A. Omstedt: Guide to process based modeling of lakes and coastal seas     

Sergei Katsev 《Journal of Paleolimnology》2013,49(4):703-705

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Non-Fickian mass transport in fractured porous media     

Sergei A. Fomin  Vladimir A. ChugunovToshiyuki Hashida 《Advances in water resources》2011,34(2):205-214

The paper provides an introduction to fundamental concepts of mathematical modeling of mass transport in fractured porous heterogeneous rocks. Keeping aside many important factors that can affect mass transport in subsurface, our main concern is the multi-scale character of the rock formation, which is constituted by porous domains dissected by the network of fractures. Taking into account the well-documented fact that porous rocks can be considered as a fractal medium and assuming that sizes of pores vary significantly (i.e. have different characteristic scales), the fractional-order differential equations that model the anomalous diffusive mass transport in such type of domains are derived and justified analytically. Analytical solutions of some particular problems of anomalous diffusion in the fractal media of various geometries are obtained. Extending this approach to more complex situation when diffusion is accompanied by advection, solute transport in a fractured porous medium is modeled by the advection-dispersion equation with fractional time derivative. In the case of confined fractured porous aquifer, accounting for anomalous non-Fickian diffusion in the surrounding rock mass, the adopted approach leads to introduction of an additional fractional time derivative in the equation for solute transport. The closed-form solutions for concentrations in the aquifer and surrounding rocks are obtained for the arbitrary time-dependent source of contamination located in the inlet of the aquifer. Based on these solutions, different regimes of contamination of the aquifers with different physical properties can be readily modeled and analyzed.  相似文献   

Dust torus formed by particles ejected from a celestial body at an arbitrary point of its elliptic orbit     

Sergei A. Orlov  Konstantin V. Kholshevnikov 《Celestial Mechanics and Dynamical Astronomy》2013,116(1):35-52

Dust comnplexes make one of the components of the Solar System. The surface shape of a typical dust complex consisting of particles ejected by a celestial body is found analytically, under reasonable assumptions (the main one being the smallness of perturbations). Parametric equations of the surface are obtained. The main properties of the surface are established and studied. Singular points are found, and the topological type of the surface as a whole and in the vicinity of the singular points (one conic points and one constriction) is examined.  相似文献   

Nature of the X-ray Source in Supernova Remnant RCW103     

Sergei B. Popov 《Astrophysics and Space Science》2000,274(1-2):285-290

I discuss the nature of the compact X-ray source in the center of the supernova remnant RCW 103. Several models, based on the accretion onto a compact object are briefly discussed. I show that it is more likely that the central X-ray source is an accreting neutron star than an accreting black hole. I also argue that models of a disrupted binary system consisting of an old accreting neutron star and a new one observed as a 69-ms pulsar are most favored. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Reply to comment by F. H. Cornet on 'Large-scale in situ permeability tensor of rocks from induced microseismicity'     

Sergei A. Shapiro  Pascal Audigane  & Jean-Jacques Royer 《Geophysical Journal International》2000,140(2):470-473

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New variable stars from the photographic archive: semi-automated discoveries,attempts at automatic classification and the new field 104 Her     

Sergei V.Antipin  Ignacio Becker  AlexANDer A.Belinski  Darya M.Kolesnikova  Karim Pichara  Nikolay N.Samus  Kirill V.Sokolovsky  Alla V.Zharova  Alexandra M.Zubareva 《天文和天体物理学研究(英文版)》2018,(8)

Using 172 plates taken with the 40-cm astrograph of the Sternberg Astronomical Institute(Lomonosov Moscow University) in 1976–1994 and digitized with a resolution of 2400 dpi, we discovered and studied 275 new variable stars. We present the list of our new variables with all necessary information concerning their brightness variations. As in our earlier studies, the new discoveries show a rather large number of high-amplitude Delta Scuti variables, predicting that many stars of this type remain not detected in the whole sky. We also performed automated classification of the newly discovered variable stars based on the Random Forest algorithm. The results of the automated classification were compared to traditional classification and showed that automated classification was possible even with noisy photographic data. However, further improvement of automated techniques is needed, which is especially important when considering the very large numbers of new discoveries expected from all-sky surveys.  相似文献   

⁴⁰Ar/³⁹Ar dating of Usol'skii sill in the south-eastern Siberian Traps Large Igneous Province: evidence for long-lived magmatism     

Alexei V. Ivanov  Sergei V. Rasskazov  Gennady D. Feoktistov  Huaiyu He  Ariel Boven 《地学学报》2005,17(3):203-208

Main part of the Siberian Traps Large Igneous Province was formed in a short time-span at the Permo-Triassic boundary c. 250 Ma. New ⁴⁰Ar/³⁹Ar dating results for the Usol'skii dolerite sill in south-eastern part of the province indicate its probable emplacement c. 6 Myr after the main Permo-Triassic magmatic phase. Compilation of the published ⁴⁰Ar/³⁹Ar and U-Pb ages implies that basaltic and related magmatism lasted in total as long as 22–26 Myr. Therefore, similar to other large igneous provinces, magmatism of the Siberian Traps combined voluminous short-lived and less prominent long-lived events.  相似文献   

Book review     

David Gubbins  Sergei E. Zharinov  Philip England  Youjiang Wang  Gerardo G. Tango  Richard Barakat  Bruno Lang  Andrzej W. Wernik 《Pure and Applied Geophysics》1990,134(2):313-332

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Low-Ti melts from the southeastern Siberian Traps Large Igneous Province: Evidence for a water-rich mantle source?     

Alexei V. Ivanov  Elena I. Demonterova  Sergei V. Rasskazov  Tatyana A. Yasnygina 《Journal of Earth System Science》2008,117(1):1-21

Siberian Traps Large Igneous Province (STLIP) is one of the most voluminous volcanic provinces on Earth. The dominant erupted rocks are low-Ti basalts, which make up 80% by volume of the classical Noril’sk lava sequence. In the west Siberian basin and Maymecha-Kotuy area, the low-Ti basalts make up about 99% and 50% by volume, respectively. Dolerite sills in the Angara-Taseevskaya Syncline at the southeastern STLIP exhibit trace element patterns and Sr isotope ratios typical of the low-Ti basalts of the Noril’sk sequence. The most Mg-rich (MgO 9.5–11 wt%) and hence least differentiated dolerites are characterized by trace element patterns with Ta-Nb depletion, low Ce/Pb and high Sr/Pr. These trace element features are similar to water-saturated, mantle wedge-derived island arc basalts. These imply an important role of subduction fluid-derived trace elements in the source of melting beneath the Angara-Taseevskaya Syncline and other regions of the STLIP. Less magnesium rocks (MgO 3.8–6.1 wt%) with less prominent Ta-Nb depletion, higher Ce/Pb and lower Sr/Pr could be produced via olivine-plagioclase fractionation of primary high-magnesium melts.  相似文献   

Development of sedimentary basins: differential stretching,phase transitions,shear heating and tectonic pressure          下载免费PDF全文

Ebbe H. Hartz  Sergei Medvedev  Daniel W. Schmid 《Basin Research》2017,29(5):591-604

Classical models of lithosphere thinning predict deep synrift basins covered by wider and thinner post‐rift deposits. However, synextensional uplift and/or erosion of the crust are widely documented in nature (e.g. the Base Cretaceous unconformity of the NE Atlantic), and generally the post‐rift deposits dominate basins fills. Accordingly, several basin models focus on this discrepancy between observations and the classical approach. These models either involve differential thinning, where the mantle thins more than the crust thereby increasing average temperature of the lithosphere, or focus on the effect of metamorphic reactions, showing that such reactions decrease the density of lithospheric rocks. Both approaches result in less synrift subsidence and increased post‐rift subsidence. The synextensional uplift in these two approaches happens only for special cases, that is for a case of initially thin crust, specific mineral assemblage of the lithospheric mantle or extensive differential thinning of the lithosphere. Here, we analyse the effects of shear heating and tectonic underpressure on the evolution of sedimentary basins. In simple 1D models, we test the implications of various mechanisms in regard to uplift, subsidence, density variations and thermal history. Our numerical experiments show that tectonic underpressure during lithospheric thinning combined with pressure‐dependent density is a widely applicable mechanism for synextensional uplift. Mineral phase transitions in the subcrustal lithosphere amplify the effect of underpressure and may result in more than 1 km of synextensional erosion. Additional heat from shear heating, especially combined with mineral phase transitions and differential thinning of the lithosphere, greatly decreases the amount of synrift deposits.  相似文献