科学60秒:含碳纳米管——让飞机更安全
来源：沪江听写酷
2011-07-29 10:00
Airplane manufacturers have been changing over from aluminum to advanced composite materials. These lighter, stronger composites are made of fibers of carbon or glass ____1____ 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 dent. Composites, though, ____2____ to the original shape, which could hide internal damage.
One technique to test composite material ____3____heat transfer. Inspectors 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 ____4____and expensive equipment.
Now M.I.T. 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 handheld device. Any internal deformations will still change the heat flow, which can be picked up by the ____5____ 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.
【视听版科学小组荣誉出品】
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 dent. Composites, though, ____2____ to the original shape, which could hide internal damage.
One technique to test composite material ____3____heat transfer. Inspectors 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 ____4____and expensive equipment.
Now M.I.T. 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 handheld device. Any internal deformations will still change the heat flow, which can be picked up by the ____5____ 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.
【视听版科学小组荣誉出品】
embedded in spring back takes advantage of bulky thermal
飞机制造经历了从铝材到复合材料的变革。将碳纤或玻璃纤维镶嵌到第二种材料（通常都是塑料）中去，就得到了更轻更结实的复合材料。 用复合材料制造飞机的好处之一就是省油效果明显。但这有个严重的弊端。当铝受热时会凹陷进去，但复合材料却会恢复原状，这可能让我们无法察觉飞机的内部损伤。 有一种技术利用热传递来测试符合材料。检测员在飞机部件旁放上一个巨大的加热器，裂缝会改变热流，而这些改变会被热感照相机感应到。但这需要昂贵的巨型机器才能办到。 如今，麻省理工的研究者设计了一个新型系统。你只需要使用复合材料中的含碳纳米管，因为碳纳米会在弱电流下产热。这过程要用到设备很小，可以用手拿着。内部变型仍然会改变热流，热流的改变仍会被热感照相机感应到。这次研究发现刊登在《纳米技术》杂志上。
