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   1637篇
  免费   44篇
  国内免费   35篇
安全科学   113篇
废物处理   11篇
环保管理   348篇
综合类   730篇
基础理论   184篇
环境理论   2篇
污染及防治   79篇
评价与监测   159篇
社会与环境   69篇
灾害及防治   21篇
  2024年   3篇
  2023年   14篇
  2022年   14篇
  2021年   29篇
  2020年   58篇
  2019年   19篇
  2018年   16篇
  2017年   45篇
  2016年   50篇
  2015年   43篇
  2014年   60篇
  2013年   75篇
  2012年   65篇
  2011年   112篇
  2010年   80篇
  2009年   130篇
  2008年   89篇
  2007年   106篇
  2006年   94篇
  2005年   82篇
  2004年   56篇
  2003年   78篇
  2002年   72篇
  2001年   43篇
  2000年   58篇
  1999年   42篇
  1998年   29篇
  1997年   18篇
  1996年   19篇
  1995年   23篇
  1994年   9篇
  1993年   23篇
  1992年   19篇
  1991年   9篇
  1990年   8篇
  1989年   5篇
  1988年   3篇
  1987年   4篇
  1986年   3篇
  1985年   2篇
  1983年   1篇
  1982年   1篇
  1981年   3篇
  1980年   2篇
  1977年   1篇
  1973年   1篇
排序方式: 共有1716条查询结果,搜索用时 226 毫秒
431.
通过对铁岭市农村生态环境存在的主要问题进行了较为详细的分析,并提出了一系列治理对策。  相似文献   
432.
我国城市生态承载力研究进展   总被引:1,自引:0,他引:1  
从生态承载力角度研究区域资源-生态-环境问题,是当今生态学、地理学和经济学等学科研究的热点与前沿领域之一。依据现有研究成果,阐述了承载力的概念和什么是城市生态承载力,并对生态承载力的研究方法、研究趋势及其研究存在的问题和方法途径及提高城市生态承载力的对策建议进行了简述。  相似文献   
433.
We conducted a study of the institutional barriers to introducing urine source separation in the urban area of Kunming, China. On the basis of a stakeholder analysis, we constructed stakeholder diagrams showing the relative importance of decision-making power and (positive) interest in the topic. A hypothetical decision-making process for the urban case was derived based on a successful pilot project in a periurban area. All our results were evaluated by the stakeholders. We concluded that although a number of primary stakeholders have a large interest in testing urine source separation also in an urban context, most of the key stakeholders would be reluctant to this idea. However, the success in the periurban area showed that even a single, well-received pilot project can trigger the process of broad dissemination of new technologies. Whereas the institutional setting for such a pilot project is favorable in Kunming, a major challenge will be to adapt the technology to the demands of an urban population. Methodologically, we developed an approach to corroborate a stakeholder analysis with the perception of the stakeholders themselves. This is important not only in order to validate the analysis but also to bridge the theoretical gap between stakeholder analysis and stakeholder involvement. We also show that in disagreement with the assumption of most policy theories, local stakeholders consider informal decision pathways to be of great importance in actual policy-making.  相似文献   
434.
The restoration of degraded systems is essential for maintaining the provision of valuable ecosystem services, including the maintenance of aesthetic values. However, restoration projects often fail to reach desired goals for a variety of ecologic, financial, and social reasons. Feasibility studies that evaluate whether a restoration effort should even be attempted can enhance restoration success by highlighting potential pitfalls and gaps in knowledge before the design phase of a restoration. Feasibility studies also can bring stakeholders together before a restoration project is designed to discuss potential disagreements. For these reasons, a feasibility study was conducted to evaluate the efficacy of restoring a tidal freshwater marsh in the Potomac River near Alexandria, Virginia. The study focused on science rather than engineering questions, and thus differed in approach from other feasibility studies that are mostly engineering driven. The authors report the framework they used to conduct a feasibility study to inform other potential restoration projects with similar goals. The seven steps of the framework encompass (1) initiation of a feasibility study, (2) compilation of existing data, (3) collection of current site information, (4) examination of case studies, (5) synthesis of information in a handbook, (6) meeting with selected stakeholders, and (7) evaluation of meeting outcomes. By conducting a feasibility study using the seven-step framework, the authors set the stage for conducting future compliance studies and enhancing the chance of a successful restoration.  相似文献   
435.
The recently-adopted global Sustainable Development Goals (SDGs) will have significant implications for national development planning in both developed and developing countries in the post-2015 period to 2030. Integrated, nationally-owned SDG strategies will be at the centre of national efforts to implement the new sustainable development agenda. The long-run processes and systems perspective that are inherent in the SDGs present complex analytical problems for policymakers and analysts. Scenario analysis and quantitative modelling will be important analytical tools to support national sustainable development planning, and there is an increasingly sophisticated suite of models available to decision makers. This paper reviews and assesses a broad range of different quantitative models that have the potential to support national development planning for the SDGs. The study develops a typology and inventory of 80 different models, and then reviews the comparative strengths, weaknesses and general utility of different models through an initial screening and subsequent multi-criteria analysis of short-listed models. Current gaps in model capabilities are highlighted in the context of providing analytical support for national development planning for the SDGs. While some existing models are particularly relevant, it is unlikely that an ideal model can analyse all SDG targets and variables of interest within a single modelling framework. Top-down ‘macro framework’ models are likely to be more useful for undertaking system-level or economy-wide scenario analysis driven by the national long-term goals and targets, and for exploring trade-offs and synergies among sectors. Bottom-up sectoral models will be able to support far more detailed option-level impact analysis of concrete interventions, technologies and investments. Combining both approaches within an analytical framework will provide a robust approach for analysis and decision-making. The results highlight a range of potential gaps in current modelling capabilities, and provide some new tools to assist with model selection.  相似文献   
436.
ABSTRACT

Ecological democracy seeks environmentally sustainable ends through broad, active democratic participation. What happens when laws fostering participation in environmental decision-making and biodiversity preservation lead to differing results? What is best for biodiversity may not be what for local citizens believe is best. I examine conflicts and congruencies in the context of Biodiversity Offsetting, REDD+ (Reducing Emissions from Deforestation and forest Degradation), and the Rewilding movement. I ask questions that are legal (Who has what legal rights to speak for or against programs that enhance biodiversity?), epistemological (Whose expertise and knowledge matters when scientists and non-scientists don't agree?), axiological (Are some values objectively better, and why?), and normative (Whose opinions about biodiversity should count?). Many people have the right to participate in an ecological democracy: But when protecting biodiversity, who does and should have the right to be heard? I problematize the role that ‘local’ actors play in decision-making and describe the variegated role that experts – particularly biologists – play in ecological democracy when biodiversity preservation matters. To determine whose values and voices should be prioritized, I describe ‘deep equity,’ an axiological and normative groundwork for determining when biodiversity-promoting policies may be preferable even if affected citizens don't agree.  相似文献   
437.
ABSTRACT

Concepts of ecological and environmental democracy seek to reconcile two normative ideals: ensuring environmental sustainability while safeguarding democracy. These ideals are frequently conceived as being in conflict, as democracy is perceived as too slow and cumbersome to deliver the urgent large-scale collective action needed to tackle environmental problems. Theories addressing the democracy-environment nexus can be situated on a spectrum from theories of ecological democracy that are more critical of existing liberal democratic institutions to theories of environmental democracy that call for reforming rather than radically transforming or dismantling those institutions. This article reviews theoretical and empirical scholarship on the democracy-environment nexus. We find continued theoretical and empirical diversity in the field, as well as vibrant debates on democratising global environmental politics, local material practices, and non-human representation. We argue for stronger dialogue between environmental political theory and empirical, policy-oriented research on democracy and sustainability, as well as further exploration of complementarities between ecological and environmental democracy. We identify four main areas of challenge and opportunity for theory and practice: public participation and populism; technocracy and expertise; governance across scales; and ecological rights and limits.  相似文献   
438.
A process has been developed to select watersheds that are representative of terrestrial ecoregions and that are relatively undisturbed by human activity. Using an existing land classification system at two hierarchical levels of resolution, representative subsets (ecodistricts) of large-scale ecoregions were selected, on the basis of their physiographic, biological, and climatological attributes, to represent the ecoregions. This was achieved using a frequency distribution analysis of existing attribute data and choosing the ecodistrict most closely resembling the most common set of conditions for that ecoregion. Within each ecodistrict, river basins were selected through a best-judgement evaluation of land use, coupled with an assessment of the size and location of each river basin, in order to meet the condition of minimal human impact. Preliminary assessment of water quality data collected from six watersheds selected in this way suggests that the process is effective in targeting regional scale river basins exhibiting the desired characteristics.  相似文献   
439.
The United States Environmental Protection Agency, with support from the US Department of Energy and the National Oceanographic and Atmospheric Administration, has been evaluating the feasibility of an effects-based (critical loads) approach to atmospheric pollutant regulation and abatement. The rationale used to develop three of the six steps in a flexible assessment framework (Strickland and others, 1992) is presented along with a discussion of a variety of implementation approaches and their ramifications. The rationale proposes that it is necessary to provide an explicit statement of the condition of the resource that is considered valuable (assessment end point) because: (1) individual ecosystem components may be more or less sensitive to deposition, (2) it is necessary to select indicators of ecosystem condition that can be objectively measured and that reflect changes in the quality of the assessment end point, and (3) acceptable status (i.e., value of indicator and quality of assessment end point at critical load) must be defined. The rationale also stresses the importance of defining the assessment regions and subregions to improve the analysis and understanding of the indicator response to deposition. Subregional definition can be based on a variety of criteria, including informed judgment or quantitative procedures. It also depends on the geographic scale at which exposure and effects models are accurate and on data availability, resolution, and quality. The research described in this article has been funded by the US Environmental Protection Agency. This document has been prepared at the EPA Environmental Research Laboratory in Corvallis, Oregon, through contract #68-C8-0006 with ManTech Environmental Technology, Inc., and Interagency Agreement #1824-B014-A7 with the US Department of Energy and at Oak Ridge National Laboratory managed by Martin Marietta Energy Systems, Inc., under Contract DE-AC05-84OR21400 with the US Department of Energy. Environmental Sciences Division Publication No. 3903. It has been subjected to the agency’s peer and administrative review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.  相似文献   
440.
本文把森林灭火看成是一个系统,称为灭火系统.文中用最优化方法讨论了这个系统.  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