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   222篇
  免费   2篇
  国内免费   1篇
安全科学   4篇
废物处理   7篇
环保管理   25篇
综合类   80篇
基础理论   49篇
污染及防治   38篇
评价与监测   7篇
社会与环境   14篇
灾害及防治   1篇
  2020年   4篇
  2019年   2篇
  2018年   4篇
  2017年   3篇
  2016年   3篇
  2015年   5篇
  2014年   7篇
  2013年   9篇
  2012年   9篇
  2011年   8篇
  2010年   5篇
  2009年   4篇
  2008年   9篇
  2007年   15篇
  2006年   11篇
  2005年   6篇
  2004年   5篇
  2003年   8篇
  2002年   5篇
  2001年   7篇
  2000年   6篇
  1999年   3篇
  1997年   4篇
  1996年   4篇
  1995年   6篇
  1994年   5篇
  1992年   4篇
  1990年   2篇
  1989年   3篇
  1985年   4篇
  1984年   2篇
  1982年   2篇
  1981年   3篇
  1979年   2篇
  1973年   2篇
  1964年   3篇
  1963年   4篇
  1961年   2篇
  1960年   4篇
  1958年   2篇
  1957年   2篇
  1956年   3篇
  1951年   1篇
  1950年   1篇
  1934年   1篇
  1933年   1篇
  1931年   2篇
  1927年   2篇
  1925年   1篇
  1924年   1篇
排序方式: 共有225条查询结果,搜索用时 390 毫秒
151.
152.
It is often thought that new procedural arrangements can help embed sustainable development as a policy goal into policy practice. This is the hope of tools such as environmental assessment, sustainability audits and sustainability indicators. Using a case study of urban regeneration in the London Borough of Southwark, this paper critically examines these claims. It shows how sustainable development was sidelined as a policy goal during the evaluation of the Master Plan for the area, the appraisal of individual projects for funding under the Single Regeneration Budget and the development of two local sustainability indicator projects. In each case the local political circumstances were key factors in shaping policy practice and outcomes. This leads to a re-evaluation of such procedural policy tools, emphasizing the importance of local governance contexts.  相似文献   
153.
154.
155.
156.
157.
158.
159.
Following the introduction of automobile catalysts in the middle of the 1980s in Germany there is an increasing emission of the platinum-group-metals platinum, palladium (Pd) and rhodium. Still, it remains unclear if these metals are bioavailable for aquatic animals and to which extent they become accumulated by the aquatic biosphere. Because of analytical problems in detecting Pd in small biological samples the present investigation concentrates on the bioavailability of this metal. To answer the question of a Pd uptake by aquatic organisms experimental studies were conducted with European eels maintained in water containing road dust at a concentration of 10 kg/100 l. Following an exposure period of four weeks, samples of liver and kidney were analysed by total-reflection X-ray fluorescence analysis after co-precipitation of Pd with mercury. These experiments revealed an uptake of traffic related Pd by European eels which showed a mean liver Pd concentration of 0.18 +/- 0.05 ng/g (wet wt.), whereas the Pd concentration in the kidney ranged below the detection limit. Thus, in this study we can demonstrate for the first time that automobile catalyst emitted Pd is bioavailable for aquatic animals.  相似文献   
160.
Background, aim, and scope Sediment-Water Toxicity Tests are an important instrument for the environmental risk assessment of native, contaminated sediments within the European Water Framework Directive. Thus, it must be guaranteed to distinguish between natural and anthropogenic adverse effects. The content of particulate (POC) and dissolved (DOC) organic carbon can affect the mobility of sediment pollutants. Different studies demonstrated that the DOC-content can influence the bioavailability of contaminants and can directly affect aquatic organisms. The aim of this study was to investigate the influence of increasing sediment organic matter on reproduction and growth of the benthic oligochaete Lumbriculus variegatus. Furthermore, the accumulation factors of the hydrophobic substances 1,1-dichloro-2,2-bis(p-chlorphenyl)ethylene (p,p'-DDE), 2´, 3, 4, 4´, 5´-Hexachlorbiphenyl (PCB 138) und 2, 2´, 4, 4´, 5, 5´-Hexachlorbiphenyl (PCB 153) were calculated considering the TOC-content and the uptake route (water-only exposure or sediment ingestion). Materials and methods The test was performed according to the OECD Guideline 225 (2007) using artificial sediment with different peat concentrations. The effect of an increasing TOC-concentration was studied in three different testmodifications with and without spiked sediment. The nominal concentration of the contaminants in spiked sediment was 50?µg/kg. Results The results showed maximum accumulation factors of 13 for both, PCB 138 and 153 and 11 for p,p'-DDE in sediments with low organic carbon content. With increasing peat content accumulation factors decreased. Thereby the ingestion of sediment was the main exposure route. Moreover preponderantly negative correlations between the organic carbon content in unspiked sediments and reproduction as well as growth of the testorganisms were detected. In combination with the test substances reproduction and growth increased with increasing organic carbon content. Discussion Hence it can be assumed that organic matter, especially humic substances, directly effected the testorganisms in the tests without spiked sediment. Due to the decrease of accumulation factors in spiked sediment with increasing TOC-content it might be possible that the availability of humic substances was reduced by conglomeration with the tested chemicals. Conclusions Therefore the possible influence of dissolved organic matter on the testorganism should be considered when assessing the results of toxicity tests and bioaccumulation studies with Lumbriculus variegatus. Recommendations and perspectives To receive detailed information about a critical DOC-concentration influencing the testorganisms further investigations about the amount of organic matter in the sediment and the DOC-concentration in the overlaying water are recommended.  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