全文获取类型
收费全文 | 498篇 |
免费 | 51篇 |
国内免费 | 369篇 |
专业分类
安全科学 | 19篇 |
废物处理 | 46篇 |
环保管理 | 40篇 |
综合类 | 528篇 |
基础理论 | 116篇 |
污染及防治 | 124篇 |
评价与监测 | 36篇 |
社会与环境 | 8篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 16篇 |
2022年 | 31篇 |
2021年 | 31篇 |
2020年 | 21篇 |
2019年 | 30篇 |
2018年 | 22篇 |
2017年 | 21篇 |
2016年 | 21篇 |
2015年 | 45篇 |
2014年 | 57篇 |
2013年 | 65篇 |
2012年 | 62篇 |
2011年 | 61篇 |
2010年 | 42篇 |
2009年 | 50篇 |
2008年 | 29篇 |
2007年 | 55篇 |
2006年 | 48篇 |
2005年 | 29篇 |
2004年 | 22篇 |
2003年 | 21篇 |
2002年 | 26篇 |
2001年 | 17篇 |
2000年 | 17篇 |
1999年 | 10篇 |
1998年 | 14篇 |
1997年 | 9篇 |
1996年 | 13篇 |
1995年 | 6篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1979年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有918条查询结果,搜索用时 46 毫秒
71.
海底铁锰氧化还原过程的模拟研究 总被引:5,自引:0,他引:5
本文用室内海水-沉积物平衡箱研究了沉积物间隙水中铁、锰的垂直变化分布和随时间变化的分布,Fe~(2+)随深度、时间的变化幅度大,在六个月的实验期内均是如此,而Mn~(2+)在放置三个月后即趋于稳定;Fe~(2+),Mn~(2+)产生的宏观经验动力学表明:Fe~(2+)受pH影响远比Mn~(2+)大,且随着深度的增加更为明显,Fe~(2+)在较下层产生速率大,而Mn~(2+)反之;Fe~(2+)的扩散转移是上覆海水向沉积物中转移,扩散量为-60.7ug/m~2d,Nn~(2+)转移方向相反,扩散量为1746.2ug/m~2.d。 相似文献
72.
Ancillary benefits of reduced air pollution in the US from moderate greenhouse gas mitigation policies in the electricity sector 总被引:3,自引:0,他引:3
Dallas Burtraw Alan Krupnick Karen Palmer Anthony Paul Michael Toman Cary Bloyd 《Journal of Environmental Economics and Management》2003,45(3):650
Actions to slow atmospheric accumulation of greenhouse gases also would reduce conventional air pollutants yielding “ancillary” benefits that tend to accrue locally and in the near-term. Using a detailed electricity model linked to an integrated assessment framework to value changes in human health, we find a tax of $25 per metric ton of carbon emissions would yield NOx-related health benefits of about $8 per metric ton of carbon reduced in the year 2010 (1997 dollars). Additional savings of $4–$7 accrue from reduced investment in NOx and SO2 abatement in order to comply with emission caps. Total ancillary benefits of a $25 carbon tax are $12–$14, which appear to justify the costs of a $25 tax, although marginal benefits are less than marginal costs. At a tax of $75, greater total benefits are achieved but the value per ton of carbon reductions remains roughly constant at about $12. 相似文献
73.
The NO/H2/O2 reaction was studied under oxidizing conditions in the 100-400 °C range over 0.1 wt% Pt supported on various metal oxides such as MgO, CeO2, SiO2, La2O3, CaO, Y2O3 and TiO2. The Pt/MgO and Pt/CeO2 catalysts showed good catalytic behaviours. Here, we find that the Pt/Mg-Ce-O catalyst, prepared from MgO and CeO2 by the sol-gel method, is a very active and selective catalyst towards N2 formation in the whole 100–400 °C range. This catalyst appears to be the most active, selective and stable one ever reported in the literature for the NO/H2/O2 reaction, even in the presence of 5%v H2O or 20 ppmv of SO2 in the feed stream.Selected article from the Regional Symposium on Chemistry and Environment, Krusevac, Serbia, June 2003, organised by Dr. Branimir Jovancicevic. 相似文献
74.
75.
76.
介绍了络合吸收结合生物转化处理NOx 技术的基本原理和目前的研究进展情况 ,并分析了该技术处理氮氧化物存在的问题和未来发展方向 相似文献
77.
The current approach for modelling ion adsorption onto binary (hydr)oxides using homogeneous surface complexation models involves the assumption of either an ideal mixture of the two surfaces (i.e. two surface sites on one surface) or a patchwise surface (i.e. two surfaces with one surface site on each surface). As the physical truth should be between these two limiting cases, a model which assumes a patchwise surface constituted of three patches is proposed. Two patches represent the distinct (hydr)oxides, and the third one a mixture of these distinct (hydr)oxides. Using the diffuse layer model, the three approaches are applied to literature data for Cd adsorption onto binary mixtures of alumina-coated silica at total constant Cd concentration and varying amounts of alumina coatings. For Cd adsorption onto these binary (hydr)oxide systems, the new approach explains the observed potential effects. The proposed model, which contains two additional adjustable parameters in terms of site concentrations or one adjustable parameter in terms of specific surface area, is more successful than the two limiting cases. The new model is then validated by predicting Ca and Zn behaviour on the same binary (hydr)oxide system. 相似文献
78.
高温下氧化焙烧细磨后的砷华生产废渣,利用软锰矿浆吸收产生的SO2气体,吸收液经净化除杂、浓缩结晶等工序可制备工业产品硫酸锰。适宜的焙烧条件如下:焙烧温度为650℃,焙烧时间为60min,废渣粒度为-97μm。选择合适的吸收工艺,Mn的浸出率可达96.20%,此时SO2脱除率为87.20%。 相似文献
79.
Brayner FM da Silva HK Barbosa AM 《Environmental science and pollution research international》2001,8(4):269-274
An analytical procedure involving a three-step sequential extraction was used to determine the chemical association of heavy metals (Zn, Cr, Mn and Fe) with the major phases (exchangable, reducible and oxidizable) in samples from a fishpond of estuarine sediments. The pond is located in the Capibaribe River estuary, within the boundaries of the city of Recife, in the State of Pernambuco in the northeast of Brazil. The total metal content was determined as well. All metals were extracted from the residual fraction at a percentage greater than 50%. 相似文献
80.
以双氯芬酸为目标有机药物污染物,探究其在以锰矿石为填料并接种了异化金属还原菌(Geobactermetallireducens,简称GS-15细菌)的垂直流人工湿地中的去除过程.结果表明,双氯芬酸在锰矿石人工湿地中的平均去除率最高为23.56%.采用XRD和XRF对反应前后的锰矿石进行物相和元素相对含量分析,得出锰(Mn)是参与降解双氯芬酸的关键响应元素.GS-15细菌利用锰矿石发生异化还原对双氯芬酸的氧化降解是锰矿石人工湿地对双氯芬酸的主要去除途径.此外,利用液质联用技术(LC-MS/MS)对降解产物进行鉴定,发现双氯芬酸被降解生成了5-羟基双氯芬酸、双氯芬酸-2,5-亚氨基琨和1,3-二氯苯三种降解产物,该研究成果对有机药物废水的深度处理提供新的方法和理论指导. 相似文献