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Benjamin P. Weiss Jérôme Gattacceca Sabine Stanley Pierre Rochette Ulrich R. Christensen 《Space Science Reviews》2010,152(1-4):341-390
The large-scale compositional structures of planets are primarily established during early global differentiation. Advances in analytical geochemistry, the increasing diversity of extraterrestrial samples, and new paleomagnetic data are driving major changes in our understanding of the nature and timing of these early melting processes. In particular, paleomagnetic studies of chondritic and small-body achondritic meteorites have revealed a diversity of magnetic field records. New, more sensitive and highly automated paleomagnetic instrumentation and an improved understanding of meteorite magnetic properties and the effects of shock, weathering, and other secondary processes are permitting primary and secondary magnetization components to be distinguished with increasing confidence. New constraints on the post-accretional histories of meteorite parent bodies now suggest that, contrary to early expectations, few if any meteorites have been definitively shown to retain records of early solar and protoplanetary nebula magnetic fields. However, recent studies of pristine samples coupled with new theoretical insights into the possibility of dynamo generation on small bodies indicate that some meteorites retain records of internally generated fields. These results indicate that some planetesimals formed metallic cores and early dynamos within just a few million years of solar system formation. 相似文献
244.
A stable, observable liquid-gas interface was realized in an experimental cell (3 × 2 × 1 cm) under microgravity conditions. The liquid used was an aqueous 6.24 10?3 molal solution of n-heptanol. A temperature gradient, established at the interface, resulted in the build-up of a Marangoni convection cell with the liquid flowing in an unusual direction (i.e. at the surface the liquid flowed from the cold to the hot side).The same experiment on Earth gives rise to a Marangoni cell superimposed on buoyancy cells. The Marangoni and the buoyancy cells then turn in opposite directions. 相似文献
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B. Ehmann L. Balázs É. Fülöp R. Hargitai P. Kabai B. Péley T. Pólya A. Vargha J. László 《Acta Astronautica》2011,68(9-10):1560-1566
This paper is about a pilot application of narrative psychological content analysis in the psychological status monitoring of Crew 71 of a space analog simulation environment, the Mars Desert Research Station (MDRS). Both the method and its theoretical framework, Scientific Narrative Psychology, are original developments by Hungarian psychologists [5] (László, 2008). The software was NooJ, a multilingual linguistic development environment [11] (Silberztein, 2008). Three measures were conceptualized and assessed: emotional status, team spirit and subjective physical comfort. The results showed the patterns of these three measures on a daily basis at group level, and allowed for detecting individual differences as well. The method is adaptable to languages involved in space psychology, e.g. Russian, French and German in addition to English. 相似文献
247.
J.-F. Crétaux W. Jelinski S. Calmant A. Kouraev V. Vuglinski M. Bergé-Nguyen M.-C. Gennero F. Nino R. Abarca Del Rio A. Cazenave P. Maisongrande 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
An accurate and continuous monitoring of lakes and inland seas is available since 1993 thanks to the satellite altimetry missions (Topex–Poseidon, GFO, ERS-2, Jason-1, Jason-2 and Envisat). Global data processing of these satellites provides temporal and spatial time series of lakes surface height with a decimetre precision on the whole Earth. The response of water level to regional hydrology is particularly marked for lakes and inland seas in semi-arid regions. A lake data centre is under development at by LEGOS (Laboratoire d’Etude en Géophysique et Océanographie Spatiale) in Toulouse, in coordination with the HYDROLARE project (Headed by SHI: State Hydrological Institute of the Russian Academy of Science). It already provides level variations for about 150 lakes and reservoirs, freely available on the web site (HYDROWEB: http://www.LEGOS.obs-mip.fr/soa/hydrologie/HYDROWEB), and surface-volume variations of about 50 big lakes are also calculated through a combination of various satellite images (Modis, Asar, Landsat, Cbers) and radar altimetry. The final objective is to achieve in 2011 a fully operating data centre based on remote sensing technique and controlled by the in situ infrastructure for the Global Terrestrial Network for Lakes (GTN-L) under the supervision of WMO (World Meteorological Organization) and GCOS (Global Climate Observing System). 相似文献
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P. van Thienen K. Benzerara D. Breuer C. Gillmann S. Labrosse P. Lognonné T. Spohn 《Space Science Reviews》2007,129(1-3):167-203
In our search for life on other planets over the past decades, we have come to understand that the solid terrestrial planets
provide much more than merely a substrate on which life may develop. Large-scale exchange of heat and volatile species between
planetary interiors and hydrospheres/atmospheres, as well as the presence of a magnetic field, are important factors contributing
to the habitability of a planet. This chapter reviews these processes, their mutual interactions, and the role life plays
in regulating or modulating them. 相似文献
250.
Tim Van Hoolst Frank Sohl Igor Holin Olivier Verhoeven Véronique Dehant Tilman Spohn 《Space Science Reviews》2007,132(2-4):203-227
This review addresses the deep interior structure of Mercury. Mercury is thought to consist of similar chemical reservoirs
(core, mantle, crust) as the other terrestrial planets, but with a relatively much larger core. Constraints on Mercury’s composition
and internal structure are reviewed, and possible interior models are described. Large advances in our knowledge of Mercury’s
interior are not only expected from imaging of characteristic surface features but particularly from geodetic observations
of the gravity field, the rotation, and the tides of Mercury. The low-degree gravity field of Mercury gives information on
the differences of the principal moments of inertia, which are a measure of the mass concentration toward the center of the
planet. Mercury’s unique rotation presents several clues to the deep interior. From observations of the mean obliquity of
Mercury and the low-degree gravity data, the moments of inertia can be obtained, and deviations from the mean rotation speed
(librations) offer an exciting possibility to determine the moment of inertia of the mantle. Due to its proximity to the Sun,
Mercury has the largest tides of the Solar System planets. Since tides are sensitive to the existence and location of liquid
layers, tidal observations are ideally suited to study the physical state and size of the core of Mercury. 相似文献