New Camera Records Invisible Motion The world is in never-ending motion, even when objects seem to be perfectly still. Researchers at the Massachusetts Institute of Technology use a special camera that shows these seemingly invisible movements. Many

发表于:2018-12-16 / 阅读(50) / 评论(0) 分类 2015年VOA慢速英语(二)月

WAN wide area network WARC World Administrative Radio Consortium WATS Wide-area telecommunications services. See Wide-area telecommunications services. Waveform amplitude (magnitude) versus time repre

发表于:2019-01-03 / 阅读(58) / 评论(0) 分类 电信英语

DCE data circuit terminating equipment DCP digital communications protocol DCS digital cross-connect system DDD direct distance dialing DDN Defense Data Network Digit L Digital L is another amplitude

发表于:2019-01-03 / 阅读(71) / 评论(0) 分类 电信英语

This is Scientific American's 60-Second Science. I'm Christopher Intagliata. Got a minute? Toss a piece of leaf onto a spider web. The spider is indifferent. Because leaves don't squirm like captured flies. But Australia's assassin bug turns the tabl

发表于:2019-01-08 / 阅读(112) / 评论(0) 分类 Scientific American(十一)月

This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute. When we think about how to represent sound visually, most of us probably picture those volume-dependent sine waves. But thats not how John Stuart Reid

发表于:2019-01-08 / 阅读(58) / 评论(0) 分类 Scientific American(一)月

President Obama's spending the last two days of his Asia tour in Japan, shoring up trade support at a regional summit after suffering a few setbacks. Earlier at the G20 meeting in Seoul, the president was unable to secure a free trade pact with South

发表于:2019-01-08 / 阅读(63) / 评论(0) 分类 2010年NPR美国国家公共电台11月