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   208篇
  免费   8篇
  国内免费   4篇
安全科学   19篇
废物处理   6篇
环保管理   55篇
综合类   38篇
基础理论   37篇
环境理论   13篇
污染及防治   25篇
评价与监测   14篇
社会与环境   10篇
灾害及防治   3篇
  2023年   2篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2019年   12篇
  2018年   2篇
  2017年   11篇
  2016年   15篇
  2015年   10篇
  2014年   7篇
  2013年   19篇
  2012年   15篇
  2011年   19篇
  2010年   12篇
  2009年   6篇
  2008年   14篇
  2007年   21篇
  2006年   7篇
  2005年   10篇
  2004年   3篇
  2003年   4篇
  2002年   2篇
  2001年   8篇
  2000年   1篇
  1999年   4篇
  1998年   3篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1991年   1篇
  1987年   1篇
  1985年   1篇
  1984年   1篇
  1978年   1篇
排序方式: 共有220条查询结果,搜索用时 281 毫秒
1.
从欧盟空气质量监测政策和监测网络建设现状两个方面描述了欧盟空气质量监测发展现状。分析了我国空气污染现状和空气质量监测体系中存在的问题,并借鉴欧盟的经验,提出了加大政策支持和财政保障力度、逐步健全空气质量监测网络体系、加强空气质量监测技术研究、完善空气质量监测数据库、开展能力建设、提高公众参与度等加强我国空气质量监测体系建设的建议。  相似文献   
2.
3.
Mycorrhiza is the main spatial and temporal linkage between different constituents in a forest ecosystem. The functional compatibility and stress tolerance of ectomycorrhizal types is species specific, and therefore the information on the ectomycorrhizal community structure can add to the understanding of processes in forest ecosystems and can also be applied as tools for bioindication of pollution stress in forest soils. We have studied the effects of pollution (N and S) on trees and forest soils by: (1) quantification of ECM types diversity as in situ indicators in forest stands, (2) determination and quantification of pollution-sensitive or -insensitive ECM types as passive monitors, (3) root growth and development of ECM on nonmycorrhizal spruce seedlings, planted at the studied sites (active monitors), and (4) ECM infection (a bioassay based on mycorrhizal inoculum potential) of seedlings in an experimental set-up as ex situ testers. ECM species richness for Norway spruce trees (Picea abies) showed higher values in unpolluted sites than in polluted ones, while the differences were not significant for European beech trees (Fagus sylvatica). As pollution-sensitive or -insensitive ECM species in spruce forests, we suggest Hydnum rufescens (sensitive) and Paxillus involutus (unsensitive). Mycorrhizal potential in Norway spruce seedlings as a bioassay for soil N and S pollution was effective, and is suggested as an additional, standardized and widely comparable system in bioindication of soil pollution.  相似文献   
4.
Sequential extraction of metals from solid media is a common analytical tool used in environmental and exploration geochemistry. A number of procedures exist, but without harmonization and standardization, meaningful comparisons are tenuous without baseline data. A newly developed, standardized sequential extraction procedure (optimized BCR) was applied to two contaminated certified reference soils from Montana, US (SRM 2710 and SRM 2711) for Cu, Pb and Zn. Four operationally defined fractions were isolated, acid extractable, reducible, oxidizable, and residual (by aqua regia). Fraction-specific concentrations, percentages and recoveries for Cu, Pb and Zn were used to explore differences between the optimized BCR procedure and three other sequential extraction schemes with published data for SRM 2710 and 2711 (i.e. Tessier scheme, Geological Survey of Canada scheme and the original BCR scheme). Results indicate significant differences between the four schemes, even for schemes that are closely associated (i.e. the original and optimized BCR schemes). Order-of-magnitude fraction-specific concentration differences were observed, especially for Pb in the reducible fraction. Differences between schemes are worrisome because trends varied between metals, between fractions and between reference soils. These data reinforce the need for increased adoption of standardized sequential extraction procedures and further examination of different solid media.  相似文献   
5.
Ten out of the 12 new EU members, used to belong to the so-called “former eastern block”, with a post WWII environmental policy radically different from the tendencies followed in Western Europe. The lack of conservation regulations has resulted in a rather harmful industrialization, regarding natural resources and environmental quality. While air pollution transfer is a phenomenon of transboundary level, there is a particular interest in examining the contribution of the new EU member states to the environmental pressure faced by the older member states and vice versa. The current study utilises the official data for almost 20 years published by the European Monitoring and Evaluation Program concerning the transboundary transfer of NOx and SO2 in order to analyse the situation and discuss the present and future environmental policy regarding air pollution.  相似文献   
6.
The article contributes to a discussion on two global issues on water: water resources management, and water supply and sanitation. Focusing on Europe, it traces the legal roots of current systems in history: as a resource, water is considered as a common property, rather than a market good; while as a public service it is usually a commodity. Public water supply and sanitation technologies and engineering have developed under three main paradigms: quantitative and civil engineering; qualitative and chemical/sanitary engineering (both on the supply side); and the most recent one, environmental engineering and integrated management (on the demand side). The cost of public drinking water is due to rise sharply in view of the two‐fold financial challenge of replacing an ageing infrastructure and keeping up with ever‐rising environmental and sanitary quality standards. Who will pay? Government subsidies, or water users? The author suggests that apparent successes with privatisation may have relied heavily on hidden government subsidies and/or the healthy state of previously installed water infrastructure: past government subsidies are still felt for as long as the lifetime of the infrastructure. The article stresses the importance of public participation and decentralized local management of water and sanitation services. Informing and involving users in water management decisions is seen as an integral part of the ‘ethics’ side of the crucial three E's (economics, environment, ethics). The article strongly argues for municipal provision of water services, and hopes that lessons learnt and solutions found in the European experience may serve water services management efforts in other regions of the world.  相似文献   
7.
In response to the extreme flood events of recent decades, the European Union has released the Floods Directive (2007/60/EC), which requires the creation of flood risk management plans. These plans do not yet exist in practice, as water management agencies have until 2015 to put them into action. This contribution will discuss two questions regarding the European flood risk management plan: First, how is the new instrument integrated into the various member states, particularly with respect to the scenario approach? Second, how prepared are the institutions for the collaborative planning paradigm of the flood risk management plan, particularly with respect to the river basin districts approach? Citing examples from France, Germany, the Netherlands, and Great Britain, this paper offers both a pessimistic and an optimistic perspective on the implementation of the new flood risk management instrument.  相似文献   
8.
The idea of the ‘smart city’ is increasingly central to debates on urban development and sustainability, and a host of cities are now pursuing ‘smartness’ as a way to improve energy efficiency, transport, and public services. However, existing research does not provide a clear picture of how this smart city agenda actually contributes to sustainability. The social science literature has been critical toward urban smartness, with most of the empirical research focusing on the politics of data-driven and entrepreneurial urbanism. This article seeks to contribute to this debate by empirically examining the role that sustainability plays in the smart city discourse. Its distinctive approach is to investigate how urban smartness and sustainability are framed by an authoritative institution (the European Union) and then to trace these framings down to a particular city (Stavanger, Norway). The data show that the smartness approach is strongly tied to innovation, technology, and economic entrepreneurialism, and sustainability does not appear to be a very important motivating driver. Nevertheless, the ‘sustainability component’ of the smart city agenda becomes clearer the closer we come to the city level.  相似文献   
9.
Hazard classification of waste is a necessity, but the hazard properties (named “H” and soon “HP”) are still not all defined in a practical and operational manner at EU level. Following discussion of subsequent draft proposals from the Commission there is still no final decision. Methods to implement the proposals have recently been proposed: tests methods for physical risks, test batteries for aquatic and terrestrial ecotoxicity, an analytical package for exhaustive determination of organic substances and mineral elements, surrogate methods for the speciation of mineral elements in mineral substances in waste, and calculation methods for human toxicity and ecotoxicity with M factors.In this paper the different proposed methods have been applied to a large assortment of solid and liquid wastes (>1 0 0).Data for 45 wastes – documented with extensive chemical analysis and flammability test – were assessed in terms of the different HP criteria and results were compared to LoW for lack of an independent classification. For most waste streams the classification matches with the designation provided in the LoW. This indicates that the criteria used by LoW are similar to the HP limit values.This data set showed HP 14 ‘Ecotoxic chronic’ is the most discriminating HP. All wastes classified as acute ecotoxic are also chronic ecotoxic and the assessment of acute ecotoxicity separately is therefore not needed. The high number of HP 14 classified wastes is due to the very low limit values when stringent M factors are applied to total concentrations (worst case method). With M factor set to 1 the classification method is not sufficiently discriminating between hazardous and non-hazardous materials. The second most frequent hazard is HP 7 ‘Carcinogenic’. The third most frequent hazard is HP 10 ‘Toxic for reproduction’ and the fourth most frequent hazard is HP 4 “Irritant – skin irritation and eye damage”. In a stepwise approach, it seems relevant to assess HP 14 first, then, if the waste is not classified as hazardous, to assess subsequently HP 7, HP 10 and HP 4, and then if still not classified as hazardous, to assess the remaining properties.The elements triggering the HP 14 classification in order of importance are Zn, Cu, Pb, Cr, Cd and Hg. Progress in the speciation of Zn and Cu is essential for HP 14. Organics were quantified by the proposed method (AFNOR XP X30-489) and need no speciation. Organics can contribute significantly to intrinsic toxicity in many waste materials, but they are only of minor importance for the assessment of HP 14 as the metal concentrations are the main HP 14 classifiers. Organic compounds are however responsible for other toxicological characteristics (hormone disturbance, genotoxicity, reprotoxicity…) and shall be taken into account when the waste is not HP 14 classified.  相似文献   
10.
Abstract: Systematic conservation assessment (an information‐gathering and prioritization process used to select the spatial foci of conservation initiatives) is often considered vital to conservation‐planning efforts, yet published assessments have rarely resulted in conservation action. Conservation assessments may lead more directly to effective conservation action if they are reoriented to inform conservation decisions. Toward this goal, we evaluated the relative priority for conservation of 7 sites proposed for the first forest reserves in the Union of the Comoros, an area with high levels of endemism and rapidly changing land uses in the western Indian Ocean. Through the analysis of 30 indicator variables measured at forest sites and nearby villages, we assessed 3 prioritization criteria at each site: conservation value, threat to loss of biological diversity from human activity, and feasibility of reserve establishment. Our results indicated 2 sites, Yiméré and Hassera‐Ndrengé, were priorities for conservation action. Our approach also informed the development of an implementation strategy and enabled an evaluation of previously unexplored relations among prioritization criteria. Our experience suggests that steps taken to ensure the closer involvement of practitioners, include a broader range of social data, encourage stakeholder participation, and consider the feasibility of conservation action can improve the relevance of assessments for conservation planning, strengthen the scientific basis for conservation decisions, and result in a more realistic evaluation of conservation alternatives.  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