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SSS 2011-03-28

时间:2011-04-27 05:44来源:互联网 提供网友:geologyforget   字体: [ ]
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    (单词翻译:双击或拖选)

This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute.

Airplane manufacturers have been changing over from aluminum1 to advanced composite materials. These lighter2, stronger composites are made of fibers3 of carbon or glass embedded4 in a second material, often plastic.

One advantage is that composite-based planes use significantly less fuel. But there's an important disadvantage. When aluminum is hit, you can see a dent5. Composites, though, spring back to the original shape, which could hide internal damage.

One technique to test composite material takes advantage of heat transfer: inspectors6 place large heaters next to a section of the plane. Any cracks will alter the flow of heat, and these changes can be picked up with a heat-sensitive camera. But this involves bulky and expensive equipment.

Now MIT researchers have designed a new system. All you need is carbon nanotubes included in the composite. Because nanotubes will heat up in response to a small electric current. This can be produced with a hand-held device. Any internal deformations7 will still change the heat flow, which can be picked up by the thermal8 camera. The research was published in the journal Nanotechnology.

This technique offers the ability to detect very small cracks—which could help keep passengers safer in the skies.

Thanks for the minute. For Scientific American's 60-Second Science, I'm Cynthia Graber.


点击收听单词发音收听单词发音  

1 aluminum 9xhzP     
n.(aluminium)铝
参考例句:
  • The aluminum sheets cannot be too much thicker than 0.04 inches.铝板厚度不能超过0.04英寸。
  • During the launch phase,it would ride in a protective aluminum shell.在发射阶段,它盛在一只保护的铝壳里。
2 lighter 5pPzPR     
n.打火机,点火器;驳船;v.用驳船运送;light的比较级
参考例句:
  • The portrait was touched up so as to make it lighter.这张画经过润色,色调明朗了一些。
  • The lighter works off the car battery.引燃器利用汽车蓄电池打火。
3 fibers 421d63991f1d1fc8826d6e71d5e15f53     
光纤( fiber的名词复数 ); (织物的)质地; 纤维,纤维物质
参考例句:
  • Thesolution of collagen-PVA was wet spined with the sodium sulfate as coagulant and collagen-PVA composite fibers were prepared. 在此基础上,以硫酸钠为凝固剂,对胶原-PVA共混溶液进行湿法纺丝,制备了胶原-PVA复合纤维。
  • Sympathetic fibers are distributed to all regions of the heart. 交感神经纤维分布于心脏的所有部分。
4 embedded lt9ztS     
a.扎牢的
参考例句:
  • an operation to remove glass that was embedded in his leg 取出扎入他腿部玻璃的手术
  • He has embedded his name in the minds of millions of people. 他的名字铭刻在数百万人民心中。
5 dent Bmcz9     
n.凹痕,凹坑;初步进展
参考例句:
  • I don't know how it came about but I've got a dent in the rear of my car.我不知道是怎么回事,但我的汽车后部有了一个凹痕。
  • That dent is not big enough to be worth hammering out.那个凹陷不大,用不着把它锤平。
6 inspectors e7f2779d4a90787cc7432cd5c8b51897     
n.检查员( inspector的名词复数 );(英国公共汽车或火车上的)查票员;(警察)巡官;检阅官
参考例句:
  • They got into the school in the guise of inspectors. 他们假装成视察员进了学校。 来自《简明英汉词典》
  • Inspectors checked that there was adequate ventilation. 检查员已检查过,通风良好。 来自《简明英汉词典》
7 deformations 51f2a68d52c73b316648d414edcdc30f     
损形( deformation的名词复数 ); 变形; 畸形; 破相
参考例句:
  • It would make no difference if the bar deformations were totally inelastic. 如果杆的变形完全是非弹性变形时这也就没有什么区别了。
  • Such readings can reveal longer-period deformations in the earth. 这种读数可以反映地球长周期的形变。
8 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。
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