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The Wonderful World of Small
There's a quiet revolution going on, and its name is nanotechnology.A host of innovations are coming our way.Some seem almost magical, like the new material created in 2004 by Ray Baughman, a professor at the University of Texas.It's stronger than steel, transparent, very, very light.A hectare-size sheet would weigh just 280 grams.
When the professor announced that he hadn't decided what to call it, he started to get emails from around the world suggesting names.Since it was so light and strong, people started calling it 'mithril'--the name of a highly prized type of armor used in The Lord of Rings.
There are other discoveries too--perhaps not so astounding, but practical and pleasant.Now there are socks that don't get smelly, pants that resist stains, windows that repel dirt and toilets that clean themselves.All this results from exploring the world of the very, very small.
Nano comes from the Greek word from dwarf.Usually nanotechnology is defined as the study and manipulation of matter smaller than 100 nanometers(毫微米)--that's the scale of things like molecules and viruses.Ten hydrogen atoms pressed together against each other are just one nanometer long.And one million nanometers fit into a millimeter.Hard to grasp? Think of it this way: If everyone in Manila were a nanometer wide, the entire population, standing shoulder to shoulder, would fit on your thumbnail.
Stunning Uses of Nanotechnology
Like Alice in Wonderland, researchers in Nanoland find themselves in a world where old rules don't apply.Small things behave differently.This is behind several innovations, including the self-cleaning toilet.The toilet bowl is sealed with a super-smooth glaze (涂层) that has microscopic holes under 30 nanometers.Because they're smaller than bacteria or other tiny particles, there's not enough room for dirt to get stuck in the suce.Flushing is basically all the work you have to do.
Researchers in Nanoland are also really, really small things with astonishing properties--like the carbon nanotube.Chris Papadopoulos of the University of Victoria, says, 'The carbon nanotube is the poster boy for nanotechnology.'
In your pencil, carbon, in the form.of graphite (石墨), is soft and easily broken.But a carbon nanotube is tough as nails--much tougher in fact.It's very thin sheet graphite that's formed into a tube.These tiny straw-like cylinders, which can be as small as half a nanometer wide, are up to 100 times stronger than steel and six times lighter.They are the hardest, stiffest, strongest materials known and are among the world's best conductors of heat and electricity.They can carry some 1000 times more electricity current than copper wire.Everybody wants them, but until now they've been in short supply and pricey.The current annual production, worldwide, is only 300 kilograms.At $ 860 a gram, carbon nanotubes cost 50 times more than gold.
When it comes to finding uses for carbon nanotubes, the range is huge.The National Research Council Canada (NRC) is looking at harnessing their strength by embedding them in construction materials, among other applications.The Boeing Company thinks nanotubes may be the source of futute improvements for high-performance aircraft.Some of the most stunning uses come out of Ray Baughman's research.Employing what he calls the 'ancient technology of spinning,' Baughman and his team developed a way of spinning carbon nanotubes into fibers that are four times tougher than spider silk, the toughest natural filament (细丝).Since they also conduct electricity, the futuristic yarns could be woven into 'smart' clothing that stores electricity, is potentially bulletproof and incorporates sensors capable of adjusting the temperature of garment.The fibers could also be made into cables for suspension bridges much longer than any we

The Wonderful World of Small
There's a quiet revolution going on, and its name is nanotechnology. A host of innovations are coming our way. Some seem almost magical, like the new material created in 2004 by Ray Baughman, a professor at the University of Texas. It's stronger than steel, transparent, very, very light. A hectare-size sheet would weigh just 280 grams.
When the professor announced that he hadn't decided what to call it, he started to get emails from around the world suggesting names. Since it was so light and strong, people started calling it 'mithril'--the name of a highly prized type of armor used in The Lord of Rings.
There are other discoveries too--perhaps not so astounding, but practical and pleasant. Now there are socks that don't get smelly, pants that resist stains, windows that repel dirt and toilets that clean themselves. All this results from exploring the world of the very, very small.
Nano comes from the Greek word from dwarf. Usually nanotechnology is defined as the study and manipulation of matter smaller than 100 nanometers(毫微米)--that's the scale of things like molecules and viruses. Ten hydrogen atoms pressed together against each other are just one nanometer long. And one million nanometers fit into a millimeter. Hard to grasp? Think of it this way: If everyone in Manila were a nanometer wide, the entire population, standing shoulder to shoulder, would fit on your thumbnail.
Stunning Uses of Nanotechnology
Like Alice in Wonderland, researchers in Nanoland find themselves in a world where old rules don't apply. Small things behave differently. This is behind several innovations, including the self-cleaning toilet. The toilet bowl is sealed with a super-smooth glaze (涂层) that has microscopic holes under 30 nanometers. Because they're smaller than bacteria or other tiny particles, there's not enough room for dirt to get stuck in the suce. Flushing is basically all the work you have to do.
Researchers in Nanoland are also really, really small things with astonishing properties--like the carbon nanotube. Chris Papadopoulos of the University of Victoria, says, 'The carbon nanotube is the poster boy for nanotechnology.'
In your pencil, carbon, in the form. of graphite (石墨), is soft and easily broken. But a carbon nanotube is tough as nails--much tougher in fact. It's very thin sheet graphite that's formed into a tube. These tiny straw-like cylinders, which can be as small as half a nanometer wide, are up to 100 times stronger than steel and six times lighter. They are the hardest, stiffest, strongest materials known and are among the world's best conductors of heat and electricity. They can carry some 1000 times more electricity current than copper wire. Everybody wants them, but until now they've been in short supply and pricey. The current annual production, worldwide, is only 300 kilograms. At $ 860 a gram, carbon nanotubes cost 50 times more than gold.
When it comes to finding uses for carbon nanotubes, the range is huge. The National Research Council Canada (NRC) is looking at harnessing their strength by embedding them in construction materials, among other applications. The Boeing Company thinks nanotubes may be the source of futute improvements for high-performance aircraft. Some of the most stunning uses come out of Ray Baughman's research. Employing what he calls the 'ancient technology of spinning,' Baughman and his team developed a way of spinning carbon nanotubes into fibers that are four times tougher than spider silk, the toughest natural filament (细丝). Since they also conduct electricity, the futuristic yarns could be woven into 'smart' clothing that stores electricity, is potentially bulletproof and incorporates sensors capable of adjusting the temperature of garment. The fibers could also be made into cables for suspension bridges much longer than any we

A.
Y
B.
N
C.
NG
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题目标签:石墨微米细丝
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【单选题】石墨以球状存在的铸铁称为(    )。

A.
灰铸铁    
B.
可锻铸铁    
C.
球墨铸铁    
D.
蠕墨铸铁

【单选题】细丝CO2气体保护焊要求弧焊电源具有()。

A.
上升外特性
B.
陡降外特性
C.
平外特性
D.
直外特性