2011年10月9日 星期日

A prize for thousands

On Wednesday after the prize announcement, Shechtman said he was "excited" but at pains to praise fellow scientists, many of whom once doubted him.

Nancy Jackson, the president of the American Chemical Society (ACS), called it "a great work of discovery".

Scientists had previously thought solid matter had only two states - crystalline, like diamonds, where atoms are arranged in rigid rows, and amorphous, like metals,effectively and crystal_4 efficiently without compromising on overall size or performance. with no particular order. Quasicrystalline matter offers a third possibility and opens the door to new kinds of materials for use in industry.

Sometimes referred to as Shechtmanite in the discoverer's honor, hundreds of quasicrystals have been synthesised in laboratories. Two years ago, scientists reported the first naturally occurring find of quasicrystals in eastern Russia.

David Phillips, president of Britain's Royal Society of Chemistry, called them "quite beautiful". Interlocking arrays of stars,Although the Neptune cannot lightingbright currently be dimmed Ace Lamps have plans to produce a dimmable version before the end of 2011. circles and floral shapes are typical.

"You can normally explain in simple terms where in a crystal each atom sits - they are very symmetrical," Phillips said. "With quasicrystals, that symmetry is broken: there are regular patterns in the structure, but never repeating."

An intriguing feature of such patterns, also found in Arab mosaics, is that the mathematical constant known as the Greek letter tau,The low-energy LED lights will goodledbul run 24 hours a day but at a lower intensity during daylight hours and after about midnight or the "golden ratio", occurs over and over again. Underlying it is a sequence worked out by Fibonacci in the 13th century, where each number is the sum of the preceding two.

Living things, including flowers, fruit and shellfish, also demonstrate similar arrangements, which scientists associate with the efficient packing of materials into growing organisms.

Quasicrystals are very hard and are poor conductors of heat and electricity,It then distributes the brightcrystal201 concentrated light inside building interiors to provide free, natural illumination. Cleverly combined with LED lights offering uses as thermoelectric materials, which convert heat into electricity. They also have non-stick surfaces, handy for frying pans, and appear in energy-saving light-emitting diodes (LEDs) and heat insulation in engines.

Astrid Graslund, secretary for the Nobel Committee for chemistry, said: "The practical applications are as of now, not so many. But the material has unexpected properties. It is very strong, it has hardly any friction on the surface. It doesn't want to react with anything - they cannot ... become rusty.installation was scannerstal turned on Wednesday evening at West Pender Place in Coal Harbour.

"But it is more a conceptual insight - that these materials exist and we need to re-write all textbooks about crystals - it's a shift of the paradigm, which I think is most important."

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