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   460篇
  免费   2篇
  国内免费   7篇
安全科学   16篇
废物处理   30篇
环保管理   64篇
综合类   42篇
基础理论   71篇
环境理论   1篇
污染及防治   158篇
评价与监测   69篇
社会与环境   17篇
灾害及防治   1篇
  2023年   9篇
  2022年   38篇
  2021年   17篇
  2020年   4篇
  2019年   8篇
  2018年   11篇
  2017年   12篇
  2016年   11篇
  2015年   9篇
  2014年   25篇
  2013年   59篇
  2012年   26篇
  2011年   20篇
  2010年   19篇
  2009年   15篇
  2008年   20篇
  2007年   22篇
  2006年   19篇
  2005年   23篇
  2004年   14篇
  2003年   8篇
  2002年   9篇
  2001年   4篇
  2000年   2篇
  1999年   4篇
  1998年   5篇
  1997年   3篇
  1996年   3篇
  1994年   3篇
  1992年   2篇
  1988年   2篇
  1987年   2篇
  1984年   2篇
  1982年   4篇
  1981年   2篇
  1980年   2篇
  1979年   3篇
  1973年   1篇
  1972年   2篇
  1968年   1篇
  1967年   2篇
  1966年   1篇
  1965年   1篇
  1964年   2篇
  1963年   1篇
  1962年   2篇
  1959年   2篇
  1958年   1篇
  1956年   2篇
  1955年   2篇
排序方式: 共有469条查询结果,搜索用时 15 毫秒
371.
Environmental Science and Pollution Research - The identification of harmful metal ions in aquatic environments is a global concern since these contaminants can have serious consequences for...  相似文献   
372.
373.
Journal of Material Cycles and Waste Management - Effective management of Municipal Solid Waste (MSW) is an essential function of the city municipal corporation. The present study reports on the...  相似文献   
374.

Among heavy metals, lead (Pb) is a non-essential metal having a higher toxicity and without any crucial known biological functions. Being widespread, non-biodegradable and persistent in every sphere of soil, air and water, Pb is responsible for severe health and environmental issues, which need appropriate remediation measures. However, microbes inhabiting Pb-contaminated area are found to have evolved distinctive mechanisms to successfully thrive in the Pb-contaminated environment without exhibiting any negative effects on their growth and metabolism. The defensive strategies used by bacteria to ameliorate the toxic effects of lead comprise biosorption, efflux, production of metal chelators like siderophores and metallothioneins and synthesis of exopolysaccharides, extracellular sequestration and intracellular bioaccumulation. Lead remediation technologies by employing microbes may appear as potential advantageous alternatives to the conventional physical and chemical means due to specificity, suitability for applying in situ condition and feasibility to upgrade by genetic engineering. Developing strategies by designing transgenic bacterial strain having specific metal binding properties and metal chelating proteins or higher metal adsorption ability and using bacterial activity such as incorporating plant growth-promoting rhizobacteria for improved Pb resistance, exopolysaccharide and siderophores and metallothionein-mediated immobilization may prove highly effective for formulating bioremediation vis-a-vis phytoremediation strategies.

  相似文献   
375.
376.
It is generally acknowledged that adapting low-lying, flood-prone deltas to the projected impacts of climate change is of great importance. Deltas are densely populated and often subject to high risk. Climate-proof planning is, however, not only a new but also a highly complex task that poses problems for existing institutional and administrative structures, which are the product of times in which climate issues were of little importance. This paper assesses the capacity of the historically grown Dutch planning institutions to promote climate-proof planning for flood-prone areas. The Adaptive Capacity Wheel provides the methodological framework. The analysis focuses on two planning projects in the west of the Netherlands: the Zuidplas Polder project at the regional level and the Westergouwe project at the local level. It is shown that the planning institutions involved in these projects enable climate-proof planning, but to a limited extent. They face five institutional weaknesses that may cause risks on the long term. To climate-proof urban developments in flood-prone areas, it is necessary to break through the strong path–dependent development of planning institutions and to build in more flexibility in existing rules and procedures.  相似文献   
377.
378.
Gupta S  Gajbhiye VT 《Chemosphere》2004,57(6):471-480
Investigations were undertaken to study the adsorption-desorption, persistence and leaching of thifluzamide (2',6'-dibromo-2-methyl-4'-trifluoromethoxy-4-trifluoro methyl-1,3-thiazole-5-carboxanilide) in an alluvial soil under laboratory conditions. The adsorption-desorption studies were carried out using batch equilibration technique. The results revealed high but weak adsorption of thifluzamide in alluvial soil with K(F) value of 9.62 and 'n' value of 0.63. About 47-62% of the adsorbed amount got desorbed in four desorption cycles, which further substantiate the hypothesis of weak binding. The hysteresis coefficient varied from 0.19 to 0.40. Persistence studies carried out at three concentration levels (0.1, 1.0 and 10.0 microgg(-1)) and under three moisture conditions (air-dry, field capacity moisture and submerged) revealed that thifluzamide is a persistent chemical and only 19.5-54.0% dissipation was recorded on 90th day. However, it appears that aerobic microbes are more efficient in degrading thifluzamide than anaerobic microbes. The preliminary leaching studies carried out in the laboratory revealed that thifluzamide was moderately mobile in alluvial soil. Only small amounts (<1%) were recovered from leachate fractions whereas major portion remained in 0-15 cm soil depth.  相似文献   
379.
The effect of a chronic exposure to sublethal concentration of mercuric chloride (0.3 mg/l) on the activities of some enzymes in the digestive system of the teleost fish Channa punctatus was examined after 15 and 30 days of treatment. Glucose-6-phosphatase was significantly inhibited in the intestine and pyloric caeca. No marked alterations were observed in the activities of maltase and lactase except for elevation in maltase activity and inhibition in lactase activity in the intestine and pyloric caeca after 15 days of treatment. Three peptidases (aminotripeptidase, glycylglycine dipeptidase and glycyl-1-leucine dipeptidase) showed decreased activities in all parts of the digestive system. A decrease was also observed in the activity of lipase except for the stomach where inhibition after 15 days was insignificant. The results indicate that the activities of all the enzymes examined are inhibited in intestine and pyloric caeca and digestion of proteins and lipids may be more affected by mercury than the digestion of some carbohydrates.  相似文献   
380.
Research has been conducted on the effect of chlorsulfuron on non-target plants but little information is available on its effects on aquatic macrophytes. Potamogeton pectinatus (sago pondweed) is an ecologically important submerged aquatic macrophyte found in freshwater bodies. Many species of wildlife use this plant as a food source. The objective of this study was to measure the phytotoxic effects of chlorsulfuron on sago pondweed. P. pectinatus plants were exposed to chlorsulfuron at 0, 0.25, 0.50, 1.0, or 2.0 ppb, in an environmental growth chamber. Plants exposed to 0.25 ppb chlorsulfuron showed a reduction in length (76%), number of leaves (50%), and number of stems (50%), compared to control plants. A reduction (47%) was also observed in the length of stems produced by plants treated with > or = 0.50 ppb chlorsulfuron. Significant reductions in wet and dry weights, and increased mortality were observed on treatments with > or = 1.0 ppb chlorsulfuron.  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