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151.
K. Zaninović 《Theoretical and Applied Climatology》1992,45(1):65-70
Summary Limits of warm and cold stress in different climatic regions are determined by means of temperature, wind speed and humidity for the period 1976–1985. These values are measured at 2 PM local time during July for warm stress and at 7 AM local time during January for cold stress. Hvar (20 m ASL) is used to represent maritime climate, Zavian on the top of Mount Velebit (1594 m ASL) and Skrad (668 m ASL) in Gorski Kotar are representative of mountainous climate, and Zagreb (128 m ASL) is representative of continental low-land climate. Values of a biometeorological Temperature-Wind Speed-Humidity (TWH)-index higher than the 98% value of the theoretical distribution fitted to empirical data represent above normal extreme conditions at a given location, and TWH values less than 2% value of the theoretical distribution represent below normal extreme conditions. For similar temperatures, it will be extremely above normal at the top of Mount Velebit (Zavian) whilst normal on the coast (Hvar), and similarly, it will be extremely below normal in Hvar but normal at Zavian.With 4 Figures 相似文献
152.
Gojko Djurašević 《Astrophysics and Space Science》1992,196(2):267-282
For the purpose of analysing light curves of active CB with an accretion disc being at the evolutional phase of an intensive matter exchange between the components a model for light-curve synthesis has been realized where the attention is given to systems like W Ser not sufficiently examined yet with regard that in them the accretion disc is formed around an ordinary star. In the paper one uses the elements presented in the first paper of this series. The model can successfully describe the essential characteristics of the observed light curves due to existence of an accretion disc and a hot spot, as well as those originated in the temperature distribution along the disc radius. The system components are considered in the framework of the nonsynchronous Roche model and the accretion disc of a constant thickness lies in the orbital plane around the star capturing the matter of the neighbouring component.The primary surrounded by the disc is situated relatively well within the Roche oval and its rotation can be significantly nonsynchronous. Near the Lagrange equilibrium pointL
1 flows from the secondary (which fills the Roche limit) the gas stream nourishing the disc. In the zone where the stream touches the lateral side of the disc a hot spot is formed.The proposed model enables estimating of the basic orbital and physical parameters of active type W Ser CB (Djuraevi, 1991) on the basis of photometric measurements by applying the inverse-problem method. 相似文献
153.
Slobodan Ninković 《Astrophysics and Space Science》1987,136(2):299-314
An analysis of the data concerning high-velocity stars from Eggen's catalogue aimed at a determination of the approximate slope of the mass function for the spherical component of our Galaxy, and at estimating the local circular velocity, as well as the local rotation velocity, as by-products, has been performed. Our conclusions are that:
- A linear dependence of the mass on the radius is very likely;
- the value of the limiting radius is most likely equal to (40±10) kpc;
- the two local velocities are approximately equal to each other, being both equal to (230±30) km s?1;
- the local escape velocity appears to be most likely equal to (520±30) km s?1;
- the total mass of a corona, obtained in this way, is (5±1)×1011 M ⊙.
154.
The chronostratigraphy of the latest Middle Pleistocene aeolian and alluvial activity on the Island of Hvar,eastern Adriatic,Croatia 下载免费PDF全文
Lara Wacha Igor Vlahović Sumiko Tsukamoto Marijan Kovačić Ozren Hasan Davor Pavelić 《Boreas: An International Journal of Quaternary Research》2016,45(1):152-164
Pleistocene aeolian sands and alluvial deposits can frequently be traced along the Mediterranean coast. Such deposits also exist along the eastern Adriatic coast and the nearby islands. Four stratigraphical sections of these deposits were studied on the Island of Hvar with the purpose of establishing a chronological framework of the aeolian–alluvial depositional system, using luminescence dating and magnetic susceptibility stratigraphy. Luminescence dating was applied on coarse‐grained feldspar and quartz grains separated from the sands. Both quartz optically stimulated luminescence (OSL) and feldspar post‐IR infrared stimulated luminescence (pIRIR) age estimates are in good agreement, with values ranging between 167±24 to 120±12 ka (OSL) and 179±18 to 131±18 ka (pIRIR measured at 290 °C) after a fading correction for the pIRIR signal. The results can be clearly correlated to around the end of oxygen isotope stage (OIS) 6 and the beginning of OSI 5, indicating that the aeolian accumulation of sands was a result of the Penultimate Glacial and climate fluctuations at the beginning of the Last Interglacial. Variations in magnetic susceptibility (MS) data can be interpreted alongside these dating results; several stronger peaks detected at the very end of the Penultimate Glacial and the initial stage of the Last Interglacial cycle most probably indicates more intensive pedogenesis resulting from a more favourable climate, probably because of climate changes. Breccias related to major bounding surfaces in association with evidence of soil formation and bioturbation could be the result of more favourable climate conditions and changes during the transition from OIS 6 to OIS 5 (Penultimate Glacial–Last Interglacial). These results are in agreement with similar data from the wider Mediterranean area. 相似文献
155.
N. Alonizan R. Qindeel N. Ben Nessib S. Sahal-Bréchot Milan S. Dimitrijević 《Journal of Astrophysics and Astronomy》2015,36(4)
Stark broadening parameters for nine neutral oxygen (O I) lines have been determined within the impact approximation and the semiclassical perturbation method. The atomic data have been taken from the TOPbase and NIST atomic databases. The electron and proton Stark widths and shifts and ion broadening parameter values for these O I lines have been calculated for electron density of 10 16 cm ?3 and for 4 different electron temperatures in the range of 5000 K to 40000 K. These Stark broadening parameters are compared with our previous results (Ben Nessib, N. et al. 1996, Physica Scripta, 54, 603–613), where we calculated Stark broadening parameters for only four O I spectral lines and where Stark widths and shifts were compared with experimental and theoretical data available in the literature. In the present paper, we have also compared our results with the Griem’s book (Griem, H. R. 1974, Spectral line broadening by plasmas) and VALD (Ryabchikova, T. et al. 2015, Physica Scripta, 90, 054005) values. 相似文献
156.
D. Ilić L. Č. Popović A. I. Shapovalova A. N. Burenkov V. H. Chavushyan A. Kovačević 《Journal of Astrophysics and Astronomy》2015,36(4)
The spectral variability of active galactic nuclei (AGN) is one of the key features that enables us to study in more detail, the structure of AGN emitting regions. Especially, the broad line profiles that vary both in flux and shape, give us invaluable information about the kinematics and geometry of the broad line region (BLR) where these lines are originating from. We give here a comparative review of the line shape variability in a sample of five type 1 AGNs, those with broad emission lines in their spectra, of the data obtained from the international long-term optical monitoring campaign coordinated by the Special Astrophysical Observatory of the Russian Academy of Science. The main aim of this campaign is to study the physics and kinematics of the BLR on a uniform data set, focusing on the problems of the photoionization heating of the BLR and its geometry, where, in this paper, we give for a first time, a comparative analysis of the variabilty of five type 1 AGNs, discussing their complex BLR physics and geometry in the framework of the estimates of the supermassive black hole mass in AGN. 相似文献
157.
Problems of sustainable development in connection with the change of biogeochemical cycle of selenium and overcoming its deficiency in Russia, Serbia, Belarus and other countries are reported. The history of the biological role of selenium as an essential trace element is discussed. A special program of «Overcoming of selenium deficiency» has been developed by researches of Russia, Serbia and Belarus in view of high morbidity rates for cardiovascular, tumor and endemic diseases affecting the population of both the above and some other countries, including children, prevalence of selenium deficiency among livestock species and aggravation of the environmental situation as a result of man-made processes. 相似文献
158.
Tanja Petrović Milena Zlokolica-Mandić Nebojša Veljković Dragana Vidojević 《Journal of Geochemical Exploration》2010
In the past researches conducted on the territory of Serbia, 5 regional geotectonic units have been distinguished with registered occurrences of 230 mineral springs. Recent analyses of the bottled mineral waters quality have not included systematic examinations of micro-components present in these waters. Based on the analyses of the bottled mineral waters (EuroGeoSurveys Geochemistry Expert Group), it has been observed that the water quality is greatly influenced by the chemical composition of igneous intrusions, regardless of the fact that the analyzed waters have been taken from different aquifers (Neogene sediments, limestone, flysch, schist). 相似文献
159.
R. Oreiro J. H. Telting R. H. Østensen M. Briquet C. Aerts U. Heber M. Vučković 《Astrophysics and Space Science》2010,329(1-2):211-216
We have produced simulated time series of high resolution spectroscopy for sdBs. We present the first results of testing classical mode identification techniques. Here, in particular, we analyse the behaviour of individual spectral lines and discuss the results and applicability of the moment method. 相似文献
160.
Hydrochemical properties of transition zone between fresh groundwater and seawater in karst environment of the Adriatic islands,Croatia 总被引:3,自引:3,他引:0
Eastern coast of the Adriatic Sea consists of karstified carbonates. It belongs to the well-known Dinaric karst region. The
coast is extremely indented and there are 718 islands with numerous rock crags and reefs. Some of the inhabited islands use
their own water resources for public water supply, or plan to do it in the future. Since karst rocks are extremely permeable,
the seawater intrudes into underground water resources, thereby forming the wedge. A wide transition zone occurs between this
seawater wedge and fresh water aquifers. Consequently, island groundwater reserves turn brackish to a certain extent. In this
study, 77 water samples were collected from a wide variety of water resources. Comprehensive statistical and mathematical
multivariate analysis of these data was performed. Simple statistical approach showed several useful correlations among some
parameters, and more complex multivariate techniques extracted three factors in connection with three natural processes: (1)
mixing with the seawater, (2) carbonate dissolution and (3) human influence (pollution) and nitrogen transformation processes.
The results of this study demonstrate that in situ measurement of electrical conductivity is adequate for the very rough field
estimation of numerous parameters. 相似文献