排序方式: 共有18条查询结果,搜索用时 15 毫秒
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Kazuo Abe Norihisa Nakagawa Katsuyuki Abo Mutsumi Tsujino 《Journal of Oceanography》2014,70(3):267-276
Distribution of silicic acid (Si(OH)4) in bottom water was investigated in the central Seto Inland Sea under stratified conditions in summer. Water samples were collected at 10 stations on April 24 and 25 and July 7 and 8, 2012. In July, stratification progressed, and a cold water mass (dome) of <20 °C appeared. In response to the cold dome, low oxygen content was observed in the bottom layer of the eastern part of Hiuchi-Nada. In this water mass site, apparent oxygen utilization values calculated from dissolved oxygen (DO) concentrations increased, coinciding with increase of Si(OH)4 concentrations from April to July. This suggests that increase of Si(OH)4 [dissolution of biogenic silica (diatom frustules)] was accompanied by DO consumption due to degradation of organic matter such as plankton soft tissue. These findings suggest that a bacterial degradation of the organic matrix that covers diatom frustules could accelerate the dissolution of biogenic silica in bottom water under stratified conditions. 相似文献
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The present work deals with spectrophotometric studies of two Be stars ( Leo and 17 Tau) using 74 telescope at Kottamia observatory.The results obtained revealed the presence of variations in the general shape and the equivalent width of the profiles of hydrogen lines in the spectrum of both stars within short period interval. 相似文献
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E. K. El-Shewy M. I. Abo el Maaty H. G. Abdelwahed M. A. Elmessary 《Astrophysics and Space Science》2011,332(1):179-186
The nonlinear properties of small amplitude dust-acoustic solitary waves (DAWs) in a homogeneous unmagnetized plasma having
electrons, singly charged ions, hot and cold dust species with Boltzmann distributions for electrons and ions have been investigated.
A reductive perturbation method was employed to obtain the Kadomstev-Petviashvili (KP) equation. The effects of the presence
of charged hot and cold dust grains on the nature of DAWs were discussed. Moreover, the energy of two temperatures charged
dusty grains were computed. The present investigation can be of relevance to the electrostatic solitary structures observed
in various space plasma environments. 相似文献
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In the course of observations of the LMC with the Glazar space telescope it was found that the star HD 269665 is unusually bright at 1640 A:m
1640 = 5
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m
± 0
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m
1,m
1640 –V = –6
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m
2. 相似文献
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El Diasty W. Sh. El Beialy S. Y. Mostafa A. R. Abo Ghonaim A. A. Peters K. E. 《Natural Resources Research》2020,29(3):2063-2102
Natural Resources Research - An oil–oil and oil–source rock correlation study was carried out using chemometric methods applied to geochemical data for 123 Upper Cretaceous—Lower... 相似文献
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Natural Hazards - To investigate the propagation of meteorological droughts to agricultural and hydrological droughts, the relationship between droughts was analyzed using observed precipitation... 相似文献