Microzoning of agates as a reflection of their formation dynamics     

V. V. Slastnikov  Yu. O. Punin  A. R. Nesterov 《Geology of Ore Deposits》2008,50(8):782-788

Agates are natural hierarchicalal structural assemblies composed largely of silica minerals: chalcedony, quartz, and quartzine. Microstructural heterogeneities, most typical of those of agate-forming minerals, are characterized by variations in periods of helicoidal twisting of chalcedony and by micrometric rhythmic alternation of zones with a low refractive index within the matrix of normal chalcedony, quartz, and quartzine. A study of the degree of crystallization of chalcedony using the Barsanova-Yakovleva method showed that neither helicoidal twisting nor refractive index zoning brought about any significant disturbance in the chalcedony structure. Helicoidal twisting is a result of the stresses caused by substitution of Si⁴⁺ for Al³⁺ asymmetric with respect to chalcedony crystal. It is suggested that layering by the refractive index developed due to accumulation of small portions of gel consisting of high silica polymers at the front of crystal growth.  相似文献   

First Find of Ga-Bearing Minerals in Ores of Ural Massive Sulfide Deposits     

N. P. Safina  N. R. Ayupova  E. V. Belogub  V. V. Maslennikov  I. A. Blinov  I. G. Zhukov  D. A. Artem’ev 《Doklady Earth Sciences》2018,480(2):746-749

Gallium-containing chlorite, mica, and magnetite (up to 14, 13, and 5–7 wt % of Ga) along with Ga hydroxides (oxyhydroxides?) were found for the first time in massive sulfide deposit in the Urals. The minerals identified within the cement of chalcopyrite–sphalerite breccias of the Shemur copper–zinc–massive sulfide deposit (Northern Urals) are associated with Ga-enriched sphalerite, chalcopyrite, and, less commonly, pyrite (33–364, 67–363, and 4–230 g/t, respectively).  相似文献   

Some questions of the night-time ionospheric E region formation in middle latitudes     

Yu.K. Chasovitin  V.P. Nesterov 《Planetary and Space Science》1976,24(2):139-145

An attempt is made to analyse known experimental data on electron density and ion composition of the night-time ionosphere; the main ideas on the night-time E region ionization source are considered; the role of dynamic processes in the irregular structure formation of the night-time ionospheric E region is discussed.  相似文献   

Problems of artificial intelligence in ecological forecasting     

I. I. Nesterov  Yu. A. Kozhevnikov  V. Yu. Ryadinskii 《Doklady Earth Sciences》2007,415(5):675-676

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Modeling of hydrodynamics and transport processes in the Dnieper–Bug Estuary     

A. A. Nesterov  V. S. Maderich 《Physical Oceanography》2008,18(6):345-356

A numerical model of baroclinic circulation based on the use of a double sigma coordinate system is presented and its application to the simulation of flows and temperature and salinity fields in the Dnieper-Bug Estuary is described. The model reproduces the salinity and temperature fields surveyed in 1998. The results of simulations reveal the existence of a global influence of the relatively narrow and deep ship channel (through which Black-Sea waters can penetrate deep into the estuary) on the transport processes. Translated from Morskoi Gidrofizicheskii Zhurnal, No. 6, pp. 66–77, November–December, 2008.  相似文献   

The ionospheric effects in D-layer and solar proton precipitation zones during the 16 February 1984 event     

M. I. Beloglazov  G. P. Beloglazova  E. V. Vashenyuk  G. A. Petrova  O. I. Shumilov  V. A. Shishaev

I. N. Zabavina

V. I. Nesterov 《Planetary and Space Science》1990,38(12):1479-1486

The results of the geophysical and VLF (10–16 kHz) radio propagation measurements on the net of observatories during the solar proton event on 16 February 1984 are analysed. It is shown that the abnormal ionization region caused by solar protons consisted of two parts. One of them was the direct access zone in the middle and morning side of the polar cap, the other was the precipitation region of the quasi-trapped particles in the mid-day and evening sectors of the auroral zone. The probable profiles of the lower ionosphere electron density are determined from the VLF and satellite data of the energetic spectra at the maximum penetration. It is shown that the effective electron concentration at the height 45 km was close to 10³ cm⁻³.  相似文献   

Ab initio study of the high-pressure behavior of CaSiO3 perovskite     

Daniel Y. Jung  Artem R. Oganov 《Physics and Chemistry of Minerals》2005,32(2):146-153

Using density functional simulations, within the generalized gradient approximation and projector-augmented wave method, we study structures and energetics of CaSiO₃ perovskite in the pressure range of the Earths lower mantle (0–150 GPa). At zero Kelvin temperature the cubic CaSiO₃ perovskite structure is unstable in the whole pressure range, at low pressures the orthorhombic (Pnam) structure is preferred. At 14.2 GPa there is a phase transition to the tetragonal (I4/mcm) phase. The CaIrO₃-type structure is not stable for CaSiO₃. Our results also rule out the possibility of decomposition into oxides.

Daniel Y. JungEmail: Phone: +41-44-6323744Fax: +41-44-6321133

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East Atlantic oscillation of the atmospheric circulation   总被引：1，自引：0，他引：1  

E. S. Nesterov 《Russian Meteorology and Hydrology》2009,34(12):794-800

For the period 1950–2007, the comparison is made between the indices of the East Atlantic and North Atlantic oscillations and between the features of the atmospheric circulation and temperature regime of the Atlantic-European region connected with various combinations of indices. The analysis is made for the factors which have caused long difference in indices in 1996–2007 and for possible causes of anomalously warm winter in Europe in 2006–2007.  相似文献   

Robotic optical telescopes global network MASTER II. Equipment, structure, algorithms     

Victor G. Kornilov  Vladimir M. Lipunov  Evgeny S. Gorbovskoy  Aleksander A. Belinski  Dmitry A. Kuvshinov  Natalia V. Tyurina  Nikolai I. Shatsky  Anatoly V. Sankovich  Aleksander V. Krylov  Pavel V. Balanutsa  Vadim V. Chazov  Artem S. Kuznetsov  Dmitry S. Zimnuhov  Victor A. Senik  Andrey G. Tlatov  Aleksander V. Parkhomenko  Denis V. Dormidontov  Vadim V. Krushinsky  Ivan S. Zalozhnyh  Aleksander A. Popov  Sergey A. Yazev  Nikolai M. Budnev  Kirill I. Ivanov  Evgeny N. Konstantinov  Oleg A. Gress  Oleg V. Chvalaev  Vladimir V. Yurkov  Yury P. Sergienko  Irina P. Kudelina 《Experimental Astronomy》2012,33(1):173-196

Presented paper describes the basic principles and features of the implementation of a robotic network of optical telescopes MASTER, designed to study the prompt (simultaneous with gamma radiation) optical emission of gamma-ray bursts and to perform the sky survey to detect unknown objects and transient phenomena. With joint efforts of Sternberg astronomical institute, High altitude astronomical station of the Pulkovo observatory, Ural state university, Irkutsk state university, Blagoveshchensk pedagogical university, the robotic telescopes MASTER?II near Kislovodsk, Yekaterinburg, Irkutsk and Blagoveshchensk were installed and tested. The network spread over the longitudes is greater than 6?h. A further expansion of the network is considered.  相似文献   

Mineralogical and Geochemical Features of Pyrite Nodules from Sulfide Turbidites in the Talgan Cu-Zn Massive Sulfide Deposit (Southern Urals)     

Ayupova  N. R.  Maslennikov  V. V.  Artem’ev  D. A.  Blinov  I. A. 《Lithology and Mineral Resources》2019,54(6):447-464

Lithology and Mineral Resources - Pyrite nodules were found in thin-layered sulfide ores localized at the flanks of the Talgan Cu-Zn massive sulfide deposit (South Urals) which consists of (1) an...  相似文献