中文摘要：

对甘肃省天水市麦积镇大气降尘粒度分布及主要矿物组成进行了分析，并以实际降尘ζ电位作为参照，根据降尘中主要矿物组成的质量百分比，提出了计算法和混合法两种模拟大气降尘在水溶液中表面电性的方法.结果表明，麦积地区大气降尘属于可吸入颗粒粒度尺寸范畴，其主要矿物组成与质量含量为：石英（57.08%）、方解石（27.79%）、钠长石（10.29%）、白云母（4.84%）. 大气降尘在纯水中呈电负性，且ζ电位随着水溶液pH增加而减小.通过对比实际降尘与拟合方法所得到的ζ电位，发现两种拟合方式与实际降尘的ζ电位具有相似的变化趋势.降尘中矿物组成主导着降尘表面电位的大小和变化趋势，其对降尘表面电位的贡献率是最主要的.

英文摘要：

Atmospheric dust fall in Maiji town of Tianshui City, Gansu Province, were investigated to track their particle size distributions and mineral compositions. Based on their zeta potential and the mass percent of main minerals, two models （calculation method and hybrid method） were presented to simulate the surface charge of atmospheric dust fall in water solution. The natural dust fall in Maiji town were categorized as the inhalable particles. Quartz （57.08%）, calcite （27.79%）, albite （10.29%） and muscovite （4.84%） were the four dominant compositions. Atmospheric dust fall in water solution displayed electronegativity, and zeta potential decreased with the increase of pH. Although differences existed between the two methods and natural dust fall, their change tendencies were similar. The main mineral compositions dominated the size and change tendencies of surface charge of natural dust fall. The contribution of the dominating mineral particles to zeta potential was critical.