首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   852篇
  免费   115篇
  国内免费   29篇
安全科学   25篇
废物处理   2篇
环保管理   447篇
综合类   249篇
基础理论   73篇
环境理论   31篇
污染及防治   42篇
评价与监测   14篇
社会与环境   75篇
灾害及防治   38篇
  2024年   4篇
  2023年   20篇
  2022年   40篇
  2021年   57篇
  2020年   59篇
  2019年   63篇
  2018年   60篇
  2017年   82篇
  2016年   101篇
  2015年   71篇
  2014年   30篇
  2013年   75篇
  2012年   22篇
  2011年   41篇
  2010年   22篇
  2009年   31篇
  2008年   38篇
  2007年   31篇
  2006年   28篇
  2005年   16篇
  2004年   19篇
  2003年   11篇
  2002年   8篇
  2001年   9篇
  2000年   9篇
  1999年   8篇
  1998年   2篇
  1997年   4篇
  1996年   3篇
  1995年   5篇
  1994年   1篇
  1993年   5篇
  1991年   1篇
  1989年   1篇
  1988年   1篇
  1987年   4篇
  1986年   3篇
  1985年   2篇
  1984年   1篇
  1981年   1篇
  1980年   1篇
  1979年   3篇
  1975年   1篇
  1974年   1篇
  1968年   1篇
排序方式: 共有996条查询结果,搜索用时 15 毫秒
711.
ABSTRACT

What would it mean to conceptualize some environmental relationships as bundles of rights, rather than as a good as generally defined by liberalism? Environmental rights are a category of human rights necessarily central to both democracy and global environmental protection and governance (ecological democracy). The world of democratic politics and governance since mid-twentieth century has been transformed by a rights revolution in which recognized rights have come to constitute a ‘global normative order.’ There are several policy spaces in which persuasive environmental rights discourses have been emerging from existing or foreseeable congruences of elite and popular environmental norms, including (1) rights involving access to information and decision-making processes; (2) rights ensuring access to food and water; and (3) rights providing environmental security to all. We analyze these three rights discourses and assess their current and necessary future trajectories. We identify next steps in achieving better understanding and more meaningful establishment of environmental rights and their integration into our thinking about human rights, with attention to how they can be reconciled with the social and cultural diversity of democratic environmental governance in coming turbulent times.  相似文献   
712.
Radionuclide wash-off is the transport of activity by flowing water over the soil surface (runoff). To complete existing reviews on long-term removal rates, this paper focuses on short-term wash-off fluxes, quantified in the literature by soil-runoff transfer factors called normalized liquid and solid entrainment coefficients (noted K(l)(*), K(s)(*)). Compiled data concerned essentially (137)Cs and (90)Sr wash-off measured under simulated rainfalls on small experimental plots after Chernobyl fallout in the exclusion zone. K(l)(*) and K(s)(*) values span approximately one order of magnitude. Their validity is limited to a season, and their representativeness is limited by restricted studied situations, notably dominant unsoluble forms in fallout, light soils and intense rainfalls. Formulas based on a simplified representation of the soil-runoff system were proposed to generalize the existing values for other conditions. However, their implementation requires a more systematic compilation of the available information, including decisive influence factors such as the fraction of exchangeable form, distribution coefficient, suspended matter enrichment ratio. Entrainment coefficients K(l)(*) and K(s)(*) were mathematically related to the transfer function approach. The proposed relationships proved their complementarity in terms of time support and captured fluctuations. Both approaches should be used in assessments to estimate average fluxes and their variability.  相似文献   
713.
Conceptual modeling is a useful tool for identifying pathways between drivers, stressors, Valued Ecosystem Components (VECs), and services that are central to understanding how an ecosystem operates. The St. Jones River watershed, DE is a complex ecosystem, and because management decisions must include ecological, social, political, and economic considerations, a conceptual model is a good tool for accommodating the full range of inputs. In 2002, a Four-Component, Level 1 conceptual model was formed for the key habitats of the St. Jones River watershed, but since the habitat level of resolution is too fine for some important watershed-scale issues we developed a functional watershed-scale model using the existing narrowed habitat-scale models. The narrowed habitat-scale conceptual models and associated matrices developed by Reiter et al. (2006) were combined with data from the 2002 land use/land cover (LULC) GIS-based maps of Kent County in Delaware to assemble a diagrammatic and numerical watershed-scale conceptual model incorporating the calculated weight of each habitat within the watershed. The numerical component of the assembled watershed model was subsequently subjected to the same Monte Carlo narrowing methodology used for the habitat versions to refine the diagrammatic component of the watershed-scale model. The narrowed numerical representation of the model was used to generate forecasts for changes in the parameters “Agriculture” and “Forest”, showing that land use changes in these habitats propagated through the results of the model by the weighting factor. Also, the narrowed watershed-scale conceptual model identified some key parameters upon which to focus research attention and management decisions at the watershed scale. The forecast and simulation results seemed to indicate that the watershed-scale conceptual model does lead to different conclusions than the habitat-scale conceptual models for some issues at the larger watershed scale.  相似文献   
714.
We used a GIS-based approach to examine the influence of road density and physical watershed features (watershed size, wetland cover, and bedrock type) on water quality in coastal marshes of Georgian Bay, Ontario. We created a GIS that included landscape information and water-quality data from a 9-year synoptic survey of 105 coastal marshes covering 28 quaternary watersheds. Multiple regressions and partial correlations were used to discern confounding effects of human-induced (road density) versus natural physical watershed determinants of water quality. Road density was the dominant factor influencing many water quality variables, showing positive correlations with specific conductivity (COND), total suspended solids (TSS), and inorganic suspended solids (ISS) and a negative correlation with overall Water Quality Index scores. Road density also showed positive correlations with total nitrate nitrogen (TNN) and total phosphorus (TP). By comparison, larger watershed area was the main factor leading to elevated TP concentrations. The proportion of the watershed occupied by wetlands explained the largest amount of variation in TNN concentrations (negative correlation) and was also negatively correlated with COND and positively correlated with TSS and ISS when we controlled for road density. Bedrock type did not have a significant effect in any of the models. Our findings suggest that road density is currently the overriding factor governing water quality of coastal marshes in Georgian Bay during the summer low-flow period. We recommend that natural variation in physical watershed characteristics be considered when developing water quality standards and management practices for freshwater coastal areas.  相似文献   
715.
The quest for sustainable communities might be fostered by a new ‘place-based’ governing approach that engages civil society and other actors in local decision-making processes. In Canada, lessons can be learned from the establishment and maintenance of biosphere reserves by networks of local communities of interests and other organisations. Biosphere reserves are created to promote conservation, biodiversity and sustainable livelihoods. Municipal and public participation in these reserves can be encouraged, promoting a local sense of place as well as sustainable community and regional development. An examination of two Canadian biosphere reserves, Riding Mountain and Long Point, illustrates how local governments and these reserves might assist each other in their mutual goals of long-term sustainability while offering a worthwhile model of local collaborative, place-based governance.  相似文献   
716.
在环境治理的问题上,20世纪人类社会所表现出来的是一种对契约、技术与制度的崇尚,反映了近代以来社会治理中的价值中立与道德祛魅精神。然而,随着环境危机事件的频发,特别是在环境以及生态问题构成了风险社会的一个重要维度的情况下,依靠契约、制度、技术的环境治理方案陷入低效甚至失灵的境地。人类命运共同体理念的提出,开拓了环境治理的新思路,让我们看到构建人与人、人与自然生命共同体的环境合作治理模式建立的希望。环境合作治理是一种可以将所有力量整合到合作行动体系中的治理模式,能够有效应对日趋恶化的环境问题,并将人类的生存与发展建立在环境友好的基础上。只有当环境治理采用了合作模式,才能在环境的维度上增强人类命运共同体的现实性。  相似文献   
717.
Deliberative forms of stakeholder participation have been widely embraced as a key measure for addressing legitimacy deficits and non-compliance in environmental governance. However, the great significance of such collaborative structures for state-stakeholder interaction is much too often accepted uncritically as an established truth in the environmental policy discourse. Building on examples from the literature on fisheries co-governance, this article constructs a conceptual and normative framework for interpreting and assessing such views about co-governance, legitimacy and compliance. Analysing central claims in this discourse in relation to different concepts and standards of legitimacy helps us identify and distinguish many powerful reasons to welcome co-governance. However, the article defends the need to do so cautiously and reflectively. It is conceptually misleading to suggest that more intense forms of co-governance will generally improve the overall level of social legitimacy and, thereby, compliance rates among stakeholders. Furthermore, it is argued that the democratic value of co-governance is not fundamental. The democratic desirability of such arrangements should be primarily assessed on instrumental-pragmatic grounds, focusing on their capacity to serve the wider ideals of equal citizenship and public reason.  相似文献   
718.
与传统城镇化相比,新型城镇化具有"以人为本、四化同步、优化布局、生态文明、文化传承"的特点。在生态文明、新型城镇化建设全面推进的背景下,如何解决城镇化建设过程中的城市生态环境问题,优化空间布局,促进区域可持续发展,成为亟需解决的重大问题。本文基于城乡耦合系统理论,提出通过城镇规模和空间优化、功能完善提升生态环境管治。针对我国城镇化发展现状,本文认为新型城镇体系下的生态环境管治应基于城镇的资源环境承载能力,在新型城镇化建设中努力夯实生态环境的基础性地位,充分发挥生态环境约束的先导作用,并通过实施有效的城镇生态环境功能分区管治策略、提升生态环境空间管治效率、构建政企民共同参与的新型城镇生态环境治理体系等措施来提升生态环境管治能力。  相似文献   
719.
为了阐明三峡库区第一大支流香溪河流域人类活动对磷输入的影响程度,收集流域所涉及的2001~2019年的乡镇统计数据,运用改进的人类活动净磷输入(NAPI)模型,分析了该流域NAPI的发展趋势.结果表明:在时间尺度上,香溪河流域2001~2019年的NAPI整体呈下降趋势;在空间尺度上,NAPI呈现东北部高于西南部的趋势,影响香溪河流域NAPI的主要乡镇为黄粮镇、峡口镇和昭君镇,占香溪河流域NAPI的63.8%;河流磷输出占NAPI的百分比为10.7%~79.5%;从NAPI结构上看,影响香溪河流域NAPI主要的影响因素为磷肥施入量,占香溪河流域NAPI的46%~68%,次要影响因素为食物磷和磷化工及磷矿开采导致磷素释放量,分别占香溪河流域NAPI的14%~32%和16%~24%;从NAPI影响因素上看,NAPI与人口密度和耕地面积占比均呈极显著正相关(P<0.001),而在小流域研究尺度上,NAPI与河流磷输出的相关性不显著(P>0.05),不具有直接的响应关系.因此,香溪河流域磷素管理应优先考虑重点区域(黄粮镇、峡口镇和昭君镇),控制化肥施用量,并提高工厂污染物排放标准.  相似文献   
720.
分析绿洲人工灌排技术发展和耕地格局变化之间的关系,对研究干旱区灌溉农业发展具有重要的意义。论文选取玛纳斯河流域为研究区,利用RS和GIS技术,对玛纳斯河流域1960年地形图,1976、1989、1997、2006、2013年Landsat遥感影像和历史水利工程建设分布图等原始数据进行处理,获得5期人工灌排渠系矢量图和6期土地利用分类矢量图,并计算人工灌排渠系长度指数和表征耕地格局的绿洲垦殖率、净耕地系数、周长面积比;利用多元逐步回归法,分析干旱区绿洲人工灌排技术对耕地格局变化的影响。结果表明:滴灌技术应用前,玛纳斯河流域耕地分布格局由灌排渠系的空间分布决定,尤其是农渠的分布格局和长度,其与耕地面积的回归方程为y=0.43x+7.38(R~2=0.90,n=33,P=0);滴灌技术应用后,耕地分布格局的变化取决于滴灌系统管网的空间分布,尤其是干管和支管的分布格局与长度,导致流域灌溉水利用系数从1960年的0.38增长到2010年的0.65。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号