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821.
Tuomo M. Saloranta 《Climatic change》2001,50(4):395-404
Science has recently faced a new challenge in that it must now provide itsbest knowledge to support the urgent policy-making concerning, e.g., risks oftechnology, environmental pollution, or the climate change. However, thisknowledge unfortunately often can host high uncertainties as the naturalsystems are complex. How to proceed when the facts given by the scientists arediverging and uncertain, while the decision-making is urgent? Funtowicz andRavetz (1992, 1993) argue that in this case traditional `Normal' science(described by Kuhn (1970)) becomes inappropriate and that science shouldbecome `Post-Normal' in order to more effectively cope with these contemporaryproblems. The philosophy, or methodology, of Post-Normal Science is brieflyintroduced and its corelation with the climate change issue, specifically withthe compilation process and summary content of the Second Assessment Report(SAR) from the Working Group I of the Intergovernmental Panel on ClimateChange (IPCC, 1996a), is viewed. It seems that climate science around IPPCcan, to a relatively large extent, be characterized as `Post-Normal'.Moreover, results from some related studies indicate that the elements ofPost-Normal Science in the IPCC have enhanced the problem-solving in theclimate change issue. 相似文献
822.
The Madden?CJulian oscillation (MJO) is the most prominent form of tropical intraseasonal variability. This study investigated the following questions. Do interannual-to-decadal variations in tropical sea surface temperature (SST) lead to substantial changes in MJO activity? Was there a change in the MJO in the 1970s? Can this change be associated to SST anomalies? What was the level of MJO activity in the pre-reanalysis era? These questions were investigated with a stochastic model of the MJO. Reanalysis data (1948?C2008) were used to develop a nine-state first order Markov model capable to simulate the non-stationarity of the MJO. The model is driven by observed SST anomalies and a large ensemble of simulations was performed to infer the activity of the MJO in the instrumental period (1880?C2008). The model is capable to reproduce the activity of the MJO during the reanalysis period. The simulations indicate that the MJO exhibited a regime of near normal activity in 1948?C1972 (3.4?events?year?1) and two regimes of high activity in 1973?C1989 (3.9 events) and 1990?C2008 (4.6 events). Stochastic simulations indicate decadal shifts with near normal levels in 1880?C1895 (3.4 events), low activity in 1896?C1917 (2.6 events) and a return to near normal levels during 1918?C1947 (3.3 events). The results also point out to significant decadal changes in probabilities of very active years (5 or more MJO events): 0.214 (1880?C1895), 0.076 (1896?C1917), 0.197 (1918?C1947) and 0.193 (1948?C1972). After a change in behavior in the 1970s, this probability has increased to 0.329 (1973?C1989) and 0.510 (1990?C2008). The observational and stochastic simulations presented here call attention to the need to further understand the variability of the MJO on a wide range of time scales. 相似文献
823.
Institutional Adaptation of Water Resource Infrastructures to Climate Change in Eastern Ontario 总被引:1,自引:1,他引:1
Institutional barriers and bridges to local climate change impacts adaptation affecting small rural municipalities and Conservation Authorities (CAs are watershed agencies) in Eastern Ontario (Canada) are examined, and elements of a community-based adaptation strategy related to water infrastructures are proposed as a case-study in community adaptation to climate change. No general water scarcity is expected for the region even under unusually dry weather scenarios. Localized quantity and quality problems are likely to occur especially in groundwater recharge areas. Some existing institutions can be relied on by municipalities to build an effective adaptation strategy based on a watershed/region perspective, on their credibility, and on their expertise. Windows of opportunity or framing issues are offered at the provincial level, the most relevant one in a federal state, by municipal emergency plan requirements and pending watershed source water protection legislation. Voluntary and soon to be mandated climate change mitigation programs at the federal level are other ones. 相似文献
824.
Summary In the present paper, a model for the diffusion of material from a point source in an urban atmosphere is incorporated. The
plume is assumed to have a well-defined edge at which the concentration falls to zero. The vertical wind shear is estimated
using logarithmic law, by employing most of the available techniques of stability categories. The concentrations estimated
from the model were compared favorably with the field observations of other investigators. 相似文献
825.
M. M. Ivanov N. N. Ivanova V. N. Golosov E. N. Shamshurina 《Geography and Natural Resources》2016,37(4):355-361
We examine the use of two alternative techniques for assessing the redistribution volumes of sorbed 137Cs within the upper components of the fluvial network, based on the concept of catchment as a lithodynamical system. In terms of one of them, we made a substantive analysis of changes in reserves on accumulative positions where the 137Cs distribution curves showed a significant increase in radionuclide content levels. We carried out a typization o the accumulation surfaces in order to extrapolate data, obtained for a group of soil profiles, to the territory of the entire catchment and to make a direct assessment of the increases in accumulation. An alternative technique was used to assess the volumes of accumulated sediment loads on accumulative positions by analyzing the 137Cs distribution curves, and to correlate with denudation zones in the drainage area under consideration. Values of the wash-out rates for the period 1986–2012 have been obtained, which are necessary for the formation of the accumulative layer observed. We calculated the volume of 137Cs swept away during 26 years after the Chernobyl accident, based on information regarding the volumes of initial reserves in the denudation zones and a correlation between the erosion rate and a specific reduction in reserves. It is established that the technique on the basis of analyzing the wash-out zones featuring high economical efficiency can be used in assessing 137Cs migration for larger territories with relatively low labor-consuming effort. 相似文献
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