scientific american - 1996 12 - traces of the big bang

scientific american   -  1996 12  -  traces of the big bang

scientific american - 1996 12 - traces of the big bang

... because the power and economy of mass- produced processors are often cited as factors in the collapse of the supercomputing market. As much cheaper and easier-to-use work- stations based on off -the- shelf ... nuclei. Consequently, the big bang model predicts that about one quarter of the mass of the normal matter of the universe is made of helium and the other...
Ngày tải lên : 12/05/2014, 15:18
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scientific american   -  2000 12  -  rulers of the jurassic seas

scientific american - 2000 12 - rulers of the jurassic seas

... two cen- turies. When dinosaurs such as Iguan- odan grabbed the attention of paleon- tologists in the 1830s, the novelty of the fish-lizards faded away. Intense in- terest in the rulers of the Jurassic ... most other verte- brates have bones in their eyes.) In the case of ichthyosaurs, the ring presumably helped to maintain the shape of the eye against the force...
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scientific american   -  1994 12  -  nasa's latest view of the earth

scientific american - 1994 12 - nasa's latest view of the earth

... loners. The families have very diÝerent char- acters, which reßect the person- ality of the matriarch. In the case of Echo, the family is low- key and nonaggressive. How the 50-year-long rela- tionships ... proÞt- able segments of the market. Among the models offered for sale in a given year, the more fuel-eÛcient ones tend to be the smaller, slower, bottom -of- the...
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scientific american   -  1995 12  -  the puzzle of consciousness

scientific american - 1995 12 - the puzzle of consciousness

... stunning movie of our watery planet. The spacecraft examined the outer expanses of the earthÕs magnet- ic Þeld and took the Þrst mea- surements of the moonÕs far side since the days of the Apol- lo program. ... returned to the earth over the low-gain antenna. Tape-search- 50 SCIENTIFIC AMERICAN December 1995 JAILBARS, slices of images taken of the asteroid...
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scientific american   -  1996 11  -  the origins of immunity

scientific american - 1996 11 - the origins of immunity

... dif- ferent risk factors may affect the expres- sion of the disorder,” the group con- cludes in the Journal of the American Medical Association. The lead author of the study, the larg- est of ... professor of psychology at the University of Liverpool, and other academics have ruffled a few well-groomed feathers in the staid linguis- tics community. Their gos-...
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scientific american   -  1993 06  -  tuning in the radio signals of ancient galaxies

scientific american - 1993 06 - tuning in the radio signals of ancient galaxies

... gam- ma-chain gene were causing the im- munodeficiency. With the further assis- tance of Howard M. Rosenblatt of the Baylor College of Medicine and Alexan- dra H. Filipovich of the University of Minnesota, ... Furthermore, if the hot end of the rod is then plunged into ice, a wave of cooling will follow the wave of heat down the length of the metal. In the...
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scientific american   -  1996 01  -  the diet - aging connection

scientific american - 1996 01 - the diet - aging connection

... perennial fear of being held hostage to the suc- cess of their favorite supplier. It dis- tributes, and thereby speeds, the work of adapting software to all the diÝerent bits of hardware used on the Internet. It ... CygnusÕs software-for-free, service-for-fee strate- gy could foster innovation. It creates an easy-to-cross bridge between the aca- demic world and the commerc...
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scientific american   -  1996 05  -  the comets' lair

scientific american - 1996 05 - the comets' lair

... case. The type of mine, the specifics of its operation, its position on the ground, the position of the victim and the char- acteristics of the environment at the ex- plosion site all affect the ... status reports. The DOE had no way of know- ing whether the project was on track. Agency managers could not even esti- mate the size of the new system. Never-...
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scientific american   -  1996 06  -  the space station

scientific american - 1996 06 - the space station

... microorganisms. If the impact of urban agriculture con- tinues to broaden, the notion of the gar- den city the turn -of- the- century dream of urban centers lined with trees and or- namental plants —may ... surprising: they whip around the planet at up to 200 meters per second. Overall, however, data from the probe’s 57-min- ute descent did not chal- lenge the prevailing...
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scientific american   -  1996 08  -  the electronic wallet

scientific american - 1996 08 - the electronic wallet

... concentration of ozone-de- pleting chemicals in the lower atmo- sphere is falling off fast. Based on their calculations, the amount had de- creased some 1 percent by the middle of last year. The decline ... can access the software that will make them something other than a sili- con-and-plastic paperweight. Larry El- lison of Oracle reckons the low price of an NC will make...
Ngày tải lên : 12/05/2014, 15:14
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