单词：mercury-hydrogen spark-gap con-verter
单词：mercury-hydrogen spark-gap con-verter 相关文章
The Mercury Mess By Samantha Levine / 2004, as first appeared in U.S. News nbsp; What are the dangers of mercury in fish? Can the mercury mess be cleaned up? 1 Are these fish safe to eat?” It’s a
彭蒙惠英语
Mercury Fillings Seem Safer over Time A study in the journal Chemical Research in Toxicology finds that mercury on the surface of dental fillings slowly turns to an inert sulfide compound, which should keep the mercury from harming the nervous system
60秒科学
HEALTH REPORT – December 11, 2002: Mercury Levels in Fish By George Grow This is the VOA Special English Health Report. Two studies are adding to the debate about the health risks of eating fish con
健康与环境
今天我们要学的词组是gap。 Gap的意思是缝隙，差距。比如年龄的差距， age gap。贫富差距，the gap between the rich and the poor。收支差距，the gap between revenue and expense。 美国的一项调查结果说，美国
英语每日一词
Craters here stretch as far as the eye can see. Although no human has ever set foot on Mercury, we have a pretty good idea of what you would see. If you are walking around on the surface of Mercury, it will look outwardly a lot like the moon. When yo
自然百科2012年
Many aspects, like its geological past, are a mystery. But some things we do know, this lonely planet has a strange sense of keeping time. Once you arrive, you have to reset your watch for a time zone like no other. It has such an unusual orbit and r
自然百科2012年
Mercury's core makes up about 60% of the planet by mass. It's about twice as big as earth. Why would it have such a huge core for such a small planet? Some people think there was a huge impact. Kind of stripped off a lot of the planet and now what we
自然百科2012年
After Messenger's 3 fly-bys, we've now mapped more than 90% of the planet. Taken from around 124 miles, these images are the clearest to date of Mercury. And it's not hard to spot a crater of epic proportions, the result of yet another Titanic collis
自然百科2012年
Reason/ you are going to go to Mercury as a travel destination would be this night sight view because it's going to be highly unique in the solar system. You have sodium thats atoms that are streaming off and giving enough to see yellow light, so you
自然百科2012年
Move away from the sun, and you'd expect things to cool down a little. Venus, the picture of coolness and calm, all pale but gully-cloaked by clouds but the planet of love is shrouded in mystery-----------draw beneath her treacherous veil at your own
自然百科2012年
You are there, on the most exciting, nerve-shattering journey in the history of man! Fifty years ago, it was easy for us to imagine Venus, closer to the Sun and wrapped in clouds, to be our scorched, tropical sister, swarming with life. There was thi
自然百科2012年
And thats the first time; it was return black-and-white panoramas of the Venus surface. These images were extremely important, because it was the first time, we ,human beings had a chance to see with our naked eyes completely different other world. W
自然百科2012年
In 1989, the space shuttle Atlantis launches the Magellan Probe toward / Venus. After a journey of 15 months, Magellan uses radar eyes to peer through the clouds from orbit. Watching form earth is Ellen Stofan. When you have that ability to pick up a
自然百科2012年
And its here in a freezer that Messenger will encounter another puzzle: can ice exist on a planet so close to the sun? It's only when the first radar observations to the surface of Mercury were obtained back in the 90s that it was discovered that Mer
自然百科2012年
On earth, Hawaii has some of the most spectacular shield volcanoes that are very similar with the volcanoes we see on Venus. The huge gently sloped volcanoes of Hawaii may be impressive. On Venus there are at least 150 ranging from this size to ten t
自然百科2012年
One of the really exciting and high-level scientific interests is whether Venus is geological active today, because there are reasons to think of the clouds on Venus only exist, because there is ongoing geological activity, so this is one of the bigg
自然百科2012年
Congratulations, you've arrived on the hottest surface in the solar system. Here, the official temperature is eight hundred seventy degrees Fahrenheit. Day or night, equator or pole, the searing heat never varies more than a few degrees, and thats wh
自然百科2012年
Despite all this scientific effort, we still don't know what triggered Venus' diabolical transformation. People debated over whether Venus ever had a moon. If Venus had a satellite at one point, could that satellite eventually impacted onto the surfa
自然百科2012年
Valor will be tackling the acid clouds of Venus with little help from flying pan technology. This being two weather balloons are we watched Venus in the mid-1980s. This with wagon machines there were two sep balloons that the Russians put them in the
自然百科2012年
You never guess the dangers on the ground from orbit, except maybe for this, massive, double-barreled storms hovering above the poles. Of this, what we called dipole features trailing around, we don't know what, really what they are, but the whole fe
自然百科2012年