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71.
72.
The Turonian-Coniacian carbonate sequence outcropping in the Melovoe-Nizhnyaya Bannovka area (Saratov region) is described
along with the characterization of its geomorphologic, sedimentologic, and sequence-stratigraphy aspects and accompanying
isopach maps. A sedimentation model is proposed for explaining factors responsible for variations in the thickness of the
sequence. 相似文献
73.
74.
Shchapova Yu. V. Votyakov S. L. Ivanov V. Yu. Pustovarov V. A. 《Geology of Ore Deposits》2010,52(7):679-687
The luminescence properties of two single zircon crystals from kimberlite of Yakutia have been studied, excited by the DORIS
HASYLAB synchrotron, Germany, within energy range from the visible to the soft X-ray region (5–25, 50–200, and 500–620 eV)
at temperatures of 300 and 10 K. The luminescence spectra in the range of 2.5 to 6.0 eV and excitation spectra of the main
bands have been examined, the physical nature of the luminescence centers has been discussed, and the luminescence properties
of a crystal containing growth (radiation) structural defects and a crystal with the same impurities but annealed in air at
1200°C are compared. The zoned structure of the mineral has been considered and the value of the energy gap (E
g) in the mineral has been estimated at 7.1 eV. Two groups of luminescence bands caused by impurities of intrinsic (growth,
radiation) nature (E
max = 2.1, 2.7–2.8, and 3.2–3.3 eV) and matrix luminescence (E
max = 4.4−4.7 and 5.4 eV) probably with the participation of excitons were distinguished on the basis of selective excitation
of zircon with different synchrotron energies relative to the gap value (E
excit < E
g, E
excit ∼ E
g, and E
excit ≫ E
g). The short-lived component with a response time of 4 ns has been revealed in the afterglow of zircon in the region of 5.4
eV. 相似文献
75.
I. Yu. Melekestseva V. A. Kotlyarov P. V. Khvorov V. N. Ivanov V. E. Beltenev I. G. Dobretsova 《Geology of Ore Deposits》2010,52(8):800-810
The porous fine-grained to microcrystalline copper-zinc ore of the Semenov-2 hydrothermal field, a site in the Semenov hydrothermal
cluster discovered in 2007 (13°31′N, MAR), is anomalously enriched in Au (22–188 ppm) and Ag (127–1787 ppm). Chalcopyrite,
isocubanite, würtzite, and opal are major minerals; sphalerite, marcasite, pyrite, and covellite are auxiliary; and galena,
pyrrhotite, native gold, silver telluride, barite, and aragonite are sporadic. Gold containing 0.31 to 23.07 wt % Ag occurs
as up to 9-μm-sized subhedral, dendritelike, and elongated grains mostly hosted in opal and less frequently in sphalerite
and in pores within isocubanite-chalcopyrite aggregate. An elongated grain (2 × 4 μm in size) of the Ag-Te phase was found
in a pore. So far only basalts have been dredged from the Semenov-2 field, but anomalous gold and silver concentrations suggest
the influence of ultramafic rocks; the latter were found 1.5 km westward, in the Semenov-1 hydrothermal field. Mineral assemblage
and morphology of gold particles indicate its primary origin in contrast to the hydrothermal fields hosted in basalts, where
gold is a product of remobilization. Zonal gold grains, found on oceanic floor for the first time, are characterized by low
Ag content in the cores and high Ag content in the outer rims, reflecting variation in formation conditions. 相似文献
76.
Zavyalov A. D. Morozov A. N. Aleshin I. M. Ivanov S. D. Kholodkov K. I. Pavlenko V. A. 《Izvestiya Atmospheric and Oceanic Physics》2022,58(8):908-924
Izvestiya, Atmospheric and Oceanic Physics - This paper is the first in a series of studies generalizing the Map of Expected Earthquakes (MEE) medium-term earthquake forecast method and analyzing... 相似文献
77.
In this model, we apply a nonlinear three-dimensional sigma-coordinate model to study the waves and currents in the Sea of Azov generated by different fields of wind forcing: a constant wind, a quickly varying real wind obtained using the data of reanalysis applying the SKIRON model, and the wind resulting from their combined forcing. This mathematical model was also applied to study the transformation of the passive admixture appearing under the influence of wind fields in the Sea of Azov considered here. We compared the results of numerical calculations with the field data obtained under the wind forcing at a number of hydrological stations. We found the regularities of the water transport driven by onshore and offshore winds, the velocities of the currents, and the characteristics of the evolution of polluted regions at different depths as functions of the nonstationary wind intensity and the velocities of the stationary currents. 相似文献
78.
A. P. Ivanov I. L. Katsev A. S. Prikhach E. P. Zege 《Izvestiya Atmospheric and Oceanic Physics》2014,50(2):188-195
Methods and algorithms for the retrieval of optical characteristics of the aerosol atmosphere and underlying surface by data from a multispectral satellite sensor (MSSS) are described. A procedure for the joint processing of MSSS and multizonal imaging system (MZIS) data is proposed and described with the aim of retrieving the albedo of the Earth’s surface with a high spatial resolution. In this case the spectral optical characteristics of the aerosol atmosphere are retrieved by MSSS data in the visible range of 400–700 nm. According to these results, transmission functions of the atmosphere in MZIS spectral channels are calculated and an atmospheric correction of MZIS data is performed. The accuracy of determining the albedo of the underlying surface in spectral channels of MZIS with high-spatial-resolution is estimated. 相似文献
79.
Vladislav V. Zelenov Elena V. Aparina Andrey V. Ivanov 《Journal of Atmospheric Chemistry》2014,71(1):33-53
Using a coated-insert flow tube reactor coupled to a low-energy electron-impact mass spectrometer with molecular beam sampling, we studied uptake of NO3 by sea salt at room temperature and [NO3]?=?8?1011???4?1013 molecule cm?3. The radical uptake coefficient γ(t) is time dependent: its initial value (γ ini) decreases exponentially with the characteristic time (τ) to its steady-state value (γ ss) at given [NO3]. The parameters γ ini, γ ss and τ depend on [NO3], whereas γ ss is water vapor independent at [H2O]?=?8?1012???1.6?1015 molecule cm?3 and RH ≤ 0.5 %. HCl and NO2 are uptake products detected in the gas phase. We used these findings to estimate γ values under tropospheric conditions for urban coastal and remote marine environments: at high NO3 (~90 ppt), the time dependence becomes important, and the γ value averaged over the aerosol lifetime is 4?10?3; at low NO3 (~1 ppt), the radical uptake is time independent and proceeds faster with γ ini?=?8?10?3 相似文献
80.
M. V. Ivanov 《Russian Journal of Pacific Geology》2014,8(4):288-299
The analysis of the concentrations and distribution of mercury in bottom sediments of marginal seas in northeastern Asia revealed that its maximum contents are characteristic of areas with an active geodynamic regime and some areas of the Amur Bay in the Sea of Japan subjected to anthropogenic impact. The geochemical associations of mercury with other chemical elements and its background concentrations in bottom sediments of these sea basins are defined. 相似文献