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  3. Diamonds are best known as the "girl’s best friend" in rings, tiaras and the Pink Panther films. Yet the aesthetic uses for thes

Diamonds are best known as the "girl’s best friend" in rings, tiaras and the Pink Panther films. Yet the aesthetic uses for thes

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问题     Diamonds are best known as the "girl’s best friend" in rings, tiaras and the Pink Panther films. Yet the aesthetic uses for these sparklers are in the minority. Today, many diamonds are made synthetically for a vast range of uses, from surgeons’ scalpels to super-fast microchips.
    Labs produce 180 tonnes of diamond each year—almost nine times as much as comes out of the ground. And its strength, clarity and chemical resistance could make it the engineering material of the 21st century. Already, there are diamond heat sinks for tiny integrated circuits, diamond coatings on joint replacements and diamond windows on space probes. Soon, a diamond coating could protect your car gearbox, and super-strong diamond threads be used to reinforce ultra-light aircraft.
    Diamond is far more than just a pretty rock. It has an impressive list of properties. As the hardest material known to science, it is resistant to attack by strong acids and alkalis and is a superb conductor of heat. This all means that there are many uses for diamond apart from the purely decorative. Because it dissipates heat so well—much better than silicon, engineers want to build microchips on layers of diamond. They could then squeeze yet more electronic components into smaller areas without the circuit overheating, to produce a new generation of super-fast computers.
    The key to diamond’s extraordinary properties is its structure. Carbon can form four strong bonds with other molecules, which is why it forms the basis of so many organic compounds and is the building block of life. When four carbon atoms are linked together in a regular lattice, the result is a diamond crystal. Another form of carbon is the graphite in pencils.
    Companies such as De Beers and General Electric have been making synthetic diamonds since the early 1950s. Almost any substance rich in carbon can be converted into diamond. General Electric chemist Robert Wentorf once made diamonds from peanut butter.
    A newer process, chemical vapour deposition(CVD), is used to produce ultra-hard diamond coatings. CVD used high temperatures but low pressures to coat a substance with carbon vapour, as a layer of small diamond crystals. These crystals will eventually join together and can be used to create huge gems. Diamonds such as this are usually sliced up to produce long scalpels or other tools.
    CVD has scientists excited. "For the first time, we have all the superlative properties of diamond in a form that’s useful for engineering applications". Says May, who uses CVD to create diamond threads by coating tungsten wire. So it seems that diamonds are not just a girl’s best friend, but an engineer’s too.
选项 A、It has many decorative uses.
B、It is the hardest material ever known.
C、It has many superlative properties.
D、It is resistant to attack by acids and alkalis.
答案C
解析
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