动态光散射中分辨流体力学半径的重叠峰  

Resolving overlap bands of hydrodynamic radius measured by dynamic light scattering method

作　　者：郑容[1] 

机构地区：[1]北京大学化学与分子工程学院,北京100871

出　　处：《计算机与应用化学》2011年第1期53-56,共4页Computers and Applied Chemistry

摘　　要：动态光散射中,宽分布体系的流体力学半径分布f(R_h)的形态有时比较复杂,呈现为重叠峰,妨碍了人们直接解释或认识数据。为了将其重叠峰分解为单峰,从而了解每个单峰的细节特征,作者针对这种重叠峰的现象,而单组分流体力学半径分布曲线一般却为非负、不对称,且其对数具有近似对称的特点,于是提出用修改的对数Gaussian和Lorentzian函数作为数学理论模型,该理论模型曲线的不对称程度,可用左、右半支不同的均方差和指数来表征。文章采用曲线拟合法分离流体力学半径分布的重叠峰。由于本文构造的目标函数比较复杂,变量个数较多,因此选择单纯型法和模拟退火法相结合,并根据实验采用温度以指数规律衰减。文章计算和分析不同分离度的理论模型,探讨分离度对重叠峰分离的影响,并作出大致的估计。模型和实例的计算证实本法有效。The curve of hydrodynamic radius of wide distribution on the basis of dynamic light scattering method sometimes shows the complicated shape with overlapped bands. When resolving the overlapped bands into the sum of the element peaks, people can realize the characteristics of each peak in detail. Although the wide distribution curve of hydrodynamic radius shows the complicated shape with overlapping bands, the one element shows the shape of positive and asymmetric and has the feature of log-symmetry like. Thus author suggested the modified log-Gaussian and log-Lorentzian theoretical functions. Varying mean root variance and exponent values of left and right branch of function denote the asymmetric degree. Author resolves overlapping bands of hydrodynamics radius with wide distribution by using the simulated anneal method on the basis of downhill simplex algorithm. We design that the temperature decreases exponentially according to experiments. In this paper author calculated the theoretical models with different the degree of peak of overlap, and analyzed the influence on the resolving result. As result, writer suggested the error estimation approximately, which related with the degree of overlap. Model and practical examples demonstrate this method is effective.

关 键 词：动态光散射 流体力学半径 分辨重叠峰 曲线拟合 

分 类 号：TE832.2[石油与天然气工程—油气储运工程] N945.12[自然科学总论—系统科学]