纳米涂层能使热传导加倍
文章来源:未知 文章作者:enread 发布时间:2012-02-16 05:19 字体: [ ]  进入论坛
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By adding an incredibly thin coating of alumina(氧化铝) to a metal surface, researchers at the Georgia Institute of Technology have doubled the rate that heat travels from a solid surface -- such as a pot on a stove -- into the liquid in the pot. The results are published in the American Institute of Physics' journal Applied1 Physics Letters. Pool boiling is the most common and familiar method of heating a container's contents, and is a remarkably2 efficient heat transfer method. The transfer of heat in this case is referred to as the "heat flux3." There exists, however, a critical point at which a solid surface gets too hot and pool-boiling efficiency is lost.

"Delaying the critical flux could play an important role in advancing thermal4 management of electronics as well as improving the efficiency of a number of energy systems," says Bo Feng, Ph.D., the Georgia Tech researcher leading this project. In boiling, bubbles carry away large amounts of heat from solid surfaces, but the bubbles also act as an insulator5(绝缘体) , preventing the liquid from rewetting the surface and thereby6 interrupting heat transfer. The alumina coating -- only a few hundreds of atoms thick (1/1,000 the thickness of a human hair) -- has a high affinity7(密切关系,吸引力) to water and, as a result, facilitates the rapid rewetting of the solid surface.

"This is the primary reason for the enhancement of heat transfer," says Feng. An atomic layer deposition8 technique was used to control the thickness. By achieving such a thin coating, the additional layer of alumina did not appreciably9 increase thermal resistance, but it did increase the overall heat transfer.

"The potential contribution of this investigation10 lies in tailoring the wettability of surfaces at the nanometer scale, thereby greatly increasing the heat transfer during pool boiling," adds G.P. "Bud" Peterson, Ph.D., director of Georgia Tech's Two-Phase Heat Transfer Lab. "This is especially promising11 for applications where the implementation12 of nanotube or nanowire arrays are possible." Nanotube and nanowire arrays are another effective way to enhance pool boiling heat transfer. Combining these two techniques -- nanotube and/or nanowire arrays and nano-coating by atomic layer deposition -- may increase pool-boiling efficiency even further.



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1 applied Tz2zXA     
adj.应用的;v.应用,适用
参考例句:
  • She plans to take a course in applied linguistics.她打算学习应用语言学课程。
  • This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。
2 remarkably EkPzTW     
ad.不同寻常地,相当地
参考例句:
  • I thought she was remarkably restrained in the circumstances. 我认为她在那种情况下非常克制。
  • He made a remarkably swift recovery. 他康复得相当快。
3 flux sg4zJ     
n.流动;不断的改变
参考例句:
  • The market is in a constant state of flux.市场行情在不断变化。
  • In most reactors,there is a significant flux of fast neutrons.在大部分反应堆中都有一定强度的快中子流。
4 thermal 8Guyc     
adj.热的,由热造成的;保暖的
参考例句:
  • They will build another thermal power station.他们要另外建一座热能发电站。
  • 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。
5 insulator b50xs     
n.隔离者;绝缘体
参考例句:
  • Few substances can equal fur as an insulator.作为绝缘体很少有其他材料能与动物皮毛相媲美。
  • A loose mulch acts on the surface as an insulator.疏松的覆盖物在土壤表面起了隔热的作用。
6 thereby Sokwv     
adv.因此,从而
参考例句:
  • I have never been to that city,,ereby I don't know much about it.我从未去过那座城市,因此对它不怎么熟悉。
  • He became a British citizen,thereby gaining the right to vote.他成了英国公民,因而得到了投票权。
7 affinity affinity     
n.亲和力,密切关系
参考例句:
  • I felt a great affinity with the people of the Highlands.我被苏格兰高地人民深深地吸引。
  • It's important that you share an affinity with your husband.和丈夫有共同的爱好是十分重要的。
8 deposition MwOx4     
n.免职,罢官;作证;沉淀;沉淀物
参考例句:
  • It was this issue which led to the deposition of the king.正是这件事导致了国王被废黜。
  • This leads to calcium deposition in the blood-vessels.这导致钙在血管中沉积。
9 appreciably hNKyx     
adv.相当大地
参考例句:
  • The index adds appreciably to the usefulness of the book. 索引明显地增加了这本书的实用价值。
  • Otherwise the daily mean is perturbed appreciably by the lunar constituents. 否则,日平均值就会明显地受到太阳分潮的干扰。
10 investigation MRKzq     
n.调查,调查研究
参考例句:
  • In an investigation,a new fact became known, which told against him.在调查中新发现了一件对他不利的事实。
  • He drew the conclusion by building on his own investigation.他根据自己的调查研究作出结论。
11 promising BkQzsk     
adj.有希望的,有前途的
参考例句:
  • The results of the experiments are very promising.实验的结果充满了希望。
  • We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。
12 implementation 2awxV     
n.实施,贯彻
参考例句:
  • Implementation of the program is now well underway.这一项目的实施现在行情看好。
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