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81.
82.
V. I. Danilov-Danilyan 《Water Resources》2005,32(5):572-579
The causes of freshwater deficiency are considered, the main causes being poor environmental conditions and excessive water consumption. The problem of water deficiency is shown to be insoluble without the development of intense water use, conservation, and protection. Based on studying water as a commodity, it is asserted that the market mechanism is not sufficient to cope with water deficiency. The potential of the international water market is shown to be very limited in contrast to the market of water-efficient processes and water-retaining products. 相似文献
83.
V. B. Titov 《Water Resources》2005,32(1):23-30
Seasonal evolution of the vertical thermal, halininc, and density structure of water in the phases of warming and heat loss is shown. The annual cycle of variability of seasonal and deep-water thermo-, halo-, and pycnocline is discussed. It is revealed that variations in the seasonal (subsurface) thermo-, halo-, and pycnocline depend on the surface environmental factors (air temperature, river runoff, and precipitation), while variations in the deep-water thermo-, halo-, and pycnocline depend on the dynamic factor impact (seasonal variations in the intensity of the general cyclonic circulation in the Black Sea).Translated from Vodnye Resursy, Vol. 32, No. 1, 2005, pp. 28–34.Original Russian Text Copyright © 2005 by Titov. 相似文献
84.
We study the mineralogical changes suffered by specimens of natural miocene red and green continental sandstones (from Pozuelos Formation and Tiomayo Formation) cropping out in the Argentine Puna that increase their bulk magnetic susceptibility and change color when thermally treated. We hypothesize that on heating siderite, which is present in small quantities as cement in the studied sandstones, would oxidize and decompose into maghemite and/or magnetite. Subsequent heating to higher temperatures sometimes would bring about the conversion of maghemite and/or magnetite to hematite. Mössbauer spectroscopy proved to be a very valuable tool for the determination of the presence of siderite in small amounts in the studied samples. The present results show that further work is needed in order to fully understand the mineralogical changes suffered by continental sandstones during heating. The characterization of such changes occurred during laboratory routines is relevant, since they can help to better understand natural processes. 相似文献
85.
J. Plomerova L. Vecsey V. Babuska M. Granet U. Achauer 《Studia Geophysica et Geodaetica》2005,49(4):541-560
We present results of an array study of seismic anisotropy beneath the Bohemian Massif (BM) showing distinct lateral and directional
variations of the fast shear-wave polarization and split-delay time consistent with variations in the P-residual spheres,
in which directional means of relative residuals are subtracted. Our analysis of the S- and P-wave anisotropy suggests that
the mantle lithosphere of the BM consists of at least three large domains with different orientation of the large-scale fabric
separated by sutures cutting most likely the whole lithosphere. Boundaries of the units are characterised by a null or small
shear-wave splitting, as well as by smaller values in the P-residual spheres. We present self-consistent 3D anisotropic models
of the lithosphere domains of the BM resulting from joint inversion of anisotropic parameters searching for a 3D orientation
of mantle fabric. While in the Saxothuringian and Sudetes parts of the BM the (a, c) foliations dip prevailingly to the N-NW,
they dip to the S and SW in the southern and eastern parts of the Moldanubian. 相似文献
86.
Comparative characteristic of several microelements (Ni, Cu, Sr, Al, Zn, Co, Mn, Pb, Cd, Hg, As) found in fish (case study of breams in the Volga basin reservoirs) is presented. Regularities of accumulation of these elements in fish depending on their concentration in the water are analyzed. Main disturbances in fish caused by the accumulation of microelements in their organs and tissues are considered. 相似文献
87.
The paper continues three-dimensional hydrodynamical computations of the formation of an accretion disk in the SS 433 system, taking into account radiative cooling explicitly, convective thermal conductivity, and radiation pressure. The computational results show that the powerful, broad flow forms an optically thick accretion disk with a gas density of 1012–1014 cm?3, a temperature of 15000–35 000 K, a radius of about 0.3, and a height of 0.2–0.3 (in units of the component separation). Spiral shocks form in the disk, and a narrow conelike cavity (tunnel) forms at the center. In this tunnel, gas is accelerated to relativistic speeds, leaving the system in the form of narrow jets. 相似文献
88.
We present the results of calculations of theoretical absorption-line profiles and radial-velocity curves for optical components in X-ray binary systems. Tidal distortion of the optical star and X-ray heating by incident radiation from the relativistic object are taken into account. An emission component forms whose intensity varies with orbital phase in the absorption-line profile in the presence of significant X-ray heating. As a result, the width of the line decreases rather than increases at quadrature. The line profiles and equivalent widths and the radial-velocity curves depend substantially on the parameters of the binary systems. This provides the possibility of directly determining component masses and orbital inclinations from high-resolution spectroscopic observations of X-ray binary systems. 相似文献
89.
T. F. Zimmie A. Pamuk K. Adalier M. B. Mahmud 《Geotechnical and Geological Engineering》2005,23(4):447-459
A series of geotechnical centrifuge physical modeling tests were performed to assess the potential use of a new cost-effective mechanically stabilized earth system for retrofitting marginally stable cohesive slopes. The proposed system utilizes the dual functions of reinforcement and drainage by directly inserting high strength non-woven geotextile strips into slopes, with little or no excavation required behind the slope face. The system significantly increases the factor of safety of potentially unstable cohesive slopes, and can be constructed at less expense and more rapidly than conventional mechanically stabilized earth systems. 相似文献
90.
Sorption edges and isotherms for Eu(III) uptake on Ca-montmorillonite and Na-illite in 0.066 mol/L Ca(ClO4)2 and 0.1 mol/L NaClO4 background electrolytes, respectively, were modelled using a quasi-mechanistic sorption model (the two site protolysis non electrostatic surface complexation and cation exchange (2SPNE SC/CE) model). For both clay minerals the Eu sorption edges could be quantitatively modelled in the pH range ∼3 to ∼10 using cation exchange reactions for Eu3+/Na+ and Eu3+/Ca2+ and three surface complexation reactions on the strong sorption sites forming ≡SSOEu2+, ≡SSOEuOH+ and ≡SSOEu(OH)2° inner sphere complexes which appear successively with increasing pH. Time resolved laser fluorescence spectroscopy (TRLFS) measurements of Cm(III) loaded Ca-montmorillonite and Na-illite were available from Part 1 of this work. De-convolution of the normalised fluorescence spectra measured at different pH values indicated three distinct Cm surface complexes, Cm complexes 1, 2 and 3 for both clay minerals, in agreement with model predictions, but with different distribution functions for the individual species. Under the assumption that Eu and Cm exhibit essentially the same hydrolysis and sorption behaviour, the Eu surface complexation constants were used to predict surface species distribution functions for Cm under the same experimental conditions used in the TRLFS measurements. Comparison of modelled and experimentally deduced species distributions indicated that for both clay minerals peak heights and widths of the three peaks did not correspond particularly well. It is shown that the calculated species distribution functions are sensitive to the values of the hydrolysis constants used in the calculations, whereas modelling the sorption edge measurements by applying the 2SPNE SC/CE approach is much less sensitive. By modifying the values of the hydrolysis constants within their uncertainty range and re-modelling the sorption edges, considerably better correspondence between the modelled and TRLFS species distribution functions was found. In particular, peak positions, heights and widths for the model predicted peaks for the ≡SSOCm2+ and ≡SSOCmOH+ species distribution, and those for Cm complexes 1 and 2 derived from TRLFS, were found to be very close for both clay minerals. However, discrepancies were still apparent between the profile for the calculated ≡SSOEu(OH)2° surface species and the Cm complex 3 species, especially in the case of Na-illite. 相似文献