在动态光散射技术中, 光强自相关数据中信号噪声对测量结果的影响, 主要取决于颗粒粒度反演算法。在多角度测量时, 角度加权则成为左右噪声对测量结果影响的又一重要因素。本文在多角度动态光散射角度加权机理分析的基础上, 研究了光强均值和迭代递归角度加权方法对测量信号噪声影响的抑制作用。结果表明, 无信号噪声时,对于单峰小粒度分布,迭代递归方法加权对小颗粒粒度分布略有展宽; 对于中、大颗粒, 光强均值法进行角度加权所得的峰值误差略有增大; 随着噪声的增加, 迭代递归法加权所得反演结果的性能指标无显著变化, 而光强均值法进行角度加权所得结果的峰值误差和分布误差均呈显著增大的趋势。306/974 nm标准双峰颗粒体系光强均值法和迭代递归法的反演峰值误差分别为0.170/0.121, 0.092/0.097, 迭代递归法峰值位置更准确, 能够验证模拟数据的结论。迭代递归法通过各个散射角逐次反演和比较粒度分布重新计算角度权重, 这种通过角度权重更新的“修正”作用, 在很大程度上抵消了噪声导致的粒度分布误差, 从而显现出抵御噪声影响的“去噪”性能。因此, 在测量噪声较大的环境下, 宜采用迭代递归方法进行多角度加权。

In dynamic light scattering technology, the influence of autocorrelation data noise on measurement results primarily depends on the particle-size inversion algorithm. In multiangle measurement, angular weighting becomes another important factor restricting the influence of noise on the measurement results.Based on the analysis of angle weighting mechanism of multiangle dynamic light scattering, the inhibition effect of the angle weighting method of light intensity average and the iterative recursive method on the measurement of noise is studied. The results demonstrate that, in the absence of noise, for the small particles of the unimodal distribution, the PSD is slightly broadened when weighted by the iterative recursive method, and for the medium and large particles, the peak value error increases slightly when the light intensity average method is adopted. With an increase in noise, the performance index of iterative recursive inversion exhibits no obvious change, while the peak value error and PSD error of the results obtained via the light intensity average method are significantly increased. The inversion peak errors of 306/974 nm standard bimodal particle system were observed to be 0.170/0.121 and 0.092/0.097, respectively. The peak positions obtained via the iterative recursive method were more accurate, and the experimental results verified the conclusions from the simulation data. The iterative recursive method recalculates the angle weight via successive inversion and comparison of the PSD of each scattering angle. The "correction" effect of angle weight updation can largely offset the PSD error caused by noise, and thus, the "de-noising" performance of resisting the impact of noise has been depicted. Therefore, in a noisy environment, the iterative recursive method should be used for multiangle weighting.