全文获取类型
收费全文 | 319篇 |
免费 | 11篇 |
国内免费 | 140篇 |
专业分类
安全科学 | 35篇 |
废物处理 | 21篇 |
环保管理 | 17篇 |
综合类 | 145篇 |
基础理论 | 57篇 |
污染及防治 | 157篇 |
评价与监测 | 9篇 |
社会与环境 | 7篇 |
灾害及防治 | 22篇 |
出版年
2023年 | 4篇 |
2022年 | 11篇 |
2021年 | 12篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 14篇 |
2017年 | 12篇 |
2016年 | 15篇 |
2015年 | 22篇 |
2014年 | 22篇 |
2013年 | 36篇 |
2012年 | 37篇 |
2011年 | 29篇 |
2010年 | 22篇 |
2009年 | 15篇 |
2008年 | 21篇 |
2007年 | 18篇 |
2006年 | 20篇 |
2005年 | 22篇 |
2004年 | 9篇 |
2003年 | 23篇 |
2002年 | 13篇 |
2001年 | 21篇 |
2000年 | 12篇 |
1999年 | 9篇 |
1998年 | 8篇 |
1997年 | 2篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1986年 | 2篇 |
1933年 | 1篇 |
排序方式: 共有470条查询结果,搜索用时 250 毫秒
251.
采用掺Al-TiO2作为改性剂制备改性膨润土,考察了微波辐射功率、辐射时间、TiO2改性剂用量、铝盐掺杂量、pH值对微污染水中COD和NH4-N去除效果的影响。实验表明,微波辐射功率为460 W,辐射时间为8 min,TiO2改性剂用量为1.3 mmol/g,铝盐掺杂量为0.2 mmol/g为最佳制备条件。pH值为6.0,改性膨润土投加量为40 mg/L,沉淀时间为30min时,对微污染水中初始浓度15 mg/L的COD和5 mg/L的NH4-N去除率分别达到92%和59%以上。 相似文献
252.
253.
254.
255.
256.
采用强化混凝与活性炭联用技术对赣江微污染水源水处理进行试验研究。试验结果表明,强化混凝与活性炭联用较常规工艺能减小出水浊度,显著提高CODMn和UV254的去除率,并有效控制出水余铝含量。原水CODMn为4.10~4.25mg/L左右,UV254为0.2~0.3mg/L时,中试系统出水浊度降低了12%左右,出水CODMn和UV254分别为0.5~0.7mg/L和0.015~0.025mg/L,各自去除率较传统工艺分别提高了36%和40%左右。试验出水余铝浓度均<0.2mg/L,NH3-N去除率没有明显提高。 相似文献
257.
Monosulfuron-ester is a new, low rate, sulfonylurea herbicide that is being promoted for annual broadleaf and gramineal weed
control; however, there is a lack of published information on its behavior in soils. The adsorption and desorption of monosulfuronester
by seven type soils were measured using a batch equilibrium technique. The results showed that the Freundlich equation fitted
its adsorption and desorption well, and the Freundlich constant values (Kf-ads) ranged from 0.88 to 5.66. Adsorption isotherms were
nonlinear with 1/nf-ads values < 1. Soil pH, organic matter (OM), and clay content were the main factors influencing its adsorption
and desorption. Adsorption and desorption were negatively correlated with pH 4.0–8.0 while positively correlated with OM and clay
content. The adsorption of monosulfuron-ester was mainly a physical process, because its free energy (ΔG) in seven soils was less than
40 kJ/mol. Monosulfuron-ester adsorption by three soils increased with increasing CaCl2 concentration using CaCl2 as a background
electrolyte. Monosulfuron-ester desorption was hysteretic in all tested soils. 相似文献
258.
Liying Jiang Guofeng Nie Runye Zhu Jiade Wang Jianmeng Chen Yubo Mao Zhuowei Cheng Willam A. Anderson 《环境科学学报(英文版)》2017,29(5):266-273
Chlorobenzene removal was investigated in a non-thermal plasma reactor using CeO2/HZSM-5 catalysts. The performance of catalysts was evaluated in terms of removal and energy efficiency. The decomposition products of chlorobenzene were analyzed. The results show that CeO2/HZSM-5 exhibited a good catalytic activity, which resulted in enhancements of chlorobenzene removal, energy efficiency, and the formation of lower amounts of by-products. With regards to CO2 selectivity, the presence of catalysts favors the oxidation of by-products, leading to a higher CO2 selectivity. With respect to ozone, which is considered as an unavoidable by-product in air plasma reactors, a noticeable decrease in its concentration was observed in the presence of catalysts. Furthermore, the stability of the catalyst was investigated by analyzing the evolution of conversion in time. The experiment results indicated that CeO2/HZSM-5 catalysts have excellent stability: chlorobenzene conversion only decreased from 78% to 60% after 75 hr, which means that the CeO2/HZSM-5 suffered a slight deactivation. Some organic compounds and chlorinated intermediates were adsorbed or deposited on the catalysts surface as shown by the results of Fourier Transform Infrared (FT-IR) spectroscopy, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of the catalyst before and after the reaction, revealing the cause of catalyst deactivation. 相似文献
259.
新型人工合成膨润土防渗卷材的研制及其渗透性能 总被引:8,自引:0,他引:8
将膨润土和胶粘剂加以混合 ,结合国外先进的粘结工艺 ,制成防渗卷材 .对膨润土类型、外封装用材料及胶粘剂的确定 ,卷材的成型工艺及卷材的渗透性能研究结果表明 ,钠基膨润土的渗透性能优于钙基膨润土 .在人工钠土中无论是加入聚丙烯酸酯类乳液还是 PM植物胶 ,在掺加的比例一定时 ,随着密度的增大 ,渗透系数下降 ;在相同密度下 ,随着掺加的比例增大 ,渗透系数下降 .人工钠土的渗透系数与水力坡度呈线性关系 .膨润土及其胶粘剂卷材与模拟浸出液间的化学配伍性较好 .膨润土卷材具有良好的自封闭性 ,在材料受损的情况下也能够通过自封闭作用达到较好的“焊接”效果 . 相似文献
260.