Study of Paschen hydrogen lines and the Ca II infrared triplet in the spectrum of the magnetic star β Cr B. II. Variation of the physical conditions in the atmosphere of the star     

N. S. Polosukhina  A. G. Shcherbakov  V. P. Malanushenko 《Astrophysics》1980,16(3):285-288

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Tables of functions encountered in the theory of resonance radiation transfer. II     

V. V. Ivanov  V. T. Shcherbakov 《Astrophysics》1965,1(1):17-22

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Time correlation of crack formation during impact fracture of rocks     

I.P. Shcherbakov  V.S. Kuksenko  A.E. Chmel 《Russian Geology and Geophysics》2013,54(2):231-236

Samples of marble and granite with different grain sizes were subjected to impact fracturing under laboratory conditions. The acoustic-emission (AE) signals generated by growing cracks were detected at 10-ns intervals. Synchronically, the fractoluminescence (FL) resulting from the breakage of interatomic bonds on the sample surface was recorded. The duration of the intervals between the AE signals was shown to be a power-law function, typical of correlated (self-similar) processes. However, the FL signals did not follow this law, because the duration of free-radical formation is much shorter than the intervals at which they appear when chemical bonds break down. The AE data indicate that new cracks appear more often in materials with a smaller grain size.  相似文献   

Hierarchy of non-extensive mechanical processes in fracturing sea ice     

Alexandre Chmel  Victor Smirnov  Igor Shcherbakov 《Acta Geophysica》2012,60(3):719-739

The fracture-induced oscillations in sea ice were detected by seismographs and seismic tiltmeters established on the Arctic ice pack. Field observations were supplemented with a laboratory experiment. The energy distributions in elastic waves generated during: (i) large-scale ice pack fragmentation over area of about 10⁵ km², (ii) local crack propagation in ice floe, and (iii) laboratory ice crashing were constructed and analyzed using principles of the Tsallis statistics. The energy release regimes at different stages of fracturing were characterized by the parameter of nonextensivity q. In terms of the non-extensive statistical mechanics, q > 1 evidences the correlated (non-extensive) dynamics of the process in nonequilibrium system, q = 1 responds to the additivity of events occurring in equilibrium system, and q < 1 takes place when the energy release is additive and limited by an upper cut-off. All these scenarios were revealed in fracture processes occurring at three hierarchic levels. The variation of the q-value demonstrates high thermodynamic changeability of the fracture process driven by irregular external source. The role of energy conservation in fracturing sea ice is discussed in connection with the observed reversible transitions between extensive and non-extensive modes of fracture.  相似文献   

A direct comparison of the properties of CRM and VRM in the low-temperature oxidation of magnetite   总被引：1，自引：0，他引：1  

A. K. Gapeev  S. K. Gribov  D. J. Dunlop  Ö. Özdemir  V. P. Shcherbakov 《Geophysical Journal International》1991,105(2):407-418

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A study of the variability of the nuclei of galaxies I. The optical variability of 3C 371     

V. I. Pronik  A. G. Shcherbakov 《Astrophysics》1970,6(4):287-290

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Legends of geochemical maps     

Yu.G. Shcherbakov 《Journal of Geochemical Exploration》1984,21(1-3)

Analysis of geochemical maps and their legends permits the proposal of several ways of improving their information content. Firstly, coherent and comparable classification of the objects to be presented must be developed. This classification should be based on strictly defined quantitative geochemical features of the objects; natural associations, anomalous elements, rocks, ore deposits and ore-bearing areas. Secondly, the most informative features of objects must be selected and uniquely displayed with a standard set of symbols. These symbols must be clear, readily understood and logically connected. The third requirement is that maps must be prepared in accordance with the tasks they are intended to deal with, must be optimally scaled, and display only appropriate information.One possible way of meeting the above-mentioned requirements, is proposed in a system of geochemical discrimination and related map presentation methods. The latter involves black hachures for the geological base, and directed colour lines and other features of colour hachures to characterize geochemical associations. Ore deposits may be characterized on the basis of eight most meaningful features encoded in one complex hieroglyph-like symbol constructed from easily understood and memorable components. This type of construction facilitates the computerized analysis of maps and makes them far more useful for prognosis, genetic reconstruction and resource evaluation.  相似文献   

Paleomagnetic studies and estimation of geomagnetic paleointensity at the early/middle Riphean boundary in rocks of the Salmi Formation (North Ladoga area)     

V. V. Shcherbakova  V. E. Pavlov  V. P. Shcherbakov  I. Neronov  V. A. Zemtsov 《Izvestiya Physics of the Solid Earth》2006,42(3):233-243

The territory of Karelia (Baltic Shield) is virtually not represented in the global paleomagnetic database for the Lower Riphean time interval (1650—1350 Ma). As regards the paleointensity H _an, the huge interval 1–2 Ga in length is represented in the global paleointensity database by only eight determinations concentrated in the interval 1–1.35 Ga. The paper presents results of paleomagnetic studies of volcanic and subvolcanic rocks composing the Early Riphean Salmi Formation, which outcrops in the valley of the lower Tulemaioki River in the northern coast area of Lake Ladoga. Results of the study indicate that, in the Early Riphean time, the East European craton was located in the tropical region of the Southern Hemisphere between 15° S and 40° S. The inferred value of H _an is close to the lower boundary of the interval (1.36–11.56) × 10²² A m², encompassing previously published intensity values of the paleofield 1–1.35 Ga; this supports the hypothesis on the existence of long intervals of a lower field in the period in question [Maquoin et al., 2003].  相似文献   

Extremely magnesian olivine in igneous rocks     

P.Yu. Plechov  V.D. Shcherbakov  N.A. Nekrylov 《Russian Geology and Geophysics》2018,59(12):1702-1717

Published data on extremely magnesian olivine (> 96 mol.% forsterite) in igneous rocks were generalized and compared with data of new high-precision electron probe microanalyses of olivine from oxidized lavas of the Tolbachik Volcano (Kamchatka), chromitites from the Ray-Iz deposit (Russia), alkaline ultrabasic lavas from San Venanzo volcanoes (Italy), and skarns from the Kuh-i-Lal deposit (Tajikistan). All the found olivines resulted from low-temperature processes, such as subsurface oxidation, interaction with carbonates, and subsolidus re-equilibration. Low-temperature formation of olivine is reflected in its structure (hematite lamellae and abundance of inclusions of ore minerals) and abnormal contents of minor components (Mn, Ni, and Ca). The Mg content of olivine increases under the influence of postmagmatic processes and can be manifested in different rocks. This gives grounds to refine the genesis of olivine of exotic composition (93-96 mol.% forsterite) in some kimberlites, komatiites, and peridotites.  相似文献   

High-K basaltic trachyandesite xenoliths in pyroclastic deposits from the Bezymianny volcano (Kamchatka)     

V.O. Davydova  P.Yu. Plechov  V.D. Shcherbakov  A.B. Perepelov 《Russian Geology and Geophysics》2018,59(9):1087-1099

Bezymianny is an active andesitic volcano of the Klyuchevskaya group, and its eruptive products are xenolith- and enclave-bearing basaltic andesites and dacites. Here we report the first occurrence of clinopyroxene-plagioclase high-potassium basaltic trachyandesite xenoliths (51.84-53.00 wt.% SiO₂, 0.45-1.95 wt.% K₂O) crystallized in the temperature range 1120-840 °C in products of modern eruptions (2007, 2011, 2012). Basaltic trachyandesite differ systematically in petrologic and geochemical characteristics from all previously studied rocks from the Bezymianny volcano. They correspond to the clinopyroxene-plagioclase porphyry rocks from the foot of the Tolbachik volcanoes.  相似文献