Sun Xiao-gang, Tang Hong, Yuan Gui-bin
Harbin Institute of Technology, Harbin 150001, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2008 Sep;28(9):1968-73.
In the total light scattering particle sizing technique, the extinction spectrum of particle system contains some information about the particle size and refractive index. The visible extinction spectra of the common monomodal and biomodal R-R particle size distribution were computed, and the variation in the visible extinction spectrum with the particle size and refractive index was analyzed. The corresponding wavelengths were selected as the measurement wavelengths at which the second order differential extinction spectrum was discontinuous. Furthermore, the minimum and the maximum wavelengths in the visible region were also selected as the measurement wavelengths. The genetic algorithm was used as the inversion method under the dependent model The computer simulation and experiments illustrate that it is feasible to make an analysis of the extinction spectrum and use this selection method of the optimal wavelength in the total light scattering particle sizing. The rough contour of the particle size distribution can be determined after the analysis of visible extinction spectrum, so the search range of the particle size parameter is reduced in the optimal algorithm, and then a more accurate inversion result can be obtained using the selection method. The inversion results of monomodal and biomodal distribution are all still satisfactory when 1% stochastic noise is put in the transmission extinction measurement values.
在全光散射颗粒粒径测量技术中，颗粒系统的消光光谱包含了一些关于颗粒尺寸和折射率的信息。计算了常见单峰和双峰R-R粒径分布的可见消光光谱，并分析了可见消光光谱随颗粒尺寸和折射率的变化。选择相应波长作为测量波长，在这些波长处二阶微分消光光谱是不连续的。此外，还选择了可见光区域的最小和最大波长作为测量波长。在相关模型下，采用遗传算法作为反演方法。计算机模拟和实验表明，对消光光谱进行分析并采用这种最佳波长选择方法在全光散射颗粒粒径测量中是可行的。通过对可见消光光谱的分析可以确定粒径分布的大致轮廓，从而在优化算法中减小粒径参数的搜索范围，进而采用该选择方法可获得更准确的反演结果。当在透射消光测量值中加入1%的随机噪声时，单峰和双峰分布的反演结果仍然令人满意。
