全文获取类型
收费全文 | 3399篇 |
免费 | 179篇 |
国内免费 | 451篇 |
专业分类
安全科学 | 671篇 |
废物处理 | 75篇 |
环保管理 | 422篇 |
综合类 | 1578篇 |
基础理论 | 390篇 |
污染及防治 | 416篇 |
评价与监测 | 163篇 |
社会与环境 | 116篇 |
灾害及防治 | 198篇 |
出版年
2024年 | 23篇 |
2023年 | 59篇 |
2022年 | 98篇 |
2021年 | 99篇 |
2020年 | 82篇 |
2019年 | 93篇 |
2018年 | 116篇 |
2017年 | 73篇 |
2016年 | 66篇 |
2015年 | 97篇 |
2014年 | 200篇 |
2013年 | 132篇 |
2012年 | 178篇 |
2011年 | 186篇 |
2010年 | 129篇 |
2009年 | 146篇 |
2008年 | 184篇 |
2007年 | 179篇 |
2006年 | 184篇 |
2005年 | 150篇 |
2004年 | 138篇 |
2003年 | 169篇 |
2002年 | 110篇 |
2001年 | 93篇 |
2000年 | 91篇 |
1999年 | 118篇 |
1998年 | 68篇 |
1997年 | 100篇 |
1996年 | 94篇 |
1995年 | 79篇 |
1994年 | 71篇 |
1993年 | 61篇 |
1992年 | 63篇 |
1991年 | 61篇 |
1990年 | 60篇 |
1989年 | 36篇 |
1988年 | 22篇 |
1987年 | 17篇 |
1986年 | 20篇 |
1985年 | 17篇 |
1984年 | 11篇 |
1983年 | 18篇 |
1982年 | 12篇 |
1981年 | 15篇 |
1980年 | 7篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有4029条查询结果,搜索用时 906 毫秒
611.
612.
613.
陈水冰 《安全.健康和环境》2008,8(11)
李清这两年过得有点不顺,先是谈了两年的女朋友散了,再就是想争取到好部门工作的计划也没有落实。最可气的是人家买股票一买一个准,他倒好,碰谁谁就跌停,真是背到家了。 相似文献
614.
615.
616.
Oram JJ McKee LJ Werme CE Connor MS Oros DR Grace R Rodigari F 《Environment international》2008,34(8):1137-1147
A mass budget of polybrominated diphenyl ethers (PBDEs) in San Francisco Bay is developed as a first step towards understanding the local sources and transport processes controlling PBDE fate in a highly urbanized estuary. Extensive monitoring of PBDEs in estuarine water and sediment, freshwater tributaries, air, and wastewater effluents and sludges were integrated with a mass budget model to provide a synthetic view of these emerging contaminants. The Bay inventories of BDE 47 and BDE 209 in 2006 were estimated to be 33+/-3 kg and 153+/-45 kg, respectively. Empirically derived estimates of annual inputs of BDE 47 and BDE 209 from all quantifiable external sources ranged from 11 to 28 kg/y and 22 to 24 kg/y, respectively. BDE 47 loads were dominated by wastewater while runoff from local tributaries represented the largest contributor to BDE 209 loads. Model results suggest the Bay PBDE inventory is highly sensitive to changes in external loads, with degradation and outflow being the major processes governing PBDE fate. The mass budget presented provides a framework for integrating future monitoring and modeling efforts. 相似文献
617.
618.
近日.笔者在基层安全生产行政审批服务中遇到这样一个天然气建设项目.该项目名称为“液化天然气调峰及综合利用项目”。建设的主要内容为:从天然气长输管道接出天然气.铺设1.8公里天然气输送管道到厂区;天然气净化装置、液化(制冷)装置、液化天然气储存装置。 相似文献
619.
城市燃气管道是一种压力管道,人工煤气属易燃易爆、有毒气体,燃气管网老化、腐蚀严重时将产生管道穿孔、泄漏等严重后果。对北方地区某市燃气管网的调查分析表明,管道运行时存在诸多不安全因素,如管网设施老化,部分管道超期服役;受气质与使用年限的影 相似文献
620.
Application of beef cattle () manure based on nitrogen (N) requirements of crops has resulted in elevated concentrations of soil test phosphorus (P) in surface soils, and runoff from this cropland can contribute to eutrophication of surface waters. We conducted a 3-yr field study (2005-2007) on a Lethbridge loam soil cropped to dryland barley () in southern Alberta, Canada to evaluate the effect of annual and triennial P-based and annual N-based feedlot manure on P and N in runoff. The manure was spring applied and incorporated. There was one unamended control plot. A portable rainfall simulator was used to generate runoff in the spring of each year after recent manure incorporation, and the runoff was analyzed for total P, total dissolved P, total particulate P, dissolved reactive P, total N, total dissolved N, total particulate N, NO-N, and NH-N. Annual or triennial P-based application resulted in significantly ( ≤ 0.05) lower (by 50 to 94%) concentrations or loads of mainly dissolved P fractions in runoff for some years compared with annual N-based application, and this was related to lower rates of annual manure P applied. For example, mean dissolved reactive P concentrations in 2006 and 2007 were significantly lower for the annual P-based (0.12-0.20 mg L) than for the annual N-based application (0.24-0.48 mg L), and mean values were significantly lower for the triennial P-based (0.06-0.13 mg L) than for the annual N-based application. In contrast, other P fractions in runoff were unaffected by annual P-based application. Our findings suggested no environmental benefit of annual P-based application over triennial P-based application with respect to P and N in runoff. Similar concentrations and loads of N fractions in runoff for the P- and N-based applications indicated that shifting to a P-based application would not significantly influence N in runoff. 相似文献