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81.
Dmitrii A. Kulik Thomas Wagner Svitlana V. Dmytrieva Georg Kosakowski Ferdinand F. Hingerl Konstantin V. Chudnenko Urs R. Berner 《Computational Geosciences》2013,17(1):1-24
Reactive mass transport (RMT) simulation is a powerful numerical tool to advance our understanding of complex geochemical processes and their feedbacks in relevant subsurface systems. Thermodynamic equilibrium defines the baseline for solubility, chemical kinetics, and RMT in general. Efficient RMT simulations can be based on the operator-splitting approach, where the solver of chemical equilibria is called by the mass transport part for each control volume whose composition, temperature, or pressure has changed. Modeling of complex natural systems requires consideration of multiphase–multicomponent geochemical models that include nonideal solutions (aqueous electrolytes, fluids, gases, solid solutions, and melts). Direct Gibbs energy minimization (GEM) methods have numerous advantages for the realistic geochemical modeling of such fluid–rock systems. Substantial improvements and extensions to the revised GEM interior point method algorithm based on Karpov’s convex programming approach are described, as implemented in the GEMS3K C/C+?+ code, which is also the numerical kernel of GEM-Selektor v.3 package (http://gems.web.psi.ch). GEMS3K is presented in the context of the essential criteria of chemical plausibility, robustness of results, mass balance accuracy, numerical stability, speed, and portability to high-performance computing systems. The stand-alone GEMS3K code can treat very complex chemical systems with many nonideal solution phases accurately. It is fast, delivering chemically plausible and accurate results with the same or better mass balance precision as that of conventional speciation codes. GEMS3K is already used in several coupled RMT codes (e.g., OpenGeoSys-GEMS) capable of high-performance computing. 相似文献
82.
Natural Metrics in the Spaces of Elliptic Orbits 总被引:1,自引:1,他引:0
Konstantin V. Kholshevnikov Nikolay N. Vassiliev 《Celestial Mechanics and Dynamical Astronomy》2004,89(2):119-125
Different natural metrizations by Hölder type on the five dimensional space of Keplerian elliptic orbits are introduced. Certain applications of topological and metrical properties of the space of Keplerian elliptic orbits to several problems of Celestial Mechanics are discussed. 相似文献
83.
Konstantin V. Kholshevnikov 《Celestial Mechanics and Dynamical Astronomy》2008,100(3):169-179
Several metric spaces of Keplerian orbits and a set of their most important subspaces, as well as a factor space (not distinguishing
orbits with the same longitudes of nodes and pericentres) are constructed. Topological and metric properties of them are established.
Simple formulae to calculate the distance are deduced. Applications to a number of problems of Celestial Mechanics are discussed. 相似文献
84.
<正>Leaf beetles Chrysomelidae of Rovno amber,from the Late Eocene,are recorded and described. Chrysomelidae of Rovno amber are represented by three subfamilies:Galerucinae(Alticini),Chrysomelinae,and Eumolpinae.Two new genera and three new species of Alticini:Manobiomorpha Nadein,gen.nov.(type species Manobiomorpha eocenica Nadein,sp.nov.),Psyllototus Nadein,gen.nov.(type species Psyllototus progenitor Nadein,sp.nov.),and Crepidodera decolorata Nadein et Perkovsky,sp.nov.are described.A new chrysomeline genus and species Paleophaedon minutus Nadein gen.nov.et sp.nov.is described.Probable trophic association of Crepidodera decolorata sp.nov.,the taxonomic positions of Manobiomorpha gen.nov.and Psyllototus gen.nov., and the composition of leaf beetle faunas of Middle and Late Eocene of Europe are discussed. 相似文献
85.
Konstantin Latychev Jerry X. Mitrovica Jeroen Tromp Robert Moucha 《Earth and Planetary Science Letters》2005,240(2):322-327
Predictions of present day secular variations in the Earth's long wavelength geopotential driven by glacial isostatic adjustment (GIA) have previously been analyzed to infer the radial profile of mantle viscosity and to constrain ongoing cryospheric mass balance. These predictions have been based on spherically symmetric Earth models. We explore the impact of lateral variations in mantle viscosity using a new finite-volume formulation for computing the response of 3-D Maxwell viscoelastic Earth models. The geometry of the viscosity field is constrained from seismic-to-mographic images of mantle structure, while the amplitude of the lateral viscosity variations is tuned by a free parameter in the modeling. We focus on the zonal J˙? harmonics for degrees ? = 2,…,8 and demonstrate that large-scale lateral viscosity variations of two to three orders of magnitude have a modest, 5-10%, impact on predictions of J˙2. In contrast, predictions of higher degree harmonics show a much greater sensitivity to lateral variation in viscosity structure. We conclude that future analyses of secular trends (for degree ? > 2) estimated from ongoing (GRACE, CHAMP) satellite missions must incorporate GIA predictions based on 3-D viscoelastic Earth models. 相似文献
86.
87.
地球磁场的新模型(英文) 总被引:3,自引:1,他引:2
Konstantin F.Tyapkin 《地学前缘》1999,6(3):75-84
根据地球内核存在有相对于外核的旋转,这里提出一个地球磁场的新模型。在这种场合下,地球磁场的本源就是电流,这种电流是由在地核团相与液相边界上的一对带电层的相对运动产生出来的(Bullen地球模型中的F层)。所提出的模型,是当前最为常见的水磁发电机模型的另一种可供选择的模型。它在能量方面已得到确证。借助该模型,有可能去解释在地表观察到的关于磁场的所有主要特性。该模型的本质,就在于它是维持地球现今磁场与构造运动的统一机制。这种统一性并不是偶然的,可以将其视为所研究现象本质的理论的最大可能性证据。 相似文献
88.
Konstantin W. Scheihing 《水文科学杂志》2020,65(9):1614-1624
ABSTRACT Viguier et al. propose an alternative conceptual model to the one presented by Scheihing to explain observed groundwater table variations at the foothills of the Andean piedmont in the Pampa del Tamarugal. It is demonstrated that the conceptual model of Viguier et al. is deficient. New findings underline that the confined aquifer of the Pampa del Tamarugal exhibits a hydraulic continuity over regional scales as proposed by Scheihing. Accordingly, short hydraulic response times of several months to distant recharge events can be confirmed. It is suggested that the investigated confined aquifer exhibits transient easterly boundary conditions, with easterly boundaries located in the Andean piedmont. These boundaries underly a periodic forcing due to occasional recharge. Several arguments are presented that support that alluvial fan channel recharge is in the investigated cases likely not a significant recharge mechanism (not to be confused with fan apex recharge). 相似文献
89.
The new retail trade and services and their emerging location pattern in St. Petersburg 总被引:1,自引:0,他引:1
The system of factors affecting the spatial distribution of the retail trade and service establishments has changed dramatically since socialist times. The administrative regulation lost its almost complete dominance and turned into one of the market forces. In contrast, the impact of the urban environment under very free market conditions substantially increased. We show the main directions of this influence. Two generalized indicators that we use describe macro trends in the development of the spatial system of retail trade and services. One of them, which we call the urban morphology, is of a concentric effect, another – transportation pattern – adds the sectoral component to the retail trade and services geography. Five systems of spatial attractions differently affect the distribution of different branches. 相似文献
90.
Jeremy S. Johnson Keith D. Gaddis David M. Cairns Charles W. Lafon Konstantin V. Krutovsky 《自然地理学》2016,37(2):93-119
Global change has become a major ecological concern that has the potential to dramatically alter plant distributions and assemblages worldwide. The specific response of plants to global change will depend on their ability to move, evolve, or adjust through phenotypic plasticity. Advances in biogeographic research are on the verge of a giant leap forward if we can take advantage of emerging tools in genetics and genomics. In this review, we appraise how new, post-Sanger, high-throughput sequencing and associated technologies can be used by next generation biogeographers to assess plant responses to global change. First, we briefly review the recent advances in genome sequencing and available approaches of genomic analysis. Secondly, we discuss the three main plant responses to global change: migration, adaptation, and phenotypic plasticity. This review is intended to spark the interest of biogeographers who do not traditionally use genetics but could benefit from including genetic and genomic tools into their research. Our goal is to illustrate that their use can contribute to new perspective and add an additional level of resolution into future biogeographic research. 相似文献