对铜原子的压力测试
文章来源:未知 文章作者:enread 发布时间:2013-10-23 07:08 字体: [ ]  进入论坛
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Scientists used the powerful X-ray laser at the U.S. Department of Energy's SLAC National Accelerator Laboratory to create movies detailing trillionths-of-a-second changes in the arrangement of copper1 atoms after an extreme shock. Movies like these will help researchers create new kinds of materials and test the strength of existing ones. This work, published Oct. 11 in Science, pinpointed2 the precise breaking point when the extreme pressures began to permanently3 deform4 the copper structure, or lattice(晶格,格子), so it could no longer bounce back to its original shape. Such experiments provide a direct test of complex computer simulations that model the behavior of many millions of atoms within tiny samples of material.
 
Such simulations are used to design stronger, more durable5 materials -- such as shielding for satellites to withstand high-speed pelting6 by space debris7 -- but they have been hard to test in the lab because of the tiny samples and short timescales involved.
 
"The results enable a number of materials experiments that can be compared to simulations at the same scales," said Despina Milathianaki, a staff scientist at SLAC's Linac Coherent Light Source (LCLS) who led the experiment. "This and future experiments, designed to provide a direct comparison with simulations, will help us to accurately8 predict the strength of materials in extreme conditions."
 
In this experiment, researchers shocked a layer of copper about 1 thousandth of a millimeter, or 1 micron thick with optical laser pulses, and then probed the copper's lattice with ultrabright X-ray pulses. They compiled the X-ray images into atomic-scale movies that detail how the lattice responded at various times after the shock, including the moment the copper reached its breaking point.
 
"The demand for research time at LCLS is already at a premium9, and these results demonstrate yet another new technique that we believe will open the door to a host of new experiments," said Sebastien Boutet, who leads LCLS's Coherent X-ray Imaging (CXI) Department, where the measurements were performed.
 
The same research team -- composed mostly of SLAC scientists, with collaborators from University of Oxford10, Stanford University and Lawrence Livermore National Laboratory -- also shocked other metals, including iron and titanium, and is analyzing11 the data obtained from those samples.
 
Follow-up research scheduled at LCLS in March seeks to extend the research to additional materials and to enlist12 other x-ray scattering13 techniques, which may provide more details about the origins of the damage in the lattice.


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1 copper HZXyU     
n.铜;铜币;铜器;adj.铜(制)的;(紫)铜色的
参考例句:
  • The students are asked to prove the purity of copper.要求学生们检验铜的纯度。
  • Copper is a good medium for the conduction of heat and electricity.铜是热和电的良导体。
2 pinpointed e23273e2459d3a2f113ef7cdb8d1c728     
准确地找出或描述( pinpoint的过去式和过去分词 ); 为…准确定位
参考例句:
  • His refusal to help simply pinpointed his cowardice. 他拒绝帮助正显示他的胆小。
  • Computers pinpointed where the shells were coming from. 计算机确定了炮弹发射的位置。
3 permanently KluzuU     
adv.永恒地,永久地,固定不变地
参考例句:
  • The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
  • The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。
4 deform L9Byo     
vt.损坏…的形状;使变形,使变丑;vi.变形
参考例句:
  • Shoes that are too tight deform the feet.(穿)太紧的鞋子会使脚变形。
  • Ice crystals begin to deform measurably.冰晶就产生某种程度的变形了。
5 durable frox4     
adj.持久的,耐久的
参考例句:
  • This raincoat is made of very durable material.这件雨衣是用非常耐用的料子做的。
  • They frequently require more major durable purchases.他们经常需要购买耐用消费品。
6 pelting b37c694d7cf984648f129136d4020bb8     
微不足道的,无价值的,盛怒的
参考例句:
  • The rain came pelting down. 倾盆大雨劈头盖脸地浇了下来。
  • Hailstones of abuse were pelting him. 阵阵辱骂冰雹般地向他袭来。
7 debris debris     
n.瓦砾堆,废墟,碎片
参考例句:
  • After the bombing there was a lot of debris everywhere.轰炸之后到处瓦砾成堆。
  • Bacteria sticks to food debris in the teeth,causing decay.细菌附着在牙缝中的食物残渣上,导致蛀牙。
8 accurately oJHyf     
adv.准确地,精确地
参考例句:
  • It is hard to hit the ball accurately.准确地击中球很难。
  • Now scientists can forecast the weather accurately.现在科学家们能准确地预报天气。
9 premium EPSxX     
n.加付款;赠品;adj.高级的;售价高的
参考例句:
  • You have to pay a premium for express delivery.寄快递你得付额外费用。
  • Fresh water was at a premium after the reservoir was contaminated.在水库被污染之后,清水便因稀而贵了。
10 Oxford Wmmz0a     
n.牛津(英国城市)
参考例句:
  • At present he has become a Professor of Chemistry at Oxford.他现在已是牛津大学的化学教授了。
  • This is where the road to Oxford joins the road to London.这是去牛津的路与去伦敦的路的汇合处。
11 analyzing be408cc8d92ec310bb6260bc127c162b     
v.分析;分析( analyze的现在分词 );分解;解释;对…进行心理分析n.分析
参考例句:
  • Analyzing the date of some socialist countries presents even greater problem s. 分析某些社会主义国家的统计数据,暴露出的问题甚至更大。 来自辞典例句
  • He undoubtedly was not far off the mark in analyzing its predictions. 当然,他对其预测所作的分析倒也八九不离十。 来自辞典例句
12 enlist npCxX     
vt.谋取(支持等),赢得;征募;vi.入伍
参考例句:
  • They come here to enlist men for the army.他们来这儿是为了召兵。
  • The conference will make further efforts to enlist the support of the international community for their just struggle. 会议必将进一步动员国际社会,支持他们的正义斗争。
13 scattering 91b52389e84f945a976e96cd577a4e0c     
n.[物]散射;散乱,分散;在媒介质中的散播adj.散乱的;分散在不同范围的;广泛扩散的;(选票)数量分散的v.散射(scatter的ing形式);散布;驱散
参考例句:
  • The child felle into a rage and began scattering its toys about. 这孩子突发狂怒,把玩具扔得满地都是。 来自《简明英汉词典》
  • The farmers are scattering seed. 农夫们在播种。 来自《简明英汉词典》
TAG标签: materials copper atoms
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