ISSN:0031-9228    

DOI:10.1063/1.2408535

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1712476

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1712480

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1712482

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1712487

出版商:AIP    

年代:1904

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2408536

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Researchers demonstrated quite dramatically nearly 10 years ago that bosonic atoms (those with integer spin) can collapse into a common ground state, known as a Bose–Einstein condensate (BEC), in which all the atoms march in lock step. This strange state is reached when the gas is so cold that the separate atomic wavefunctions overlap. It was natural, then, to look for the equivalent of BEC in a gas of fermionic atoms (with half‐integer spin). Of course, the Pauli exclusion principle prevents even two fermions from occupying the same ground state, but there are ways around this quantum restriction.

ISSN:0031-9228    

DOI:10.1063/1.1712488

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

A frustrated listener might well define grand opera as musical theater where you have a hard time making out the words even when they're being sung in your own language. Conceding the point, many opera houses nowadays always flash surtitles above the proscenium. Comprehension is particularly difficult in the higher reaches of the soprano register. Hector Berlioz long ago warned composers not to put crucial words in the soprano's mouth at high notes.

ISSN:0031-9228    

DOI:10.1063/1.1712489

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

In a colloidal dispersion, particles much bigger than atoms are spread more or less uniformly amid a molecular fluid. Paint is a colloidal dispersion; so are ice cream, smog, and shampoo.

ISSN:0031-9228    

DOI:10.1063/1.1712490

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Humans will revisit the Moon by 2019 and then touch down on Mars a decade later, according to a new NASA road map issued by President Bush. However, two days after the president's 14 January announcement, NASA Administrator Sean O'Keefe, citing safety and budget concerns, canceled the space shuttle's $600 million final service mission (SM‐4) to the Hubble Space Telescope. Without a service mission, the HST is expected to last only until about 2007, chopping two years off its anticipated lifetime. The SM‐4 cancellation “was a complete shock and devastating for everyone,” says Steve Beckwith, director of the Space Telescope Science Institute (STScI) in Baltimore, Maryland, which operates the HST.

ISSN:0031-9228    

DOI:10.1063/1.1712491

出版商:AIP    

年代:1904

数据来源: AIP