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281.
The present paper reports 9 species of pontoniine shrimps collected from Hainan IS-land ,South China Sea ,by the Joint Chinese-German Marine Biology Expeditions,in which Peri-climenaeus arabicus (Calman,1939) and Periclimenaeus hecate (Nobili,1904) are recorded for the first time from Hainan Island. 相似文献
282.
The problem of perfect fluid distribution in spatially homogeneous and anisotropic Bianchi type VI0 space-time is considered in a scalar tensor theory of gravitation proposed by Saez and Ballester (1985). Exact solutions
of the field equations are derived when the metric potentials are functions of cosmic time only. Some physical and geometrical
properties of the solutions are also discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
283.
S. Viti 《Astrophysics and Space Science》2003,285(3-4):791-800
In this article, some aspects of the clumpy nature of molecular clouds are reviewed. In particular the observational evidence
for small-scale structures both in low and high mass star forming regions will be discussed. I will review some examples of
`clumpiness' such as: i) the molecular clumps ahead of HH objects and how the study of the physical and chemical nature of
these clumps is important for the understanding of the clumpiness of the Interstellar Medium; and ii)hot cores and their use
as a tool to study the early phases of massive star formation.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
284.
Stellar population synthesis at the resolution of 2003 总被引:2,自引:0,他引:2
285.
The trans-Neptunian belt has been subject to a strong depletion that has reduced its primordial population by a factor of one hundred over the solar system's age. One by-product of such a depletion process is the existence of a scattered disk population in transit from the belt to other places, such as the Jupiter zone, the Oort cloud or interstellar space. We have integrated the orbits of the scattered disk objects (SDOs) so far discovered by 2500 Myr to study their dynamical time scales and the probability of falling in each of the end states mentioned above, paying special attention to their contribution to the Oort cloud. We found that their dynamical half-time is close to 2.5 Gyr and that about one third of the SDOs end up in the Oort cloud. 相似文献
286.
Combining the results of the inverse problem of dynamics with the theory of multiseparability of planar potentials, we find biparametric families of orbits, whose existence guarantees the multiseparability of the potential. We also study the allowed regions of the plane, where these orbits are traced. 相似文献
287.
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289.
An additional investigation has been carried out of the rational model (Aslanov, 2000) of the separation of drops from the tops of the unstable wave formation on the molten surface of a meteoroid. The ratio of the wavelength of unstable hydrodynamic disturbances to the diameter of drops has been calculated in a mathematically closed form. Particular theoretical estimates of the size of the region of spraying of molten drops agree with prevailing sizes given in the known classification of the forms of meteoroid fragmentation. 相似文献
290.
In the 19th century De la Rue, Stewart, and Loewy carried out a compilation of drawings and photographs of the solar sunspots corresponding to the interval 1832–1868. Using these drawings and photographs, they determined fortnightly values of the percentage of the solar photosphere covered by the sunspots. In this work, we have performed a spectral analysis of these data in order to determine possible periodic signals. In addition to the 11-year solar cycle, short cycles of about 330 days and 30–50 days have been recovered, lacking the 150–160 days period discovered by other authors using several solar activity indicators. 相似文献