首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Analysis of changes in the vertical distribution of tritium in the Caspian Sea water mass in 1994–1996 led to a conclusion that the sea level fall that started in 1996 was accompanied by a rearrangement of the water mass steady hydrological structure characteristic of the high sea-level stand.__________Translated from Vodnye Resursy, Vol. 32, No. 4, 2005, pp. 406–409.Original Russian Text Copyright © 2005 by Brezgunov, Ferronskii.  相似文献   

2.
Floods: Genesis, Socioeconomic and Environmental Impacts   总被引：2，自引：0，他引：2  
The concept of “flood” is formulated with regard to socioeconomic and environmental impacts. An ingenious classification of floods according to their genesis is suggested. Socioeconomic impacts of floods are discussed. A classification of floods according to their socioeconomic damage is proposed. Environmental impacts of floods are studied.__________Translated from Vodnye Resursy, Vol. 32, No. 4, 2005, pp. 389–398.Original Russian Text Copyright © 2005 by Istomina, Kocharyan, Lebedeva.  相似文献   

3.
A system of efficient on-line monitoring of the state of water in surface water bodies is developed. The expediency of using new general-purpose bioassays for the integral express evaluation of the natural-water toxic impact on living organisms is substantiated. Fundamentally new methods of bioassaying with gasteropoda from special laboratory cultures (“PRM-TESTS”) used as test organisms are presented. The results of complex hydrochemical and biological (toxicological) investigations with PRM-TESTS as applied to water bodies in St. Petersburg are discussed.__________Translated from Vodnye Resursy, Vol. 32, No. 4, 2005, pp. 425–434.Original Russian Text Copyright © 2005 by Kurilenko, Zaitseva.  相似文献   

4.
The general picture of wetting the East European Plain in 1966–1985 is established by studying the trajectories of more than 5000 cyclones in the Northern Hemisphere. The role of the Arctic High as a regulator of the paths of the Atlantic cyclones is established. It is shown that the majority of rivers of the East European Plain feature higher rate of streamflow in the years with the El Nino effect.Translated from Vodnye Resursy, Vol. 32, No. 1, 2005, pp. 108–114.Original Russian Text Copyright © 2005 by Babkin, Klige.  相似文献   

5.
A method is proposed for calculating the hydrodynamic parameters of flows in water bodies with shallow and deep zones. Calculation of flow parameters in the Sea of Azov is given as an example.Translated from Vodnye Resursy, Vol. 32, No. 1, 2005, pp. 55–60.Original Russian Text Copyright © 2005 by Chikin.  相似文献   

6.
Zusammenfassung 1) Es werden Multipollösungen der skalaren Wellengleichung 2 f/t 2 – c2 div gradf=0 betrachtet. Einerseits kann man solche Lösungen direkt durch Kugelfunktionenn-ter Ordnung ausdrücken, anderseits aus der Einpollösungf=1/p F(t–p/c) durch Differentiation nachn Richtungen erhalten. Es wird der Zusammenhang zwischen den Ergebnissen der beiden Verfahren gezeigt. — 2) Für die Energiedichte und den Energiefluss durch Kugelflächen bei kleinen elastischen Verschiebungen werden Ausdrücke in Kugelkoordinaten angegeben. — 3) Für die Wellengleichung grad div –b 2 rot rot werden rotationsfreie Multipollösungen angegeben und Ausdrücke für Energiedichte und Energiefluss hergeleitet. — 4) Das gleiche wird für divergenzfreie Multipollösungen durchgeführt. — 5) Es werden Multipole betrachtet, die weder rotationsfrei noch divergenzfrei sind. Als Spezialfälle werden Multipole mit zeitlich begrenzter und solche mit periodischer Erregung gezeigt, ferner Lösungen der Wellengleichung, die sowohl rotationsfrei wie divergenzfrei sind. — 6) Es wird gezeigt, wie man die elastischen Wellen, die im Sinne vonStokes von einem Herdgebiet endlicher Ausdehnung ausgehen, näherungsweise durch elastische Multipole darstellen kann. — 7) Es wird angedeutet, wie man durch Messung von Komponenten von oder u.s.w. in Punkten im Innern des Mediums die Erregung und Energie von elastischen Multipolen bestimmen kann. Ferner wird auf den Fall hingewiesen, wo ein rotationsfreier Einpol sich im Innern eines Halbraumes befindet und die Messungen an seiner Oberfläche ausgeführt werden.
Summary (On foci of elastic waves in isotropic homogeneous media) — 1) Multiplets as solutions of the scalar wave equation 2 f/t 2 – c2 div gradf=0 are considered. Such solutions can be obtained either directly by aid of spherical harmonics of ordern, or by differentiating the single polef=1/p F(t–p/c) with respect ton directions. The relations between the results of those two procedures are shown. — 2) In the case of small elastic displacements , the density of energy and the flow of energy through spherical surfaces are expressed by spherical coordinates. — 3) Multiplets which satisfy the equation of motion =a 2 grad div b 2 curl curl and the equation curl = 0 are given, and expressions for the density and flow of energy are found. — 4) The same is done with multiplets satisfying the equation of motion and the equation div = 0. — 5) General multiplets which satisfy the equation of motion are treated. As special cases, multiplets with excitation of finite length and multiplets with periodic excitation are considered, furthermore solutions of the equation of motion and of the equations curl = 0 and div = 0 are given. — 6) It is shown how elastic waves whose origin is a region of finite extension in the sense given byStokes, can be approximated by elastic multiplets. — 7) Some indications are given on the problem of how to find the functions of excitation and the energy of an elastic multiplet by measuring components of or etc., at points in the interior of the medium. The same problem is considered in the case of the single elastic pole. = grad 1/p F (t–p/a), if the measurements are made at the surface of an elastic half space.
  相似文献   

7.
Energy balance of an ice-covered flow in a constant-slope reach of a regulated river is considered. The ratio of energy losses for viscous friction to the total flow energy is evaluated. The turbulence intensities of an open and ice-covered flows are compared.Translated from Vodnye Resursy, Vol. 32, No. 1, 2005, pp. 48–54.Original Russian Text Copyright © 2005 by Dolgopolova.  相似文献   

8.
Two main groups of methods used for comprehensive evaluation of continental surface water quality are analyzed. A new method of comprehensive evaluation of the degree of continental surface water contamination, developed by the authors of this paper based on a combination of the differentiated and comprehensive approaches, is described in detail.Translated from Vodnye Resursy, Vol. 32, No. 1, 2005, pp. 61–69.Original Russian Text Copyright © 2005 by Nikanorov, Yemelyanova.  相似文献   

9.
Regularities of bacteria distribution in the bottom sediments of the Upper Volga reservoirs are studied. Human-induced changes in the structure and activity of bacteriobenthos communities occurring in water body areas adjacent to towns and settlements are described. Reservoir zones subject to long-term human impact are distinguished.__________Translated from Vodnye Resursy, Vol. 32, No. 4, 2005, pp. 489–499.Original Russian Text Copyright © 2005 by Kosolapov, Krylova, Kopylov.  相似文献   

10.
Concentration of oil hydrocarbons in the bottom sediments of water bodies in Khanty-Mansi Autonomous Okrug has been analyzed. Statistical methods have been used to confirm the dependence of contamination level on the frequency of accidents in oil fields. Areas with heavily contaminated bottom sediments have been singled out.Translated from Vodnye Resursy, Vol. 32, No. 1, 2005, pp. 85–89.Original Russian Text Copyright © 2005 by Moskovchenko.  相似文献   

11.
Results of field observations and numerical modeling of hydrogen sulfide pollution of the Sea of Azov in 2001 are presented.Translated from Vodnye Resursy, Vol. 32, No. 2, 2005, pp. 171–183.Original Russian Text Copyright © 2005 by Debolskaya, Yakushev, Sukhinov.  相似文献   

12.
The results of studying the vertical profile of wind velocity and the vortex-formation mechanism in the atmospheric layer immediately adjacent to the water surface under the condition of developing wind wave are considered. Materials of field and laboratory experiments are used.__________Translated from Vodnye Resursy, Vol. 32, No. 3, 2005, pp. 295–300.Original Russian Text Copyright © 2005 by Anisimova, Pokazeev, Soboleva, A. Speranskaya, O. Speranskaya.  相似文献   

13.
The results of integrated microbiological studies of the Sheksna Reservoir are presented. The environmental conditions of its water and soil, which are exposed to diverse anthropogenic impact, are assessed. Parts of the reservoir with persistent anthropogenic pollution, which are environmentally unfavorable in terms of the state of silt microflora, are recognized.Translated from Vodnye Resursy, Vol. 32, No. 1, 2005, pp. 70–78.Original Russian Text Copyright © 2005 by Dzyuban.  相似文献   

14.
Accumulation of salts in lakes with small catchment areas and substrate composed of magmatogene, metamorphized, and sedimentary rocks have been studied. Direct dependence of the chemical composition of salt-lake waters on that of deep-seated endogenous waters is demonstrated. Groups of salt lakes have been found to form linear rows or ellipses.Translated from Vodnye Resursy, Vol. 32, No. 1, 2005, pp. 13–17.Original Russian Text Copyright © 2005 by Dzyuba, Kulagina.  相似文献   

15.
Mercury pollution of the Dubossary Reservoir in the Dniester River was studied with the use of bioindicators (higher aquatic plants, epiphyte suspension, Xanthoria parietina lichen). The maximum mercury concentration in bioindicators is recorded in the zone near the Rezinsko-Rybnitskii Complex, which incorporates two large cement works and a metallurgical plant.__________Translated from Vodnye Resursy, Vol. 32, No. 4, 2005, pp. 464–469.Original Russian Text Copyright © 2005 by G. Munteanu, V. Munteanu.  相似文献   

16.
The experience of application of special submerged artificial plant for the improvement of the quality of polluted waters in Guanting Reservoir in Northern China is considered. Under the hydrodynamic load of 0.15–0.45 m3/day, the efficiency of organic matter removal (in units of permanganate oxidability CODMn) and NH 4 + -N from water amounted to 50 and 70% in summer and 15 and 50% in winter, respectively. These characteristics were found to decrease with increasing hydrodynamic load and decreasing water temperature.__________Translated from Vodnye Resursy, Vol. 32, No. 4, 2005, pp. 500–503.Original Russian Text Copyright © 2005 by Liu Hong, Dai Ming-li, Ouyang Wei, Kong Xiang-hui, Liu Pei-bin.  相似文献   

17.
On Some Issues of Maintaining Water Quality and Self-Purification   总被引：7，自引：0，他引：7  
Generalizations presented in this paper represent, in systematized form, the basic elements of the qualitative theory of water self-purification in freshwater and marine ecosystems. Recommendations are given for maintaining water quality and sustainable development of water resources. Results of experimental studies of the effect exerted by Triton X-100 and OMO synthetic detergent on mollusks Unio tumidus.__________Translated from Vodnye Resursy, Vol. 32, No. 3, 2005, pp. 337–346.Original Russian Text Copyright © 2005 by Ostroumov.  相似文献   

18.
The role of bogs as filters on the path of pollutant migration to surface and subsoil waters is demonstrated. Sorption hysteresis is shown to play a major role in the retention of pollutants by peat mass. The mathematical problem of pollutant transport and absorption in bogs is formulated and solved numerically.Translated from Vodnye Resursy, Vol. 32, No. 2, 2005, pp. 205–213.Original Russian Text Copyright © 2005 by Belyaev, Dzhamalov, Krichevets, Polyakova, Yushmanov.  相似文献   

19.
Summary The mechanism of beating of Pc3 type pulsations is studied. Using the method of numerical computation of a sonagram (the method of frequency-time analysis) a set of samples of pulsations from the Budkov Observatory is treated (1968–1969) mostly at K-indices equal to 2–3. By comparing f–t diagrams with the spectra of the samples an attempt has been made at interpreting the beating as a superposition of the frequency components, contained in the pulsation signal. In most observed cases it is possible to determine two close frequencies, the difference of which is on the average =5.4 mHz. The average carrier frequency of the samples was =37.6 mHz, and the average frequency of the beating =2.7 mHz. The interval of observed values of fB amounted to 1–5 mHz. A tendency was observed for fB to increase with increasing degree of disturbance of the geomagnetic field.  相似文献   

20.
A mass-balance model was developed for the prediction of the biomass and annual production of phytoplankton, macrophytes, epiphytes, and phytobenthos (primary producers), bacterioplankton and bacteriobenthos (reducers), herbivorous and predator zooplankton, zoobenthos, planktivorous fish, benthivorous fish, and predatory fish (consumers). The model is controlled by a small number of parameters.__________Translated from Vodnye Resursy, Vol. 32, No. 3, 2005, pp. 361–370.Original Russian Text Copyright © 2005 by Boulion.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号