全文获取类型
收费全文 | 677篇 |
免费 | 5篇 |
国内免费 | 8篇 |
专业分类
安全科学 | 15篇 |
废物处理 | 35篇 |
环保管理 | 72篇 |
综合类 | 111篇 |
基础理论 | 134篇 |
污染及防治 | 227篇 |
评价与监测 | 52篇 |
社会与环境 | 43篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 8篇 |
2022年 | 17篇 |
2021年 | 24篇 |
2020年 | 5篇 |
2019年 | 10篇 |
2018年 | 27篇 |
2017年 | 33篇 |
2016年 | 42篇 |
2015年 | 24篇 |
2014年 | 38篇 |
2013年 | 60篇 |
2012年 | 33篇 |
2011年 | 54篇 |
2010年 | 33篇 |
2009年 | 29篇 |
2008年 | 37篇 |
2007年 | 41篇 |
2006年 | 26篇 |
2005年 | 22篇 |
2004年 | 21篇 |
2003年 | 14篇 |
2002年 | 17篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1979年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1964年 | 2篇 |
1963年 | 2篇 |
1962年 | 1篇 |
1957年 | 1篇 |
1947年 | 1篇 |
1942年 | 2篇 |
1941年 | 2篇 |
1932年 | 1篇 |
排序方式: 共有690条查询结果,搜索用时 78 毫秒
641.
642.
643.
644.
A Decision-Support System for Prioritizing Restoration Sites on the Mississippi River Alluvial Plain 总被引:4,自引:0,他引:4
Daniel W. Llewellyn Gary P. Shaffer Nancy Jo Craig Lisa Creasman David Pashley Mark Swan Cindy Brown 《Conservation biology》1996,10(5):1446-1455
Conversion of forested wetlands to agricultural use and the resulting fragmentation of the landscape has led to concerns for the functional integrity of the Mississippi River Alluvial Plain ecosystem. We describe an effort spearheaded by The Nature Conservancy to initiate a multi-decade partnership dedicated to creating and implementing a viable, cooperative, landscape-level restoration project in the Mississippi River Alluvial Plain. Important phases of the process during the first 5 years were (1) initiation of the development of an extensive network of partners, including state and federal agencies, private land owners, conservation groups, academicians, and other interested citizens; (2) development of a geographic information system (GIS) for the entire extent of the ecosystem; and (3) for one watershed, the Tensas basin in northeastern Louisiana, refinement of a high resolution GIS to generate more detailed land-use conversion statistics to demonstrate the feasibility of a semi-objective, landscape-scale restoration planning procedure, including methodology for prioritization of existing wetland forest patches and areas most suitable for reforestation and connection via corridors. 相似文献
645.
646.
Luyssaert S Raitio H Vervaeke P Mertens J Lust N 《Journal of environmental monitoring : JEM》2002,4(6):858-864
Sampling can be the source of the greatest errors in the overall results of foliar analysis. This paper reviews the variability in heavy metal concentrations in tree crowns, which is a feature that should be known and understood when designing a suitable leaf sampling procedure. The leaf sampling procedures applied in 75 articles were examined. Most of the environmental studies used a closely related form of the UN/ECE-EC leaf sampling procedure, which was developed for the long-term monitoring of forest condition. Studies with objectives outside the UN/ECE-EC field of application should utilize a sampling procedure that is in accordance with the objectives of the study and based on the observed variation in pilot and similar studies. The inherent sources of heavy metal variability inside the stand, i.e. the crown class, stand management, site properties, crown dimensions, infections, seasons, etc. were discussed, but the underlying causes of this variability are rarely understood. The inherent variability in tree crowns is the reason for using leaf sampling as a tool in pollution studies. The objectives of a pollution study determine which sources of variability are utilized by the researcher. 相似文献
647.
Santosh Kumar Mohmmad Y. Wani Joonseok Koh João M. Gil Abilio J.F.N. Sobral 《环境科学学报(英文版)》2018,30(7):77-84
One of today's major challenges is to provide green materials for a cleaner environment. We have conducted studies on carbon dioxide(CO2) adsorption and conversion to valuable products by an ecofriendly approach based in chitosan/graphene oxide(CSGO) nanocomposite film. Rheological behavior indicates that the CSGO has a better solvation property than the pure chitosan. An adsorption capacity of 1.0152 mmol CO_2/g of CSGO nanocomposite at4.6 bar was observed. The catalytic behavior of the CSGO nanocomposite in the presence of tetra-n-butylammonium iodide(n-Bu4 NI) as co-catalyst was evaluated for the cycloaddition of CO_2 to epoxides, to give cyclic carbonates, in the absence of any solvent. These results strongly suggest that the CSGO nanocomposite may open new vistas towards the development of ecofriendly material for catalytic conversion and adsorption of CO_2 on industrial scale. 相似文献
648.
Sílvia Maria Martelli Geovana Rocha Plácido Moore João Borges Laurindo 《Journal of Polymers and the Environment》2006,14(3):215-222
In poultry industry chicken feathers are normally hydrolyzed and used to prepare animal feed. In this work the use of this material to prepare films was investigated. Keratins were extracted from chicken feathers with 2-mercaptoethanol in concentrated urea solution using sodium dodecyl sulfate (SDS). The effect of varying the amount of sorbitol on properties of chicken feather keratin (CFK) was investigated. As the concentration of plasticizer increased, the moisture content (MC) of these films increase, the monolayer MC increased from 0.060 (without plasticizer) to 0.482 g water/g dry matter (0.30 g sorbitol/g keratin). The water vapor permeability (WVP) varied between 0.096 g/m s Pa and 8.098 g/m s Pa for films without sorbitol and with 0.30 g sorbitol/g keratin, respectively. Film strength decreased from 5.13 MPa to 0.45 MPa and the elongation at break achieved the maximum value of 52.75% for samples with 0.02 g sorbitol/g keratin. The dry matter density didn’t change significantly, varying between 0.86–0.89 g/cm3 for all samples. Films with potential applications in food packaging can be obtained from CFKs. However, further researches are necessary to decrease film solubility and increase mechanical resistance. 相似文献
649.
Magalhães JM Silva JE Castro FP Labrincha JA 《Journal of environmental management》2005,75(2):157-166
In EU countries approximately 150,000 tons/year of galvanic sludges are generated by 4000 industrial units from the corresponding wastewater treatment plants. These sludges are generally classified as hazardous (European Waste Catalogue as adopted in Council Decision 2000/532/CE and as amended by Decisions 2001/118/EC, 2001/119/EC and 2001/573/CE), basically due to the presence of heavy metals. This work attempts to better understand the physical and chemical characteristics of these sludges, by studying 39 samples collected in different Portuguese industries that should represent all kinds of similar wastes independent of their place of generation. Chemical composition and leaching characteristics are given, together with density, grain size distribution, and specific surface area values. Statistical analysis was used for grouping the wastes according to chemical parameters, which might be useful to predict potential reuse as raw materials for different applications. 相似文献
650.
Laboratory stream microcosms have been used to study transport, fate, and effects of toxic substances in stream ecosystems. Several general concerns exist in utilizing laboratory streams in this way. We summarize some of the most important and difficult of these problems and endeavor to provide theoretical understanding, evaluation, and empirical approaches necessary for making laboratory stream ecosystem studies more useful in solving problems of toxic substance behavior in natural stream ecosystems. Well-designed laboratory streams and other microcosms are complex dynamic systems that can contribute to our understanding of the behavior of toxic substances. But such systems are far too complex and dynamic to be employed as bioassay, monitoring, or predictive tools, as individual organisms have been. 相似文献