英语四级考试考前冲刺题2016

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Here’s the Totally Amazing Wonder Material That Could Revolutionize Technology

the technology industry,every new product or service seems to come with the promise that it is an innovation with the potential to change the hene(石墨烯)，a form of carbon，might actually do just that.

B.“Graphene is a wonderful material，”Jeanie Lau，a professor of physics at the University of California at Riverside，told Fortune.“It conducts heat 10 times better than copper and electricity 100 times better than silicon，is transparent like plastic，extremely lightweight,extremely strong,yet flexible and the past decade，it has taken the scientific and technology communities by storm，and has become the most promising electronic material to supplement or replace silicon.”

hene has already found its way into a number of compelling applications，Lau instance，“since it is both transparent and electrically conductive—two attributes rarely found in the same material in nature—it has tremendous potential as the transparent electrode in lays;solar cells，and touch screens，”she explained.“Companies such as Samsung that invest heavily in this area have already secured patents，produced prototypes，and are expected to bring products to market in a few years.”Wearable electronic devices，aviation components，broadband photodetectors(光电检测器)，radiation-resistant coatings，sensors，and energy storage are among numerous other areas of active said.

many researchers and investors，the ultimate application is graphene-based transistors，the building blocks of modem getting there may take some time.

　　A child of graphite

t produced in a lab back in 2004，graphene is essentially a single layer of pure carbon atoms bonded together in a honeycomb lattice so thin it’s actually considered two-dimensional.“We generally regard anything less than 10 layers of graphene as graphene;otherwise，it’s graphite，”said Aravind Vijayaraghavan，a lecturer in nanomaterials at the University of Manchester.

“graphene”is a bit of an umbrella term.“To oversimplify,there are two major types of graphene，”Michael Patterson，CEO of Graphene Frontiers， first：“Nanoplatelets，”which are powders or flakes made from e have been around for a while and are“not really super-sexy,”Patterson said.“You mix them into polymers(聚合物)or inks or rubbers to make them conductive.”In flake form，graphene is already on its way to becoming a commodity,Patterson other type—in sheet or film form—is where graphene’s biggest promise hene sheets have“incredible potential for electronics，”Patterson the near term，that potential may manifest in situations where the quantity requirements are“not that great”and where quality or conductivity doesn’t have to be as high，such as in basic touch-screen applications，he ucts that use graphene in this way could arrive to market in the next six to 1 2 months.

ing a little further out，graphene can be employed in membranes used for water heed-Martin already has a patented product known as Perforene.“It’s real and it works，but it won’t be economically viable until the product reaches an industrial scale where the cost is measured in pennies per square inch”rather than dollars or tens of dollars per square inch，Patterson explained.

“That’s where we’re working today.”

‘It’s expensive and low-capacity’

H. But use of graphene in semiconductors—the technology’s Holy Grail—is likely a decade away.“Many of the challenges presented by graphene are common to most new materials，”Paul Smith,a patent associate with the Intellectual Property Law Group at Fenwick & West，told Fortune.“The trick is figuring out how to synthesize graphene in a way that first is manufacturable beyond lab scale;second，preserves the desirable properties of the material;and third，can be integrated into a product or technology.”

hesizing graphene in sheet form is considerably more expensive and time-consuming than producing graphene eas the latter typically involves a“quick and dirty”process by which bulk graphite is disassembled into millions of tiny pieces，Lau explained，large sheets of graphene are carefully“grown”on substrates(基板)such as copper，germanium，or silicon carbide.

J. Graphene sheets are also prone to defects and“very difficult to make in good quality,”Ron Mertens，owner and editor of ，uction capacity is also very limited.“There are thousands of small companies that can make graphene，but it’s expensive and low-capacity,”Mertens und wafer measuring one inch in diameter,for instance，costs about$1 00，he added.