New variable stars from the photographic archive: semi-automated discoveries,attempts at automatic classification and the new field 104 Her     

Sergei V.Antipin  Ignacio Becker  AlexANDer A.Belinski  Darya M.Kolesnikova  Karim Pichara  Nikolay N.Samus  Kirill V.Sokolovsky  Alla V.Zharova  Alexandra M.Zubareva 《天文和天体物理学研究(英文版)》2018,(8)

Using 172 plates taken with the 40-cm astrograph of the Sternberg Astronomical Institute(Lomonosov Moscow University) in 1976–1994 and digitized with a resolution of 2400 dpi, we discovered and studied 275 new variable stars. We present the list of our new variables with all necessary information concerning their brightness variations. As in our earlier studies, the new discoveries show a rather large number of high-amplitude Delta Scuti variables, predicting that many stars of this type remain not detected in the whole sky. We also performed automated classification of the newly discovered variable stars based on the Random Forest algorithm. The results of the automated classification were compared to traditional classification and showed that automated classification was possible even with noisy photographic data. However, further improvement of automated techniques is needed, which is especially important when considering the very large numbers of new discoveries expected from all-sky surveys.  相似文献   

Comparison of Field and Satellite Data on the Total Cloudiness for the Atlantic Ocean in the Period 2004–2014     

Sinitsyn  A. V.  Gulev  S. K. 《Oceanology》2022,62(1):1-7

Oceanology - The aim of this study is to compare satellite measurements of the total cloudiness with visual observations of clouds. This makes it possible to compare “different...  相似文献   

Kampelite,Ba3Mg1.5Sc4(PO4)6(OH)3·4H2O,a new very complex Ba-Sc phosphate mineral from the Kovdor phoscorite-carbonatite complex (Kola Peninsula,Russia)     

Yakovenchuk  Victor N.  Ivanyuk  Gregory Yu.  Pakhomovsky  Yakov A.  Panikorovskii  Taras L.  Britvin  Sergei N.  Krivovichev  Sergey V.  Shilovskikh  Vladimir V.  Bocharov  Vladimir N. 《Mineralogy and Petrology》2018,112(1):111-121

Mineralogy and Petrology - Kampelite, Ba3Mg1.5Sc4(PO4)6(OH)3·4H2O, is a new Ba-Sc phosphate from the Kovdor phoscorite-carbonatite complex (Kola Peninsula, Russia). It is orthorhombic, Pnma,...  相似文献   

Structure and Variability of the Meridional Overturning Circulation in the North Atlantic Subpolar Gyre, 2007–2017     

Gladyshev  S. V.  Gladyshev  V. S.  Gulev  S. K.  Sokov  A. V. 《Doklady Earth Sciences》2018,483(2):1524-1527

Doklady Earth Sciences - The vertical structure and interannual and long-term variability of the meridional overturning circulation in the North Atlantic Subpolar Gyre is analyzed. A close...  相似文献   

The Structure and Long-Term Variability of the Bottom Layer in the Irminger Sea     

S. V. Gladyshev  V. S. Gladyshev  L. A. Pautova  S. K. Gulev  N. V. Politova  A. V. Sokov 《Doklady Earth Sciences》2018,481(2):1025-1028

This paper shows the important role that circulation can play in the long-term variability of thermohaline properties of the bottom layer in the Irminger Sea, and the increase in salinity in the 21st century in spite of intense ice melting in the Arctic and freshening of the upper and intermediate layers that started over the last 5–7 years in the North Atlantic.  相似文献   

Non-Fickian mass transport in fractured porous media     

Sergei A. Fomin  Vladimir A. ChugunovToshiyuki Hashida 《Advances in water resources》2011,34(2):205-214

The paper provides an introduction to fundamental concepts of mathematical modeling of mass transport in fractured porous heterogeneous rocks. Keeping aside many important factors that can affect mass transport in subsurface, our main concern is the multi-scale character of the rock formation, which is constituted by porous domains dissected by the network of fractures. Taking into account the well-documented fact that porous rocks can be considered as a fractal medium and assuming that sizes of pores vary significantly (i.e. have different characteristic scales), the fractional-order differential equations that model the anomalous diffusive mass transport in such type of domains are derived and justified analytically. Analytical solutions of some particular problems of anomalous diffusion in the fractal media of various geometries are obtained. Extending this approach to more complex situation when diffusion is accompanied by advection, solute transport in a fractured porous medium is modeled by the advection-dispersion equation with fractional time derivative. In the case of confined fractured porous aquifer, accounting for anomalous non-Fickian diffusion in the surrounding rock mass, the adopted approach leads to introduction of an additional fractional time derivative in the equation for solute transport. The closed-form solutions for concentrations in the aquifer and surrounding rocks are obtained for the arbitrary time-dependent source of contamination located in the inlet of the aquifer. Based on these solutions, different regimes of contamination of the aquifers with different physical properties can be readily modeled and analyzed.  相似文献   

Der Bau von Nordost-Asien nach neueren Forschungen     

Sergei Obrutschew 《International Journal of Earth Sciences》1934,25(6):388-422

Ohne Zusammenfassung  相似文献   

New Experimental Platform for Studies of Turbulence and Turbulent Mixing in Accelerating and Rotating Fluids at High Reynolds Numbers     

Sergei S. Orlov  Snezhana I. Abarzhi 《Astrophysics and Space Science》2007,307(1-3):241-244

We present a new experimental platform for studies of turbulence and turbulent mixing in accelerating and rotating fluids. The technology is based on the ultra-high performance optical holographic digital data storage. The state-of-the-art electro-mechanical, electronic, and laser components allow for realization of turbulent flows with high Reynolds number (>10⁷) in a relatively small form-factor, and quantification of their properties with extremely high spatio-temporal resolutions and high data acquisition rates. The technology can be applied for investigation of a large variety of hydrodynamic problems including the fundamental properties of non-Kolmogorov turbulence and turbulent mixing in accelerating, rotating and multiphase flows, magneto-hydrodynamics, and laboratory astrophysics. Unique experimental and metrological capabilities enable the studies of spatial and temporal properties of the transports of momentum, angular momentum, and energy and the identification of scalings, invariants, and statistical properties of these complex turbulent flows.  相似文献   

Simulations of star formation in a gaseous disc around Sgr A*– a failed active galactic nucleus     

Sergei Nayakshin  Jorge Cuadra †  Volker Springel 《Monthly notices of the Royal Astronomical Society》2007,379(1):21-33

  相似文献   

Close stars and accretion in low-luminosity active galactic nuclei     

Sergei Nayakshin 《Monthly notices of the Royal Astronomical Society》2004,352(3):1028-1036

  相似文献