Absorption Enhancement of Coated Absorbing Aerosols: Validation of the Photo-Acoustic Technique for Measuring the Enhancement
Absorption Enhancement of Coated Absorbing Aerosols: Validation of the Photo-Acoustic Technique for Measuring the Enhancement
复制标题
DOI：
10.1080/02786820903117932
复制
发表时间：
2009-07
影响因子：
5.2
通讯作者：
D. Lack;C. Cappa;E. Cross;P. Massoli;A. Ahern;P. Davidovits;T. Onasch
中科院分区：
文献类型：
--
作者：
D. Lack;C. Cappa;E. Cross;P. Massoli;A. Ahern;P. Davidovits;T. Onasch
利用光声吸收光谱仪（PAS）和光腔衰荡气溶胶消光光谱仪（CRD-AES），结合米氏理论，测量了吸收性聚苯乙烯球（APSS）的折射率（RI）。用PAS和CRD-AES研究了油酸对APSS的增吸和消光作用。然后将实验增强与涂层球Mie理论的预测进行比较。测得的吸收和消光增强都同意建模的增强，平均在5%以内。还使用基于过滤器的吸收技术（颗粒烟灰吸收光度计，PSAP）测量APSS的吸收，并显示出显著的尺寸依赖性偏差，如基于过滤器的方法测量的未涂覆和涂覆的APSS的吸收显著低于PAS所证明的。这些结果表明，应用光声测量半挥发性大气物种涂层吸收颗粒产生的吸收增强的有效性。
A photo-acoustic absorption spectrometer (PAS) and a cavity ring down aerosol extinction spectrometer (CRD-AES) were used, in conjunction with Mie Theory, to measure the refractive index (RI) of absorbing polystyrene spheres (APSS). The PAS and CRD-AES were also used to measure the absorption and extinction enhancement after these APSS were coated in oleic acid. The experimental enhancements were then compared to predictions from coated-sphere Mie Theory. The measured absorption and extinction enhancements both agreed with modeled enhancements to within an average of 5%. A filter-based absorption technique (particle soot absorption photometer, PSAP) was also used to measure the absorption by the APSS and showed a significant size-dependent bias, as evidenced by the filter-based method measuring significantly lower absorption for both uncoated and coated APSS compared to the PAS. These results suggest the validity of applying photo-acoustics to measure the absorption enhancement created by semi-volatile atmospheric species coating absorbing particles.