后由 yqiu2 于 2007-10-9 15:44 编辑 ]
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