排序方式： 共有4条查询结果，搜索用时 15 毫秒
1
1.
2.
Long-term monitoring programs for measurement of atmospheric mercury concentrations are presently recognized as powerful tools for local,regional and global studies of atmospheric long-range transport processes,and they could also provide valuable information about the impact of emission controls on the global budget of atmospheric mercury,their observance and an insight into the global mercury cycle. China is believed to be an increasing atmospheric mercury emission source. However,only a few measurements of mercury,to our knowledge,have been done in ambient air over China. The highly-time resolved atmospheric mercury concen-trations have been measured at Moxi Base Station （102°72′E 29°92′N,1640 m asl） of the Gongga Alpine Ecosystem Observation and Experiment Station of Chinese Academy of Sciences （CAS） from May 2005 to June 2006 by using a set of Automatic Atmospheric Mercury Speciation Analyzers （Tekran 2537A）. Measurements were carried out with a time resolution of every 15 minutes. The overall average total gaseous mercury （TGM） covering the measurement periods was 4±1.38 ng·m^-3 （N=57310）,which is higher than the global background level of approximately 1.5～2.0 ng·m^-3. The measurements in all seasons showed a similar diurnal change pattern with a high concentration during daytime relative to nighttime and maximum concentration near solar noon and minimum concentration immediately before sunrise. The presence of diurnal TGM peaks during spring and summer was found earlier than that during autumn and winter. When divided seasonally,it was found that the concentrations of TGM were highest in winter with 6.13 ± 1.78 ng·m^-3 and lowest in summer with 3.17 ± 0.67 ng·m^-3. There were no significant differences in TGM among wind sectors during each season. Whereas Hg generally exhibited significant correlations with the parameters,such as temperature,saturated vapor pressure,precipitation,ultraviolet radiation （UV） and atmospheric pressure at the whole measurement stage,and t 相似文献
3.
贵阳市大气中气态汞形态分布特征的初步研究 总被引：7，自引：1，他引：7
2002年3月份我们对贵阳市大气的气态汞形态进行了采样分析。大气气态总汞用Tekran537A大气自动测汞仪采集测定。活性气态汞用镀KCl扩散管采集，热还原法分解并以冷原子荧光法(CVAFS)分析。结果显示，采样期间贵阳市气态总汞平均浓度为7．09ng/m^3，活性气态汞平均含量38．3pg/m^3。气态总汞浓度远高于全球背景浓度值；活性气态汞浓度稍高于欧洲和美国的边远地区。活性气态汞浓度与大气相对湿度呈负相关关系，相关系数为—0．39(α＜0．01)。由于大气相对湿度较高，活性气态汞只占气态总汞的0．5％。原子态汞和活性气态汞的基本来源是燃煤释放。 相似文献
4.
1