全文获取类型
收费全文 | 883篇 |
免费 | 42篇 |
国内免费 | 344篇 |
专业分类
安全科学 | 73篇 |
废物处理 | 50篇 |
环保管理 | 49篇 |
综合类 | 539篇 |
基础理论 | 156篇 |
污染及防治 | 295篇 |
评价与监测 | 47篇 |
社会与环境 | 24篇 |
灾害及防治 | 36篇 |
出版年
2023年 | 16篇 |
2022年 | 39篇 |
2021年 | 32篇 |
2020年 | 30篇 |
2019年 | 27篇 |
2018年 | 40篇 |
2017年 | 35篇 |
2016年 | 41篇 |
2015年 | 42篇 |
2014年 | 62篇 |
2013年 | 92篇 |
2012年 | 79篇 |
2011年 | 71篇 |
2010年 | 71篇 |
2009年 | 77篇 |
2008年 | 56篇 |
2007年 | 63篇 |
2006年 | 45篇 |
2005年 | 26篇 |
2004年 | 31篇 |
2003年 | 36篇 |
2002年 | 30篇 |
2001年 | 33篇 |
2000年 | 33篇 |
1999年 | 16篇 |
1998年 | 23篇 |
1997年 | 20篇 |
1996年 | 21篇 |
1995年 | 23篇 |
1994年 | 18篇 |
1993年 | 14篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 8篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1961年 | 1篇 |
排序方式: 共有1269条查询结果,搜索用时 15 毫秒
491.
用微宇宙法研究稀土元素在富营养化水体中的归趋 总被引:1,自引:0,他引:1
本文利用静态实验室水生微宇宙的方法研究了轻、中、重三类五种稀土混合物(La,Ce,Sm,Gd,Y)在富营养水体、底泥、浮萍、大型蚤、螺蛳和金鱼中的分布和富集。结果表明,稀土在水生微宇宙各组分中的分布和积累的趋势为轻稀土>中稀土>重稀土。稀土元素在水体中6h后基本趋于平衡,其大部分为底泥所吸附;不同生物对稀土的分布和富集存在着较大的差异,其趋势为浮萍>大型蚤>螺蛳>金鱼。 相似文献
492.
Yasong Li Shasha Yin Shijie Yu Ling Bai Xudong Wang Xuan Lu Shuangliang Ma 《环境科学学报(英文版)》2021,33(1):354-368
In this study, we conducted an observation experiment from May 1 to June 30, 2018 in Zhengzhou, a major city in central China, where ground ozone (O3) pollution has become serious in recent years. The concentrations of O3 and its precursors, as well as H2O2 and meteorological data were obtained from the urban site (Yanchang, YC), suburban (Zhengzhou University, ZZU) and background sites (Ganglishuiku, GLSK). Result showed that the rates of O3 concentration exceeded Chinese National Air Quality Standard Grade II (93.3 ppbv) were 59.0%, 52.5%, and 55.7% at the above three sites with good consistency, respectively, indicating that O3 pollution is a regional problem in Zhengzhou. The daily peak O3 appeared at 15:00–16:00, which was opposite to VOCs, NOx, and CO and consistent with H2O2. The exhaustive statistical analysis of meteorological factors and chemical effects on O3 formation at YC was advanced. The high concentration of precursors, high temperature, low relative humidity, and moderately high wind speed together with the wind direction dominated by south and southeast wind contribute to urban O3 episodes in Zhengzhou. O3 formation analysis showed that reactive alkenes such as isoprene and cis-2-butene contributed most to O3 formation. The VOCs/NOx ratio and smog production model were used to determine O3-VOC-NOx sensitivity. The O3 formation in Zhengzhou during early summer was mainly under VOC-limited and transition regions alternately, which implies that the simultaneous emission reduction of alkenes and NOx is effective in reducing O3 pollution in Zhengzhou. 相似文献
493.
XIAO Jun-ping WANG Xue-feng ZHOU Qing-xiang FAN Xiao-yuan SU Xian-f Bai Hua-hu DUAN Hai-jing 《环境科学学报(英文版)》2007,19(5):622-627
A rapid, simple and sensitive method was demonstrated for the determination of phenolic compounds in water samples by alternating-current oscillopolarographic titration. With the presence of sulfuric acid, phenol could be transferred into a nitroso-compound by reacting with NaNO2. The titration end-point was obtained by the formation of a sharp cut in the oscillopolarographic with infinitesimal NaNO2 on double platinum electrodes. The results showed that phenol concentration had an excellent linear relationship over the range of 4.82×10-6-9.65×10-3 mol/L, the RSD of the proposed method was lower than 1.5%, and the spiked recoveries of three real water samples were in the range of 95.6%-106.9%. 相似文献
494.
495.
介绍了测定砷含量的分光光度法,该方法可以应用于大气颗粒物中的痕量砷的敏感性测定。测定、考察了北方城市大气中砷浓度及日变化规律,结果表明,分光光度法显色稳定,灵敏度高。将此方法获得的结果与原子吸收法所得到的结果进行比较,两者高度吻合。进行了柴油机动车尾气中砷含量的测定,结果表明,其尾气中含有一定量的砷。 相似文献
496.
497.
Yuanyuan Ji Fuhong Gao Zhenhai Wu Lei Li Dandan Li Hao Zhang Yujie Zhang Jian Gao Yingchen Bai Hong Li 《环境科学学报(英文版)》2020,32(9):225-239
Benzene homologues are important chemical precursors to the formation of ground-level ozone and secondary organic aerosol (SOA) in the atmosphere, in addition, some toxic species are harmful to human health. Strict countermeasures have been taken to fight air pollution since 2013, and total amount control of volatile organic compounds is being promoted in China at present. Therefore, it is important to understand the pollution situation and the control status of ambient benzene homologues in China. This paper reviews research progress from published papers on pollution characteristics, atmospheric photochemical reactivity, health risk assessment and source identification of ambient benzene homologues in recent years in China, and also summarizes policies and countermeasures for the control of ambient benzene homologues and the relevant achievements. The total ambient levels of benzene, toluene, ethylbenzene and xylenes (BTEX) shows a declining tendency from 2001 to 2016 in China. The mass concentrations of BTEX are generally higher in southern regions than in northern regions, and they present vertical decreasing variation characteristics with increasing altitude within the height range of about 5500 m. Toluene has the highest ozone formation potential and SOA formation potential both in urban areas and background areas, while benzene poses an obvious carcinogenic risk to the exposed adult populations in urban areas. Source identification of ambient benzene homologues suggested that local governments should adopt differentiated control strategies for ambient benzene homologues. Several recommendations are put forward for future research and policy-making on the control of ambient benzene homologues in China. 相似文献
498.
499.
500.