ISSN:0031-9228    

DOI:10.1063/1.2207009

出版商:AIP    

年代:1906

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2207014

出版商:AIP    

年代:1906

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2207024

出版商:AIP    

年代:1906

数据来源: AIP

摘要:

In 1970 Vitaly Efimov derived a bizarre result. If, his analysis showed, one could weaken the interaction between two particles, then just at the point when the two‐body bound state vanishes, an infinite series of three‐body bound states would emerge out of the quantum blue.

ISSN:0031-9228    

DOI:10.1063/1.2207026

出版商:AIP    

年代:1906

数据来源: AIP

摘要:

In May 2001, MIT's Nicholas Makris and his then postdoctoral fellow Purnima Ratilal were searching for the ancient riverbeds buried within the continental shelf off the New Jersey coastline. Although hidden in muck when the sea level rose during the last ice age, those ancient channels had been previously mapped using high‐frequency sonar that distinguished the slight density differences in the sediment. Researchers sent a signal, listened for its echo, and then deconvolved the spectral components to resolve underwater features.

ISSN:0031-9228    

DOI:10.1063/1.2207027

出版商:AIP    

年代:1906

数据来源: AIP

摘要:

Since 1995, almost 200 extrasolar planets have made themselves known by spectral Doppler oscillation as they tug their host stars to and fro. In the last two years, a very different technique—gravitational microlensing—has revealed only three planets. But the most recent microlensing discovery makes clear the special advantages of that technique for finding Earth‐like planets. In January, a worldwide collaboration of three microlensing groups—PLANET, OGLE, and MOA—reported the discovery of a planet of roughly 5.5 Earth masses(M⊕)circling a red‐dwarf star with an orbital radius of about 2.6 astronomical units (1 AU is Earth's orbital radius). It's the lightest extrasolar planet ever discovered.

ISSN:0031-9228    

DOI:10.1063/1.2207028

出版商:AIP    

年代:1906

数据来源: AIP

摘要:

Parisians sipping coffee in outdoor cafe´s owe their comfort to the circulation patterns of the North Atlantic Ocean. Surface currents carry warm water from the tropics to high latitudes, where the water grows colder and hence denser. In the far north, this dense, cold, and salty water sinks to depths from one to six kilometers, where it forms the southward‐flowing deep water of the North Atlantic, as depicted in the schematic in figure 1. Because the ocean exchanges heat with the atmosphere, any disruption in this so‐called meridional overturning circulation (MOC) is likely to impact the climate on the adjoining land masses.

ISSN:0031-9228    

DOI:10.1063/1.2207029

出版商:AIP    

年代:1906

数据来源: AIP

摘要:

“Part of apartheid involved destroying people's aspirations,” says Thebe Medupe, a South African astronomer. “Imagine being a black child and all the time reading about other peoples' histories and other peoples' way of doing things. You start having doubts about whether you played any role in human history.”

ISSN:0031-9228    

DOI:10.1063/1.2207030

出版商:AIP    

年代:1906

数据来源: AIP

摘要:

The measurement of mass is due for a makeover, pending convergence of two experiments. That consensus was reached last October by the International Committee for Weights and Measures, and the kilogram—along with the ampere, kelvin, and mole—could be redefined in terms of fundamental constants as early as 2011.

ISSN:0031-9228    

DOI:10.1063/1.2207031

出版商:AIP    

年代:1906

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2207034

出版商:AIP    

年代:1906

数据来源: AIP