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   215篇
  免费   4篇
安全科学   3篇
废物处理   6篇
环保管理   11篇
综合类   69篇
基础理论   66篇
污染及防治   45篇
评价与监测   10篇
社会与环境   8篇
灾害及防治   1篇
  2023年   12篇
  2022年   8篇
  2021年   3篇
  2020年   4篇
  2019年   6篇
  2018年   12篇
  2017年   15篇
  2016年   11篇
  2015年   11篇
  2014年   11篇
  2013年   19篇
  2012年   15篇
  2011年   25篇
  2010年   6篇
  2009年   8篇
  2008年   13篇
  2007年   4篇
  2006年   9篇
  2005年   7篇
  2004年   3篇
  2003年   8篇
  2002年   4篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1996年   2篇
排序方式: 共有219条查询结果,搜索用时 18 毫秒
91.
92.
93.
Concentrations of POPs in Great skua eggs from Shetland are among the highest in North Atlantic seabirds, with up to 11,600 μg/kg (ww) DDE and up to 17,900 μg/kg ww ∑PCB. Concentrations of legacy POPs were significantly lower in 2008 than 1980. Decreases were greatest for least persistent compounds. Median ∑PBDEs increased from 99 μg/kg ww in 1980 to 173 μg/kg ww in 2008. There were changes in Great skua breeding season diet, with more adult Herring and Mackerel and less Sandeel. These changes increase exposure to POPs, since Herring and Mackerel accumulate more POPs than Sandeels. In both years, eggs with higher δ15N had higher POP concentrations. In 1980, birds feeding more on demersal discard fish from trawl fisheries and less on Sandeels, had higher POP levels in eggs. In 2008, individuals feeding more on Herring and Mackerel, and less on discards, had higher POP levels in eggs.  相似文献   
94.
Volatilization of pesticides participates in atmospheric contamination and affects environmental ecosystems including human welfare. Modelling at relevant time and spatial scales is needed to better understand the complex processes involved in pesticide volatilization. Volt'Air-Pesticides has been developed following a two-step procedure to study pesticide volatilization at the field scale and at a quarter time step. Firstly, Volt'Air-NH3 was adapted by extending the initial transfer of solutes to pesticides and by adding specific calculations for physico-chemical equilibriums as well as for the degradation of pesticides in soil. Secondly, the model was evaluated in terms of 3 pesticides applied on bare soil (atrazine, alachlor, and trifluralin) which display a wide range of volatilization rates. A sensitivity analysis confirmed the relevance of tuning to Kh. Then, using Volt'Air-Pesticides, environmental conditions and emission fluxes of the pesticides were compared to fluxes measured under 2 environmental conditions. The model fairly well described water temporal dynamics, soil surface temperature, and energy budget. Overall, Volt'Air-Pesticides estimates of the order of magnitude of the volatilization flux of all three compounds were in good agreement with the field measurements. The model also satisfactorily simulated the decrease in the volatilization rate of the three pesticides during night-time as well as the decrease in the soil surface residue of trifluralin before and after incorporation. However, the timing of the maximum flux rate during the day was not correctly described, thought to be linked to an increased adsorption under dry soil conditions. Thanks to Volt'Air's capacity to deal with pedo-climatic conditions, several existing parameterizations describing adsorption as a function of soil water content could be tested. However, this point requires further investigation. Practically speaking, Volt'Air-Pesticides can be a useful tool to make decision about agricultural practices such as incorporation or for the estimation of overall pesticide volatilization rates, and it holds promise for time specific dynamics.  相似文献   
95.
Soils down slope of roads have been affected over decades by road salting in the UK uplands. Salt additions to fresh soil facilitate dispersal of organic matter so there is a potential risk of release of DON and DOC to nearby rivers where these run parallel to roads. Over time, however, salting enhances soil pH of naturally acid soils, and thus organic matter degradation through to CO2, thereby, lowering soil organic matter content. In addition any relatively labile organic matter may have already been dispersed. Thus, it is hypothesised that enhanced DOC mobilisation should only be a potential problem if soils not previously exposed to salt become heavily exposed in the future. This paper combines data from field observations and laboratory simulations to elucidate mechanisms controlling organic matter mobilisation processes to determine what controls spatial and temporal trends in DOC concentrations in soil solutions down slope of roads. Organic matter solubilisation is dependent on the degree of road salt exposure soils have had. The laboratory experiment provided evidence that there are two competing effects upon which solubilisation is dependent (a) pH suppression and (b) sodium dispersion. Other organic matter solubility models, if correct, link quite well with the authors "when it's gone, it's gone" hypothesis.  相似文献   
96.
Demographic change and economic decline produce modified urban land use pattern and densities. Compared to the beginning of the 90s after the German reunification, nowadays massive housing and commercial vacancies followed by demolition and perforation come to pass in many cities of the former GDR. In consequence, a considerable surplus of urban brownfields has been created. Furthermore, the decline in the urban fabric affects social infrastructure and urban greenery of local neighbourhoods. Here, urban planning enters into ‘uncharted territory’ since it needs to assess the socio-environmental impact of shrinkage.In order to carry out such an evaluation quantitatively, a multi-criteria assessment scheme (MCA) was developed and applied. Firstly, we identified infrastructure and land use changes related to vacancy and demolition. Secondly, demolition scenarios for the coming 20 years were applied in order to give an idea for a long-term monitoring approach at the local district level. A multi-criteria indicator matrix quantifies the socio-environmental impact on both urban greenery and residents. Using it, we set demolition scenarios against urban ‘quality of life’ targets. Empirical evidence comes from Leipzig, in eastern Germany, a representative case study for urban shrinkage processes.The results show that shrinkage implies socio-environmental changes of residential livelihoods, however, does not simply increase or decrease the overall urban quality of life. The integrated assessment of all indicators identifies environmental and social opportunities, as well as the challenges a shrinking city is faced with.  相似文献   
97.
The threat of sea-level rise and climate change means that coastal managers are being increasingly asked to make long-term assessments of potential coastal impacts and responses. In the UK, shoreline management planning (for flood and erosion hazards) and spatial planning now takes a 100 year perspective. An integrated framework across a wide range of physical and social issues is required for the assessment of coastal impacts and consequently for making sound management decisions. This paper provides an overview of the development of the ‘Tyndall Coastal Simulator’ including the underlying philosophy that is being followed. The Simulator is based on a series of linked climate models (CM) within a nested framework which recognises three spatial scales: (i) the global (GCM) scale; (ii) the regional scale and (iii) the Simulator Domain (a physiographic unit, such as a coastal sub-cell). Within the nesting, the larger scale provides the boundary conditions for the smaller scale. The models feed into each other and describe a range of relevant processes: sea level, tides, surges, waves, sediment transport and coastal morphology. Different climate scenarios, as well as the range of uncertainty, are being explored. Communication of results is a major issue and the Simulator includes a dedicated GIS-based user interface that allows a wide range of queries of model outputs. The paper demonstrates the possibility of developing an integrated framework that is multi-scale and capable of linking various models in order to simulate complex coastal processes and consequently allowing long-term assessments that are useful for setting future management plans.  相似文献   
98.
According to almost all forward-looking studies, the world′s energy consumption will increase in the future decades, mostly because of the growing world population and the long-term development of emerging countries. The effort to contain global warming makes it hard to exclude nuclear energy from the global energy mix.  相似文献   
99.

This paper examines how the concept of sustainable development is being put into practice by local policy partnership networks. We suggest that due to the highly contested nature of the concept, these networks are facing problems in trying to unravel what sustainable development actually means. Few organisations are grappling with the more fundamental implications of the concept and, as a result, policies for sustainability are being developed cheek by jowl with those of economic growth and competitiveness. Moreover, established local policy networks play a dominant role in defining a vision of sustainable development to the detriment of groups outside the policy process. Mechanisms and institutions need to be established to widen participation and debate on the issue and to draw upon lessons and ideas from organisations outside established networks, such as environmental and campaign groups, third sector organisations, community associations and socially responsible businesses. Este documento examina como el concepto de desarrollo sostenible esta siendo puesto en práctica por redes de sociedades normativas locales. Nosotros sugerimos que debido a la alta naturaleza competitiva del concepto, estas redes estan enfrentando problemas al tratar de desenredar lo que significa realmente desarrollo sostenible. Pocas organizaciones están intentando resolver las implicaciones mas fundamentals del concepto y como resultado las políticas para la sostenibilidad estan siendo desarrolladas lado a lado con esas de crecimiento económico y competitividad. Además, las redes normativas locales establecidas juegan un papel predominante en definir una visión de desarrollo sostenible para el detrimento de grupos por fuera del proceso regulador. Los mecanismos y las instituciones necesitan ser establecidos para ampliar la participación y debatir sobre el asunto y para deducir sobre lecciones e ideas tomadas de organizaciones por fuera de las redes establecidas tales como grupos ambientales y de campaña, organizaciones del tercer sector, asociaciones comunitarias y negocios socialmente responsables.  相似文献   
100.
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