雅思阅读全真练习系列（五）

　　Key and Explanations:

　　1. D

　　See Paragraph 3: ...Alex Mischenko, of Cambridge University. Using commercially available paraelectric film, he and his

　　colleagues have generated temperature drops...

　　2. C

　　See Paragraph 5: The first Pentium chips sold by Dr Moore's company, Intel, in 1993, ran at 60m cycles a second.

　　3. F

　　See Paragraph 8: ...Rama Venkatasubramanian, of Nextreme Thermal Solutions in North Carolina, claims to have

　　made thermoelectric refrigerators that can sit on the back of computer chips and cool hotspots by 10℃.

　　4. E

　　See Paragraph 8: Ali Shakouri, of the University of California, Santa Cruz, says his are even smaller梥o small that they

　　can go inside the chip.

　　5. B

　　See Paragraph 9: To improve on this, IBM's research laboratory in Zurich is experimenting with tiny jets that stir the

　　liquid up and thus make sure all of it eventually touches the outside of the channel--the part where the heat exchange

　　takes place.

　　6. TRUE

　　See Paragraph 2: ...paraelectric materials. These act like batteries when they undergo a temperature change: attach

　　electrodes to them and they generate a current.

　　7. FALSE

　　See Paragraph 3 (That may be enough to change the phenomenon from a laboratory curiosity to something with

　　commercial applications. ) and Paragraph 4 (As to what those applications might be, Dr Mischenko is still a little hazy. He

　　has, nevertheless, set up a company to pursue them. He foresees putting his discovery to use in more efficient domestic

　　fridges?

　　8. FALSE

　　See Paragraph 5: Heat is released every time a logical operation is performed inside a microprocessor, so the faster

　　the processor is, the more heat it generates. Doubling the frequency quadruples the heat output.

　　9. NOT GIVEN

　　See Paragraph 9: In the future, therefore, a combination of microchannels and either thermoelectrics or paraelectrics

　　might cool computers.

　　10. D

　　See Paragraph 6: Tweaking the processor's heat sinks ?has reached its limit. So has tweaking the fans that circulate air

　　over those heat sinks. And the idea of shifting from single-core processors to systems?also seems to have the end of the

　　road in sight.

　　11. heat

　　See Paragraph 1: Today's high-tech world, however, demands high-tech refrigeration. Heat pumps are no longer up

　　to the job. The search is on for something to replace them.

　　12. paraelectric

　　See Paragraph 3: Using commercially available paraelectric film, he and his colleagues have generated temperature

　　drops five times bigger than any previously recorded.

　　13. thermoelectric

　　See Paragraph 7: ...the thermoelectric effect. Like paraelectric materials, this generates electricity from a heat source

　　and produces cooling from an electrical source. Unlike paraelectrics, a significant body of researchers is already working

　　on it.

　　14. radiator

　　See Paragraph 9: The last word in computer cooling, though, may go to a system even less techy than a heat pump--a

　　miniature version of a car radiator.