scientific american - 1997 06 - the microchip that rewires itself

... CRAWFORD Copyright 1997 Scientific American, Inc. News and Analysis Scientific American June 1997 31 But the videotapes revealed that dis- satisfied females rarely assume the prop- er position for ... could be probes that mea- sure thermal conductivity. But for iden- tifying TNT, the main charge in 80 per- cent of mines, systems that “sniff” va- pors might offer the be...

Ngày tải lên: 12/05/2014, 15:26

... idea that they were the few Cretaceous survivors. The foundation of this theory began to shake in 1981, when fossils of Òop- posite birdsÓ were unearthed in China and, then, all over the Northern ... scan. The participants then judged how much sentiment they had mustered. George found that men and women deemed themselves equal- ly sad, but the brain activity of the two SCIENTI...

Ngày tải lên: 12/05/2014, 15:01

... measure- ments of the brisk Jovian winds have permitted slightly more conclusive the- ories about the planet’s meteorology. Be- fore the probe plunged, scientists won- dered whether the thermal ... ATP is phosphocrea- tine, itself a high-energy, phosphate-bear- ing molecule. The energy released by the breakdown of the phosphocreatine mol- ecule is used to resynthesize ATP....

Ngày tải lên: 12/05/2014, 15:08

... polydiacety- lene film, which happens to be blue. But the binding of E. coli toxin to the other part of the molecule (the cell-surface re- ceptor) breaks the links joining the lip- ids to one another, ... wake. The ultra- violet glow detected by this instru- ment therefore outlines the shape of the sun’s wind. So far these mea- surements indicate that the solar wind is mor...

Ngày tải lên: 12/05/2014, 15:21

... preda- tors. Once the cubs can move, though, the mothers bring them out into the open to join the rest of the pride. If any of the other females have cubs, they form a crèche and remain in near-con- stant ... of other males. Male lions display their greatest ca- pacity for teamwork while ousting in- vaders the situation that presents the greatest threat to their common self-...

Ngày tải lên: 12/05/2014, 15:23

... not seem to be the stuff of wild urban legend anymore. Neverthe- less, the rich mythology that has sprung up around the 840-acre island makes it a must-see stop on the con- spiracy theorist’s world ... the fiber that finally makes earth-tethered satellites possible. Considering that the longest-known nano- tubes are on the order of one millimeter, thoughts of a 35,800-kilome...

Ngày tải lên: 12/05/2014, 16:03

... of which-stars- are-not-like -the- others. The sun and most other stars swirl around the galactic center within a thin circular disk. Nearly a century ago, however, astronomers noticed that some stars ... grow the same way that planets do: from the agglomeration of smaller units. The layering of the Milky Way bears that out. On the other hand, cold-dark-matter theories hav...

Ngày tải lên: 12/05/2014, 16:08

... all that much. Most of the wom- en in the rural areas have that same cy- cle, and they teach the same values to their children. They teach their sons to order; they teach their daughters that they ... test the hypothesis that defects in the gam- ma-chain gene were causing the im- munodeficiency. With the further assis- tance of Howard M. Rosenblatt of the Baylor College...

Ngày tải lên: 12/05/2014, 14:49

... Scientific American, Inc. SCIENTIFIC AMERICAN June 1994 33 I n 1939 a 33-year-old French mathe- matician proved that a profound conjecture about the behavior dis- played by prime numbers as they ... by then they knew that the U.S. intended to send humans into orbit around the moon later that month. This launch presented the Sovi- ets with perhaps their Þnal opportuni- ty...

Ngày tải lên: 12/05/2014, 14:56

... Copyright 1997 Scientific American, Inc. News and Analysis32 Scientific American October 1997 So last summer the group experiment- ed with the two structures, first on computer models, then on the real ... Bal- asubramanian. Last year, while chatting in the car on the way home from a con- ference, Regan suggested that two pro- teins being studied in the lab might just...

Ngày tải lên: 12/05/2014, 15:30