Anomalous variations in the ionospheric <Emphasis Type="Italic">F</Emphasis><Subscript>2</Subscript>-layer structure at geomagnetic midlatitudes of the Southern and Northern hemispheres at the transition from summer to winter conditions under low solar activity     

A. V. Pavlov  N. M. Pavlova  S. F. Makarenko  V. N. Shubin 《Geomagnetism and Aeronomy》2008,48(3):327-336

The structure and dynamics of the ionosphere and plasmasphere at low solar activity under quiet geomagnetic conditions on January 15–17, 1985, and July 10–13, 1986, over Millstone Hill station and Argentine Islands ionosonde, the locations of which are approximately magnetically conjugate, have been theoretically calculated. The detected correction of the model input parameters makes it possible to coordinate the measured and calculated anomalous variations in the electron density NmF2 at the height hmF2 of the ionospheric F2 layer over Argentine Islands ionosonde as well as the calculated and measured values of NmF2 and electron temperature at the hmF2 height over Millstone Hill station. It has been shown that vibrationally excited N₂ and O₂ molecules almost do not influence the formation of the winter anomaly under the conditions of low solar activity. A difference between the influence of electronically excited O⁺ on N _e ions under winter and summer conditions forms not more than 11% of the N _e winter anomaly event in the F ₂ layer and topside ionosphere. The model without electronically excited O⁺ ions reduces the duration of the N _e winter anomaly event. It has been shown that the seasonal variations in the composition of the neutral atmosphere form mainly the NmF2 winter anomaly event over the Millstone Hill radar at low solar activity.  相似文献   

Biomineralization of platinum by microorganisms     

L. M. Pavlova  V. I. Radomskaya  L. P. Shumilova  A. M. Ionov  P. Sorokin 《Doklady Earth Sciences》2017,473(2):457-460

The mechanism of platinum biomineralization by microscopic fungi is displayed based on data of electron microscopy, infrared and X-ray photoelectronic spectroscopy. It was suggested the platinum sorption process by microscopic fungi has some stages. The initial interaction is carried out by the mechanisms of physical and chemical sorption. Hereafter the reduction process of adsorbed platinum ions up to zero state is performed, probably, for account of organic compounds, which are produced by fungi biomass as metabolism result, and the process terminates by nulvalent particles aggregating up to nanosize forms. Obtained data on the platinum biomineralization extends the concept concerning the character of forming platinum nanoparticles in carbonous paleobasin.  相似文献   

Natural-climatic changes in the Yana-Indigirka lowland during the terminal Kargino time and habitat of late Paleolithic man in northern part of East Siberia     

V. V. Pitul&#;ko  E. Yu. Pavlova  S. A. Kuz&#;mina  P. A. Nikol&#;skii  A. E. Basilyan  V. E. Tumskoi  M. A. Anisimov 《Doklady Earth Sciences》2007,417(8):1256-1260

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Oil in the lake of world heritage     

O. M. Khlystov  A. G. Gorshkov  A. V. Egorov  T. I. Zemskaya  N. G. Granin  G. V. Kalmychkov  S. S. Vorob&#;eva  O. N. Pavlova  M. A. Yakup  M. M. Makarov  V. I. Moskvin  M. A. Grachev 《Doklady Earth Sciences》2007,415(5):682-685

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Diagenesis of Organic Matter in the Top Layer of the Sediments of the Peter the Great Bay in Hypoxia Locations     

P. Ya. Tishchenko  Yu. A. Barabanshchikov  T. I. Volkova  A. A. Marjash  T. A. Mikhailik  G. Yu. Pavlova  S. G. Sagalaev  P. P. Tishchenko  N. D. Khodorenko  E. M. Shkirnikova  M. G. Shvetsova 《Geochemistry International》2018,56(2):171-181

During Cruise 62nd of the R/V “Professor Gagarinsky” in September, 2014, the carbonate system of sediments and contents of nutrients and organic carbon in pore water were studied in two geochemical stations located in hypoxia areas in the Peter the Great Bay. It was established that the concentrations of silica, phosphorus, and ammonium increase by 5, 10, and 20 times, respectively, with sediment depth to 70–80 cm. The alkalinity, dissolved inorganic carbon, and the partial pressure of carbon dioxide significantly increase with depth, while рН value and organic matter (ОM) decrease. Changes in the chemical composition of pore water with sediment depth (0–80 cm) are caused by anaerobic microbial degradation of OM, concentration of which in the top sediment layer is 2–3%. The degradation products of OM in the bottom waters of bay and pore waters of bottom sediments indicate that its main sources are diatoms. During hypoxia, the oxygen demand rate by sediment surface near Furugelm Island is estimated to be 5 mmol/(m² day). A combination of such factors as downwelling circulation, the absence of photosynthetically active radiation, and the high oxygen demand rate at the water/sediment interface provides hypoxia formation in the depressions of the Peter the Great Bay bottom topography.  相似文献   

Distribution of organic matter in rocks of the Bazhenov horizon (West Siberia)     

A.E. Kontorovich  E.V. Ponomareva  L.M. Burshtein  V.N. Glinskikh  N.S. Kim  E.A. Kostyreva  M.A. Pavlova  A.P. Rodchenko  P.A. Yan 《Russian Geology and Geophysics》2018,59(3):285-298

We studied the distribution of organic carbon in rocks of the Bazhenov horizon, a unique object of predominantly biogenic sedimentation in the West Siberian sedimentary basin. The contents of organic carbon in the rocks were determined using the data from 4094 core analyses and core-log relationships derived from 48,500 radioactive- and electrical-log measurements. For the Bazhenov and Tutleima Formations, both approaches gave the same results. The average content of organic carbon in the rocks is 7.7%. These data were used to compile a detailed map of the distribution of organic carbon contents in sedimentary rocks of the basin. It was shown that the average organic carbon content in the rocks increases from 2-4% on the periphery of the basin to 10-12% in its central, deepest part. The distribution of C_org values in the basin is highly asymmetric. The highest C_org values are observed in the southwestern part of the basin interior, where beds with > 10% C_org range in thickness from 5 to 12-15 m. In sections, the highest C_org values are observed in their middle and upper parts, composed predominantly of silicites and mixtites enriched in biogenic silica.  相似文献   

The first mineralogical,geochemical, and isotope-geochronological data on neogene alkaline basaltic volcanism of the Heven Zalu Uriin Sar’dag Plateau (Northern Mongolia)     

A. B. Perepelov  S. S. Tsypukova  E. I. Demonterova  L. A. Pavlova  A. V. Travin  D. Bat-Ulzii 《Doklady Earth Sciences》2010,434(1):1230-1234

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