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   181篇
  免费   3篇
  国内免费   6篇
安全科学   30篇
废物处理   1篇
环保管理   31篇
综合类   77篇
基础理论   6篇
污染及防治   17篇
评价与监测   17篇
社会与环境   7篇
灾害及防治   4篇
  2023年   4篇
  2022年   2篇
  2021年   3篇
  2020年   13篇
  2019年   1篇
  2018年   3篇
  2017年   2篇
  2016年   5篇
  2015年   1篇
  2014年   8篇
  2013年   7篇
  2012年   10篇
  2011年   9篇
  2010年   9篇
  2009年   10篇
  2008年   8篇
  2007年   8篇
  2006年   15篇
  2005年   7篇
  2004年   5篇
  2003年   4篇
  2002年   8篇
  2001年   7篇
  2000年   3篇
  1999年   3篇
  1998年   4篇
  1997年   2篇
  1996年   3篇
  1995年   3篇
  1994年   3篇
  1993年   1篇
  1992年   2篇
  1991年   4篇
  1990年   1篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1985年   3篇
  1984年   3篇
  1981年   1篇
  1979年   1篇
排序方式: 共有190条查询结果,搜索用时 15 毫秒
121.
西北地区生态环境与可持续发展关系的实证研究   总被引:1,自引:0,他引:1  
张云翌 《环境保护科学》2010,36(1):28-30,47
以研究西北地区的生态环境可持续发展为中心,采用实证研究,根据西北地区生态环境现状,对西北地区的资源条件进行分析。利用协调度,评估西北地区的可持续发展程度,指出以生态建设为中心的可持续发展战略在西北地区建设中的重要性,提出改善西北地区生态环境、实现可持续发展的建议与具体设想。  相似文献   
122.
水质在线监测系统作为自动化、信息化、科学化的现代高效的监管模式,已经纳入到城镇污水处理厂的日常管理工作中。文章以大连市某城镇污水处理厂为例,介绍了在线监测系统的实际运行情况,结果表明:监测数据准确度较高,总体运行安全可靠。  相似文献   
123.
The global application of nitrogen is far greater than phosphorus, and it is widely involved in the eutrophication of lakes and reservoirs. We used a bibliometric method to quantitatively and qualitatively evaluate nitrogen research in eutrophic lakes and reservoirs to reveal research developments, current research hotspots, and emerging trends in this area. A total of 2695 articles in the past 25 years from the online database of the Scientific Citation Index Expended(SCI-Expanded) were analyzed. Articles in this area increased exponentially from 1991 to 2015.Although the USA was the most productive country over the past 25 years, China achieved the top position in terms of yearly publications after 2010. The most active keywords related to nitrogen in the past 25 years included phosphorus, nutrients, sediment, chlorophyll-a, carbon,phytoplankton, cyanobacteria, water quality, modeling, and stable isotopes, based on analysis within 5-year intervals from 1991 to 2015 as well as the entire past 25 years. In addition, researchers have drawn increasing attention to denitrification, climate change, and internal loading. Future trends in this area should focus on:(1) nutrient amounts, ratios, and major nitrogen sources leading to eutrophication;(2) nitrogen transformation and the bioavailability of different nitrogen forms;(3)nitrogen budget, mass balance model, control, and management;(4) ecosystem responses to nitrogen enrichment and reduction, as well as the relationships between these responses; and(5)interactions between nitrogen and other stressors(e.g., light intensity, carbon, phosphorus, toxic contaminants, climate change, and hydrological variations) in terms of eutrophication.  相似文献   
124.
Sudan is the largest country in Africa with an area of about 2.5 million km2; the country hosts a population of about 31 million people. About two-thirds of the country area is located within arid and semi-arid regions. Recently, especially during the last half of the previous century, these regions were subject to various forms of land degradation. This paper discusses the general prospects and constraints of desert agriculture. It also presents a detailed case study of West Omdurman, which is located in a semi-desert climatic zone. The ambitious plans to utilise the area for agricultural production were initiated because of the relatively fertile soil, availability of water and the proximity of the area to marketing and export centres. The paper discusses the different land use systems experienced in the area, reasons for failure are identified and possible remedies discussed. In addition, constraints facing the proposed West Omdurman Canal Project are also discussed. Finally, the paper reviews the major research findings of Rawakeeb Dryland Research Center with regard to promoting agricultural productivity.  相似文献   
125.
Inhibition of gap junctional intercellular communication (GJIC) is affiliated with tumor promotion process and it has been employed as an in vitro biomarker for evaluation of tumor promoting effects of chemicals. In the present study we investigated combined effects of anthropogenic environmental contaminants 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB 153) and fluoranthene, cyanotoxins microcystin-LR and cylindrospermopsin, and extracts of laboratory cultures of cyanobacteria Aphanizomenon gracile and Cylindrospermopsis raciborskii, on GJIC in the rat liver epithelial cell line WB-F344. Binary mixtures of PCB 153 with fluoranthene and the mixtures of the two cyanobacterial strains elicited simple additive effects on GJIC after 30 min exposure, whereas microcystin-LR and cylindrospermopsin neither inhibited GJIC nor altered effects of PCB 153 or fluoranthene. However, synergistic effects were observed in the cells exposed to binary mixtures of anthropogenic contaminants (PCB 153 or fluoranthene) and cyanobacterial extracts. The synergistic effects were especially pronounced after prolonged (6-24 h) co-exposure to fluoranthene and A. gracile extract, when mixture caused nearly complete GJIC inhibition, while none of the individual components caused any downregulation of GJIC at the same concentration and exposure time. The effects of cyanobacterial extracts were independent of microcystin-LR or cylindrospermopsin, which were not detected in cyanobacterial biomass. It provides further evidence on the presence of unknown tumor promoting metabolites in cyanobacteria. Clear potentiation of the GJIC inhibition observed in the mixtures of two anthropogenic contaminants and cyanobacteria highlight the importance of combined toxic effects of chemicals in complex environmental mixtures.  相似文献   
126.
20年来,上海市已培育、发展、形成了一支稳定的环境科学研究队伍。回顾了这支队伍承担的上海市环保局下达的470余项科研项目中,一些主要的课题取得了卓越成果。在回顾的同时,对加强环境保护科研工作提出了五点意见。  相似文献   
127.
本文在富拉尔基区可持续发展能力分析的基础上,提出了投入机制。  相似文献   
128.
徐玉军 《环境科技》2006,19(2):28-30
循环经济是世界社会经济发展的必然要求,在我国更是具有特殊的地位和内涵,开展循环经济的研究,特别是有关循环经济激励机制的研究尤为迫切。循环经济激励机制建立对我国当前循环经济发展十分必要,建议从宏观规划、经济、产业、技术、思想、宣传、法律法规和政绩考核等8个方面实施一系列激励政策措施来促进循环经济的快速发展。  相似文献   
129.
本文在稀释后硫化物溶液稳定性实验研究的基础上,提出硫化物溶液用纯水稀释均匀性好,但稳定性差;用pH4.5的缓冲溶液稳定和用0.2%乙酸锌—乙酸钠溶液稀释可在2周内使用;用乙酸锌—乙酸钠溶液稀释,稀释溶液可稳定3周的结论。  相似文献   
130.
城市环境空气污染预报研究进展   总被引:10,自引:0,他引:10  
主要介绍了城市环境空气污染预报的方法,综述了城市环境空气污染预报的国内外研究现状,主要介绍了美国第三代Momdel-3 CMAQ模式系统和中国科学院大气所的嵌套网格空气质量预报系统(NAQPMS),以及最新的多模式污染预报技术,本文最后指出中国目前的大气环境形势比较严峻,城市环境空气污染预报模式还存在一些问题,并探讨了今后的发展方向。  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