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71.
We comment briefly on a recent paper by Fuhrmann which claims that about half of the sample of halo stars in the solar neighbourhood presented by Fuchs and Jahreiß [A&A 329 (1998) 81] are actually thick disc stars. By referring to star counts in the CADIS survey we argue that this is rather unlikely. 相似文献
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Several lines of neutral oxygen observed at various positions on the solar disk were used to study the influence of (1) the temperature distribution, (2) the velocity field, and (3) the damping on the line profiles and the abundance of oxygen in the photosphere. Theoretical profiles were calculated on the basis of four different model atmospheres in LTE. It was found that the model proposed by Holweger (1967) best reproduced the center-to-limb observations of the lines studied. The weighted mean of the oxygen abundance turned out to be log
O = 8.83 on the basis of log
H = 12.00. 相似文献
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75.
Eclogite is essentially a bi-mineralogic high-grade metamorphic rock consisting of garnet and omphacite and is the product of high-to-ultrahigh pressure metamorphism of basaltic rocks due to the subduction of oceanic crust or the thickening/subduction of … 相似文献
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The magnetization density of Mn2SiO4 was determined by diffraction with polarized neutrons at 20 K (antiferromagnetic spin state) in an applied magnetic field of 4.62 Tesla. A unique data set of 199 flipping-ratios was registered up to sin Θ/gl=9.0/nm, and the magnetic moments for the different sites were derived (μ(M1)=2.56(2) μ B, μ(M2)=4.33(2) μ B) after correction of field-induced ferromagnetic moments and antiphase domains. Fourier inversion of the magnetic structure factors produced the magnetization density in the unit cell with small contributions close to those oxygens involved in superexchange. 相似文献
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79.
A wealth of data on the state of the environment is being created in innumerable programmes world-wide. Optimal use of this data requires that information on its existence is available, that it can be readily accessed and — most important — that the data be compiled and classified in a compatible way. Achieving this is the basic aim of harmonization of environmental measurement. Although great care is generally taken to harmonize data collected within programmes, harmonization between programmes remains a major goal for the future.In 1989 UNEP established an office as a basis for the planned Harmonization of Environmental Measurement Project under the auspices of the Global Environmental Monitoring System (GEMS). The office describes the mission, rationale, and objectives of the project and the concepts underlying the harmonization of information on the environment collected at different levels and in different programmes. 相似文献
80.