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661.
南洋  张倩倩  张碧辉 《环境科学》2020,41(2):499-509
为探究中国典型区域地表PM2.5浓度长期时空变化及其影响因素,运用广义可加模型(GAM)对1998~2016年均0. 01°×0. 01°地表PM2.5浓度网格化数据进行分析.典型区域多年平均PM2.5浓度从高到低:华东华中地区(40. 5μg·m-3)>华北地区(37. 4μg·m-3)>华南地区(27. 8μg·m-3)>东北地区(23. 7μg·m-3)>四川盆地(22. 4μg·m-3).东北地区PM2.5年际变化呈现明显上升趋势;其他地区1998~2007年呈上升趋势,2008~2016年出现下降趋势.在典型区域PM2.5浓度空间分布上,PM2.5浓度分布呈现显著的空间差异,多年来各区域PM2.5浓度高值分布相对稳定. PM2.5浓度变化的单因素GAM模型中,所有影响因素...  相似文献   
662.
"3S"技术在生态环境动态监测中的应用研究   总被引:17,自引:0,他引:17  
针对传统生态环境动态监测方法的不足,论述了"3S"技术的特点与优势,并结合"四川省岷江中上游生态环境遥感综合调查与评价"项目,介绍了应用"3S"技术进行生态环境动态监测的方法和流程.  相似文献   
663.
新形势下,中国生态环境监测面临新任务和新挑战,迫切需要明确发展思路和方向。因此,从环境监测管理体系、业务体系、标准方法体系等方面,举例浅析了美国、欧盟等发达国家和地区环境监测业务的发展现状,并从法制建设、体系优化、方法标准等方面对比分析了中国与发达国家和地区的差异及不足,总结归纳了适用于中国国情的先进经验与启示。在此基础上,初步研判了当前和今后一段时期中国生态环境监测的发展方向,并提出了相关建议,为加快推动实现中国生态环境监测的跨越式发展提供参考和借鉴。  相似文献   
664.
This special issue of Disasters on humanitarian governance focuses on risk and order. Its contributions show the tensions between humanitarian normative ideals and practical consequences, as many of the ordering effects are associated with either intended or unintended consequences. This introduction offers a conceptual framing of humanitarian governance. Defining humanitarian governance as a subset of global governance, the paper shows how humanitarians have attempted to improve the consequences of their work by fighting instrumentalisation and instituting rationalisation processes. It adapts four questions, originally formulated by Michael Barnett ( 2013 ), to examine the ways in which humanitarian governance functions in more detail: what kind of world is being imagined and produced through the specific concern with order and risk? Who governs? How is this a form of humanitarian governance and how is it organised? And finally, what are the principal techniques of such governance? The conclusion summarises the main findings and sets an agenda for further research.  相似文献   
665.
The reintroduction of a species that is extinct in the wild demands caution because reintroduction locations may be associated with threats, such as hunting, poor-quality habitat, and climate change. This is the case for Cyanopsitta spixii (Spix's Macaw), which has been extinct in the wild since 2000. The few living individuals were created in captivity and will be used in a reintroduction project within the species’ original distribution area, the Caatinga domain (Brazil). Because the occurrence records for this bird are old and inaccurate, we investigated the current and future environmental suitability of the 14 plant species used by C. spixii as resource. These plants are key elements for the long-term reestablishment of the species in the wild, so the use of models helps in the assessment of the effects of climate change on the availability of these resources for the species and informs selection of the best places for reintroduction. We based our models of environmental suitability on 19 bioclimatic variables and nine physical soil and topography variables. Climate projections were created for the present and for the year 2070 with an optimistic (SSP2-4.5) and a pessimistic (SSP5-8.5) climate scenario. Both future climate scenarios lead to a reduction in area of environmental suitability that overlapped for all the plant species: 33% reduction for SSP2-4.5 and 63% reduction for SSP5-8.5. If our projections materialize, climate change could thus affect the distribution of key resources, and the maintenance of C. spixii would depend on restoration of degraded areas, especially riparian forests, and the preservation of already existing natural areas. The Caatinga domain is very threatened by habitat loss and, for the success of this reintroduction project, the parties involved must act to protect the species and the resources it uses.  相似文献   
666.
Temperature rise due to climate change is putting many arctic and alpine plants at risk of extinction because their ability to react is outpaced by the speed of climate change. We considered assisted species migration (ASM) and hybridization as methods to conserve cold-adapted species (or the genes thereof) and to minimize the potential perturbation of ecosystems due to climate change. Assisted species migration is the deliberate movement of individuals from their current location to where the species’ ecological requirements will be matched under climate projections. Hybridization refers to crossbreeding of closely related species, where for arctic and alpine plants, 1 parent is the threatened cold-adapted and the other its reproductively compatible, warm-adapted sibling. Traditionally, hybridization is viewed as negative and leading to a loss of biodiversity, even though hybridization has increased biodiversity over geological times. Furthermore, the incorporation of warm-adapted genes into a hybrid may be the only means for the persistence of increasingly more maladapted, cold-adapted species. If approached with thorough consideration of fitness-related parameters of the source population and acknowledgement of the important role hybridization has played in shaping current biodiversity, ASM and hybridization could help save partial or whole genomes of key cold-adapted species at risk due to climate change with minimal negative effects on ecosystem functioning.  相似文献   
667.
Current conservation templates prioritize biogeographic regions with high intensity ecosystem values, such as exceptional species richness or threat. Intensity-based targets are an important consideration in global efforts, but they do not capture all available opportunities to conserve ecosystem values, including those that accrue in low intensity over large areas. We assess six globally-significant ecosystem values—intact wilderness, freshwater availability, productive marine environments, breeding habitat for migratory wildlife, soil carbon storage, and latitudinal potential for range shift in the face of climate change—to highlight opportunities for high-impact broadly-distributed contributions to global conservation. Nations can serve as a cohesive block of policy that can profoundly influence conservation outcomes. Contributions to global ecosystem values that exceed what is predicted by a nation's area alone, can give rise to countries with the capacity to act as ‘conservation superpowers’, such as Canada and Russia. For these conservation superpowers, a relatively small number of national policies can have environmental repercussions for the rest of the world.  相似文献   
668.
The Kyoto Protocol on global warming has provoked great controversy in part because it calls for heavier burdens on wealthy countries than on developing countries in the effort to control climate change. The U.S. Senate voted unanimously to oppose any agreement that does not require emissions reductions in low-income countries. The ethics of this position are examined in this paper which shows that there are good moral reasons for supporting the provisions of the Kyoto Protocol. Such a conclusion follows easily from considerations of distributive justice but can also be supported by more narrowly self-interested arguments. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
669.
1960~2014年秦岭南北无霜期时空变化特征及对比分析   总被引:1,自引:0,他引:1  
全球气候变暖背景下,自然生态环境敏感区农业热量资源的时空特征研究具有重要的现实意义。依据1960~2014年秦岭南北47个气象站数据,利用线性趋势、M-K检验和kriging插值法对无霜期时空变化进行分析。结果显示:从时间上看,秦岭南北无霜期随纬度增加而减少,初霜日和无霜期在年际波动中略有下降后快速上升,终霜日在波动中略有上升后快速下降。55年来无霜期呈显著的延长趋势且发生增多突变,秦岭以北、秦岭南坡、汉水流域和巴巫谷地的延长速率分别为0.400 6、0.280 4、0.396 1和0.407 5 d/a,突变年份分别为1999、2002、2001和1990年。从空间上看,无霜期平均值和标准差由南向北增加,80%站点初霜日推后、终霜日提前和无霜期延长。多数无霜期延长是初霜日推后与终霜日提前的共同影响。无霜期在28个站点呈波动变化,19个站点发生突变,突变时间多在1990s~2000s,2000s的突变区域面积最大且集中分布在东北部。分析结果可为气候变化对生态环境和农业生产布局的影响提供参考。  相似文献   
670.
Responsive accommodation is a political strategy that addresses concerns about a policy proposal by incorporating amendments that address those concerns. This approach can broaden the policy’s appeal, but is strategically risky, as it can alienate the policy’s base of support. We examine this strategy and its application in the politics of climate change. Using a novel survey experiment, relative public support is evaluated for two amendments to a carbon tax proposal – revenue neutrality assurances and a carbon tariff – designed to ease concerns about taxes and global competitiveness. Analysis shows that support for a carbon tax increases when coupled with a carbon tariff, but decreases among some of the policy’s supporters when described as revenue-neutral. These results suggest that policymakers using a responsive accommodation strategy must carefully weigh its possible risks and rewards in their particular context.  相似文献   
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