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   374篇
  免费   9篇
  国内免费   3篇
安全科学   15篇
废物处理   11篇
环保管理   92篇
综合类   43篇
基础理论   93篇
环境理论   1篇
污染及防治   76篇
评价与监测   36篇
社会与环境   11篇
灾害及防治   8篇
  2023年   2篇
  2022年   2篇
  2021年   4篇
  2020年   4篇
  2019年   7篇
  2018年   8篇
  2017年   10篇
  2016年   7篇
  2015年   8篇
  2014年   16篇
  2013年   20篇
  2012年   15篇
  2011年   28篇
  2010年   14篇
  2009年   17篇
  2008年   18篇
  2007年   23篇
  2006年   16篇
  2005年   16篇
  2004年   18篇
  2003年   13篇
  2002年   8篇
  2001年   12篇
  2000年   9篇
  1999年   10篇
  1998年   3篇
  1997年   6篇
  1996年   8篇
  1995年   2篇
  1994年   5篇
  1993年   7篇
  1992年   5篇
  1991年   4篇
  1990年   4篇
  1989年   4篇
  1988年   4篇
  1987年   6篇
  1986年   8篇
  1985年   1篇
  1984年   3篇
  1983年   3篇
  1982年   1篇
  1981年   3篇
  1979年   1篇
  1973年   1篇
  1972年   1篇
  1970年   1篇
排序方式: 共有386条查询结果,搜索用时 15 毫秒
381.
Depleted uranium (DU) has become a soil contaminant of considerable concern in many combat zones and weapons-testing sites around the world, including locations in Europe, the Middle East and the USA, arising from its dispersion via the application of DU-bearing munitions. Once DU is released into the environment its mobility and bioavailability will, like that of other contaminants, largely depend on the type of associations it forms in soil and on the nature of the soil components to which it binds. In this study we used the BCR sequential extraction scheme to determine the partitioning of DU amongst soil fractions of texturally varying soils from locations affected by weapons-testing activities. Isotopic analyses (MC-ICP-MS and alpha-spectrometry) were performed to verify the presence of DU in whole soils and soil fractions and to determine any preferential partitioning of the contaminant. Results identified soil organic matter as being consistently the most important component in terms of DU retention, accounting for 30-100% of DU observed in the soils examined. However, at greater distances from known contamination points, DU was also found to be largely associated with the exchangeable fraction, suggesting that DU can be mobilised and transported by surface and near-surface water and does remain in an exchangeable (and thus potentially bioavailable) form in soils.  相似文献   
382.
Territoriality is an emerging concept of importance in organizations. Unfortunately, there does not exist currently a valid measure of territoriality with which to conduct research on territoriality in organizations. I developed a theoretically driven four-factor measure of territoriality. Six hundred and sixty-three people working in office settings completed an online survey about their territorial behaviors. Using confirmatory factor analysis I found that the four-factor structure had acceptable fit. I also found preliminary evidence of construct validity. Collectively, the results support the validity of the measure, thus providing an instrument for studying territoriality in organizations. I then discuss specific implications of this measure for both research and practise.  相似文献   
383.
Ning B  Graham NJ  Zhang Y 《Chemosphere》2007,68(6):1173-1179
The indirect reaction of octylphenol (OP) and nonylphenol (NP) with hydroxyl radicals (*OH) during ozonation was investigated at pH values ranging from 6 to 9. A parameter Rct, representing the ratio of the *OH-exposure to the ozone-exposure, was measured using a method involving a low concentration of p-chlorobenzoic acid as a *OH-probe compound during the ozonation. By assuming that Rct is a constant value at a given pH, the second order rate constants of the alkylphenol reaction with hydroxyl radicals were determined as 1.4(+/-0.2) x 10(10) and 1.1(+/-0.2) x 10(10) M(-1) s(-1) for OP and NP, respectively. The proportions of each alkylphenol degraded by direct molecular ozone reaction and indirect hydroxyl radical reaction were predicted at different pH values. The contribution of indirect *OH reactions with each AP was found to represent over 50% of the total degradation for pH approximately 7, and the contribution increases substantially with pH>7.  相似文献   
384.
Biological early warning systems represent a set of tools that may be able to respond to certain chemical monitoring requirements of recent European legislation, the Water Framework Directive (WFD2000/60/EC), that aims to improve and protect water quality across Europe. In situ biomonitoring was performed along the rivers Meuse (NL), Aller (GER) and Rhine (F) within the frame of the European Union-funded Project SWIFT-WFD. Gammarus pulex was used as a test organism during the evaluation of the Multispecies Freshwater Biomonitor(R) (MFB), an online biomonitor to quantitatively record different behaviour patterns of animals. At the river Meuse G. pulex reacted to pulse exposure of either a mixture of trace metals or of several organic xenobiotics, by showing up to 20% decreased locomotory activity (already at the 1st pulse) and increased mortality (at 2nd or 3rd pulse only). G. pulex deployed within the MFB system were observed to survive well at the monitoring station on the Aller (100%) and monitoring did not result in the measurement of chemical irregularities. In contrast, deployment at the monitoring station on the Rhine river demonstrated that the test organism was able to detect chemical irregularities by up to 20% decreased locomotory activity in the animals. The MFB proved to be an alert system for water quality monitoring at sensitive sites and sites with accidental pollution.  相似文献   
385.
Municipal solid waste management in the capital city of Indonesia, Jakarta, is examined from a point of view of researchers and waste management practitioners. Major impediments to waste management in Jakarta include non-involvement of stakeholders in planning and decision-making, unskilled staff undertaking the duty, the absence of long-term waste management strategies, and weak coordination between authorities and neighbourhood association workers who undertake primary collection. It was revealed that lack of resources is seen as the least important of all impediments. The success of managing solid waste in Jakarta cannot be separated from the presence and the role of a neighbourhood association, which performs waste collection on a daily basis as well as keeping their respective areas clean by employing their own waste service workers. A neighbourhood-based waste management strategy is a promising solution for Jakarta, because it is more applicable and suitable for Jakarta's context compared to community-based waste management. The performance of this approach is examined and the improvement for wider adoption is discussed for a long-term solution.  相似文献   
386.
Localized stressors compound the ongoing climate-driven decline of coral reefs, requiring natural resource managers to work with rapidly shifting paradigms. Trait-based adaptive management (TBAM) is a new framework to help address changing conditions by choosing and implementing management actions specific to species groups that share key traits, vulnerabilities, and management responses. In TBAM maintenance of functioning ecosystems is balanced with provisioning for human subsistence and livelihoods. We first identified trait-based groups of food fish in a Pacific coral reef with hierarchical clustering. Positing that trait-based groups performing comparable functions respond similarly to both stressors and management actions, we ascertained biophysical and socioeconomic drivers of trait-group biomass and evaluated their vulnerabilities with generalized additive models. Clustering identified 7 trait groups from 131 species. Groups responded to different drivers and displayed divergent vulnerabilities; human activities emerged as important predictors of community structuring. Biomass of small, solitary reef-associated species increased with distance from key fishing ports, and large, solitary piscivores exhibited a decline in biomass with distance from a port. Group biomass also varied in response to different habitat types, the presence or absence of reported dynamite fishing activity, and exposure to wave energy. The differential vulnerabilities of trait groups revealed how the community structure of food fishes is driven by different aspects of resource use and habitat. This inherent variability in the responses of trait-based groups presents opportunities to apply selective TBAM strategies for complex, multispecies fisheries. This approach can be widely adjusted to suit local contexts and priorities.  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