全文获取类型
收费全文 | 556篇 |
免费 | 68篇 |
国内免费 | 201篇 |
专业分类
安全科学 | 56篇 |
废物处理 | 42篇 |
环保管理 | 37篇 |
综合类 | 366篇 |
基础理论 | 79篇 |
污染及防治 | 195篇 |
评价与监测 | 23篇 |
社会与环境 | 7篇 |
灾害及防治 | 20篇 |
出版年
2023年 | 11篇 |
2022年 | 33篇 |
2021年 | 28篇 |
2020年 | 35篇 |
2019年 | 26篇 |
2018年 | 25篇 |
2017年 | 35篇 |
2016年 | 33篇 |
2015年 | 42篇 |
2014年 | 43篇 |
2013年 | 53篇 |
2012年 | 40篇 |
2011年 | 51篇 |
2010年 | 39篇 |
2009年 | 36篇 |
2008年 | 39篇 |
2007年 | 36篇 |
2006年 | 28篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 16篇 |
2002年 | 21篇 |
2001年 | 16篇 |
2000年 | 20篇 |
1999年 | 17篇 |
1998年 | 9篇 |
1997年 | 13篇 |
1996年 | 14篇 |
1995年 | 11篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1990年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有825条查询结果,搜索用时 31 毫秒
1.
低温液氮与泡沫混合液直接接触产生氮气泡沫是一种新型的掺混形式,利用液氮高汽化比的特点,搭建液氮泡沫可视化实验装置,进行氮气-水两相流及液氮泡沫流动特性的研究。结果表明,液氮相变产生大量氮气,其与泡沫液混合产生泡沫,温度有所回升,最终趋于泡沫混合液温度;管路沿程压降较小;液氮射流破碎及流动过程可分为6个区域:低温液氮区、向上循环翻滚区、滞留区、泡沫与泡沫混合液混合区、致密泡沫区、泡沫混合液区。流体向下游流动过程中持续发泡;为防止管路结冰,需合理控制泡沫混合液与液氮流量。 相似文献
3.
He Genhe Wang Xiaodong Liu Xu Xiao Xiaoyu Huang Shoucheng Wu Jichun 《Russian Journal of Ecology》2018,49(6):524-533
Russian Journal of Ecology - The present study characterized the nutrients availability of three rare earth tailings deserted in different time stages in Southern Jiangxi of China, and revealed the... 相似文献
4.
Afshin Shabani Xiaodong Zhang Xuefeng Chu Timothy P. Dodd Haochi Zheng 《Journal of the American Water Resources Association》2020,56(2):297-309
Devils Lake is a terminal lake located in northeast North Dakota. Because of its glacial origin and accumulated salts from evaporation, the lake has a high concentration of sulfate compared to the surrounding water bodies. From 1993 to 2011, Devils Lake water levels rose by ~10 m, which flooded surrounding communities and increased the chance of an overspill to the Sheyenne River. To control the flooding, the State of North Dakota constructed two outlets to pump the lake water to the river. However, the pumped water has raised concerns about of water quality degradation and potential flooding risk of the Sheyenne River. To investigate these perceived impacts, a Soil and Water Assessment Tool (SWAT) model was developed for the Sheyenne River and it was linked to a coupled SWAT and CE‐QUAL‐W2 model that was developed for Devils Lake in a previous study. While the current outlet schedule has attempted to maintain the total river discharge within the confines of a two‐year flood (36 m3/s), our simulation from 2012 to 2018 revealed that the diversion increased the Sheyenne River sulfate concentration from an average of 125 to >750 mg/L. Furthermore, a conceptual optimization model was developed with a goal of better preserving the water quality of the Sheyenne River while effectively mitigating the flooding of Devils Lake. The optimal solution provides a “win–win” outlet management that maintains the efficiency of the outlets while reducing the Sheyenne River sulfate concentration to ≤600 mg/L. 相似文献
5.
Lai Xiaodong Liu Zhiming Luo Sumei 《Environmental science and pollution research international》2020,27(30):37363-37376
Environmental Science and Pollution Research - In the context of global warming and environmental deterioration, the environment impact assessment is a crucial institutional guaranty to assure less... 相似文献
6.
A series of WO3/CeO2 (WOx/CeO2) catalysts were synthesized by wet impregnation of ammonium metatungstate on a CeO2 support. The resulting solid acid catalysts were characterized by X-ray diffraction (XRD), UV-Vis spectroscopy (UV-Vis), Raman spectroscopy (Raman), in-situ Fourier transform infrared spectroscopy (in-situ FT-IR) of ammonia adsorption, NH3-TPD, H2 temperature-programmed reduction (H2-TPR), NH3/NO oxidation and activity measurements for NOx reduction by NH3 (NH3-SCR). The results show that polytungstate (WOx) species are the main species of tungsten oxide on the surface of ceria. The addition of tungsten oxide enhances the Brönsted acidity of ceria catalysts remarkably and decreases the amount of surface oxygen on ceria, with strong interaction between CeO2 and WOx. As a result, the N2 selectivity of NH3 oxidation and NH3-SCR at high temperatures (> 300℃) is enhanced. Therefore, a wide working temperature window in which NOx conversion exceeds 80% (NOx conversion > 80%) from 200 to 450℃, is achieved over 10 wt.% WOx/CeO2 catalyst. A tentative model of the NH3-SCR reaction route on WOx/CeO2 catalysts is presented. 相似文献
7.
8.
9.
10.