Abstract Aerodynamic diameter and chemical compositions of single aerosol are obtained by single particle mass spectrometry (SPMS) in real time. 摘要 单粒子质谱(SPMS)能够在线测量气溶胶粒子的粒径和化学组成，在大气化学研究、环境污染监测等方面有广泛的应用前景。
Keywords impactors;cut-off size;aerodynamic diameter;PM_（2.5） fine particles; 冲击式大气采样器;切割直径;空气动力学直径;PM_（2.
The office has been humming with activity. 办公室一直忙着搞活动。
The threat of war has depressed business activity. 战争的威胁使经济萧条。