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31.
Isotopic age of the Permian-Triassic basaltic magmatism in the Polar Cis-Urals: Rb-Sr and Sm-Nd data
V. L. Andreichev Yu. L. Ronkin O. P. Lepikhina A. F. Litvinenko 《Stratigraphy and Geological Correlation》2007,15(3):258-266
Two basaltic lava flows are confined to the Permian-Triassic boundary in succession of continental deposits of the Polar Cis-Urals that is confirmed by Rb-Sr (250 ± 15 Ma) and Sm-Nd (249 ± 17 Ma) dates obtained for the lower flow in the Paemboi-Khalmer-Yu area of the Korotaikha depression. The analyzed basalts are correlative in age with Siberian plateau basalts (250 Ma) and the Permian-Triassic boundary dated at 251 Ma in the Meishan section of marine deposits in South China. 相似文献
32.
33.
Liudmila I. Litvinenko Aleksandr I. Litvinenko Elena G. Boiko Kirill Kutsanov 《中国海洋湖沼学报》2015,33(6):1436-1450
In Western Siberia(Russia) there are about 100 Artemia lakes with total area over 1 600 km 2.Geographically these lakes are located between 51°–56°N and 61°–82°E.In general these lakes are shallow(depth less than 1.5 m),small or medium size(0.1 to 10 km 2);they are chloride;their total salinity is from 40 to 250 g/L.The harvesting of cysts per year is only in 20–40 lakes.In Russia 550 tons of dry Artemia cysts(14%–18% of the world production) were harvested annually.This includes about 350 tons in the Altai region and 200 tons in other regions.During our regular 20-year study period the cyst harvest was:95 tons in Kurgan;65 tons in Omsk,20 tons in Novosibirsk,20 tons in Tyumen.Ways of increasing cyst harvest in Russia are considered in this article.During the last 30 years the harvest of cysts in Russia has increased from 7–20 to 500–600 tons.A significant influence of dryness of the year was found on productivity in selected lakes,but taken for all the lakes together,the relationship was not significant.The optimal salinity for productivity of cysts in the lakes was determined.Analysis of productivity of the lakes and the harvesting results showed that the stocks of cysts are underutilized by approximately 1.7 times. 相似文献
34.
The rate of two-dimensional flux pile-up magnetic reconnection is known to be severely limited by gas pressure in a low-beta plasma of the solar corona. As earlier perturbational calculations indicated, however, the pressure limitation should be less restrictive for three-dimensional flux pile-up. In this paper the maximum rate of reconnection is calculated in the approximation of reduced magnetohydrodynamics (RMHD), which is valid in the solar coronal loops. The rate is calculated for finite-magnitude reconnecting fields in the case of a strong axial field in the loop. Gas pressure effects are ignored in RMHD but a similar limitation on the rate of magnetic merging exists. Nevertheless, the magnetic energy dissipation rate and the reconnection electric field can increase by several orders of magnitude as compared with strictly two-dimensional pile-up. Though this is still not enough to explain the most powerful solar flares, slow coronal transients with energy release rates of order 1025– 1026 erg s–1and heating of quiet coronal loops are within the compass of the model. 相似文献
35.
The problem of pressure limitations on the rate of flux pile-up magnetic reconnection is studied. We first examine the recent suggestion of Jardine and Allen (1998) for moderating the build-up of magnetic pressure in the current sheet by considering inflows with nonzero vorticity. An analytic argument shows, however, that unbounded magnetic pressures in the limit of small resistivities can be avoided only at the cost of unphysical dynamic pressures in the plasma. Hence, the pressure limitation on the reconnection rate in a low-beta plasma cannot be avoided completely. Nevertheless, we demonstrate that reconnection can be more rapid in a new solution that balances the build-up in dynamic pressure against both the plasma and magnetic pressures. This exact MHD solution has the characteristics of merging driven by the coalescence instability. The maximum energy release rate of the model is capable of explaining a modest solar flare. 相似文献
36.
The results of the treatment of the database on the spectrofluorometric studies of aromatic hydrocarbons (AHC) [over 500 bottom
stations] allowed the authors to show the high informativity of the technique used not only for geological environmental studies
but also for gaining knowledge of the genetic parameters of the organic matter. The principal spectral characteristics of
the bottom sediments were established for different lithofacies groups of sediments. The results obtained, which were verified
by the data of the chromatographic mass spectrometry, allow one to consider the research method developed to be suitable for
multipurpose geochemical surveys. 相似文献
37.
A. V. Litvinenko N. N. Filatov M. S. Bogdanova V. A. Karpechko I. A. Litvinova Yu. A. Salo 《Water Resources》2014,41(4):454-463
Stages of anthropogenic transformation of Vygozero are demonstrated. Hydrographic and hydrologic characteristics are given to the Vogozersko-Ondskoe Reservoir and its drainage area at different stages of its development. The current state and dynamics of the economic use of the reservoir and its watershed are estimated with the use of GIS-technologies (databases and GIS “Water Users of the Republic of Karelia”). 相似文献
38.
Traditional models for particle acceleration by magnetic reconnection in solar flares assumed a constant electric field in
a steady reconnecting magnetic field. Although this assumption may be justified during the gradual phase of flares, the situation
is different during the impulsive phase. Observed rapid variations in flare emissions imply that reconnection is non-steady
and a time-varying electric field is present in a reconnecting current sheet. This paper describes exploratory calculations
of charged particle orbits in an oscillating electric field present either at a neutral plane or a neutral line of two-dimensional
magnetic field. A simple analytical model makes it possible to explain the effects of particle trapping and resonant acceleration
previously noted by Petkaki and MacKinnon in a numerical simulation. As an application, electron acceleration to X-ray generating
energies in impulsive solar flares is discussed within the context of the model. 相似文献
39.
In the northwestern Zeya──Bureya sedimentary basin, the authors studied coal deposits, including Ivanovsko-Erkovetskyu brown coal square on which is worked off largest Erkovetsky field of brown coal, extending to south flank of the Mesozoic──Cenozoic Belogor'e depression. The verified stratigraphic scheme of the coalfield sedimentary sequence is substantiated by palynological data on core samples from 18 boreholes sampled in the course of detailed prospecting and by paleobotanical analysis of sections in the Yuzhnyi sector of the coalfield. Sections of the Erkovtsy, Arkhara Boguchan, and Raichikha brown-coal mines are correlated. Stratigraphic subdivisions distinguished in the studied sedimentary succession are the middle and upper Tsagayan subformations (the latter incorporating the Kivda Beds), Raichikha and Mukhino formations. 相似文献
40.
T.V. Kezina N.D. Litvinenko 《东北亚地学研究》2007,10(2):130-147
In the northwestern Zeya-Bureya sedimentary basin, the authors studied coal deposits, including Ivanovsko-Erkovetskyu brown coal square on which is worked off largest Erkovetsky field of brown coal, extending to south flank of the Mesozoic-Cenozoic Belogor'e depression. The verified stratigraphic scheme of the coalfield sedimentary sequence is substantiated by palynological data on core samples from 18 boreholes sampled in the course of detailed prospecting and by paleobotanical analysis of sections in the Yuzhnyi sector of the coalfield. Sections of the Erkovtsy, Arkhara Boguchan, and Raichikha brown-coal mines are correlated. Stratigraphic subdivisions distinguished in the studied sedimentary succession are the middle and upper Tsagayan subformations (the latter incorporating the Kivda Beds), Raichikha and Mukhino formations. 相似文献