Heliospheric modulation of cosmic rays in solar cycles 19–23     

G. F. Krymsky  P. A. Krivoshapkin  S. K. Gerasimova  P. Yu. Gololobov  V. G. Grigor’ev  S. A. Starodubtsev 《Astronomy Letters》2012,38(9):609-612

The previously developed basic theory of the heliospheric modulation of high-energy cosmic rays is generalized to lower energies. Comparison of the theory with the results of long-term observations of cosmic rays in the stratosphere carried out by the group from the Lebedev Institute of Physics inMoscow andMurmansk shows satisfactory agreement. The cosmic rays are shown to behave quite differently when even and odd solar cycles alternate. Possible causes of the anomalously high cosmic-ray intensity recorded during the last solar activity minimum are discussed.  相似文献   

Comparative hydrochemical assessment of the current state of some water bodies in the Upper Volga     

I. L. Grigor’eva  A. B. Komissarov 《Water Resources》2014,41(3):280-293

Results of field studies of water chemistry in the Upper Volga and some its tributaries in the reach between the Volga source and Tver City, as well as in lakes Sterzh, Vselug, Peno, and Volgo, which are constituent parts of the Verkhnevolzhskoe Reservoir, as well as Selizharovskii Pool of Lake Seliger. The year-to-year and season-to-season dynamics of the hydrochemical regime of the examined water bodies and their variations downstream the Volga under the effect of natural and anthropogenic factors are analyzed.  相似文献   

Study of changes in the physiological state of cyanobacteria caused by weak ultrasonic treatment     

Rumyantsev  V. A.  Grigor’eva  N. Yu.  Chistyakova  L. V. 《Doklady Earth Sciences》2017,475(2):939-941

The effect of weak ultrasonic radiation with a frequency of 60 kHz on photosynthetic activity of living cells of cyanobacteria was studied using microspectrometric methods for the first time. An inhibitory effect on the physiological state of separate cells and the whole culture was demonstrated. A high efficiency of the method developed by the authors of this article for determination of the viability of cyanobacterial cultures in vivo for the purpose of operational environmental monitoring of the results of weak external influences was demonstrated.

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Y Leonis: light curve solution revised and search for photometric variations of the primary minima     

Vlad Turcu  Alexandru Pop  Alexandru Marcu  Dan Moldovan 《Astrophysics and Space Science》2011,331(1):105-113

The interest in the study of the Algol binary system Y Leonis is justified not only by its light curve having a very deep primary minimum, and pulsating character of its primary component, but also by the complex behavior of its O–C curve which is featured by the presence of long and short time scale modulations. Taking into account the previously inferred K spectral type of the secondary component, one may expect that one of the involved periodicities could be related to magnetic cycles of this star. We gave the Wilson-Devinney solution of the eclipse light curve using our observational data obtained during 2009. The long- and short-term photometric variability of Y Leo is approached both through literature data and new CCD data. Even though these data are scarce, they revealed significant variability in the maximum and minimum brightness of this binary system at long time-scale. The nature of the rapid photometric variations during the deepest phase of primary minima can hardly be explained only by weak δ Scuti pulsations of the primary component which is still visible in partial eclipses.  相似文献   

Calculating snow-avalanche return period from tree-ring data     

Flaviu Meseșan  Ionela G. Gavrilă  Olimpiu T. Pop 《Natural Hazards》2018,94(3):1081-1098

The return period is a key element used for snow-avalanche characterization. To calculate the return period, historical data regarding past snow-avalanche activity are required. In mountain areas where past snow avalanches are poorly documented, dendrogeomorphic approaches constitute a reliable method for the reconstruction of past snow avalanches at the temporal scale of living trees. This paper presents an automated method for calculating the snow-avalanche return period using a digital elevation model and the location of the trees disturbed by every reconstructed snow-avalanche occurrence. Unlike the existing method, the method we propose requires neither the calculation of return period for every sampled tree nor the use of interpolation. This new method is based on the determination of spatial extent for every past snow-avalanche occurrence using the upslope area algorithm. The number of past snow-avalanche occurrences is calculated for every pixel of the path. The chronology length is divided by the number of past snow-avalanche occurrences to obtain the return period. In the present paper, both the proposed method and the existing method are applied to calculate the return period for three confined snow-avalanche paths located in Parâng Mountains, part of the Romanian Carpathians. Results are compared and discussed.  相似文献   

Emergence of magnetic flux at the solar surface and the origin of active regions     

V. M. Grigor’ev  L. V. Ermakova  A. I. Khlystova 《Astronomy Reports》2009,53(9):869-878

The evolution of photospheric velocities from the first minutes after the emergence of fresh magnetic flux and the formation of the first pores in active region NOAA 10488 is studied with a time resolution of 1 min and spatial resolution of 4″. The emerging magnetic flux of a major active region is initially a bundle of magnetic-flux loops. Some of these loops erupt through the system of supergranular cells with speeds of up to 1 km/s within 15–25 min and form pores and small spots. It is suggested that the development of a pore represents the emergence of a horizontal magnetic field, which is converted into elements with a strong vertical magnetic field. The region of ascending plasma initially coincides with the zero line of a bipolar magnetic pair. Downflow and upflow regions are related to and appear with the development of pores. During the first hours of their evolution, the trailing-polarity pores exhibit downflows with mean speeds of ∼500 m/s, while upflows with speeds of ∼250 m/s dominate near the leading-polarity pores. It is concluded that a matter flow from the leading to the trailing end is present in the rising loop of a magnetic flux tube, in agreement with well-known numerical-simulation results. The flow that develops in the magnetic-flux tube erupting through the convection zone persists when pores and small spots emerge in the photosphere, at least during the first hours of their evolution.  相似文献   

Observational capabilities of the new medium- and low-resolution spectrograph at the 1.6-m telescope of the Sayan Observatory     

R. A. Burenin  A. L. Amvrosov  M. V. Eselevich  V. M. Grigor’ev  V. A. Aref’ev  V. S. Vorob’ev  A. A. Lutovinov  M. G. Revnivtsev  S. Yu. Sazonov  A. Yu. Tkachenko  G. A. Khorunzhev  A. L. Yaskovich  M. N. Pavlinsky 《Astronomy Letters》2016,42(5):295-306

The capabilities of the new medium- and low-resolution spectrograph installed recently on the 1.6-m AZT-33IK telescope at the Sayan Observatory of the Institute of Solar–Terrestrial Physics to solve the problems of ground-based optical support for the future all-skyX-ray survey of the SRGobservatory are discussed. Results of the test observations of galaxy clusters, active galactic nuclei (AGNs) and quasars, and cataclysmic variables performed immediately after the installation of the spectrograph on the telescope are presented. The results of these observations show that the AZT-33IK telescope equipped with the new medium- and low-resolution spectrograph can provide a substantial fraction of the necessary optical observations in the program of ground-based optical support for the all-sky survey of the SRG observatory.  相似文献   

Elements with high first ionization potential in the new chemical composition of the solar photosphere     

R. B. Teplitskaya  S. A. Grigor’eva 《Geomagnetism and Aeronomy》2011,51(7):873-878

The responses of element abundances to the atmospheric model were statistically analyzed. The summarized 1998 data (1D models) and summarized 2009 data (3D models) were compared. A significant statistical dependence between the response value and the first ionization potential (FIP) of an element was shown. This phenomenon may be caused by the presence of regions in the photosphere where the temperature and magnetic field configuration favor fractionation of neutrals and ions. This, in turn, leads to a certain diffusion process similar to the coronal FIP effect. This type of diffusion is not taken into account in photospheric models. In this case, a new chemical composition of the Sun (3D) with decreased C, N, O and Ne abundances is appropriate only to narrow layers in the lower chromospheres (and possibly in the deep photosphere) and does not require revision of the standard solar model.  相似文献   

Large-scale mapping of neotectonics of platform territories: Case study of Moscow     

S. V. Grigor’eva  V. I. Makarov 《Water Resources》2011,38(7):906-919

The experience in large scale (1: 50000–1: 10000) neotectonic mapping of platform areas is discussed. The structural characteristics of the geological environment (the large size of major structural forms, the extremely low gradients, speeds, and the amplitudes of the most recent and modern tectonic movements, etc.) cause some difficulties for their cartographic representation. A considerable part of legends of neotectonic maps of platforms mostly reflect the geomorphologic component, which is an indirect indicator to the most recent structures and, in essence, such maps are geomorphologic-neotectonic. The large-scale neotectonic mapping requires a comprehensive analysis of the nature and age of all significant elements of earth surface topography and the structure of Cenozoic deposits, the identification of the regularities in their space and time development that can be caused by and attributed to geodynamic factors. Such studies must be based on materials of medium- and small-scale generalizations.  相似文献   

Differentiated Mafic–Ultramafic Intrusions of the Kruglogorsky Type in the Noril’sk Area: Petrology and Ore Potential     

S. F. Sluzhenikin  K. N. Malitch  A. V. Grigor’eva 《Petrology》2018,26(3):280-313

Intrusions of the Kruglogorsky type are an integral part of magmatic formations in the Noril’sk area. The marginal portions of these intrusions are composed of microdolerite, dolerite, and contact gabbrodolerite. The central parts of the intrusions consist of leucogabbro and of olivine-free, olivine-bearing, and olivine gabbro-dolerite. Leucogabbro is a characteristic rock of this type of intrusions and sometimes composes up to half of the thicknesses of the rock units. The rocks with plagioporphyritic textures are widespread. Olivine-free, olivine-bearing, and olivine gabbro-dolerite occur as horizons with indistinct boundaries, which are unevenly distributed over the vertical sections of the lithological units. The olivine is the most magnesian (Fo_89-64) and richest in Ni (up to 0.23 wt % NiO) in the olivine gabbro-dolerite. The clinopyroxene is represented by augite (Fs_12-29). The rock-forming minerals are typically zoned. The Sr isotopic composition of the rocks (calculated for an age of 250 Ma) varies within a considerable range (⁸⁷Sr/⁸⁶Sr = 0.705972–0.708006), due to metasomatic alterations. The variations in the Nd and Sr isotopic composition of the Kruglogorsky intrusion are close to those in rocks of the Noril’sk-type ore-bearing intrusions. The olivine-bearing and taxitic gabbro-dolerite host Pt–Cu–Ni ore mineralization, which are of economic value for disseminated ores of the Talnakh area.  相似文献