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81.
Nikolay V. Ukhov 《冰川冻土》2004,26(Z1):179-183
The rational usage of low productive cryogenic landscapes in the North-Eastern part of Russia is impossible without carrying out special engineering preparation [1]. The preventing from negative that often has destructive cryogenic processes in the area of ice-covered permafrost soils, provided by its thawing into the marginally necessary depth in the whole area. The simplest and the most effective engineering method of faulting as an age-old stock (reserve) of surplus moisture in the form of ice from the upper parts of permafrost soils is the creation of continuous furrows net on the whole surface. This method also raises the fertility of soils, reduces acidity, and raises microbiological activity and the degree of internal structure decaying. Thermophysical calculations and the results of the field study in the experimental firing grounds are the available evidences of this method which raises the thermal stability of cryogenic landscapes while mastering of global climate changes in different parts of cryolithozone. 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.
84.
Multispectral polarimetry as a tool to investigate texture and chemistry of lunar regolith particles
Yuriy Shkuratov Nikolay Opanasenko Yevgen Grynko Viktor Korokhin Gorden Videen Urs Mall 《Icarus》2007,187(2):406-416
We report results of telescope polarimetric imaging of the Moon with a CCD LineScan Camera at large phase angles, near 88°. This allows measurements of the polarization degree with an absolute accuracy better than 0.3% and detection of features with polarization contrast as small as 0.1%. The measurements are carried out in two spectral bands centered near 0.65 and 0.42 μm. We suggest characterizing the lunar regolith with the parameter a(Pmax)A, where Pmax,A, and a are the degree of maximum polarization, albedo, and the parameter describing the linear regression of the correlation Pmax-A. The parameter bears significant information on the particle characteristic size and packing density of the lunar regolith. We also suggest characterizing the lunar regolith with color-ratio images obtained with a polarization filter at large phase angles. We here consider the color-ratios C||(0.65/0.42 μm) and C⊥(0.65/0.42 μm). Using light scattering model calculations we show that the color-ratio images obtained with a polarization filter at large phase angles suggest a new tool to study the lunar surface. In particular, it turns out that the color-ratios C||(0.65/0.42 μm) and C⊥(0.65/0.42 μm) are sensitive to somewhat different thicknesses of the surfaces of regolith particles. We consider the applicability of the Hubble Space Telescope, the Very Large Telescope (ESO), and a spacecraft on a lunar polar orbit for polarimetric observations of the lunar surface. 相似文献
85.
de la Vara Alba Cabos William Sein Dmitry V. Sidorenko Dmitry Koldunov Nikolay V. Koseki Shunya Soares Pedro M. M. Danilov Sergey 《Climate Dynamics》2020,54(11-12):4733-4757
Climate Dynamics - Despite the efforts of the modelling community to improve the representation of the sea surface temperature (SST) over the South Eastern Tropical Atlantic, warm biases still... 相似文献
86.
Victor P. Nechaev Evgene V. Sklyarov Yukio Isozaki Nikolay N. Kruk Alexey V. Travin Yukiyasu Tsutsumi Eugenia V. Nechaeva 《Island Arc》2021,30(1):e12426
More than 30 mafic dykes crop out in the Sergeevka belt in the coastal South Primorye, Far East Russia, of which geologic settings have been unclear for years. This study conducted major- and trace elements characterization, Sr–Nd isotope analyses, and Ar–Ar amphibole and U–Pb zircon datings for these rocks in order to identify their origin. The results demonstrated that all dykes are characterized by high Ba/Yb and low Nb/Y, Zr/Y, and Th/Yb ratios, which suggest their origin from arc melts derived from thin wedge mantle and shallow-dipping slab. These dykes are clearly separated into two distinct age/geochemistry suites; that is, the Paleogene and Early Cretaceous one with dolerites/basalts and adakitic rocks, and the Permian–Triassic one with high-Mg and high-Al gabbro-dolerite varieties. Their geochemistry suggests that the older suite was sourced from a primitive depleted MORB mantle (DMM)-type mantle, whereas the younger suite from an enriched mantle II (EM2)-type mantle domain. The transition in source type from DMM to EM2 occurred during the Jurassic-earliest Cretaceous time, probably by a strong influence of a mantle plume onto the long-continuing subduction-related magmatism. The plume influence reached the maximum when the unique meimechite-picrite complex formed in the region. 相似文献
87.
Nikolay Kolev Ivan Grigorov Ivan Kolev P. C. S. Devara P. Ernest. Raj K. K. Dani 《Boundary-Layer Meteorology》2007,124(1):99-115
We present measurements of the vertical aerosol structure and the aerosol optical depth in the lower troposphere performed
above the city of Sofia (an urban area situated in a mountain valley), western Bulgaria by means of a ground-based aerosol
lidar operating continuously for a number of years. The lidar measurements were accompanied by measurements of the aerosol
optical depth (AOD) in the visible and near infrared regions of the spectrum performed in October 2004 using Microtops II
radiometers. The maximum values of the AOD were found to occur 1–2 h before the complete development of the atmospheric boundary
layer, i.e. during the residual layer destruction, which confirms our hypothesis concerning the slope circulation effect on
the processes taking place in the atmospheric boundary layer. The AOD values obtained by the lidar are lower than those taken
by the sun photometer. Further, the AOD exhibits two different types of behaviour. In the case of a ‘clear atmosphere’ (i.e.
in the absence of volcanic eruptions and/or dust transport from the Sahara) most of the aerosol accumulated within the atmospheric
boundary layer over the urban area considered. The combined use of the two instruments allows the comparison between the optical
characteristics of the atmospheric aerosol (e.g. aerosol extinction coefficient, etc.) obtained by the lidar and through an
independent method (sun photometer). 相似文献
88.
Yevgeniy I. Aleksandrov Nikolay N. Bryazgin Eirik J. Førland Vladimir F. Radionov Pavel N. Svyashchennikov 《Polar research》2005,24(1-2):69-85
Observation data of temperature, precipitation and snow depth have been compiled and generalized climatologically for a network of 38 stations in and around the Barents and Kara seas, for the period 1951–1992. The monthly precipitation totals were corrected for measuring errors, and the correction method is described in detail. The corrected precipitation values show that the annual precipitation in the region ranges from more than 500 mm along the coast of the Kola Peninsula to less than 200 mm in parts of the north-eastern Kara Sea. The solid fraction of the annual precipitation ranges from 70% in northern parts to 35% in southern parts. For the period 1951–1992 the analysis indicates decreasing trends in annual values of temperature, precipitation and snow depths in the north-eastern parts of the region. 相似文献
89.
Ilya V VekslerAlexander M Dorfman Donald B Dingwell Nikolay Zotov 《Geochimica et cosmochimica acta》2002,66(14):2603-2614
The main objectives of this study were to investigate conditions for stable and metastable liquid immiscibility in dry borosilicate synthetic systems and to evaluate effects of temperature and bulk melt composition on two-liquid element partitioning and boron speciation. To distinguish between the stable immiscibility and quench heterogeneity, we used high-temperature centrifuge phase separation. For the case of stable liquid immiscibility, silica-rich (LS) and borate-rich (LB) conjugate liquids formed two distinct layers separated by a sharp meniscus. The liquids were quenched into glasses, which were analysed by electron microprobe. Some of the glasses were also studied by Raman spectroscopy. We used several synthetic mixtures along the danburite-anorthite (CaB2Si2O8-CaAl2Si2O8) and danburite-reedmergnerite (CaB2Si2O8-NaBSi3O8) joins. In addition, we studied four complex, six-component, Mg-bearing compositions with variable Na2O and Al2O3 contents. The experiments show that the width of the LS-LB miscibility gap decreases more rapidly with the B-Al substitution (in the danburite-anorthite join) than with the Ca-Na substitution, implying that interactions between network-forming elements have a greater effect on borate-silicate unmixing than the nature of network-modifying cations. Ca and Mg partition strongly to the depolymerised borate-rich liquid with LB-LS partition coefficients of ∼40 and higher. On the other hand, two-liquid partition coefficients of Na and Al in most cases are close to 1 and show complex variations with temperature and bulk melt composition. Raman spectra of LB glasses quenched at different temperatures suggest that the proportion of trigonal boron in bulk boron content decreases with decreasing temperature. The change in boron speciation appears to affect Al and Na two-liquid partitioning in such a way that at low temperatures, the latter element becomes more compatible with LS. 相似文献
90.
This paper is a review of applications of density functional theory (DFT) in compositional hydrodynamics. The basic idea is representation of the entropy or the Helmholtz energy of the mixture as the functional depending on the molar densities of chemical components (density functional). The hydrodynamics is governed by local conservation laws of chemical components, momentum, and energy, while constitutive relations and boundary conditions are introduced in accordance with the explicit form of the density functional. The general ideas and the history of the DFT in compositional hydrodynamics are discussed. Then the DFT for multiphase multicomponent mixtures is presented including the exposition of the first principles, governing equations and constitutive relations, and explicit expressions of density functional depending on physical situation. The DFT-based numerical simulator is described, and several multiphase simulation results are presented to illustrate the scope and effectiveness of DFT: sessile drop with and without surfactant, droplet breakup in shear flow, and three-phase hydrodynamics with mobile solid phase. Also, two practical scenarios with multiphase simulations in micro-CT porous rock models are presented: two-phase immiscible water-oil flow and three-phase water-gas-condensate flow with phase transitions. All numerical results are obtained by essentially the same code; both the number of chemical components and the Helmholtz energy have been set up in accordance with physical situation. 相似文献