化学学报 ›› 2000, Vol. 58 ›› Issue (8): 935-941. 上一篇    下一篇

研究论文

离散时空形式的表征分离效果的整体优化泛函

梁恒;谭伟华   

  1. 西安交通大学分离科学研究所
  • 发布日期:2000-08-15

The integral optimizing functional (IOF) indicating separation efficiency in discrete space-time format

Liang Heng;Tan Weihua   

  • Published:2000-08-15

根据信息的定义,获得了表征任何带分离效果的整体优化泛函的离散时空形式H~s(t~k)。它是溶质系统在时变的外加力场作用下从分离环境获得的分离信息量。H~s(t~k)由线性部H~s~L(t~k)和非线性部H~s~N(t~k)构成,其中线性部与当代分离科学一直采用的塔板数、峰容量、分离度和色谱分离度统计量等参数一样,都是以峰宽为基准测量尺度,故它们均不可能表征测量尺度(峰宽)以内溶质分布的不均匀性对实际分离效果的影响,因而完全失去了溶质在空间不均匀分布的分形特性。非线性部是对线性部不可缺少的修正,它精确地度量了溶质分布不均匀引起的信息量变化。在任何实际带分离中,对于一定的溶质分布构型和指定的分离效果,H~s(t~k)具有确定的比特值。计算机信真结果证明H~s(t~k)具有上述特征。H~s(t~k)的发现为实现分离过程的动态优化控制奠定了基础。

关键词: 离散时空, 分离效果, 热力学

Based on the definition of information, integral optimizing functional (IOF) in the discrete spacetime format, H~s(t~k), was obtained to indicate separation efficiency. The physical essential of H~s(t~k) is the information amount that the solute system gains from its separation surroundings in time-varying external force fields, which can accurately indicate integral and time-varying separation efficiency in any actual separation process. H~s(t~k) can be naturally partitioned into both linear and non-linear portions. The linear portion and almost all the parameters of separation efficiency in contemporary seapration science (e. g. theoretical plate high, resolution, resolution product, peak capacity, the chromatographic resolution statistic and the variety of them, etc.) are based on a common measure yardstick-zone width, which fails in measuring non- uniform distributions of solute zones in the topological space that the solute occupies. The linear portion is only a special case of H~s (t~k) if the number of volume elements is assumed to be one in the whole topological space. The non-linear portion is an indispensable correction of the linear portion for accurately measure of actual zone distributions, and it depends upon the type of homeomorphism configurations of zone distributions. The results of computer simulation of Gaussian and various exponentially modified Gaussian peaks support the theoretical predictions. The discovery of H~s(t~k) lays a solid foundation of real-time control and dynamic optimization of actual separation processes with non-equilibrium thermodynamic separation theory.

Key words: SEPARATION EFFICIENCY, THERMODYNAMICS

中图分类号: