On the origin of type III fundamental     

A. B. Eremin  V. V. Zaitsev 《Solar physics》1985,102(1-2):99-110

A two-component scheme for the generation of type III fundamental radiation is proposed. The first component of the fundamental arises at a plasma level _{L t} because of the Rayleigh scattering of the plasma waves into electromagnetic radiation. The other component arises at _{L t} /2 because of the decay of the first component into plasma waves and the subsequent rescattering of the plasma waves into electromagnetic radiation _t 2( _t /2). By its properties (location, directivity, polarization) the second component is essentially the same as the second harmonic radiation produced by a stream of fast electrons at _L ( _t /2). This scheme is used to solve the main problems (localization and directivity of the source, polarization of type III fundamental) of the harmonic theory of type III solar bursts.  相似文献   

The structure of the turbulent shock wave propagating in the solar atmosphere across the magnetic field     

V. V. Zaitsev  O. G. Parfenov  A. V. Stepanov 《Solar physics》1978,60(2):279-291

A consistent account of plasma turbulence in magnetohydrodynamics equations describing transport processes across the magnetic field is presented. The structure of the perpendicular shock wave generated in the solar atmosphere, as a result of either local disturbance of the magnetic field or dense plasma cloud motion with a frozen-in magnetic field, has been investigated. The region of parameters in the solar atmosphere at which the electron-ion relative drift velocity u exceeds the electron thermal velocity V _eand generation of radio emission becomes possible, has been determined. The plasma turbulence inside the front has been shown, under conditions of solar corona, not to cause the oscillation structure of shock front to break down. Under chromospheric conditions, the shock profile is aperiodical. Then, the condition u > V_ecan be satisfied and shock waves having an Alfvén Mach number M which exceeds the critical value M _c 3.3 for aperiodical shock waves can exist (Eselevich et al., 1971a). Arguments are given in favour of the fact that perpendicular shock waves are generated in the Sun's atmosphere when dense plasma clouds, with a frozen-in magnetic field, are expanded.  相似文献   

Neotectonics and geodynamics of the Kuznetsk Basin     

L. V. Panina  V. A. Zaitsev 《Moscow University Geology Bulletin》2012,67(6):332-339

This work describes the peculiarities of neotectonics and geodynamic development of the Kuznetsk Basin since the Oligocene. The complex of studies included structural-geomorphological analysis with interpretation, satellite image data processing, and field observations. The studies we carried out allowed us to reveal that the modern dislocations in the Kuznetsk Basin are characterized by an arched-block style of tectonic movement. The modern structural pattern of the Kuznetsk Basin is a combination of wide uplifts separated by narrow depressions and weak zones (fault zones, fracture zones, and zones of rock disintegration) of northwestern, northeastern, submeridional, and sublatitudinal strike. As a result of these studies, the relationships between modern and ancient tectonic structures and the geodynamic features of the development of modern dislocations that depend on the degree of activization of tectonic structures have been revealed. Statistical analysis of the results of the interpretation allowed us to reveal areas of high permeability and higher dislocation density in the geological setting with a higher concentration of methane.  相似文献   

Carbon and oxygen isotope compositions of Lower-Middle Ordovician carbonate rocks in the northwestern Russian platform     

A. V. Zaitsev  B. G. Pokrovsky 《Lithology and Mineral Resources》2014,49(3):272-279

Carbon and oxygen isotope compositions of Lower-Middle Ordovician carbonate rocks in the northwestern Russian Platform (eastern Ladoga Klint, Lynna River, and Babino quarry sections) are considered. In the studied section interval, average δ¹³C and δ¹⁸O values are 0 ± 0.5 and ?5 ± 0.5‰ (V-PDB), respectively. Two closely-spaced negative carbon isotope excursions with the amplitude of 2‰ are established near the Lower-Middle Ordovician boundary (between the Floian and Dapingian stages). The lower part of the Darriwilian Stage is marked by the gradual decrease in δ¹³C values to 1‰. Excursions of δ¹³C do not correlate with δ¹⁸O variations and can be considered as primary. The carbon isotope event defined at the Lower-Middle Ordovician boundary is traceable at the interregional level and represents a promising stratigraphic reference level. It may likely be explained by decrease in the relative rate of organic matter burial due to sea level fall and expansion of well-aerated shallow-water basins with a low primary production of phytoplankton.  相似文献   

A ¹⁴C-dating and oxygen-isotope diagram of a Holocene-reformed ice wedge on the Chara River (Transbaikal region)     

Yu. K. Vasil&#;chuk  V. N. Zaitsev  A. C. Vasil&#;chuk 《Doklady Earth Sciences》2006,407(2):265-270

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Observations of Solar Type II bursts at frequencies 10–30 MHz     

V.N. Mel'nik  A.A. Konovalenko  H.O. Rucker  A.A. Stanislavsky  E.P. Abranin  A. Lecacheux  G. Mann  A. Warmuth  V.V. Zaitsev  M.Y. Boudjada  V.V. Dorovskii  V.V. Zaharenko  V.N. Lisachenko  C. Rosolen 《Solar physics》2004,222(1):151-166

We present the results of radio telescope UTR-2 observations of solar Type II radio bursts in the 10–30 MHz frequency range. These events possess a fine structure consisting of fast drift sub-bursts similar to Type III bursts. The frequency drift rate of the Type II bursts at decameter wavelengths is smaller than 0.1 MHz s^–1. One of these bursts with herringbone structure has a wave-like backbone that almost does not drift. The features of the observed bursts are discussed.  相似文献   

Type-II Spicules as Important Sources of Both Heating and Sustain the Mass Loss of Solar Corona     

Zaitsev  V. V.  Stepanov  A. V.  Kronshtadtov  P. V. 《Geomagnetism and Aeronomy》2021,61(8):1116-1121

Geomagnetism and Aeronomy - Heat fluxes from hot open magnetic flux tubes into the surrounding corona as a possible source of corona heating are determined. In order to compensate for radiation and...  相似文献   

Neotectonics and geodynamics of the Scythian Plate     

V. A. Zaitsev  L. V. Panina 《Moscow University Geology Bulletin》2011,66(1):1-5

Based on the results of structural-geomorphological analysis and tectonophysical modeling we identified an active geodynamic area in the basement of the Scythian Plate, which includes the Rostov salient, the northern part of the Stavropol uplift, Kuma-Tyulenev swell, and the eastern part of the Karpinskii swell and Astrakhan salient. This area is also characterized by maximal lineament densities, high heat flow, seismicity and the occurrence of hydrocarbon accumulations. It has been shown that the orientation of deformations within the Scythian Plate and Greater Caucasus orogen exhibits good correlation with those documented in the modern structural geometry of the Schythian Plate.  相似文献   

Phase equilibria in the system lamprophyllite-nepheline     

V. A. Zaitsev  L. N. Kogarko  V. G. Senin 《Geochemistry International》2013,51(11):889-895

Experimental studies of the melting diagram for the lamprophyllite-nepheline system and data on the phases crystallizing in this system indicate that lamprophyllite incongruently melts with the origin of melt and titanium oxide. The maximum temperature at which nepheline and lamprophyllite can occur in equilibrium is estimated at 833 ± 6°C. Our pioneering data on lamprophyllite crystallization from melt prove that this mineral can be of magmatic genesis. The distribution coefficients between lamprophyllite and melt are evaluated for K (0.1–0.25), Mn (0.82–1.06), Fe (0.13–0.40), and Mg (0.82–1.5); and the Sr/Ba lamprophyllite/melt exchange coefficient is estimated at 1.8–3.7.  相似文献   

Seasonal Cycle of the Near-Surface Diurnal Wind Field Over the Bay of La Paz,Mexico     

Cuauhtémoc Turrent  Oleg Zaitsev 《Boundary-Layer Meteorology》2014,151(2):353-371

The results of numerical simulations of the troposphere over the Bay of La Paz, calculated for the months of January, April, July and October during the period 2006–2010 with the Weather Research and Forecast (WRF v3.5) regional model, are used to describe the seasonal features of the diurnal cycle of planetary boundary-layer winds. Two distinct near-surface diurnal flows with strong seasonal variability were identified: (1) a nocturnal and matutinal breeze directed from the subtropical Pacific Ocean, over the Baja California peninsula and the Bay of La Paz, into the Gulf of California that is associated with the regional sea-surface temperature difference between those two major water bodies; and (2) a mid to late afternoon onshore sea-breeze related to the peninsula’s daily cycle of insolation heating that evolves with counter-clockwise rotation over the Bay of La Paz. The model results reveal the interaction over Baja California of opposing afternoon sea-breeze fronts that originate from the subtropical Pacific Ocean and the Gulf of California, with a convergence line forming over the peaks of the peninsula’s topography and the associated presence of a closed vertical circulation cell over the Bay of La Paz and the adjacent Gulf. The collision of the opposing sea-breeze fronts over the narrow peninsula drives convection that is relatively weak due to the reduced heat source and only appears to produce precipitation sporadically. The spatial structure of the sea-breeze fronts over the Bay of La Paz region is complex due to shoreline curvature and nearby topographic features. A comparison of the numerical results with available meteorological near-surface observations indicates that the modelling methodology adequately reproduced the observed features of the seasonal variability of the local planetary boundary-layer diurnal wind cycle and confirms that the low-level atmospheric circulation over the Bay of La Paz is dominated by kinetic energy in the diurnal band. The strongest (weakest) diurnal flows occur during the summer (winter) in response to the seasonally varying magnitudes of the daily land–sea thermal contrast and the regional subtropical Pacific Ocean–Gulf of California sea-surface temperature difference.  相似文献