中文摘要：

采用检测单个粒子的薄膜法，探讨了澳门岛海洋大气中甲磺酸（MSA）粒子的浓度、粒子百分数、粒径和pH值及其一般变化特征。结果表明，MSA粒子在大气中的浓度为6．7×10^-11～24．5～10^-11 nmol／m^3，粒子百分数为9.3％～33．8％，pH值为1．63～2．51，当量直径为1．1294～1．4371μm．上述指标与季节及日变化具有明显的相关性，MSA粒子的浓度、占总粒子的百分数在夏季达到最大值；随着气温的降低和相对湿度的增大，MSA粒子的当量直径增大、酸性增强，在春季，其当量直径具有最大值，pH值则具有最小值；而一天当中，MSA粒子的浓度在下午时达到最大，早晨最小．

英文摘要：

The concentration and percentage, diameter, pH value, and general variational characteristics of methane sulfonic acid （MSA） particles collected from the marine atmosphere of Macao Island of China were studied using the thin film method for single particle detection. The concentration of MSA particle in the atmosphere was 6.7×10^-11 -24.5×10^-11 nmol/m^3, the number were 9.3%-33.8%, the pH value 1.63-2.51, and the equivalent diameter 1.1294-1.4371μm. There was obvious seasonal and daily variations of these parameters. The concentration and number percentage of MSA particle reached their maxima in summer; the equivalent diameter and acidity of MSA particle increased with the decreased of air temperature and increasing of the relative humidity, attaining maximum and minimum respectively in spring. During the day, highest MSA particle concentration appeared in the afternoon and lowest in the morning.