全文获取类型
收费全文 | 1176篇 |
免费 | 86篇 |
国内免费 | 501篇 |
专业分类
安全科学 | 98篇 |
废物处理 | 71篇 |
环保管理 | 103篇 |
综合类 | 673篇 |
基础理论 | 251篇 |
污染及防治 | 398篇 |
评价与监测 | 43篇 |
社会与环境 | 36篇 |
灾害及防治 | 90篇 |
出版年
2024年 | 4篇 |
2023年 | 40篇 |
2022年 | 84篇 |
2021年 | 62篇 |
2020年 | 54篇 |
2019年 | 48篇 |
2018年 | 62篇 |
2017年 | 76篇 |
2016年 | 74篇 |
2015年 | 103篇 |
2014年 | 110篇 |
2013年 | 126篇 |
2012年 | 132篇 |
2011年 | 115篇 |
2010年 | 80篇 |
2009年 | 72篇 |
2008年 | 86篇 |
2007年 | 63篇 |
2006年 | 42篇 |
2005年 | 41篇 |
2004年 | 19篇 |
2003年 | 28篇 |
2002年 | 27篇 |
2001年 | 27篇 |
2000年 | 24篇 |
1999年 | 25篇 |
1998年 | 22篇 |
1997年 | 20篇 |
1996年 | 21篇 |
1995年 | 21篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
排序方式: 共有1763条查询结果,搜索用时 15 毫秒
931.
932.
933.
Mg/Al水滑石对水中痕量邻苯二甲酸酯的吸附动力学和热力学 总被引:1,自引:1,他引:0
研究了Mg/A1水滑石对水中痕量邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二(2一乙基己基)酯(DEHP)和邻苯二甲酸二辛酯(DnOP)的吸附动力学和热力学特性。结果表明,在所研究的浓度范围内,3种邻苯二甲酸酯的吸附动力学曲线均符合准二级速率方程,DMP、DEHP和DnOP分别在600、200和200min基本达到吸附平衡;3种邻苯二甲酸酯的吸附等温线基本符合Langmuir和Freundlich吸附等温方程;在283~308K范围,pH=6.36,3种邻苯二甲酸酯初始浓度均为50μg/L时,吸附过程△H为负值且绝对值为5~12kJ/mol,表明吸附为放热过程,以表面物理吸附为主,邻苯二甲酸酯在Mg/Al水滑石上的吸附是色散力、诱导力、取向力和氢键力等多种作用力协同作用的结果。 相似文献
934.
The New York/New Jersey Harbor (also known as the Hudson River Estuary) is heavily contaminated with polychlorinated biphenyls (PCBs) arising in part from inputs from the Upper Hudson River, which is a Superfund site containing historical PCB contamination, and also due to inputs from the New York City metropolitan area. The Contamination Assessment and Reduction Project (CARP) measured PCBs and other contaminants in ambient water samples collected throughout the Harbor region during 1998-2001. In order to investigate the sources of PCBs to the NY/NJ Harbor, this data base of PCB concentrations was analyzed using Positive Matrix Factorization (PMF). This analysis resolved seven factors that are thought to be associated with sources such as the Upper Hudson River, storm water runoff, combined sewer overflows (CSOs), and wastewater effluents. The PMF model also produced a factor that appears to be related to sites contaminated with Aroclor 1260. To the extent that the NY/NJ Harbor is typical of urbanized estuaries throughout the United States, these results suggest that storm water runoff is probably a significant source of PCBs to surface waters in urban areas. 相似文献
935.
936.
Performance and characteristics of biosorption of Pb(II) had been studied in a batch system using the fungal strain biomass, KC-2. The biosorption performance was investigated by analysing the effects of such factors as the initial pH, initial Pb(II) concentration, and contact time at 303 K. The maximum Pb(II) adsorption was obtained at pH 5.0. The experimental data were described by the pseudo first-order, pseudo second-order and intraparticle diffusion kinetic models, and were closely followed the pseudo second-order kinetic model. The equilibrium experimental data were well fitted to Langmuir model and the maximum biosorption capacity was 84.03 mg g(-1). The adsorption mechanism was examined by FTIR, SEM and EDAX analysis. Results indicated that carboxylic, hydroxyl and amine groups were involved in the biosorption and ion exchange mechanism existed. 相似文献
937.
Li Y Su B Liu J Du X Huang G 《Journal of the Air & Waste Management Association (1995)》2011,61(7):771-777
To assess the effects of three types of Mg and P salt mixtures (potassium phosphate [K3PO4]/magnesium sulfate [MgSO4], potassium dihydrogen phosphate [K2HPO4]/MgSO4, KH2PO4/MgSO4) on the conservation of N and the biodegradation of organic materials in an aerobic food waste composting process, batch experiments were undertaken in four reactors (each with an effective volume of 30 L). The synthetic food waste was composted of potatoes, rice, carrots, leaves, meat, soybeans, and seed soil, and the ratio of C and N was 17:1. Runs R1-R3 were conducted with the addition of K3PO4/ MgSO4, K2HPO4/MgSO4, and KH2PO4/MgSO4 mixtures, respectively; run R0 was a blank performed without the addition of Mg and P salts. After composting for 25 days, the degrees of degradation of the organic materials in runs R0-R3 were 53.87, 62.58, 59.14, and 49.13%, respectively. X-ray diffraction indicated that struvite crystals were formed in runs R1-R3 but not in run R0; the gaseous ammonia nitrogen (NH3-N) losses in runs R0-R3 were 21.2, 32.8, 12.6, and 3.5% of the initial total N, respectively. Of the tested Mg/P salt mixtures, the K2HPO4/ MgSO4 system provided the best combination of conservation of N and biodegradation of organic materials in this food waste composting process. 相似文献
938.
939.
940.
要创建和谐生态工业园区应做到:坚持“环保优先”,强化环保基础设施建设;以“发展高科技、实现产业化”为根本目标;调整产业结构,改变经济增长方式,实现可持续发展;加大力度促进企业发展;大力加强环保宣传。 相似文献