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   1246篇
  免费   29篇
  国内免费   18篇
安全科学   107篇
废物处理   7篇
环保管理   240篇
综合类   583篇
基础理论   74篇
环境理论   3篇
污染及防治   35篇
评价与监测   125篇
社会与环境   58篇
灾害及防治   61篇
  2023年   2篇
  2022年   5篇
  2021年   12篇
  2020年   20篇
  2019年   15篇
  2018年   10篇
  2017年   16篇
  2016年   35篇
  2015年   25篇
  2014年   35篇
  2013年   58篇
  2012年   49篇
  2011年   68篇
  2010年   54篇
  2009年   76篇
  2008年   55篇
  2007年   80篇
  2006年   71篇
  2005年   60篇
  2004年   56篇
  2003年   66篇
  2002年   56篇
  2001年   50篇
  2000年   67篇
  1999年   42篇
  1998年   40篇
  1997年   35篇
  1996年   25篇
  1995年   18篇
  1994年   21篇
  1993年   17篇
  1992年   14篇
  1991年   9篇
  1990年   6篇
  1989年   2篇
  1988年   4篇
  1987年   2篇
  1986年   5篇
  1985年   6篇
  1984年   2篇
  1982年   1篇
  1981年   2篇
  1979年   1篇
排序方式: 共有1293条查询结果,搜索用时 125 毫秒
981.
辐射环境监测优化布点的特征分析方法   总被引:4,自引:2,他引:2  
介绍了特征分析方法的基本原理及其MATLAB语言实现过程,并将特征分析法、传统布点法,以及BP人工神经网络法对同一地区辐射环境监测优化布点的核素含量均值作了比较,结果表明,用特征分析法优选出的采样点位,其核素含量均值对传统布点法的相对偏差均为负值,且<10%,即便与BP法相比,也不失其优越性,表明用特征分析法监测一个地区环境辐射平均水平的优化布点是十分理想的.  相似文献   
982.
为了开展电厂环境噪声预测及评价工作,提出了电厂环境噪声预测数学模型,研制出电算程序。此模型吸取了众多模型的优点,声源模式有点源、分布面源、体源和线源;传播方式分近场和远场;障碍物影响考虑了反射,衍射和衍射的反射。用此模型对耒阳电厂环境噪声进行计算,计算与实测结果表明,此模型精度高,软件实用、方便。  相似文献   
983.
环境信息分类编码标准化   总被引:4,自引:0,他引:4       下载免费PDF全文
本文论述了我国环境信息分类编码标准化工作及其重要意义,着重探讨了信息分类的方法,提出了对我国环境信息分类编码工作的意见。   相似文献   
984.
信息不对称对发展循环经济的不利影响及对策分析   总被引:13,自引:0,他引:13  
信息不对称理论在经济活动中的作用越来越大。本文结合昆山市发展循环经济的实践 ,分析了发展循环经济过程中信息不对称的主要表现 ,揭示了信息不对称对发展循环经济的负面影响 ,进而论证了大力发展环境信息服务业是解决环境信息不对称的最佳方式 ,是发展循环经济、生态工业、生态农业等环保型事业的重要保障  相似文献   
985.
Nesar Ahmed  Max Troell 《Ambio》2010,39(1):20-29
Freshwater prawn (Macrobrachium rosenbergii) farming in Bangladesh has, to a large extent, been dependent on the supply of wild larvae. Although there are 81 freshwater prawn hatcheries in the country, a lack of technical knowledge, inadequate skilled manpower, and an insufficient supply of wild broods have limited hatchery production. Many thousands of coastal poor people, including women, are engaged in fishing for wild prawn larvae along the coastline during a few months each year. On average, 40% of the total yearly income for these people comes from prawn larvae fishing activity. However, indiscriminate fishing of wild larvae, with high levels of bycatch of juvenile fish and crustaceans, may impact negatively on production and biodiversity in coastal ecosystems. This concern has provoked the imposition of restrictions on larvae collection. The ban has, however, not been firmly enforced because of the limited availability of hatchery-raised larvae, the lack of an alternative livelihood for people involved in larvae fishing, and weak enforcement power. This article discusses the environmental and social consequences of prawn larvae fishing and concludes that, by increasing awareness among fry fishers, improving fishing techniques (reducing bycatch mortality), and improving the survival of fry in the market chain, a temporal ban may be a prudent measure when considering the potential negative impacts of bycatch. However, it also suggests that more research is needed to find out about the impact of larvae fishing on nontarget organisms and on the populations of targeted species.  相似文献   
986.
Neighborhood satisfaction,physical and perceived naturalness and openness   总被引:1,自引:0,他引:1  
This study examined neighborhood satisfaction in relation to naturalness and openness. It used Geographic Information System (GIS) and Landsat satellite imagery to physically measure the environmental attributes. Through path analysis it examined the relationship among the attributes, resident ratings of those environmental attributes, their satisfaction with them, and their overall neighborhood satisfaction (n = 725). We expected overall neighborhood satisfaction to relate to the resident's ratings of the environmental attributes and to the physical measures of them. The path model showed that overall neighborhood satisfaction was associated directly with the physical measure of building density and indirectly with the physical measure of vegetation rate through perception and evaluation of them. The perceptions and evaluations of the attributes related to one another. With refinements, GIS and Landsat data geo-related to survey data can offer a powerful tool for understanding the complex nature of neighborhood satisfaction and behavior.  相似文献   
987.
Risk management of chemicals requires information about their adverse effects such as toxicity and persistence, for example. Testing of chemicals allows for improving the information base for regulatory decision‐making on chemicals' production and use. Testing a large number of chemicals with limited time and resources forces a prioritization of chemicals. This paper proposes a decision model that provides a ranking of chemicals according to “urgency to test”. The model adopts a value‐of‐information approach describing the expected welfare gains from regulatory actions that respond to test information. We determine the value‐of‐information of tests revealing chemicals' levels of toxicity and persistence. We compare our findings to the prioritization of chemicals in the new European Chemicals Regulation “REACH”, where several tens of thousands of chemicals are to be tested in order to fill existing information gaps and to implement more effective risk management. We find that the main lines of chemicals' prioritization under REACH receive backing from our decision model. However, prioritization for testing can be further improved by accounting for testing costs and the sensitivity of regulatory action with respect to the test information.  相似文献   
988.
Grigorakis K  Rigos G 《Chemosphere》2011,85(6):899-919
Aquatic farming has been considered, during the last decades, as the fastest growing food production industry powered by governmental and technological impulsion. Compensation for fisheries decline, creation of new jobs and source of financial windfall are the most important benefits. However, similar to most of the human food-production activities, aquaculture raised several issues related to the environmental welfare and consumer safety. An effort to record the aquaculture-environment and -human safety interactions with regard to the Mediterranean mariculture, is attempted herein. We focused on this geographical area due to its individualities in both the hydrological and physicochemical characteristics and the forms of aquaculture activities. The cage farming of euryhaline marine fish species and more recently of bluefin tuna and mollusk farming are the dominating aquaculture activities. The impacts of these activities to the environment, through wastes offloads, introduction of alien species, genetic interactions, disease transfer, release of chemicals, use of wild recourses, alterations of coastal habitats and disturbance of wildlife, are analytically considered. Also the consumer safety issues related to the farming are assessed, including generation of antibiotic-resistant microorganisms, contaminants transferred to humans though food chain and other hazards from consumption of aquacultured items. Within these, the major literature findings are critically examined and suggestions for scientific areas that need further development are made. The major tasks for future aquaculture development in this region are: (i) to ensure sustainability and (ii) to balance the risks to public or environmental health with the substantial economical benefits. In regard with monitoring, tools must be created or adapted to predict the environmental costs and estimate consumer impact. At a canonistic and legal basis, the establishment of appropriate legal guidelines and common policies from all countries involved should be mandatory.  相似文献   
989.
Carbamazepine is a psychiatric pharmaceutical widely detected in aquatic environments. Due to its generalized occurrence and environmental persistence it might be considered as an anthropogenic pollution indicator. In this research, a previously developed enzyme-linked immunosorbent assay (ELISA), based on a commercial monoclonal antibody, was applied to the quantification of carbamazepine in ground, surface and wastewaters and results were validated by liquid chromatography-tandem mass spectrometry (LC-MS/MS).The performance of the applied ELISA methodology was tested in the presence of high concentrations of sodium chloride and dissolved organic matter. The method was not significantly affected by matrix effects, being adequate for the quantification of carbamazepine in environmental samples, even without sample pre-treatment. This method allows the quantification of carbamazepine in the range of 0.03-10 μg L−1, with a relative error lower than 30%. Due to a pH dependent cross-reactivity with cetirizine, an antihistaminic drug, the assay also enabled the quantification of cetirizine in the samples.The application of the developed method to the quantification of carbamazepine was performed by using environmental samples with very different matrices, collected in the geographical area of Ria de Aveiro, an estuarine system located in the North of Portugal. Carbamazepine was detected in all analyzed wastewater samples and in one surface water with concentrations between 0.1 and 0.7 μg L−1. Validation with LC-MS/MS revealed that results obtained by ELISA are 2-28% overestimated, which was considered highly satisfactory due to the absence of sample pre-treatments.  相似文献   
990.
搜索     
《环境》2007,(10)
  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