全文获取类型
收费全文 | 513篇 |
免费 | 40篇 |
国内免费 | 30篇 |
专业分类
安全科学 | 22篇 |
废物处理 | 18篇 |
环保管理 | 263篇 |
综合类 | 102篇 |
基础理论 | 39篇 |
环境理论 | 1篇 |
污染及防治 | 61篇 |
评价与监测 | 30篇 |
社会与环境 | 22篇 |
灾害及防治 | 25篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 4篇 |
2021年 | 17篇 |
2020年 | 8篇 |
2019年 | 11篇 |
2018年 | 14篇 |
2017年 | 26篇 |
2016年 | 13篇 |
2015年 | 28篇 |
2014年 | 23篇 |
2013年 | 46篇 |
2012年 | 19篇 |
2011年 | 36篇 |
2010年 | 16篇 |
2009年 | 47篇 |
2008年 | 38篇 |
2007年 | 27篇 |
2006年 | 26篇 |
2005年 | 16篇 |
2004年 | 29篇 |
2003年 | 16篇 |
2002年 | 9篇 |
2001年 | 8篇 |
2000年 | 12篇 |
1999年 | 6篇 |
1998年 | 9篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 7篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有583条查询结果,搜索用时 15 毫秒
581.
调整农村能源结构是改善西部农业生态环境的核心问题之一 总被引:2,自引:0,他引:2
农村能源建设是农业生态系统的中心枢纽之一,通过小型高效沼气池发酵,一方面,改善了我国绝大部分地区农户用能结构及居住环境条件,促使农民的传统生活习惯向现代文明转变,提高农民的生活质量。另一方面,可减少薪柴的樵采,保护植树造林成果,提高森林覆盖率,治理水土流失,实现农作物秸杆的合理利用,增加土壤有机质,改善农业生态环境,促进农业可持续发展。 相似文献
582.
In this study, a dual-interval fixed-mix stochastic programming (DFSP) method is developed for planning water resources management systems under uncertainty. DFSP incorporates interval-parameter programming (IPP) and fuzzy vertex analysis (FVA) within a fixed-mix stochastic programming (FSP) framework to address uncertain parameters described as probability distributions and dual intervals. It can also be used for analyzing various policy scenarios that are associated with different levels of economic consequences since penalties are exercised with recourse actions against any infeasibility. A real case for water resources management planning of Zhangweinan River Basin in China is then conducted for demonstrating the applicability of the developed DFSP method. Solutions in association with α-cut levels are generated by solving a set of deterministic submodels, which are useful for generating a range of decision alternatives under compound uncertainties. The results can help to identify desired water-allocation schemes for local sustainable development that the prerequisite water demand can be guaranteed when the available water resource is scarce. 相似文献
583.
One of the most challenging issues in the field of sustainable design is that of limiting the environmental impact of structural systems, as they contribute significantly to raw material consumption, global carbon emissions and solid waste production. This paper addresses the approach of the reuse of steel structure without melting which allows for savings in steel mass and the reduction of waste amounts offering moreover an opportunity to avoid environmental burdens related to the recycling process. Recent studies have stressed the technical feasibility of this strategy, which appears particularly effective in those countries in which a building's life is rather short, such as in Japan and US, though its application encounters more difficulties in most European countries, owing to longer building use. Besides stressing the architectural and structural feasibility of the above-mentioned strategy, this research work aims to quantify the mass savings that are achievable in this manner by presenting a real case study set in Italy. It consists in a railway station, which has been designed keeping in mind the partial employment of structural elements recovered from an old industrial building that is no longer in use. To estimate the amount of steel saved, two different structural models for the designed building have been carried out and compared. In the first one, the structure has been designed on the assumption of the reusing of recovered structural elements; in the second one, the same structure has been designed considering the use of new elements only. The final result of the analysis shows that steel reuse allowed for savings of up to 30% of steel. 相似文献