准晶体来自地外空间-凯发k8官网

准晶体来自地外空间
文章来源:未知 文章作者:enread 发布时间:2012-08-10 05:30 字体: [ ] 
(单词翻译:双击或拖选)
results from an expedition to far eastern russia that set out to find the origin of naturally occurring quasicrystals(准晶体) have provided convincing evidence that they arrived on earth from outer space. writing in iop publishing's journal reports on progress in physics, paul j steinhardt and luca bindi reveal that new, naturally occurring quasicrystal samples have been found in an environment that does not have the extreme terrestrial conditions needed to produce them, therefore strengthening the case that they were brought to earth by a 1. furthermore, their findings reveal that the samples of quasicrystals were brought to the area during the last glacial period, suggesting the meteorite(陨星) was most likely to have hit earth around 15 000 years ago.
 
"the fact that the expedition found more material in the same location that we had spent years to track down is a tremendous 2 of the whole story, which is significant since the meteorite is of great interest because of its extraordinary age and contents," said steinhardt.
 
in their report, steinhardt and bindi describe the expedition in which ten scientists, two drivers and a cook travelled 230 km into the koryak mountains of far eastern russia to pan one and a half tons of 3 by hand, and survey local streams and mountains.
 
the group of researchers were on the look-out for naturally occurring quasicrystals -- a unique class of solids that were first synthesized in the laboratory by israeli scientist dan shechtman in 1982. he was awarded the nobel prize for chemistry in 2011 for this discovery.
 
the concept of quasicrystals was first introduced by steinhardt and his student dov levine. until their work, it had been believed that all solids, 4 or natural, form ordinary crystals -- materials whose entire structure is made of a single-type cluster of atoms that repeat at regular 5, joining together in much the same way as identical tiles in bathroom tiling.


点击收听单词发音收听单词发音  

1 2wny1     
n.陨石;流星
参考例句:
  • the meteorite in jilin exhibition hall is believed to be the largest in the world.吉林展览馆的陨石被认为是世界上最大的。
  • the famous murchison meteorite smashed into the australian ground in 1969.1969年著名的默奇森陨石轰然坠落在澳大利亚。
2 zymya     
n.证实,确认,批准
参考例句:
  • we are waiting for confirmation of the news.我们正在等待证实那个消息。
  • we need confirmation in writing before we can send your order out.给你们发送订购的货物之前,我们需要书面确认。
3 isbyk     
n.沉淀,沉渣,沉积(物)
参考例句:
  • the sediment settled and the water was clear.杂质沉淀后,水变清了。
  • sediment begins to choke the channel's opening.沉积物开始淤塞河道口。
4 zhtzy     
adj.合成的,人工的;综合的;n.人工制品
参考例句:
  • we felt the salesman's synthetic friendliness.我们感觉到那位销售员的虚情假意。
  • it's a synthetic diamond.这是人造钻石。
5 f46c9d8b430e8c86dea610ec56b7cbef     
n.[军事]间隔( interval的名词复数 );间隔时间;[数学]区间;(戏剧、电影或音乐会的)幕间休息
参考例句:
  • the forecast said there would be sunny intervals and showers. 预报间晴,有阵雨。
  • meetings take place at fortnightly intervals. 每两周开一次会。
上一篇: 下一篇:
tag标签: space earth meteorite
发表评论
请自觉遵守互联网相关的政策法规,严禁发布色情、暴力、反动的言论。
评价:
表情:
验证码:点击我更换图片
最新评论
网站地图