ISSN:0031-9228    

DOI:10.1063/1.2410002

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1628983

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1628984

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1628986

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.1628987

出版商:AIP    

年代:1903

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2410003

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

What a difference is made by one‐half quantum unit of spin. Atoms with integer spins—bosons—can collapse into a common ground state when sufficiently cold; the result is a collective state known as a Bose–Einstein condensate (BEC). But atoms with half‐integer spins—fermions—are excluded from occupying the same quantum states. The lowest‐energy configuration they can reach is to fill all levels up to the Fermi energy—the highest level that would be occupied at absolute zero.

ISSN:0031-9228    

DOI:10.1063/1.1628989

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Earth scientists routinely monitor the levels of carbon they find in the planet's biomass, atmosphere, and oceans. But to judge by the composition of basaltic magma and the flux of carbon dioxide coughed out by volcanoes, the amount of carbon sequestered within Earth's voluminous mantle—estimated to be a few hundred parts per million (ppm) by weight—is roughly a thousand times larger than the amount on the surface. The presence of so huge a reservoir of carbon separated by mere kilometers from the comparatively tiny one on the surface has spurred researchers to figure out where and in what form the carbon is stored within Earth's interior.

ISSN:0031-9228    

DOI:10.1063/1.1628990

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

In the late 1990s, the James Clerk Maxwell Telescope, with its Submillimetre Common‐User Bolometric Array (SCUBA), gazed deep into space. The array, built at the Royal Observatory, Edinburgh, in Scotland, looked for submillimeter (100–1000 &mgr;m) radiation, and saw significant quantities of luminous matter. Observers reasoned that SCUBA had seen high‐redshift (z) analogs of infrared emissions from dust heated by starlight in low‐zgalaxies.

ISSN:0031-9228    

DOI:10.1063/1.1628991

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Cancer kills its victims when the tumor burden in their bodies reaches about1013cells. Before then, when a tumor comprises about1010cells and is the size of a sugar cube, a physician can usually find it in an x ray or MRI scan. At that stage, if treated promptly, a victim may survive.

ISSN:0031-9228    

DOI:10.1063/1.1628992

出版商:AIP    

年代:1903

数据来源: AIP