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131.
132.
Abstract This study quantifies global changes in irrigation requirements for areas presently equipped for irrigation of major crop types, using climate projections from 19 GCMs up to the 2080s. Analysis is based on results from the global eco-hydrological model LPJmL that simulates the complex and dynamic interplay of direct and indirect climate change effects upon irrigation requirements. We find a decrease in global irrigation demand by ~17% in the ensemble median, due to a combination of beneficial CO2 effects on plants, shorter growing periods and regional precipitation increases. In contrast, increases of >20% are projected with a high likelihood (i.e. in more than two thirds of the climate change scenarios) for some regions, including southern Europe, and, with a lower likelihood, for parts of Asia and North America as well. If CO2 effects were not accounted for, however, global irrigation demand would hardly change, and increases would prevail in most regions except for southern Asia (where higher precipitation is projected). We stress that the CO2 effects may not be realized everywhere, that irrigation requirements will probably increase further due to growing global food demand (not considered here), and that a significant amount of water to meet future irrigation requirements will have to be taken from fossil groundwater, environmental flow reserves or diverted rivers. Editor D. Koutsoyiannis; Associate editor A. Montanari Citation Konzmann, M., Gerten, D., and Heinke, J., 2013. Climate impacts on global irrigation requirements under 19 GCMs, simulated with a vegetation and hydrology model. Hydrological Sciences Journal, 58 (1), 1–18. 相似文献
133.
134.
Markus Tum Franziska Strauss Ian McCallum Kurt Günther Erwin Schmid 《Carbon balance and management》2012,7(1):1-13
Background
Accurate, high-resolution mapping of aboveground carbon density (ACD, Mg C ha-1) could provide insight into human and environmental controls over ecosystem state and functioning, and could support conservation and climate policy development. However, mapping ACD has proven challenging, particularly in spatially complex regions harboring a mosaic of land use activities, or in remote montane areas that are difficult to access and poorly understood ecologically. Using a combination of field measurements, airborne Light Detection and Ranging (LiDAR) and satellite data, we present the first large-scale, high-resolution estimates of aboveground carbon stocks in Madagascar.Results
We found that elevation and the fraction of photosynthetic vegetation (PV) cover, analyzed throughout forests of widely varying structure and condition, account for 27-67% of the spatial variation in ACD. This finding facilitated spatial extrapolation of LiDAR-based carbon estimates to a total of 2,372,680 ha using satellite data. Remote, humid sub-montane forests harbored the highest carbon densities, while ACD was suppressed in dry spiny forests and in montane humid ecosystems, as well as in most lowland areas with heightened human activity. Independent of human activity, aboveground carbon stocks were subject to strong physiographic controls expressed through variation in tropical forest canopy structure measured using airborne LiDAR.Conclusions
High-resolution mapping of carbon stocks is possible in remote regions, with or without human activity, and thus carbon monitoring can be brought to highly endangered Malagasy forests as a climate-change mitigation and biological conservation strategy. 相似文献135.
Sven Klimpel Markus Wilhelm Busch Tracey Sutton Harry Wilhelm Palm 《Deep Sea Research Part I: Oceanographic Research Papers》2010,57(4):596-603
Seven meso- and bathy-pelagic fish species from the Mid-Atlantic Ridge (MAR) were firstly studied for fish parasites and feeding ecology. With a total of seven parasite species, the 247 meso- and bathy-pelagic deep-sea fish specimens belonging to the families Melamphaidae (3 spp.), Myctophidae (3 spp.) and Stomiidae (1 sp.) revealed low parasite diversity. The genetically identified nematodes Anisakis simplex (s.s.) and Anisakis pegreffii from the body cavity, liver and muscles of Myctophum punctatum were the most abundant parasites, reaching a prevalence of 91.4% and mean intensity of 3.1 (1–14). Anisakis sp. (unidentified) infected Chauliodus sloani and Poromitra crassiceps. Bothriocephalidean and tetraphyllidean cestode larvae infected Benthosema glaciale, the latter also occurring in C. sloani and Scopelogadus beanii, at low prevalences. Adult parasites at low infection rates included the digenean Lethadena sp. (2.9%), and the two copepod species Sarcotretes scopeli (5.7%) and Tautochondria dolichoura (5.3–11.4%). The myctophid Lampanyctus macdonaldi and the melamphaid Scopelogadus mizolepis mizolepis were free of parasites. Analyses of the stomach contents revealed crustaceans, especially copepods and euphausiids for the myctophids and also amphipods for the melamphaids as predominant prey items. While all stomachs showing distinct content comprising often unidentified ‘tissue’ (possibly gelatinous zooplankton), only C. sloani preyed upon fish. Though this feeding habit would enable transfer of a variety of crustacean-transmitted parasites into the fish, the parasite fauna in the meso- and bathy-pelagic fish was species poor. All observed parasites showed low host specificity, demonstrating no distinct pattern of host–parasite co-evolution. The MAR is no barrier for the parasite distribution in the North Atlantic meso- and bathy-pelagial. 相似文献
136.
The nature of Ultraluminous X-ray Sources – X-ray sources which exceed the Eddington luminosity for a ∼10 M
⊙ black hole – remains a mystery. One possible explanation is an inhomogeneous accretion disk around a solar mass black hole
where photon transport through radiation-pressure dominated “photon bubbles” can lead to super-Eddington accretion. While
previous studies of this model have focused primarily on its radiation-hydrodynamics aspects, here we explore some observational
implications of such a model with a Monte Carlo–Fokker Planck radiation transport code. 相似文献
137.
138.
An earthquake catalogue has been prepared for the whole area of Turkey (within latitudes 35.5° N to 42.5°N and longitudes 25.5°E to 45.0°E) for the years 1913 to 1970. By computer recalculation of all source parameters and by using a consistent system for magnitude determinations, we have aimed at the highest possible homogeneity and completeness within the limits given. 相似文献
139.
Markus Båth 《Earth》1981,17(4):315-398
The magnitude recommendations adopted by the IASPEI Assembly at Zürich in 1967 have had both a stabilizing and a stimulating effect on magnitude determinations and related research. From 1967 onwards, one magnitude research paper has appeared on the average almost every week, thus making this parameter the most studied one in seismology. New facilities and more accurate methods, e.g., concerning instrumental equipment and interpretation techniques, have made it possible to improve earlier achievements. The application of magnitude scales has been extended in all respects, e.g., with regard to epicentral distances, focal depths, wave types and wave periods. Magnitude—frequency relations have become the most investigated equations within seismology, observationally as well as theoretically. They have wide applications, e.g., for estimating the maximum magnitudes of future earthquakes — an important item in earthquake prediction. The magnitudes provide significant information on other source parameters, such as wave energy, fault length, seismic moment. Relations between different types of magnitude yield valuable information on source properties. For instance, relations between magnitudes based on body and surface waves are used for efficient discrimination between earthquakes and underground explosions. It is our purpose to review the magnitude development in the post-Zürich period (1967–1980), partly for geologists, tectonophysicists and engineers, who need an overview, partly for seismologists, who need an introduction to an overwhelmingly comprehensive literature. 相似文献
140.
Markus Båth 《Tectonophysics》1980,61(4):T15-T22
For Swedish earthquakes, the average magnitude increases gently with the focal depth, whereas the seismic wave energy exhibits significant maxima at 15, 23 and 28 km depth. The earthquake fracture risk is estimated to be about 10?6 for an underground storage facility in a carefully selected site. 相似文献