Groundwater Hydrochemistry of Suprapermafrost–Intrapermafrost Flow in Their Discharge Areas in Central Yakutia     

Pavlova  N. A.  Shepelev  V. V.  Galanin  A. A.  Efremov  V. S. 《Water Resources》2020,47(4):581-590

Water Resources - The results of long-term studies of a group of aufeis-forming Buluus groundwater sources are given. A stow, which has been formed by the spring, contains the drainage area of the...  相似文献   

SDO Data Artifacts and Anticorrelation of Oscillations in the Sunspot Magnetic Field and Umbral Area     

Korolkova  O. A.  Efremov  V. I. 《Geomagnetism and Aeronomy》2019,59(7):827-831

Geomagnetism and Aeronomy - The paper considers a special class of artifacts that appears in the useful signal when the source moves along a discrete matrix of the receiver. A parasitic component...  相似文献   

Field studies of the motion of sediments in the coastal zone of the sea     

V. Z. Dykman  O. I. Efremov  E. V. Man’kovskaya 《Physical Oceanography》2011,20(5):379-395

We present the results of measurements carried out with the help of the “Donnaya Stantsiya” complex of equipment in the coastal zone of the Crimean shelf near Evpatoriya and near the southeast end of the Kosa Tuzla Island. For the same intensity of winds in these regions, the intensities of waves and turbulence in the coastal zone near Evpatoriya are much higher and, hence, the fluxes of suspended sediments are more intense. The accumulated data are intended for the correction of the kinetic model used for the evaluation of the characteristics of the field of suspended sediments in the shallow-water areas.  相似文献   

Superassociations and Stellar Complexes in Galaxies     

Yu. N. Efremov 《Astrophysics》2004,47(2):273-286

The basic characteristics of stellar complexes and superassociations, as well as the differences between these kinds of gigantic groups of young stars, are discussed. The main difference is that superassociations are the result of induced (triggered) star formation, while the stars and clusters in stellar complexes develop as a result of the spontaneous processes typical of galactic gaseous disks.  相似文献   

Filter apparatus for studying the sun's short-wave emission     

A.I. Efremov  A.L. Podmoshenskii  M.A. Ivanov  V.N. Nikiforov  O.N. Efimov 《Planetary and Space Science》1962,9(12):987-992

  相似文献   

The spectrum of umbral oscillations of the Scheuer-Thomas sunspot model     

V. I. Zhukov  V. I. Efremov  B. T. Nuraliev 《Solar physics》1987,109(2):403-404

Proper periods are calculated for oscillations of an isothermal gaseous layer with a homogeneous vertical magnetic field, limited by two rigid horizontal boundaries. The obtained results are in good agreement with the observed umbral oscillations in a sunspot.  相似文献   

The nature of peculiar stellar complexes     

Yu. N. Efremov 《Astronomy Reports》2002,46(10):791-804

The nature of stellar complexes with peculiar populations and morphologies is investigated. The existence in the LMC of complexes made up of isolated stars, on the one hand, and consisting exclusively of clusters, on the other hand, could be due to different turbulence patterns in the initial gaseous medium. Arc-shaped stellar complexes are unlikely to be the result of star formation in a gaseous shell swept up by a central source of pressure, and instead probably reflect the shape of a bow shock that develops when a sufficiently dense cloud is subject to dynamical pressure. A peculiar arc-shaped complex in NGC 6946, which contains a young, massive cluster, may be the result of an oblique infall of a high-velocity cloud onto a region of the gaseous disk of the Galaxy with a strong, regular magnetic field; the properties of this complex can be explained as the result of a collision of the resulting shocks. The arc-shaped complexes in the LMC were also probably produced by high-velocity clouds moving obliquely through the more tenuous gas of the LMC disk. A similar complex in NGC 300 may owe its origin to the effect produced on a dense cloud by the shock from an extremely powerful external explosion, whose stellar remnant may have survived as an X-ray source now located along the line of symmetry of the arc of the complex. The rareness of such structures can be explained by the narrow range of conditions under which they can develop.  相似文献   

Long-period oscillations of the line-of-sight velocities in and near sunspots at various levels in the photosphere     

V. I. Efremov  L. D. Parfinenko  A. A. Solov’ev 《Astronomy Reports》2007,51(5):401-410

New observational data on long-period oscillations of the line-of-sight velocities detected via the Doppler shifts of spectral lines observed at various heights in and near sunspots are presented. The sunspots and nearby magnetic elements oscillate with periods ranging from 40 to 80 min. The oscillations in the line-of-sight velocities persist over the entire observation session (up to four hours). These results support theoretical models in which this phenomenon represents natural long-period oscillations (vertical-radial displacements) of entire magnetic elements (sunspots, pores, and magnetic knots) about some stable equilibrium positions.  相似文献   

Long-period oscillations of sunspots according to simultaneous ground-based and space observations     

V. E. Abramov-Maximov  V. I. Efremov  L. D. Parfinenko  A. A. Solov’ev  K. Shibasaki 《Geomagnetism and Aeronomy》2013,53(7):909-912

An analysis of oscillatory processes with periods not shorter than several tens of minutes in three isolated sunspots, which were observed during identical periods in the optical and radio bands, is illustrated. SDO/HMI magnetograms at an interval of 45 s and radio maps at a wavelength of 1.76 cm, obtained using a Nobeyama radioheliograph (NoRH), have been used. The time profiles, which were constructed based on the NoRH and SDO/HMI data, indicate that the oscillations of the radioemission correlate with those of the sunspot magnetic field. The wavelet spectra and cross-wavelet transform reveal common oscillation periods of 30–40, 70–100, and 150–200 min. The identical oscillation periods, found using fundamentally different methods from ground-based and space observations, confirm the solar nature of these oscillations, which can be interpreted as oscillations of a sunspot as a whole.  相似文献   

Rb/Sr isotope studies of Cretaceous granitoids in the central Chukchi region: correctness of geochronological interpretation of results     

S.V. Efremov  S.I. Dril&#x;  G.P. Sandimirova  I.V. Sandimirov 《Russian Geology and Geophysics》2010,51(12):1257-1261

The validity of the Rb/Sr isotopic ages of Cretaceous granitoid complex in the central Chukchi region has been verified. The performed studies showed that the Rb/Sr isotopic ages of late-orogenic granitoids are not reliable. Their variation can be explained in terms of the mixing of primary mantle magmas with continental-crust matter. Most probably, the variation is due to the constant compositions of mixing components and their proportions.  相似文献