Many of the Burgess specimens have now been assigned to living phyla just where Walcott put them in the first place. 许多布尔吉斯标本现在已经归到活着的动物的门里就是沃尔科特最初放置它们的地方。 Hallucigenia and s

发表于:2018-12-18 / 阅读(84) / 评论(0) 分类 万物简史

This is Scientific Americans 60-Second Science. Im Steve Mirsky. Got a minute? To keep your car purring, you have to change the oil. Such maintenance produces eight billion gallons of used motor oil annually. Some waste oil does get re-refined to pro

发表于:2018-12-24 / 阅读(72) / 评论(0) 分类 Scientific American(三)月

This is Scientific American's 60-Second Science. I am Steve Mirsky.Got a minute? Talk about your vicious cycles. A new study finds that belly fat could be making you hungrier. Which would lead to more belly fat. The research was performed at the Univ

发表于:2019-01-08 / 阅读(73) / 评论(0) 分类 Scientific American(四)月

Algae seem harmless enough. These precursors to plants thrive throughout the world's waters. But these single-celled plants have global consequences. We can thank them for oxygen in the atmosphere, oil in the lithosphere as well as dead zones in the

发表于:2019-01-08 / 阅读(56) / 评论(0) 分类 Scientific American(十一)月

Protamine sulfate is a drug that reverses the anticoagulant effects of liver compounds such as heparin. Protamine is extracted from the sperm of salmon and other species of fish, and then made into a protamine sulfate injection which is a necessary d

发表于:2019-01-19 / 阅读(66) / 评论(0) 分类 世界各地新闻集锦

WASHINGTON, Aug. 4 (Xinhua) -- Researchers have found a way to turn mouse embryonic stem cells into sperm and this finding opens up new avenues for infertility research and treatment, according to astudy published Thursday in the online edition of jo

发表于:2019-02-04 / 阅读(115) / 评论(0) 分类 英语新闻