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91.
92.
In a recently published paper, Worm et al. [Impacts of biodiversity loss on ocean ecosystem services. Science 2006;314:787–90.] project “the global collapse of all taxa currently fished” by 2048. Using their criteria and data, this paper shows that the number of not-collapsed fisheries actually increased over time to a plateau of about 5600 in 1985–2003. Furthermore, if trends are projected into the future, more than half of the world's fisheries would always be in a recovered state. 相似文献
93.
Trevor G. Dix 《新西兰海洋与淡水研究杂志》2013,47(2):363-374
Neopeltopsis pectinipes gen. et sp. nov. is described and figured from sublittoral marine algae at Wellington, New Zealand; the genus is an addition to the Peltidiidae Sars. The genus is compared with the other genera of the family, and a revised key is given to the genera of the Peltidiidae. 相似文献
94.
95.
Dust emission from wet and dry playas in the Mojave Desert,USA 总被引:1,自引:0,他引:1
Richard L. Reynolds James C. Yount Marith Reheis Harland Goldstein Pat Chavez Jr. Robert Fulton John Whitney Christopher Fuller Richard M. Forester 《地球表面变化过程与地形》2007,32(12):1811-1827
The interactions between playa hydrology and playa‐surface sediments are important factors that control the type and amount of dust emitted from playas as a result of wind erosion. The production of evaporite minerals during evaporative loss of near‐surface ground water results in both the creation and maintenance of several centimeters or more of loose sediment on and near the surfaces of wet playas. Observations that characterize the texture, mineralogic composition and hardness of playa – surfaces at Franklin Lake, Soda Lake and West Cronese Lake playas in the Mojave Desert (California), along with imaging of dust emission using automated digital photography, indicate that these kinds of surface sediment are highly susceptible to dust emission. The surfaces of wet playas are dynamic surface texture and sediment availability to wind erosion change rapidly, primarily in response to fluctuations in water‐table depth, rainfall and rates of evaporation. In contrast, dry playas are characterized by ground water at depth. Consequently, dry playas commonly have hard surfaces that produce little or no dust if undisturbed except for transient silt and clay deposited on surfaces by wind and water. Although not the dominant type of global dust, salt‐rich dusts from wet playas may be important with respect to radiative properties of dust plumes, atmospheric chemistry, windborne nutrients and human health. Published in 2007 by John Wiley & Sons, Ltd. 相似文献
96.
Ralph M. Gailis Alexander Hill Eugene Yee Trevor Hilderman 《Boundary-Layer Meteorology》2007,122(3):577-607
Fluctuating plume models provide a useful conceptual paradigm in the understanding of plume dispersion in a turbulent flow.
In particular, these models have enabled analytical predictions of higher-order concentration moments, and the form of the
one-point concentration probability density function (PDF). In this paper, we extend the traditional formalism of these models,
grounded in the theory of homogeneous and isotropic turbulent flow, to two cases: namely, a simple sheared boundary layer
and a large array of regular obstacles. Some very high-resolution measurements of plume dispersion in a water channel, obtained
using laser-induced fluorescence (LIF) line-scan techniques are utilised. These data enable us to extract time series of plume
centroid position (plume meander) and dispersion in the relative frame of reference in unprecedented detail. Consequently,
experimentally extracted PDFs are able to be directly compared with various theoretical forms proposed in the literature.
This includes the PDF of plume centroid motion, the PDF of concentration in the relative frame, and a variety of concentration
moments in the absolute and relative frames of reference. The analysis confirms the accuracy of some previously proposed functional
forms of model components used in fluctuating plume models, as well as suggesting some new forms necessary to deal with the
complex boundary conditions in the spatial domain. 相似文献
97.
Three and a half thousand packages of chemicals, including at least 956 containing hazardous substances were washed ashore on to the beaches of southern England. They were believed at the time to have come from the wreck of the Aeolian Sky. There is now a strong suspicion that half the packages, including 32 canisters of arsenic trichloride, were lost from the deck cargo of another vessel in the English Channel. Despite difficulties in identifying the contents of many unlabelled chemical packages found on the shore, most were recovered during clearance operations by Local Authorities. Although there was no evidence of any ecological damage, 20 people were taken to hospital for treatment or precautionary medical examinations following contact with opened or leaking packages. This incident raised questions regarding international reporting procedures, liability and compensation arrangements following losses of packaged chemical cargoes at sea. 相似文献
98.
99.
Brown seaweeds are often employed in single species toxicity testing to study the association between the pollutant and the biota in contaminated marine habitats. We have used Fucus serratus (Phaeophyta) from one Cu resistant and one non-resistant population to evaluate the effect of prior exposure to metal pollution on toxicological endpoints. Analysis of comparative toxicity was conducted for embryo rhizoid elongation and adult relative growth rate (RGR). Algae that had previously been exposed to Cu expressed consistently lower levels of sensitivity to Cu than those that had no history of exposure to the pollutant. For both non-resistant and resistant populations rhizoid length was a more sensitive endpoint than adult RGR. While early life history stages of brown algae are generally regarded as being pollution-sensitive and inhibition of spore and embryo rhizoid elongation is frequently used as endpoints in bioassays, the test results may be affected by prior exposure of the parent algae to the pollutant. We conclude that the effect of prior exposure should be considered when comparing endpoints between studies and when selecting material for future testing. 相似文献