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大黄及其复方中药制剂中蒽醌衍生物的含量测定 被引量:20
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作者 张志荣 侯世祥 +2 位作者 黄园 廖工铁 尹华熙 《华西药学杂志》 CAS CSCD 北大核心 1994年第4期225-227,共3页
采用硫酸水解、溶剂多次萃取的分离方法,利用蒽醌衍生物在碱性条件下呈红色的特点、用可见分光光度法测定其含量。在所试浓度0.788~3.152mg/100ml范围内线性关系良好。平均回收率为96.97%(n=9.RSD=... 采用硫酸水解、溶剂多次萃取的分离方法,利用蒽醌衍生物在碱性条件下呈红色的特点、用可见分光光度法测定其含量。在所试浓度0.788~3.152mg/100ml范围内线性关系良好。平均回收率为96.97%(n=9.RSD=3.11%)。本法方便快速,不需昂贵仪器设备,适于基层应用。 展开更多
关键词 蒽醌衍生物 分光光度法 大黄 中学化学成分
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Chemical Composition of Summertime PM_(2.5) and Its Relationship to Aerosol Optical Properties in Guangzhou,China 被引量:7
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作者 Tao Jun Cheng Tian-Tao Zhang Ren-Jian 《Atmospheric and Oceanic Science Letters》 2012年第2期88-94,共7页
Urban aerosols have a large effect on the deterioration of air quality and the degradation of atmospheric visibility.Characterization of the chemical composition of PM 2.5 and in situ measurements of the optical prope... Urban aerosols have a large effect on the deterioration of air quality and the degradation of atmospheric visibility.Characterization of the chemical composition of PM 2.5 and in situ measurements of the optical properties of aerosols were conducted in July 2008 at an urban site in Guangzhou,Southern China.The mean PM 2.5 concentration for the entire period was 53.7±23.2 μg m 3.The mean PM 2.5 concentration (82.7±25.4 μg m 3) on hazy days was roughly two times higher than that on clear days (38.8±8.7 μg m 3).The total water-soluble ion species and the total average carbon accounted for 47.9%±4.3% and 35.2%±4.5%,respectively,of the major components of PM 2.5.The increase of secondary and carbonaceous aerosols,in particular ammonium sulfate,played an important role in the formation of haze pollution.The mean absorption and scattering coefficients and the single scattering albedo over the whole period were 53±20 M m 1,226±111 M m 1,and 0.80±0.04,respectively.PM 2.5 had a high linear correlation with the aerosol extinction coefficient,elemental carbon (EC) was correlated with aerosol absorption,and organic carbon (OC) and SO 4 2 were tightly linked to aerosol scattering. 展开更多
关键词 fine aerosol particle chemical composition aerosol optical coefficient
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Influence of multi-chemical-component aerosols on the microphysics of warm clouds in North China 被引量:3
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作者 YANG SuYing MA JianZhong +3 位作者 HU ZhiJin YAN Peng CHEN Yue WANG Wei 《Science China Earth Sciences》 SCIE EI CAS 2011年第3期451-461,共11页
An adiabatic bin-sized cloud parcel model is developed by incorporating the multi-chemical-component (MCC) aerosol effects into the UWyo single-chemical-component (SCC) parcel model. The effects of MCC aerosols on the... An adiabatic bin-sized cloud parcel model is developed by incorporating the multi-chemical-component (MCC) aerosol effects into the UWyo single-chemical-component (SCC) parcel model. The effects of MCC aerosols on the warm cloud microphysics in North China are investigated with the model. The simulations are initialized using the data on chemical components and number size distribution of aerosols measured during the IPAC (Influence of Pollution on Aerosols and Cloud Microphysics in North China) campaign in spring 2006. It is found that the MCC aerosols in North China increase the cloud droplet number concentration (CDNC) and decrease the effective radius more efficiently than pure ammonium-sulfate aerosols. It is also shown that the MCC aerosols in North China can narrow the cloud droplet spectra (CDS) by increasing CDNC in small size and decreasing CDNC in large size. Our results indicate that aerosol chemical components and their size distributions can influence the microphysics of warm clouds, and thus affect atmospheric radiation and precipitation. This should attract more attentions in weather and climate change research in the future. 展开更多
关键词 AEROSOLS chemical component CCN cloud microphysics cloud model
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