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The composition of Galactic Cosmic Ray Sources (GCRS) shows the following features: (i) an enhancement of the refractory elements
relative to the volatile ones, and (ii) an enhancement of the heavier volatile elements relative to the lighter ones; this
mass dependence should reflect a mass-to-charge (A/Q) dependence of the acceleration efficiency; among the refractory elements,
there is only a very weak enhancement of heavier species, or none at all. We consider it fortuitous that the GCRS composition
resembles that of the solar corona, which is biased according to first ionization potential. In a companion paper by Ellison
et al. (1998, this issue), this GCRS composition is interpreted in terms of a supernova shock wave acceleration of interstellar
and/or circumstellar (e.g., 22Ne-rich Wolf-Rayet wind) gas phase and especially dust grain material. These two papers summarize
and complement the content of two papers that recently appeared in Astrophys. J. (Meyer et al., 1997; Ellison et al., 1997).
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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A. Collette S. Robertson 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
We present a novel instrument concept to measure the energy and mass spectra of ions incident on the lunar surface, based on the E-parallel–B or Thomson-parabola device used extensively as a diagnostic in the plasma fusion community. The Apollo-era Suprathermal Ion Detector Experiment (SIDE) was the first instrument package to perform in-situ measurements of ions incident on the lunar surface. The ions can originate from a variety of sources, including the solar wind, the Earth’s magnetotail, and photoionization of the thin lunar atmosphere. The species and energy distribution of ions arriving at the lunar surface depend in a complicated and poorly-understood fashion on the phase of the lunar day, the position of the Moon with respect to the Earth, and on the local plasma environment. 相似文献
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Space Science Reviews - We summarize our model of galactic cosmic-ray (GCR) origin and acceleration, wherein a mixture of interstellar and/or circumstellar gas and dust is accelerated by a... 相似文献
4.
Jean-Paul Zahn 《Space Science Reviews》1998,85(1-2):79-90
While the solar convection zone is very well mixed by its turbulent motions, chemical composition gradients build up in the
radiative interior due to microscopic diffusion and settling, and to nuclear burning. Standard models, which ignore any type
of macroscopic transport, cannot explain the depletion of lithium in solar-type stars, as they evolve; neither do they account
for the observed profile of molecular weight at the base of the solar convection zone.
Such macroscopic transport can be achieved through thermally driven meridian currents, through turbulent diffusion generated
by differential rotation and possibly through gravity waves. These processes transport also angular momentum, and therefore
the internal rotation profile of the Sun provides a crucial test for their relative importance. So does also the behavior
of tidally locked binaries, which appear to destroy less lithium than single stars of the same mass.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Serge Habraken Jean-Marc Defise Jean-Paul Collette Pierre Rochus Pierre-Alexis D'Odemont Michel Hogge 《Acta Astronautica》2001,48(5-12)
This paper presents some research activities conducted at the Centre Spatial de Liege (CSL) in the field of space solar arrays and concentration.With the new generation of high efficiency solar cells, solar concentration brings new insights for future high power spacecrafts. A trade-off study is presented in this paper. Two different trough concentrators, and a linear Fresnel lens concentrator are compared to rigid arrays. Thermal and optical behaviors are included in the analysis.Several technical aspects are discussed:
- • Off-pointing with concentrators induces collection loss and illumination non uniformity, reducing the PV efficiency.
- • Concentrator deployment increases the mission risk.
- • Reflective trough concentrators are attractive and already proven. Coating is made of VDA (Aluminum). A comprehensive analysis of PV conversion increase with protected silver is presented.
- • Solar concentration increases the heat load on solar cells, while the conversion efficiency is significantly decreasing at warm temperatures.
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Flavien Mercier Luca Cerri Jean-Paul Berthias 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
The DORIS instrument on Jason-2 is the first of a new generation. The satellite receivers have now seven simultaneous measurement channels, with synchronous dual frequency phase and pseudo-range measurements. These measurements are now described in a similar manner as GPS measurements and an extension of the RINEX 3.0 format has been defined for DORIS. Data are available to users with a shorter latency. 相似文献
7.
Jean-Paul Malingreau 《Space Policy》1985,1(1):62-75
The changing context of space remote sensing applications is described in terms of evolving needs and capabilities in South-east Asia and in terms of recent policy decisions in spacefaring nations. Emphasis is placed on the need for a technology which allows the monitoring of, eg the exploitation and degradation of natural resources, crop development, climatic effects and the like. The implications of policy adjustments in the US LANDSAT programme, including its proposed commercialization, are discussed, and the potential role of other existing and future satellites is reviewed. 相似文献
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