火山是女人最好的朋友?-凯发k8官网

火山是女人最好的朋友?
文章来源:未知 文章作者:enread 发布时间:2012-05-17 05:49 字体: [ ] 
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scientists from the university of southampton have discovered a 1 unrecognised 2 process, similar to one that is used in chocolate manufacturing, which gives important new insights into the 3 of volcanic 4. the scientists investigated how a process called 'fluidised(液化) spray granulation(粗糙) ' can occur during kimberlite(金伯利岩) eruptions to produce well-rounded particles containing fragments from earth's 6, most 7 diamonds. this physical process is similar to the gas injection and spraying process used to form smooth coatings on confectionary(糖果) , and layered and delayed-release coatings in the manufacture of 9 and fertilisers.

kimberlite volcanoes are the primary source of diamonds on earth, and are formed by gas-rich magmas from mantle depths of over 150 km. kimberlite volcanism involves high-intensity explosive eruptions, forming 11(发散的) pipes or 'diatremes', which can be several hundred metres wide and several kilometres deep. a 12 and previously mysterious feature of these pipes are 'pelletal lapilli ' -- well-rounded magma coated fragments of rock consisting of an inner 'seed' particle with a complex 10, thought to represent 13(淬火的) magma.

these pelletal lapilli form by spray granulation when kimberlite magma 14 into earlier volcaniclastic infill close to the diatreme root zone. intensive degassing produces a gas jet in which the seed particles are 15 fluidised and coated by a spray of low-viscosity melt.

in kimberlites, the occurrence of pelletal lapilli is linked to diamond grade (carats per tonne), size and quality, and therefore has economic as well as academic significance.

dr thomas gernon, lecturer in earth science at the university of southampton, says: "the origin of pelletal lapilli is important for understanding how magmatic pyroclasts are transported to the surface during explosive eruptions, offering fundamental new insights into 5 dynamics and 16 on 18 conditions, notably gas 19."

"the ability to tightly 17 gas 20 is significant, as it enables estimation of the maximum diamond size transported in the flow. gas fluidisation and magma-coating processes are also likely to affect the diamond surface properties."

dr gernon and colleagues studied two of the world's largest diamond mines in south africa and lesotho. in the letseng pipe in lesotho, pelletal lapilli have been found in association with concentrations of large diamonds (up to 215 carat), which individually can fetch up to tens of millions of pounds. knowledge of flow dynamics will inform models of mineral transport, and ultimately could improve resource 21.

dr gernon, who is based at the national oceanography centre at southampton's waterfront campus, says: "this multidisciplinary research, incorporating earth sciences, chemical and mechanical engineering, provides evidence for fluidised granulation in natural systems which will be of considerable interest to engineers and chemical, 8 and food scientists who use this process routinely. the scale and 22 of this granulation process is unique, as it has not previously been recognised in natural systems."



点击收听单词发音收听单词发音  

1 bkzzzc     
adv.以前,先前(地)
参考例句:
  • the bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • let me digress for a moment and explain what had happened previously.让我岔开一会儿,解释原先发生了什么。
2 blgzq     
adj.火山的;象火山的;由火山引起的
参考例句:
  • there have been several volcanic eruptions this year.今年火山爆发了好几次。
  • volcanic activity has created thermal springs and boiling mud pools.火山活动产生了温泉和沸腾的泥浆池。
3 nuszqq     
n.力学,动力学,动力,原动力;动态
参考例句:
  • in order to succeed,you must master complicated knowledge of dynamics.要取得胜利,你必须掌握很复杂的动力学知识。
  • dynamics is a discipline that cannot be mastered without extensive practice.动力学是一门不做大量习题就不能掌握的学科。
4 ca60b8eba3620efa5cdd7044f6dd0b66     
n.喷发,爆发( eruption的名词复数 )
参考例句:
  • there have been several volcanic eruptions this year. 今年火山爆发了好几次。 来自《简明英汉词典》
  • over 200 people have been killed by volcanic eruptions. 火山喷发已导致200多人丧生。 来自辞典例句
5 uomxv     
n.火山爆发;(战争等)爆发;(疾病等)发作
参考例句:
  • the temple was destroyed in the violent eruption of 1470 bc.庙宇在公元前1470年猛烈的火山爆发中摧毁了。
  • the eruption of a volcano is spontaneous.火山的爆发是自发的。
6 y7tzs     
n.斗篷,覆罩之物,罩子;v.罩住,覆盖,脸红
参考例句:
  • the earth had donned her mantle of brightest green.大地披上了苍翠欲滴的绿色斗篷。
  • the mountain was covered with a mantle of snow.山上覆盖着一层雪。
7 1hex9     
adv.值得注意地,显著地,尤其地,特别地
参考例句:
  • many students were absent,notably the monitor.许多学生缺席,特别是连班长也没来。
  • a notably short,silver-haired man,he plays basketball with his staff several times a week.他个子明显较为矮小,一头银发,每周都会和他的员工一起打几次篮球。
8 f30zr     
adj.药学的,药物的;药用的,药剂师的
参考例句:
  • she has donated money to establish a pharmaceutical laboratory.她捐款成立了一个药剂实验室。
  • we are engaged in a legal tussle with a large pharmaceutical company.我们正同一家大制药公司闹法律纠纷。
9 be065c8a4af3a2d925d11969faac34cf     
n.医药品;药物( pharmaceutical的名词复数 )
参考例句:
  • the development of new pharmaceuticals 新药的开发
  • the companies are pouring trillions of yen into biotechnology research,especially for pharmaceuticals and new seeds. 这些公司将大量资金投入生物工艺学研究,尤其是药品和新种子方面。 来自《简明英汉词典》
10 rxsxl     
n.(圆物的)边,轮缘;边界
参考例句:
  • the water was even with the rim of the basin.盆里的水与盆边平齐了。
  • she looked at him over the rim of her glass.她的目光越过玻璃杯的边沿看着他。
11 d7d416587b95cf7081b2b1fd0a9002ea     
分开( diverge的现在分词 ); 偏离; 分歧; 分道扬镳
参考例句:
  • plants had gradually evolved along diverging and converging pathways. 植物是沿着趋异和趋同两种途径逐渐演化的。
  • with member-country bond yields now diverging, 'it's a fragmented set of markets. 但随着成员国债券收益率之差扩大,市场已经分割开来。
12 spsze     
adj.明眼的,惹人注目的;炫耀的,摆阔气的
参考例句:
  • it is conspicuous that smoking is harmful to health.很明显,抽烟对健康有害。
  • its colouring makes it highly conspicuous.它的色彩使它非常惹人注目。
13 dae604e1ea7cf81e688b2bffd9b9f2c4     
解(渴)( quench的过去式和过去分词 ); 终止(某事物); (用水)扑灭(火焰等); 将(热物体)放入水中急速冷却
参考例句:
  • he quenched his thirst with a long drink of cold water. 他喝了好多冷水解渴。
  • i quenched my thirst with a glass of cold beer. 我喝了一杯冰啤酒解渴。
14 3fd55f59bc5bc27ecdb23a5321933d8f     
v.侵入,侵扰,打扰( intrude的第三人称单数 );把…强加于
参考例句:
  • an outraged movie like stone's intrudes upon a semipermanent mourning. 像斯通这种忿忿不平的电影侵犯到美国人近乎永恒的哀悼。 来自互联网
  • he intrudes upon our hospitality. 他硬要我们款待他。 来自互联网
15 4ibz1o     
adv.同时发生地,同时进行地
参考例句:
  • the radar beam can track a number of targets almost simultaneously.雷达波几乎可以同时追着多个目标。
  • the windows allow a computer user to execute multiple programs simultaneously.windows允许计算机用户同时运行多个程序。
16 d178923285d63e9968956a0a4758267e     
强制( constraint的名词复数 ); 限制; 约束
参考例句:
  • data and constraints can easily be changed to test theories. 信息库中的数据和限制条件可以轻易地改变以检验假设。 来自英汉非文学 - 科学史
  • what are the constraints that each of these imply for any design? 这每种产品的要求和约束对于设计意味着什么? 来自about face 3交互设计精髓
17 xpczl     
vt.限制,约束;克制,抑制
参考例句:
  • she tried to constrain herself from a cough in class.上课时她竭力忍住不咳嗽。
  • the study will examine the factors which constrain local economic growth.这项研究将考查抑制当地经济发展的因素。
18 yipwe     
n.通风口,排放口;开衩;vt.表达,发泄
参考例句:
  • he gave vent to his anger by swearing loudly.他高声咒骂以发泄他的愤怒。
  • when the vent became plugged,the engine would stop.当通风口被堵塞时,发动机就会停转。
19 rlyzx     
n.速度,速率
参考例句:
  • einstein's theory links energy with mass and velocity of light.爱因斯坦的理论把能量同质量和光速联系起来。
  • the velocity of light is about 300000 kilometres per second.光速约为每秒300000公里。
20 64d80206fdcbbf917808c5b00e0a8ff5     
n.速度( velocity的名词复数 );高速,快速
参考例句:
  • in experimenting we find out that sound travels with different velocities through different substances. 在实验中,我们发现声音以不同的速度通过不同的物质而传播。 来自《现代汉英综合大词典》
  • a gas in thermal equilibrium has particles of all velocities. 处于热平衡的气体,其粒子有一切速度。 来自辞典例句
21 7d0657785d6e5832f8576c61c78262ef     
n.评估( assessment的名词复数 );评价;(应偿付金额的)估定;(为征税对财产所作的)估价
参考例句:
  • he was shrewd in his personal assessments. 他总能对人作出精明的评价。 来自《简明英汉词典》
  • surveys show about two-thirds use such assessments, while half employ personality tests. 调查表明,约有三分之二的公司采用了这种测评;而一半的公司则采用工作人员个人品质测试。 来自百科语句
22 ko9z3     
n.复杂(性),复杂的事物
参考例句:
  • only now did he understand the full complexity of the problem.直到现在他才明白这一问题的全部复杂性。
  • the complexity of the road map puzzled me.错综复杂的公路图把我搞糊涂了。
tag标签: process diamonds colcanoes
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