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The paper deals with the procedure for the generation and optimization of the trajectory plan for missions in neighboring circumsolar space by means of gravity-assist maneuvers near Venus and Earth. An optimum flight trajectory proposed for use in the prospective Intergelio-Zond Russian mission is presented as an example of the described procedure.  相似文献   
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Dust particles obtained by filtering fresh snow collected from May to September 2017 in the vicinity of Vostok station in Antarctica were examined using a scanning electron microscope. The collection of dust particles contains 197 spherules ranging from 0.5 to 117 μm in diameter, the most abundant ones (n = 188) by far being iron oxide spherules. Analyses of meteorological and human activity data suggest an extraterrestrial origin of most of the spherical particles. The particle size distribution histogram showed a smooth increase in their number with decreasing size and a dramatic drop at sizes smaller than 3 μm. The number of spherical particles has an uneven distribution over time, with an intense peak in July 27–28, 2017 which correlates by dates with the peak of the Southern Delta Aquariids meteor shower. The size distribution of the particles collected during the same period indicates the presence of a mechanism that accelerates their fall to the Earth. We propose that they are effective centers of condensation of ice crystals in stratospheric clouds. Our data indicate that collection of micrometeorites with sizes of several microns from the fresh snow is possible, opening a new way for sampling micrometeorites, including separate meteor showers.  相似文献   
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Oceanology - During cruise 43 of the R/V Akademik Nikolaj Strakhov (September 21–October 9, 2019), new data were obtained on the bottom relief, sedimentation, and hydrological regime of the...  相似文献   
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Kosov  V. I.  Ivanov  G. N.  Levinskii  V. V.  Ezhov  E. V. 《Water Resources》2001,28(4):407-412
The distribution of heavy metals in the Volga bottom deposits is studied. According to the degree of pollution with heavy metals, three stretches are singled out within the river reach under consideration. A drastic increase in Cu and Cd concentrations in bottom deposits is established. A close statistical correlation between Cu and Pb accumulation and the organic matter content of bottom deposits is revealed.  相似文献   
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Oceanology - During the 59th cruise of the P/V Akademik Ioffe (September–October 2021), geophysical, sedimentological, hydrological, hydrochemical, and biological studies were carried out in...  相似文献   
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