| 西北地区河谷城市大气降尘环境磁学特征及其环境意义 |
| 摘要点击 1535 全文点击 2074 投稿时间：2010-12-01 修订日期：2011-01-21 |
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| 中文关键词 大气降尘 环境磁学 大气污染 西北地区 河谷城市 |
| 英文关键词 dustfall environmental magnetism air pollution Northwest China valley city |
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| 中文摘要 |
| 应用环境磁学方法对西北地区重点污染城市兰州和清洁对照点黄花滩两地大气降尘的磁学特征进行对比研究，分析了大气降尘磁性矿物含量、 类型和颗粒大小等磁学性质及其对城市大气污染的指示意义.结果表明，兰州市大气污染较为严重，大气降尘中磁性矿物含量明显高于黄花滩，且呈现冬季明显高于其他季节的变化趋势.两地降尘样品磁学特征均受磁铁矿控制，并含有一定数量的磁赤铁矿和赤铁矿，磁性矿物为准单畴和多畴颗粒.大气降尘磁性矿物含量的年际变化表明，随着各种污染防治措施的实施，兰州市大气污染总体上呈现逐年减轻的变化趋势，并得到很好的稳定和控制.通过与其他城市大气降尘磁学特征的比较分析可知，兰州市大气污染明显受到市区地形的影响.随着磁学机制和应用研究的不断深入，环境磁学方法逐渐成为监测和评价大气污染水平、 判断污染物来源的重要手段. |
| 英文摘要 |
| Lanzhou is one of the seriously polluted cities in Northwest China. Dustfall samples collected in Lanzhou and the countryside Huanghuatan were studied using magnetic methods. The results reveal that the content of magnetic mineral in dustfall samples from Lanzhou is much higher than that of Huanghuatan. At the same time, it has a much higher lever in winter than that of other seasons. The main magnetic minerals in the dustfall from both places are magnetite, maghemite and hematite, and the main magnetic grain sizes in dustfall samples are mainly pseudo single-domain(PSD) and multi-domain(MD). Although the air in Lanzhou is polluted seriously, the air quality has been improved greatly during the past decades and controlled well in recent years. Compared with other cities, air pollution in Lanzhou is affected significantly by urban terrain. This research also reveals that environmental magnetism has become a more and more important method in air pollution study. |
