Lithostructural Geological-Genetic Model and Mineral Composition of the Krasnokutsk Rare Metal–Titanium Placer Deposit (Ukraine)     

Ganzha  E. A.  Lalomov  A. V.  Chefranova  A. V.  Grigor’eva  A. V.  Magazina  L. O. 《Lithology and Mineral Resources》2019,54(6):465-479

Lithology and Mineral Resources - The paper presents the geological setting, structure, lithology, and placer-controlling factors in the Krasnokutsk placer rare metal–titanium deposit located...  相似文献   

Investigation of the peculiarities of artificial electromagnetic signal propagation at high latitudes in the range 0.1–10 Hz     

E. D. Tereshchenko  N. V. Ivanov  A. E. Sidorenko  V. F. Grigor’ev 《Geomagnetism and Aeronomy》2010,50(5):632-642

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Emergence of hard X-rays at weak nonstationary processes in active regions     

V. I. Vybornov  I. Yu. Grigor’eva  M. A. Livshits  E. F. Ivanov 《Geomagnetism and Aeronomy》2015,55(8):1112-1117

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Basic Aspects of a Methodological Approach to Assessing the Seismic Resistance of Soils     

V. N. Kutergin  V. V. Sevost’yanov  K. V. Pankov  R. G. Kal’bergenov  L. V. Grigor’eva 《Water Resources》2017,44(7):968-977

A method is proposed for assessing the seismic resistance of soils, involving the analysis of seismic data (with soil conditions taken into account), the choice and specification of amplitude–frequency spectrum parameters, experimental studies of soil samples with specified cyclic load parameters, analysis of the dependence of soil behavior on the overload factor, and calculating the ultimate overload factor based on the comparison of accepted and ultimate effect levels. The paper gives the results of practical application of the developed approach to assessing the seismic resistance of a shelf area in the Northern Caspian Sea.  相似文献   

Unsteady free convection flow past an infinite plate with constant suction and heat sources     

I. Pop  V. M. Soundalgekar 《Astrophysics and Space Science》1979,62(2):389-396

An analysis of a two-dimensional unsteady free convective flow of an incompressible viscous fluid past an infinite vertical porous plate has been carried out under the following conditions: (i) constant suction, (ii) the plate temperature oscillating in time about a constant non-zero mean, (iii) presence of the temperature-dependent sources in the fluid. Approximate solutions have been derived for the mean velocity and temperature fields, the transient velocity and temperature fields, the amplitude and the phase of the skin-friction and the rate of heat transfer. It is shown that an increase inS (the source-strength), leads to an increase in the value of |B| (the amplitude of the skin-friction) and |Q| (the amplitude of the rate of heat transfer), in case of air, but in case of water |B| and |Q| decrease.  相似文献   

Mariinskite from the Bazhenovskii ophiolite complex: The second finds in the world     

Yu. V. Erokhin  V. V. Khiller  K. K. Zoloev  M. P. Popov  V. V. Grigor’ev 《Doklady Earth Sciences》2014,455(2):408-410

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Light curve shape variability of SZ cassiopeiae between 1978–1994     

Alexandru Pop  Steliana Codreanu 《Astrophysics and Space Science》2001,275(3):247-258

The aim of our investigation was toapproach the problem of identification for possiblevariability of light curve shape in case of theclassical Cepheid SZ Cassiopeiae. In order to performsuch a study we analysed eight observational data setsobtained through V photoelectrical photometry,covering a time base of 16 years. We applied theFourier decomposition technique to each data set; theobtained Fourier coefficients were used to calculatethe corresponding amplitude ratios and phasedifferences. Their time behavior were finally studiedin order to search for evidences of the variability ofthe light curve shape.  相似文献   

Physics of post-eruptive solar arcades: Interpretation of RATAN-600 and STEREO spacecraft observations     

M. A. Livshits  A. M. Urnov  F. F. Goryaev  L. K. Kashapova  I. Yu. Grigor’eva  T. I. Kal’tman 《Astronomy Reports》2011,55(10):918-927

Results of simultaneous measurements of radiation fluxes from post-eruption arcades on the Sun at 171, 195, 284, and 304 ? (from STEREO spacecraft data) and at radio wavelengths (from the RATAN-600 radio telescope) are presented. An original probabilistic approach developed earlier by Urnov was used to determine the differential emission measure. This method requires no regularization, and the obtained results do not depend on the choice of the temperature grid. This approach has yielded the differential measure of emission at temperatures approximately from 0.3 to 15 MK. The subsequent calculation of thermal magnetobremsstrahlung in a multi-temperature model with the magnetic field decreasing with height produces a spectrum similar to that observed on RATAN-600. Thus, in many non-stationary events with modest powers, a thermal multi-temperature model is quite able to explain the emission of post-eruption arcade systems, and it is not necessary to invoke the emission of accelerated particles. The proposed model enables direct estimation of the ratio of the magnetic and gas pressures at the tops of post-eruption arcades, and determination of the conditions required for the origin of secondary nonstationary processes in the decay stage of the main flare.  相似文献   

Estimating the computation accuracy of mixed waves in the ocean on the basis of present-day numerical models     

E. S. Nesterov  Z. K. Abuzyarov  G. A. Grigor’eva  I. N. Davidan  V. I. Dymov  T. A. Pasechnik 《Russian Meteorology and Hydrology》2011,36(10):669-676

An estimate of the computation accuracy of wind waves is obtained on the basis of three mathematical models used for the diagnosis and forecast of wind waves at the Hydrometcenter of Russia, US National Weather Service, and European Centre for Medium-Range Weather Forecasts. The accuracy estimation was carried out for the whole year 2006 by means of the comparison of model computations based on different wind fields with hourly instrumental observations of waves at 16 buoys in the North Atlantic. The computation accuracy was estimated on the basis of six statistical characteristics. Besides, the estimates for various wave height ranges for months and seasons of the year are made for all buoys and grouped into three geographical areas: the coasts of the United States, Canada, and Great Britain. The essential differences are revealed in the accuracy of model-based computation of waves in the areas of the ocean with different wind wave regimes, in different seasons of the year, and within various wave height ranges. The obtained results indicate the necessity to improve the present-day methods of diagnosis and forecast of wind waves.  相似文献   

Active regions near the recent solar-cycle minimum: Relation between plasma heating and electrical currents     

I. Yu. Grigor’eva  M. A. Livshits  G. V. Rudenko  I. I. Mysh’yakov 《Astronomy Reports》2013,57(8):611-621

Data on small active regions on the Sun collected over three years (2007–2009) are analyzed. Under very quiescent conditions (a low X-ray background level), the shapes of the coronal loops of some active regions correspond fairly well to the shapes of magnetic-field lines calculated in a potential approximation. This is true of several active regions (e.g., the group AR 10999 in June 2008) in which no flares more powerful than B3 were observed. The radio emission of this active region detected by the RATAN-600 telescope was very weak and virtually no polarization was detected. Subflares were observed in most groups. It is demonstrated using AR 10933 (January 2007) as an example that a growth in the soft X-ray emission by up to factors of ten simultaneous with an increase in the radio flux is characteristic for such active regions. A source with the opposite polarization developed to the Northwest of the main spot in AR 10933. A series of SOHO/MDI (and also Hinode) magnetograms shows the emergence of new magnetic flux before the development of this polarized source, which continued for several hours on January 8, 2007. The current density at surfaces located at various heights is estimated based on observations of the total vector magnetic field (Hinode data) and a non-linear, force-free magnetic-field extrapolation. The height-integrated current becomes appreciably stronger at two nodes above a field neutral line, near the location of the main emerging flux. This supports the idea that the emergence of new magnetic flux is a key factor in the evolution of active regions at all stages of their existence. The development of this picture could help in elucidating the inter-relationship between current enhancements, plasma heating, and particle acceleration, in both weak active regions and strong activity complexes.  相似文献