发布时间： 2016年06月07日

考研英语阅读理解全真模拟题工学类试题（三十三）

Bryant Linares has one heck of a secret family recipe： how to make world-class diamonds. Seven years ago his father， Robert， produced a diamond in a high-pressure chamber of carbon gas and dropped it into an acid solution to clean it off. When he returned the next morning， he expected to find the usual yellow stone——a crude artificial diamond of some use to industry， perhaps， but not the stuff of dreams. At first there didn't seem to be any stone at all. Then he saw， at the bottom of the beaker， so clear it was almost invisible， a perfect quarter-carat crystal of pure carbon. “It was the eureka moment，” says Bryant. His father had managed what many scientists had given up on long ago： to manufacture a stone that wouldn't look out of place on an engagement ring.

Man-made diamonds are nothing new——industry started making them in the 1950s， and each year about 80 tons of low-quality synthetic diamonds are used in tools like drill bits and sanders. High-quality crystals， though， open up huge possibilities， jewelry being the least of them. Scientists are most excited about the prospect of making diamond microchips. As chips have shrunk over the years， engineers have struggled with ways of dissipating the heat they create. Because silicon， the main component of semiconductors， breaks down at about 200 degrees Fahrenheit， some experts believe a new material will be needed in a decade or so. Diamonds might fit the bill. They can withstand 1，000 degrees， and electrons move through them so easily that they would tend not to heat up in the first place. Engineers could cram a lot more circuits onto a diamond-based micro-chip——if they could perfect a way of making pure crystals cheaply.

The race is on. After working in secrecy for years refining their technique， the Linareses' company， Apollo Diamond， now spits out 20 carats a week， both for jewelry and for diamond wafers that could be fashioned into microchips. Rivals have also been busy. Gemesis， a Sarasota， Fla.， firm， has developed a “diamond growth chamber”——a press that squeezes out high-quality diamonds in much the same way that the early presses made rough ones. Gemesis is making blue diamonds——rare and sought-after gemstones.

Chipmakers are also getting into the act. The Japanese firm Nippon Telegraph and Telephone has already made prototype diamond semiconductors， and the Japanese government is actively promoting the technology. Most U.S. research is going on in universities and military labs， but Intel has recently taken an interest. Before the technology is ready for prime time， chipmakers will have to come up with a way to keep out impurities during manufacturing. And the attribute that makes diamonds so attractive——their hardness——also makes them difficult to manipulate.

The new diamonds are likely to show up first as tiny light-emitting diodes， or LEDs， in flat-screen displays and high-definition televisions. And then， of course， there's jewelry. Although synthetics still carry a stigma， even experts can't tell the difference. Natural-diamond merchants claim they aren't worried， but De Beers has made a device that can distinguish between the natural stones and the synthetics and is distributing it to jewelers. Will consumers care? We might find out next year when Gemesis is ready to market its blue diamonds in the United States.

注(1)：本文选自Newsweek，10/25/2004， p60-61， 2p， 3c

注(2)：本文习题命题模仿对象2002年真题Text 4

1. From the first paragraph， we learn that______________.

[A] All the diamonds are almost invisible.

[B] Many scientists had tried hard to make perfect crystals long time ago.

[C] His father expected to find a diamond used in industry.

[D] Diamond are produced with carbon gas.

2. Which of the following statements is not true according to the text?

[A] Diamond can withstand higher degree than silicon.

[B] The main component of semiconductors will be replaced in a few years.

[C] High-quality crystals have least usages， esp. in jewelry.

[D] Engineers could not find perfect ways of making pure crystal cheaply.