ISSN:0031-9228    

DOI:10.1063/1.2364218

出版商:AIP    

年代:1906

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2364219

出版商:AIP    

年代:1906

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2364224

出版商:AIP    

年代:1906

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2364226

出版商:AIP    

年代:1906

数据来源: AIP

摘要:

If quantum computers, molecular memories, and other futuristic devices for handling quantum information are to work, physicists and engineers will need rules for building the underlying circuits. And because quantum coherence is so fragile and fleeting, those rules should hold at high frequencies.

ISSN:0031-9228    

DOI:10.1063/1.2364227

出版商:AIP    

年代:1906

数据来源: AIP

摘要:

Neural networkshave become a fertile meeting ground for biologists, physicists, and computer scientists. Studies of surprisingly skilled animal behavior have challenged physicists to explain sensory capabilities that seem to exceed the physical limitations of sense organs and neural interactions. For example, a barn owl at night deduces the direction to an unsuspecting mouse by perceiving the interaural arrival‐time difference of its rustling with microsecond accuracy (see PHYSICSTODAY, June 2001, page 20). But how can that be when the characteristic time of an individual neuronal process is 100 times slower?

ISSN:0031-9228    

DOI:10.1063/1.2364228

出版商:AIP    

年代:1906

数据来源: AIP

摘要:

To polarize the nucleiin a material, the standard approach is to apply a static magnetic field in the desired direction. A second method, recently demonstrated by experimenters at the University of California, Berkeley, is to apply a rotating field and induce magnetization in the direction of the rotation axis.

ISSN:0031-9228    

DOI:10.1063/1.2364229

出版商:AIP    

年代:1906

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2364230

出版商:AIP    

年代:1906

数据来源: AIP

摘要:

Body armoris saving the lives of US troops in Iraq and Afghanistan. At the same time, though, it's leading to a whole new range of head and limb injuries in people who previously would not have survived, says Geoffrey Ling, program manager at the Defense Advanced Research Projects Agency. Upper‐body injuries, in particular the loss of hands or arms, have become more common; each week in Iraq, several American troops lose a limb. To improve the lives of these young amputees, DARPA has launched a two‐phase, four‐year, $70 million research program to build a better prosthetic arm.

ISSN:0031-9228    

DOI:10.1063/1.2364231

出版商:AIP    

年代:1906

数据来源: AIP

摘要:

A winged telescopegot a reprieve this summer when its funding was restored by NASA. The Stratospheric Observatory for Infrared Astronomy (SOFIA), a 2.5‐meter telescope aboard a modified Boeing 747 jet, is now expected to take its maiden test flight this winter and to begin collecting data at the end of the decade.

ISSN:0031-9228    

DOI:10.1063/1.2364232

出版商:AIP    

年代:1906

数据来源: AIP