研究论文
张代洲,赵春生,秦瑜.沙尘粒子的成分和形态分析[J].环境科学学报,1998,18(5):449-456
沙尘粒子的成分和形态分析
- COMPOSITION AND MORPHOLOGY ANALYSES OF DUST PARTICLES
- 基金项目：
- 作者
- 单位
- 张代洲
- 北京大学环境科学中心大气环境与污染控制国家联合重点实验室, 北京 1008971
- 赵春生
- 北京大学地球物理系, 北京 1008971
- 秦瑜
- 北京大学地球物理系, 北京 1008971
- 摘要：采用试剂薄膜法和X射线能谱,分析了1995年春季发生在北京5次沙尘过程中采集的单个沙尘粒子的特征,粒子按粒径分为粗粒子(d>1μm)和细粒子(1μm≥d>0.1μm), 除了沙尘粒子呈不规则形状,主要集中在粗粒子段外,得到的其它主要结果如下：几乎没有沙尘粒子含有可溶性硫酸盐,含硫粒子的能谱中硫的峰也不明显,并且含有硝酸盐的沙尘粒子仅占总沙尘粒子数的11%, 远远低于无沙尘时硝酸盐粒子所占的比例。这些结果说明,发生于中国北部和西北地区的沙尘在中国大陆内传输过程中,其本身成分变化不大,仍以其源区的组成成分为主。另外在个别沙尘过程中的采样分析表明,北京市内的建筑粉尘有时也是局地的尘源,它们在粗细粒子中都有,外形呈规则的立方体结晶状,所含的地壳元素以Ca为主。
- Abstract：Thin film methods and X-ray energy dispersive analyses were applied to detect the individual dust particles collected in five dust episodes occurring in Beijing in the spring of 1995.The particles were classified into coarse(d>>1μm) and fine (1μm≥d>0.1μm) modes according to their diameters. Dust particles had irregular shapes and concentrated in the coarse mode, which were detected by previous studies, besides, some new aspects were found.Few dust particles contained water soluble sulfate although some particles had minor picks of sulfur in their X-ray spectra. The ratio of nitrate containing particles to total dust particles was 11%, which was much smaller than that in mineral particles collected in non dust periods. These results proved the composition of the dust particles originated from the north and northwest parts of China would not considerably change during their transport from the source to Beijing. In addition, some mineral particles, which were supposed to be emitted from construction sites, were found in some cases. Such particles had regular cube shapes and appeared in both coarse and fine modes. The main mineral element they contained was calcium.
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