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991.
共享社会经济路径(Shared Socioeconomic Pathways, SSPs)是新一代气候变化情景的重要组成部分。SSPs从提出至今已有10年的发展,对于推动气候变化预估与影响研究、支撑气候政策决策的作用逐渐凸显。文中基于179篇主题检索文献分析了SSPs发展和应用的进展,以及在当前气候变化研究中的应用特点。研究发现,次国家和部门层面的SSPs故事线拓展开始兴起,水资源、土地和健康是影响评估领域的关注焦点,方法学上强调模型间耦合与多模型比较。当前SSPs在中国的发展与应用集中于基本要素的预估及气候影响评估,路径对各省间及城乡间社会经济发展差异的刻画有待加强。基于情景发展和应用的现状,最后从加强与气候建模团队的合作、支持影响与脆弱性研究、拓展全球情景、加强模型间比较、提高决策支持力5个方面讨论了SSPs的未来研究展望。  相似文献   
992.
Australia's vulnerability to climate variability and change has been highlighted by the recent drought (i.e. the Big Dry or Millennium Drought), and also recent flooding across much of eastern Australia during 2011 and 2012. There is also the possibility that the frequency, intensity and duration of droughts may increase due to anthropogenic climate change, stressing the need for robust drought adaptation strategies. This study investigates the socio-economic impacts of drought, past and present drought adaptation measures, and the future adaptation strategies required to deal with projected impacts of climate change. The qualitative analysis presented records the actual experiences of drought and other climatic extremes and helps advance knowledge of how best to respond and adapt to such conditions, and how this might vary between different locations, sectors and communities. It was found that more effort is needed to address the changing environment and climate, by shifting from notions of ‘drought-as-crisis’ towards acknowledging the variable availability of water and that multi-year droughts should not be unexpected, and may even become more frequent. Action should also be taken to revalue the farming enterprise as critical to our environmental, economic and cultural well-being and there was also strong consensus that the value of water should be recognised in a more meaningful way (i.e. not just in economic terms). Finally, across the diverse stakeholders involved in the research, one point was consistently reiterated: that ‘it's not just drought’. Exacerbating the issues of climate impacts on water security and supply is the complexity of the agriculture industry, global economics (in particular global markets and the recent/ongoing global financial crisis), and demographic changes (decreasing and ageing populations) which are currently occurring across most rural communities. The social and economic issues facing rural communities are not just a product of drought or climate change – to understand them as such would underestimate the extent of the problems and inhibit the ability to coordinate the holistic, cross-agency approach needed for successful climate change adaptation in rural communities.  相似文献   
993.
Agricultural risk management policies under climate uncertainty   总被引:1,自引:0,他引:1  
Climate change is forecasted to increase the variability of weather conditions and the frequency of extreme events. Due to potential adverse impacts on crop yields it will have implications for demand of agricultural risk management instruments and farmers’ adaptation strategies. Evidence on climate change impacts on crop yield variability and estimates of production risk from farm surveys in Australia, Canada and Spain, are used to analyse the policy choice between three different types of insurance (individual, area-yield and weather index) and ex post payments. The results are found to be subject to strong uncertainties and depend on the risk profile of different farmers and locations; the paper provides several insights on how to analyse these complexities. In general, area yield performs best more often across our countries and scenarios, in particular for the baseline and marginal climate change (without increases in extreme events). However, area yield can be very expensive if farmers have limited information on how climate change affects yields (misalignment in expectations), and particularly so under extreme climate change scenarios. In these more challenging cases, ex post payments perform well to increase low incomes when the risk is systemic like in Australia; Weather index performs well to reduce the welfare costs of risks when the correlation between yields and index is increased by the extreme events. The paper also analyses the robustness of different instruments in the face of limited knowledge of the probabilities of different climate change scenarios; highlighting that this added layer of uncertainty could be overcome to provide sound policy advice under uncertainties introduced by climate change. The role of providing information to farmers on impacts of climate change emerges as a crucial result of this paper as indicated by the significantly higher budgetary expenditures occurring across all instruments when farmers’ expectations are misaligned relative to actual impacts of climate change.  相似文献   
994.
Understanding the factors that give rise to greater or lesser adaptive capacity among households with in a community could allow government interventions to target the right groups of people. In this paper we study such factors, making use of a household survey administered in the Indian state of Odisha. In the survey, we queried respondents for the adaptations that they had engaged in to deal with the risk of drought, as well as a number of indicators for adaptive capacity taken from the literature. We found a large number of indicators of adaptive capacity to correlate with one or more adaptations taken. However, many of these indicators, while increasing the likelihood that one adaptation would be taken, also decreased the likelihood that another would be taken, and hence were not unambiguous determinants of greater adaptive capacity in general. One indicator, access to crop insurance, stood out as particularly effective: it correlated with an increased likelihood of engaging in two separate yield-raising adaptations, and correlated with a decreased likelihood of engaging in two additional adaptations that would have the effect of reducing yields. The results suggest that further attention to crop insurance may be warranted, as well as further research to determine if the other indicators may be effective in other contextual settings.  相似文献   
995.
The present study was undertaken to assess baseline distribution patterns for soil lichens occurring in the principal biomes of southern Africa, and to analyse their relationship to selected environmental parameters. Among the lichen species found across our survey sites, four distinct groups could be delineated, each as distinct consortium of lichen species sharing particular morphological characters (e.g. growth-form, pigmentation and type of photobiont kind). These groups are largely correlated with specific environmental parameters. These findings suggest that lichens may serve as valuable bioindicators for evaluating climate and soil change in this region of Africa.  相似文献   
996.
This paper presents characteristics of droughts simulated by global climate models (GCMs) under enhanced greenhouse gases conditions. We used a drought index called the Reconnaissance Drought Index (RDI) which takes both rainfall and potential evapotranspiration into account to investigate variations of droughts among 12 regions in Australia. The RDI was applied to simulated climate variables from 14 GCMs performed for the IPCC 4th Assessment Report.The results show a general increase in drought areal extent and/or frequency for most regions. However, the increases are not significant over the North West, North Queensland, Queensland East Coast and Central Queensland. For most regions, the change beyond 2030 is larger than that prior to 2030, but the uncertainty in the projections also increases with time. By 2030, there is a likely (>66% probability) risk of twice or more drought affected area and/or twice as often drought frequency over South West Western Australia. By 2050, this will include the Murray-Darling Basin, South Australia and Victoria, and by 2070 this will extend to New South Wales and Tasmania. For North Queensland such a risk is unlikely (<33% probability) for the next 100 years. This information can be considered indicative in long-term planning focussing on sustainability.  相似文献   
997.
According to trend computations at three stations each in Sahara desert (Libya), characterized by a “hot” desert type (“BWh”, according to the Koeppen climate classification), and in Central Asia (Xinjiang, China) identified as a “cold” desert type (“BWk”, after Koeppen), increasing annual temperatures were detected over the period 1955-2005 corresponding with global temperature warming. From 1955-1978, negative (decreasing) temperature trends were, however, observed at all three hot desert stations and at two of the three cold desert stations. From 1979-2005, strikingly positive temperature trends were seen at all six stations. In seasonal respects, winter (December to February) and summer (June to August) show different temperature trends over the period 1955-2005: the hot desert experienced an increasing temperature trend at a greater extent in summer than in winter; vice-versa, in the cold desert positive trends were computed for winter and negative for summer. It can also be observed that mostly hot desert warming occurred in summer, opposite to cold desert warming in winter.  相似文献   
998.
内蒙古草原的畜牧业气候   总被引:1,自引:1,他引:0  
孙金铸 《地理研究》1988,7(1):36-45
畜牧业的发展是我国农业发展的一个重要方面,天然牧草是畜牧业的主要物质基础,本文试图对影响牧草和牲畜的地理分布及生物生产力作一初步分析。  相似文献   
999.
A global to regional modeling system has been developed to evaluate precipitation under doubled CO2. The National Centers for Environmental Prediction (NCEP) regional spectral model (RSM) is initialized and forced by current and doubled CO2 simulations from the NCAR community climate model (CCM3). Three RSM simulations, RSM0, RSM1, and RSM2, with resolution of 280, 50 and 15 km, are examined. The RSM0 setup resolution matches the T42 CCM3 simulations. The RSM2 simulation is centered over Taiwan. Due to incompatibility of the model physics, noticeable differences between RSM0 and CCM3 are found, especially in wintertime, which suggests that simulation from RSM0, rather than CCM3, should be used to contrast high-resolution regional variations produced by RSM1 or RSM2 simulations.While the spatial distributions of RSM1 and RSM2 simulations over Taiwan are greatly improved over the CCM3 simulation, the intensity of the unique wintertime drizzle is overestimated, especially in RSM2. There is also a spurious northward extension of the precipitation pattern from the subtropical warm-pool region. Thus the regional response to doubled CO2, which consists of more summerlike wintertime precipitation characteristics over the northeastern and eastern sides of Taiwan, with increased intensity mostly in the extreme events, is still in doubt and must be examined with improved global and regional models.  相似文献   
1000.
本文从B.Saltzman的海温—海冰模式出发,得到了一个描述海冰范围变化的随机气候模型,接着对模型的性质进行了一些分析和讨论,并把从模型得到的模拟谱与计算的南极海冰扩展范围的观测谱做了比较。  相似文献   
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