全文获取类型
收费全文 | 2770篇 |
免费 | 336篇 |
国内免费 | 1175篇 |
专业分类
安全科学 | 330篇 |
废物处理 | 111篇 |
环保管理 | 239篇 |
综合类 | 2087篇 |
基础理论 | 407篇 |
环境理论 | 1篇 |
污染及防治 | 614篇 |
评价与监测 | 186篇 |
社会与环境 | 168篇 |
灾害及防治 | 138篇 |
出版年
2024年 | 15篇 |
2023年 | 86篇 |
2022年 | 222篇 |
2021年 | 193篇 |
2020年 | 210篇 |
2019年 | 146篇 |
2018年 | 157篇 |
2017年 | 164篇 |
2016年 | 170篇 |
2015年 | 196篇 |
2014年 | 235篇 |
2013年 | 264篇 |
2012年 | 312篇 |
2011年 | 264篇 |
2010年 | 228篇 |
2009年 | 232篇 |
2008年 | 208篇 |
2007年 | 164篇 |
2006年 | 162篇 |
2005年 | 83篇 |
2004年 | 84篇 |
2003年 | 69篇 |
2002年 | 75篇 |
2001年 | 51篇 |
2000年 | 62篇 |
1999年 | 57篇 |
1998年 | 29篇 |
1997年 | 25篇 |
1996年 | 24篇 |
1995年 | 17篇 |
1994年 | 15篇 |
1993年 | 15篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1970年 | 1篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1961年 | 1篇 |
1959年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有4281条查询结果,搜索用时 15 毫秒
121.
Chengliang Li Andreas Schffer Harry Vereecken Marc Heggen Rong Ji Erwin Klumpp 《环境科学学报(英文版)》2013,25(3):466-472
The aggregation of multi-walled carbon nanotubes (MWCNTs) in the aqueous phase not only inhibits their extensive utilization in various aspects but also dominates their environmental fate and transport.The role of surfactants at low concentration in the aggregation of MWCNTs has been studied,however the effect of perfluorinated surfactants at low concentration is uncertain.To understand this interfacial phenomenon,the influences of perfluorooctanoic acid (PFOA),and sodium dodecyl sulfate (SDS) as a control,on MWCNT aggregation in the aqueous phase were examined by the UV absorbency method.Influences of pH and cationic species on the critical coagulation concentration (CCC) value were evaluated.The CCC values were dependent on the concentration of PFOA,however a pronounced effect of SDS concentration on the CCC values was not observed.The CCC values of the MWCNTs were 51.6 mmol/L in NaCl and 0.28 mmol/L in CaCl 2 solutions,which suggested pronounced differences in the effects of Na+ and Ca2+ ions on the aggregation of the MWCNTs.The presence of both PFOA and SDS significantly decreased the CCC values of the MWCNTs in NaCl solution.The aggregation of the MWCNTs took place under acidic conditions and was not notably altered under neutral and alkaline conditions due to the electrostatic repulsion of deprotonated functional groups on the surface of the MWCNTs. 相似文献
122.
Yilei Yu Xianfang Song Yinghua Zhang Fandong Zheng Ji Liang Dongmei Han Ying M Hongmei Bu 《环境科学学报(英文版)》2013,25(9):1754-1763
Reclaimed water was successfully used to recover the dry Chaobai River in Northern China, but groundwater may be polluted. To ensure groundwater protection, it is therefore critical to identify the governing factors of groundwater chemistry. Samples of reclaimed water, river and groundwater were collected monthly at Chaobai River from January to September in 2010. Fifteen water parameters were analyzed. Two kinds of reclaimed water were different in type (Na-Ca-Mg-Cl-HCO3 or Na-Ca-Cl-HCO3 ) and concentration of nitrogen. The ionic concentration and type in river were similar to reclaimed water. Some shallow wells near the river bed had the same type (Na-Ca-Mg-Cl-HCO3 ) and high concentration as reclaimed water, but others were consistent with the deep wells (Ca-Mg-HCO3 ). Using cluster analysis, the 9 months were divided into two periods (dry and wet seasons), and all samples were grouped into several spatial clusters, indicating different controlling mechanisms. Principal component analysis and conventional ionic plots showed that calcium, magnesium and bicarbonate were controlled by water-rock interaction in all deep and some shallow wells. This included the dissolution of calcite and carbonate weathering. Sodium, potassium, chloride and sulfate in river and some shallow wells recharged by river were governed by evaporation crystallization and mixing of reclaimed water. But groundwater chemistry was not controlled by precipitation. During the infiltration of reclaimed water, cation exchange took place between (sodium, potassium) and (calcium, magnesium). Nitrification and denitrification both happened in most shallow groundwater, but only denitrification in deep groundwater. 相似文献
123.
124.
125.
生活垃圾处理问题是环保问题中的重要组成部分,,但目前我国生活垃圾处理水平较低,已造成了严重的环境污染。本文通过对我国生活垃圾处理方式及发展趋势的分析,根据生活垃圾的特点及管理中存在的一些问题,提出了我国生活垃圾处理的发展趋势及相应的管理对策。 相似文献
126.
萃取技术是一种样品前处理方法,可以用于水环境等领域的监测。其中较为受推崇的主要是快速萃取技术和固相萃取技术。本文通过快速萃取技术原理的简单分析,重点将其与传统的几种萃取技术进行了比较,并对未来的发展趋势作了简要展望。 相似文献
127.
128.
129.
130.