全文获取类型
收费全文 | 3241篇 |
免费 | 19篇 |
国内免费 | 35篇 |
专业分类
安全科学 | 71篇 |
废物处理 | 158篇 |
环保管理 | 373篇 |
综合类 | 460篇 |
基础理论 | 1192篇 |
污染及防治 | 635篇 |
评价与监测 | 214篇 |
社会与环境 | 187篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 5篇 |
2021年 | 12篇 |
2020年 | 10篇 |
2019年 | 8篇 |
2018年 | 119篇 |
2017年 | 126篇 |
2016年 | 206篇 |
2015年 | 64篇 |
2014年 | 21篇 |
2013年 | 62篇 |
2012年 | 439篇 |
2011年 | 227篇 |
2010年 | 39篇 |
2009年 | 43篇 |
2008年 | 64篇 |
2007年 | 77篇 |
2006年 | 83篇 |
2005年 | 408篇 |
2004年 | 537篇 |
2003年 | 418篇 |
2002年 | 56篇 |
2001年 | 48篇 |
2000年 | 25篇 |
1999年 | 32篇 |
1998年 | 8篇 |
1997年 | 14篇 |
1996年 | 5篇 |
1995年 | 15篇 |
1994年 | 10篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 14篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1979年 | 2篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1967年 | 5篇 |
1966年 | 2篇 |
排序方式: 共有3295条查询结果,搜索用时 15 毫秒
1.
2.
3.
Pyrite ash is created as waste from the roasting of pyrite ores during the production of sulphuric acid. These processes generate great amounts of pyrite ash waste that is generally land filled. This creates serious environmental pollution due to the release of acids and toxic substances. Pyrite ash waste can be utilized in the iron production industry as a blast furnace feed to process this waste and prevent environmental pollution. The essential parameters affecting the pelletization process of pyrite ash were studied using bentonite as a binder. Experiments were then carried out using bentonite and a mixture of bentonite with calcium hydroxide and calcium chloride in order to make the bentonite more effective. The metallurgical properties of pyrite ash, bentonite, calcium hydroxide, calcium chloride, a mixture of these and sintered pellets were studied using X-ray analysis. The crushing strength tests were carried out to investigate the strength of pyrite ash waste pellets. The results of these analyses showed that pyrite ash can be agglomerated to pellets and used in the iron production industry as a blast furnace feed. The crushing strength of the pellets containing calcium hydroxide and calcium chloride in addition to bentonite was better than the strength of pellets prepared using only bentonite binder. 相似文献
4.
5.
6.
Kristina?D.?RothleyEmail author Charlene?Rae 《Environmental Modeling and Assessment》2005,10(2):107-113
In this paper we apply graph theory in a reserve selection exercise to explore the tradeoffs between maintaining connectivity and minimizing the total area of a protected area network. Rather than focus on a single organism, we used a multi-species approach and looked at the tradeoff curves for organisms with varying dispersal abilities. We first generated the tradeoff curves using a graph-based metric to determine the importance of individual patches for maintaining connectivity. We then performed an analogous set of analyses using patch size as a surrogate measure of importance. 相似文献
7.
8.
A modular approach to Integrated Assessment modeling 总被引:1,自引:0,他引:1
In this paper, we present a new approach to model coupling that probably forms the methodological basis of a new generation of Integrated Assessment models. This approach respects the knowledge and expertise that is embodied in existing models and encourages their gradual evolution. Modularity is the guiding principle. Our approach is distinguished by the way modules are coupled which is based on an interplay of a job control module, a numerical coupling module, and a couple of stand-alone functional modules. The numerical coupling module - the core component - serves to treat the feedbacks between the functional modules. A first implemented example that couples an economic and a climate module by means of a two-phase meta-optimization is presented here. The algorithm and mathematical structure behind are discussed as well as important features such as convergence behavior and reliability. 相似文献
9.
10.
Santamaría-Fernández R Moreda-Piñeiro A Hill SJ 《Journal of environmental monitoring : JEM》2002,4(2):330-336
The optimisation of a simple multielement extraction method employing an experimental design approach is described. The method uses centrifugation to pass one extractant solution at varying pH through a contaminated soil sample. The nature and concentration of the acid, rate of centrifugation and time, number of sequential leachates and the ratio of extractant volume: sample weight have been studied in order to obtain the optimum conditions for extraction. A fractional factorial experimental design was performed, and the results were used to identify significance which was then evaluated by carrying out a central composite experimental approach. Once optimum conditions had been obtained, sequential leaches were analysed by ICP-AES and chemometrics were employed to identify the composition of each component. Comparisons have been made with previous studies and tentative assignments, based on well defined separated fractions and percentage compositions for individual elements, used to identify the different physico-chemical components in the sample. 相似文献