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Solar System Research - Within the framework of Tsallis nonextensive statistics, the criteria for the Jeans gravitational instability are derived for a self-gravitating protoplanetary disk, whose... 相似文献
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Sergey N. Vorobyev Oleg S. Pokrovsky Larisa G. Kolesnichenko Rinat M. Manasypov Liudmila S. Shirokova Jan Karlsson Sergey N. Kirpotin 《水文研究》2019,33(11):1579-1594
Detailed knowledge of the flood period of Arctic rivers remains one of the few factors impeding rigorous prediction of the effect of climate change on carbon and related element fluxes from the land to the Arctic Ocean. In order to test the temporal and spatial variability of element concentration in the Ob River (western Siberia) water during flood period and to quantify the contribution of spring flood period to the annual element export, we sampled the main channel year round in 2014–2017 for dissolved C, major, and trace element concentrations. We revealed high stability (approximately ≤10% relative variation) of dissolved C, major, and trace element concentrations in the Ob River during spring flood period over a 1‐km section of the river channel and over 3 days continuous monitoring (3‐hr frequency). We identified two groups of elements with contrasting relationship to discharge: (a) DIC and soluble elements (Cl, SO4, Li, B, Na, Mg, Ca, P, V, Cr, Mn, As, Rb, Sr, Mo, Ba, W, and U) negatively correlated (p < 0.05) with discharge and exhibited minimal concentrations during spring flood and autumn high flow and (b) DOC and particle‐reactive elements (Al, Fe, Ti, Y, Zr, Nb, Cs, REEs, Hf, Tl, Pb, and Th), some nutrients (K), and metalloids (Ge, Sb, and Te), positively correlated (p < 0.05) with discharge and showed the highest concentrations during spring flood. We attribute the decreased concentration of soluble elements with discharge to dilution by groundwater feeding and increased concentration of DOC and particle‐reactive metals with discharge to leaching from surface soil, plant litter, and suspended particles. Overall, the present study provides first‐order assessment of fluxes of major and trace elements in the middle course of the Ob River, reveals their high temporal and spatial stability, and characterizes the mechanism of river water chemical composition acquisition. 相似文献
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V. G. Trifonov E. A. Shalaeva L. Kh. Saakyan D. M. Bachmanov V. A. Lebedev Ya. I. Trikhunkov A. N. Simakova A. V. Avagyan A. S. Tesakov P. D. Frolov V. P. Lyubin E. V. Belyaeva A. V. Latyshev D. V. Ozherelyev A. A. Kolesnichenko 《Geotectonics》2017,51(5):499-519
New data on the stratigraphy, faults, and formation history of lower to middle Pleistocene rocks in Late Cenozoic basins of northwestern Armenia are presented. It has been established that the low-mountain topography created by tectonic movements and volcanic activity existed in the region by the onset of the Pleistocene. The manifestations of two geodynamic structure-forming factors became clear in Pleistocene: (i) collisional interaction of plates due to near-meridional compression and (ii) deep tectogenesis and magma formation expressed in the distribution of vertical movements and volcanism. The general uplift of the territory, which was also related to deep processes, reached 350–500 m in basins and 600–800 m in mountain ranges over the last 0.5 Ma. The early Pleistocene (~1.8 Ma) low- and medium-mountain topography has been reconstructed by subtraction of the latest deformations and uplift of the territory. Ancient human ancestry appeared at that time. 相似文献
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M. L. Kopp V. E. Verzhbitsky A. A. Kolesnichenko T. Yu. Tveritinova N. Yu. Vasil’ev V. A. Korchemagin A. O. Mostryukov A. I. Ioffe 《Geotectonics》2014,48(4):273-291
This paper presents the first cartographic reconstruction of the recent stress field for the southeastern Russian Plate and the southern Urals based on computer analysis of the extensive body of measurements of mesostructural kinematic markers. Comparison of this reconstruction with macro- and mesostructural data on the dynamics of recent dislocations at the platform leads to the following conclusions: (1) spatial variations of the stress field reflect the pressure on the platform’s lithosphere from the Caucasus-Kopet Dagh collisional orogen and the intraplate linear rise of the recent Urals, presumably related to the Central Asian collision zone; (2) when passing through the heterogeneous crust of the platform, the collision stresses were distorted: in the vertical section, compression decreased upward (especially in strike-slip-stress regime) and even gave way to extension above uplifting hanging wall of thrust faults and crests of swells; in plan view, compression (including in the strike-slip-stress regime) increased at basement uplifts; on the contrary, extension increased near syneclises, as well as lateral squeezing directed here along strike-slip faults; (3) reconstructions based on data variable in scale and type (results of macro- and mesostructural observations processed by differing statistical means with leading use of computer programs) do not contradict but supplement one another. Taken together, they represent the complete pattern of the recent stress state; (4) our results can be used for applied purposes to introduce clarity into the kinematics of the known faults, especially for revealing strike-slip offsets and how the intraplate earthquakes relate to faults and flexures of a certain kinematics. In general, they indicate that tectonodynamic analysis is promising for solving regional tectonic problems. 相似文献
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M. Ya. Marov A. V. Kolesnichenko K. K. Manuilov V. P. Osipov 《Solar System Research》2010,44(5):393-402
The methodology and the main features of the Thermophob experiment developed for the direct analysis of the thermophysical
properties of the surface of the Martian satellite Phobos from the Phobos-Grunt lander are considered. The methodical and engineering aspects of the measurements are discussed, and the design of the instrument
and the potential of the interpretation of the measurement results with accounting for the theoretical estimates and the data
of the laboratory tests are discussed. 相似文献
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A. V. Kolesnichenko 《Solar System Research》2010,44(4):334-347
This paper considers the modern approach to the thermodynamic modeling of developed turbulent flows of a compressible fluid
based on the systematic application of the formalism of extended irreversible thermodynamics (EIT) that goes beyond the local
equilibrium hypothesis, which is an inseparable attribute of classical nonequilibrium thermodynamics (CNT). In addition to
the classical thermodynamic variables, EIT introduces new state parameters—dissipative flows and the means to obtain the respective
evolutionary equations consistent with the second law of thermodynamics. The paper presents a detailed discussion of a number
of physical and mathematical postulates and assumptions used to build a thermodynamic model of turbulence. A turbulized liquid
is treated as an indiscrete continuum consisting of two thermodynamic sub-systems: an averaged motion subsystem and a turbulent
chaos subsystem, where turbulent chaos is understood as a conglomerate of small-scale vortex bodies. Under the above formalism,
this representation enables the construction of new models of continual mechanics to derive cause-and-effect differential
equations for turbulent heat and impulse transfer, which describe, together with the averaged conservations laws, turbulent
flows with transverse shear. Unlike gradient (noncausal) relationships for turbulent flows, these differential equations can
be used to investigate both hereditary phenomena, i.e., phenomena with history or memory, and nonlocal and nonlinear effects.
Thus, within EIT, the second-order turbulence models underlying the so-called invariant modeling of developed turbulence get
a thermodynamic explanation. Since shear turbulent flows are widespread in nature, one can expect the given modification of
the earlier developed thermodynamic approach to developed turbulence modeling (see Kolesnichenko, 1980; 1998; 2002–2004; Kolesnichenko
and Marov, 1985; Kolesnichenko and Marov, 2009) to be used in research on a broad class of dissipative phenomena in various
astro- and geophysical applications. In particular, a major application of the proposed approach is the reconstruction of
the processes in the preplanetary circumsolar disk, which might help solve the fundamental problems of stellar-planetary cosmogony. 相似文献
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The periodicity, dynamics, and kinematics of the insufficiently studied Cenozoic (Alpine) movements in the Donets Fold Edifice
and its framework are considered. The synthesis of the available data on the Donets Basin (Donbass) and the adjacent territories
of the Russian and Scythian plates shows that the Early Alpine, or Laramian epoch of deformation in the Paleocene and the
Late Alpine, or recent epoch of deformation in the early Miocene-Quaternary were divided by a tectonic pause in the Eocene
and Oligocene. Judging from macrostructural pattern and results of mesotectonic observations, both epochs were characterized
by meridional compression and latitudinal extension but substantially differed in the scope of deformation and the style of
structure. The former developed to the west of the Donbass and resulted in compression of diapirs in the Dnieper-Donets Aulacogen,
whereas the latter created the recent Donets-Azov Swell and brought about right-lateral strike-slip faulting along the North
Donets and Persianovsky faults bounding the Donbass. The recent movements and related deformation in the eastern area, including
the substantial role of right-lateral strike-slip faulting, more intense deformation in comparison with Laramian movements,
and the mobilization of the basement not only in the Dnieper-Donets Aulacogen but also far beyond its limits allow us to connect
these phenomena with coeval orogeny in the Greater Caucasus. The nature of the moderate Laramian movements confined to the
axial zone of the aulacogen is more questionable; however, it can be explained in terms of within-plate reactivation of western
and part of eastern Europe as a response to plate collision in the Alps, Dinarides, and Pontides in combination with coeval
onset of spreading in the North Atlantic and Arctic, which created counter-pressure from the north. The eventual result of
both processes was inversion and compression of some European aulacogens, including the Dnieper-Donets Aulacogen. 相似文献
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Unlike classical studies in which the gravitational instability criterion for astrophysical disks is derived in the framework of traditional kinetics or hydrodynamics, we propose to consider the totality of fluffy dust clusters of various astrophysical objects, in particular, protoplanetary subdisks, as a special type of continuous medium, i.e., fractal medium for which there are points and areas not filled with its components. Within the deformed Tsallis statistics formalism, which is intended to describe the behavior of anomalous systems with strong gravitational interaction and fractal nature of phase space, we derive, on the basis of the modified kinetic equation (with the collision integral in the Bhatnagar-Gross-Krook form), the generalized hydrodynamic Euler equations for a medium with the fractal mass dimension. Considering the linearization of the q-hydrodynamics equations, we investigate the instability of an infinitely homogeneous medium to obtain a simplified version of the modified gravitational instability criterion for an astrophysical disk with fractal structure. 相似文献
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This paper considers, in the context of modeling the evolution of a protoplanetary cloud, the hydrodynamic aspects of the theory of concurrent processes of mass transfer and coagulation in a two-phase medium in the presence of shear turbulence in a differentially rotating gas–dust disk and of polydisperse solid particles suspended in a carrying flow of solid particles. The defining relations are derived for diffuse fluxes of particles of different sizes in the equations of turbulent diffusion in the gravitational field, which describe the convective transfer, turbulent mixing, and sedimentation of disperse dust grains onto the central plane of the disk, as well as their coagulation growth. A semiempirical method is developed for calculating the coefficients of turbulent viscosity and turbulent diffusion for particles of different kinds. This method takes into account the inverse effects of dust transfer on the turbulence evolution in the disk and the inertial differences between disperse solid particles. To solve rigorously the problem of the mutual influence of the turbulent mixing and coagulation kinetics in forming the gas–dust subdisk, the possible mechanisms of gravitational, turbulent, and electric coagulation in a protoplanetary disk are explored and the parametric method of moments for solving the Smoluchowski integro-differential coagulation equation for the particles' size distribution function is considered. This method takes into account the fact that this distribution belongs to a definite parametric class of distributions. 相似文献