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Astronomy Reports - The aim of this study is to search for close binary gravitationally bound pairs of open star clusters (CBOCs). We divided the observed pairs of clusters into visual binaries...  相似文献   
2.
Lithology and Mineral Resources - Main regularities in the manifestation of epigenetic processes in Lower Vendian terrigenous rocks of the Nepa–Botuoba anteclise are established. Evolution of...  相似文献   
3.
Basic regularities of secondary processes in reservoir rocks of the Yarakta Horizon are described with rocks in the Yarakta field as example. To achieve the formulated goal, we elucidated rock types in the studied section, its structure and distribution of reservoir rocks, as well as types of secondary alterations and their influence on filtration-capacity properties. The studies revealed that reservoir rocks of the Yarakta Horizon were formed on an alluvial-deltaic plain on the southeastern slope of the Nepa-Botuoba anteclise. The pore space of reservoir rocks is determined by conditions of their formation and peculiarities of secondary alterations. Maximal filtration-capacity values are characteristic of gritstones, as well as coarse-grained and inequigranular sandstones developed in the lower and middle parts of the Yarakta Horizon. The intergranular space of reservoir rocks in the lower part of the reservoir is substantially “healed” by secondary processes (regeneration, dolomitization, sulfatization, and salinization), probably, due to the gravitational seepage of stratal fluids, mineralization of which increased with time.  相似文献   
4.
The results of geochronological, mineralogical, petrographical, and geochemical study of the Ilbokich ultramafic lamprophyre are reported. The specific features in the mineral and chemical compositions of the studied ultramafic lamprophyre indicate that it can be regarded as a variety similar to aillikite, while other differences dominated by K-feldspar can be referred to damtjernite. According to Rb–Sr analysis, ultramafic lamprophyre dikes intruded at the turn of the Early and Middle Devonian, about 392 Ma ago. This directly proves the existence of Early Paleozoic alkali–ultramafic magmatism in the northern part of the southwest Siberian Platform. A finding of Devonian alkali–ultramafic lamprophyre is of dual predictive importance. On the one hand, it is indicative of the low probability of finding large diamond-bearing deposits in close association with aillikite. On the other hand, it can be indicative of a possible large Devonian diamond province in the studied territory, where diamondiferous kimberlite is structurally separated from aillikite.  相似文献   
5.
A study of cluster characteristics and internal kinematical structure of the middle-aged Pleiades open star cluster is presented. The individual star apexes and various cluster kinematical parameters including the velocity ellipsoid parameters are determined using both Hipparcos and Gaia data. Modern astrometric parameters were taken from the Gaia Data Release 1 (DR1) in combination with the Radial Velocity Experiment Fifth Data Release (DR5). The necessary set of parameters including parallaxes, proper motions and radial velocities are used for \(n=17\) stars from Gaia DR1+RAVE DR5 and for \(n=19\) stars from the Hipparcos catalog using SIMBAD data base. Single stars are used to improve accuracy by eliminating orbital movements. RAVE DR5 measurements were taken only for the stars with the radial velocity errors not exceeding \(2~\mbox{km}/\mbox{s}\). For the Pleiades stars taken from Gaia, we found mean heliocentric distance as \(136.8 \pm 6.4\) pc, and the apex position is calculated as: \(A_{CP}=92^{\circ }.52\pm 1^{\circ }.72\), \(D_{CP}=-42^{\circ }.28\pm 2^{\circ }.56\) by the convergent point method and \(A_{0}=95^{\circ }.59\pm 2^{\circ }.30\) and \(D_{0}=-50^{\circ }.90\pm 2^{\circ }.04\) using AD-diagram method (\(n=17\) in both cases). The results are compared with those obtained historically before the Gaia mission era.  相似文献   
6.
The stagewise optical and electron-microscopic analysis of the texture and mineralogy of the Upper Riphean–Lower Vendian gravelly–sandy rocks (Taseeva Group) in the Irkineevo–Chadobetsk riftogenic trough revealed a wide spectrum of secondary transformations: gravitational corrosion of allothigenic minerals, their plastic deformation, intense fracturing, and authigenic mineral formation. Traces of low-temperature hydrothermal processes were recorded. The multistage nature of authigenic mineral formation is attributed to the periodic resumption of tectonic dislocations owing to reactivation of fluid dynamics and thermal impulses ΔT.  相似文献   
7.
The internal kinematics of the Ursa Majoris stellar flow is considered. The details of the flow structure are considered, and new candidate members are searched for using high-precision Gaia DR1 TGAS data. The flow structure is studied using apex diagrams, which have been shown to be effective in studies of open clusters. To select member-stars of the flow, a chain of filters was applied to the spatial coordinates and velocities, photometric data, and elemental abundances of potential members. The nonuniform kinematic structure of the flow, manifest through its separation into different velocity directions for the core and three groups in the corona, is confirmed. Several filters were used to identify three candidate members. These included apex diagrams, MV?(B?V)0 diagrams, and the abundances of Fe, Mg, Al, Si, Ti, and Ni.  相似文献   
8.
Geotectonics - The geological and sedimentological interpretation of several time and deep seismic profiles within junction zone of the Volga‒Ural area of the East European Platform,...  相似文献   
9.
The Lower Cambrian Usol’e Formation in the Kamov arch of the Baikit anteclise includes stratiform intrusions confined to several levels. According to isotopic?geochronological investigations, the age of stratiform intrusions composed of olivine dolerites is estimated to be 256.0 ± 3.2 Ma.  相似文献   
10.
We describe the archive of scans of the astronomical plates obtained in the observations of comet Hale–Bopp. The observations were carried out from August 17, 1996, to April 29, 1997, at the Zeiss-400/2000 astrograph of the Zvenigorod Observatory of the Institute of Astronomy of the Russian Academy of Sciences (INASAN). The archive contains the images that can be used in astrometric, photometric, and astrophysical studies. In some of the plates, the size of the comet reaches 6.3° (23 cm). In many scans, the details of the cometary tail, including individual jets, vortexes, etc., are clearly distinguishable. The archive of the images is available free.  相似文献   
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