全文获取类型
收费全文 | 699篇 |
免费 | 32篇 |
国内免费 | 270篇 |
专业分类
安全科学 | 60篇 |
废物处理 | 52篇 |
环保管理 | 50篇 |
综合类 | 383篇 |
基础理论 | 137篇 |
污染及防治 | 230篇 |
评价与监测 | 28篇 |
社会与环境 | 33篇 |
灾害及防治 | 28篇 |
出版年
2023年 | 11篇 |
2022年 | 33篇 |
2021年 | 29篇 |
2020年 | 22篇 |
2019年 | 26篇 |
2018年 | 27篇 |
2017年 | 32篇 |
2016年 | 26篇 |
2015年 | 50篇 |
2014年 | 63篇 |
2013年 | 80篇 |
2012年 | 51篇 |
2011年 | 63篇 |
2010年 | 46篇 |
2009年 | 34篇 |
2008年 | 42篇 |
2007年 | 54篇 |
2006年 | 34篇 |
2005年 | 26篇 |
2004年 | 20篇 |
2003年 | 26篇 |
2002年 | 22篇 |
2001年 | 17篇 |
2000年 | 22篇 |
1999年 | 28篇 |
1998年 | 18篇 |
1997年 | 16篇 |
1996年 | 17篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1993年 | 10篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 9篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有1001条查询结果,搜索用时 15 毫秒
511.
澳门松山市政公园优势种的种间关联性分析 总被引:3,自引:0,他引:3
为了探明澳门松山市政公园群落的物种组成和种间关系,在对其群落进行样方调查的基础上,利用方差比率法、γ2检验以及种间关联度指数对物种关联性进行了分析.结果表明:澳门松山市政公园群落内共有维管束植物119种,其中乔木34种,灌木44种,麒本植物18种,草本植物23种.该群落内物种整体关联性表现为显著的正关联;55个优势种组成的1 485对种对中,有242对表现出显著或极显著关联性.其中有241对种对表现出正关联性.占所有关联对数的99.59%,占总种对数的16.23%;仅1对种对表现出负关联性占所有关联对数0.41%,占总种对数的0.067%. 相似文献
512.
Hongxun HOU Shuying WANG Yongzhen PENG Zhiguo YUAN Fangfang YIN Wang GAN 《Frontiers of Environmental Science & Engineering》2009,3(1):106-111
The anaerobic-anoxic oxidation ditch (A2/O OD) process is popularly used to eliminate nutrients from domestic wastewater. In order to identify the existence of denitrifying phosphorus removing bacteria (DPB), evaluate the contribution of DPB to biological nutrient removal, and enhance the denitrifying phosphorus removal in the A2/O OD process, a pilot-scale A2/O OD plant (375 L) was conducted. At the same time batch tests using sequence batch reactors (12 L and 4 L) were operated to reveal the significance of anoxic phosphorus removal. The results indicated that: The average removal efficiency of COD, N H 4 + , P O 4 3 - , and TN were 88.2%, 92.6%, 87.8%, and 73.1%, respectively, when the steady state of the pilot-scale A2/O OD plant was reached during 31-73 d, demonstrating a good denitrifying phosphorus removal performance. Phosphorus uptake took place in the anoxic zone by poly-phosphorus accumulating organisms N O 2 - could be used as electron receptors in denitrifying phosphorus removal, and the phosphorus uptake rate with N O 2 - as the electron receptor was higher than that with N O 3 - when the initial concentration of either N O 2 - or N O 3 - was 40 mg/L. 相似文献
513.
514.
515.
516.
Hou Yali Wang Qunwei 《Environmental science and pollution research international》2023,30(6):13960-13973
Environmental Science and Pollution Research - This paper uses bibliometrics to characterize the knowledge systems of big data, artificial intelligence (AI), and energy based on the Science... 相似文献
517.
Xiang Dongmei Zhu Lin Yang Song Hou Xiaomin 《Environmental science and pollution research international》2023,30(5):11936-11945
Environmental Science and Pollution Research - As one of the triazine herbicides with widespread usage in agriculture, metribuzin exerted nonnegligible hazardous effects on plants via excessive... 相似文献
518.
Nan Fang Zhou Lu Zhongbei Zhang Zhiguang Hou Shuang Liang Bo Wang 《Journal of environmental science and health. Part. B》2020,55(6):566-573
AbstractTomatoes have been widely planted in greenhouses and fields in China. Soil-borne diseases are more harmful to tomatoes than other types of diseases. Dimethyl disulfide (DMDS) was used as a novel fumigant instead of methyl bromide to control soil-borne diseases. To assess the safety of DMDS for use on tomatoes, its dissipation and terminal residues were investigated at three different locations under greenhouse and open field conditions. The QuEChERS method was simplified using gas chromatography with mass spectrometry detection and combined with liquid-liquid extraction purification to allow determination of DMDS levels in both the tomatoes and the soil. The average recovery of the method was between 85.3 and 98.6%, with the relative standard deviation (RSD) ranging from to 1.9–10.3%. The dissipation and terminal residues of DMDS in the tomatoes and the soil were analyzed using the method, the results of which showed that the half-life of DMDS ranged from 0.3–6.5 d in the soil at three different locations. The terminal residues of DMDS in the tomatoes and the soil were not detected. This study provided data that the Chinese government can use to support appropriate and safe guidance for the use of DMDS on agriculture. 相似文献
519.
为满足日益严苛的排水标准,将A~2O工艺叠加膜组件是提高出水水质的有效措施。采用恒压膜通量实验、三维荧光光谱、分子排阻色谱和红外光谱对A~2O工艺各阶段混合液的膜污染潜力及其对应的污染物组成进行了分析,从膜污染的角度考察了A~2O工艺与膜组件的最优结合形式。结果表明:好氧段混合液的恒压膜通量远高于厌氧和缺氧段的混合液,其溶解性有机物含量最少,且主要为不易发生膜污染的大分子惰性腐殖酸和微生物代谢产物;而厌氧和缺氧混合液中含有大量溶解性有机物,主要为氨基酸、蛋白质类物质,容易引发膜污染。因此,建议在实际工程中将膜组件应用于好氧阶段的泥水分离,不仅能有效提高出水水质,还能有效降低膜污染。以上结果可为膜组件用于A~2O工艺的提标改造提供参考。 相似文献
520.
水和废水中2,4-滴、2,4-二氯酚、2,4,6-三氯酚的测定 总被引:1,自引:0,他引:1
用Ultra-2320μm柱分离2,4-滴,2,4-二氯酚及2,4,6-三氯酚。保证了检测结果有足够的精确度。用直接进水样技术而不必处理水样,使检测结果更趋精确。 相似文献