单词：cesium vapor cathode
单词：cesium vapor cathode 相关文章
[00:06.37]The United States has a new official clock. [00:10.95]The clock began operating late last year in the American city of Boulder,Colorado. [00:18.39]Experts say the new clock is so exact that it will neither gain nor lose so much as one secon
美国英语听力80篇
Youve given some thought to oxygen, carbon, uranium. But youve probably never mused about the element ytterbium, symbol Yb. A new study by scientists at the National Institute of Standards and Technology, or NIST, says that ytterbium could find a rol
Scientific American(八)月
This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute. Batteries of the future need to deliver more energy, and they need to be smaller. Researchers at MIT think they have developed a technology that can, a
Scientific American(四)月
BEIJING, Oct. 21 (Xinhuanet) -- A team of European researchers announced that they have found vast water vapor out of our solar system, according to a study in the U.S. journal Science Friday. Using Herschel Space Observatory, a European Space Agency
英语新闻
I know not that any other author has hinted of the matter; 我不知道是否有其他作家提及此事， but by inference it seems to me that the sturgeon must be divided in the same way as the whale, 不过据我推断，鲟鱼也一定是按大鲸
白鲸记
Surmounting Life's Obstacles - Do You Cling to What You Were Before? 跨越生命中的障碍 您还坚持原来的样子吗? A little stream flowed down from a high mountain far, far away through many villages and forests, until it reached a desert.
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