Statistical thermodynamics evaluation of polymer–polymer miscibility

The Simha and Somcynsky (S–S) statistical thermodynamics theory was used to compute the solubility parameters as a function of temperature and pressure [δ = δ(T, P)], for a series of polymer melts. The characteristic scaling parameters required for this task, P*, T*, and V*, were extracted from the pressure–temperature–volume (PVT) data. To determine the potential polymer–polymer miscibility, the dependence of δ versus T (at ambient pressure) was computed for 17 polymers. Close proximity of the δ versus T curves for four miscible polymer pairs: PPE/PS, PS/PVME, and PC/PMMA signaled the usefulness of this approach. It is noteworthy, that the tabulated solubility parameters (derived from the solution data under ambient conditions) propounded the immiscibility of the PVC/PVAc pair. The computed values of δ also suggested miscibility for polymer pairs of unknown miscibility, namely PPE/PVC, PPE/PVAc, and PET/PSF. In recognizing the limitations of the solubility parameter approach (the omission of several thermodynamic contributions), these preliminary results are auspicious because they indicate a new route for estimating the miscibility of any polymeric material at a given temperature and pressure. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2909–2915, 2004     

新的基团法估算沸点下蒸发焓

提出了估算沸点下蒸发焓的含基团重量分率的基团法和估算式，拟合团贡献值，对３８５种有机物的计算平均偏差约为１．５％。所提出的新方法明显优于３种对应状态和用蒸发熵的基团法。     

偏心因子数据的计算方法研究进展

从偏心因子(acentric factor)的定义出发，分析了ω数据的确定方法和获取数据的手段，评述了国内外ω计算方法的近期进展，包括对应态蒸气压关联方程法、对应态基团贡献法(CSGC)、图论法及拓扑法等，指出了各种方法的优缺点及最新的计算发展方向。     

OCCL编译器中符号表的研究及设计

OCCL是笔者做的一个新型ANSIC编译器，文中介绍在前人的工作基础上，笔者用哈希表———层次独立对应法以及最迟分配初始化法对OCCL的符号表进行设计。最终结果使编译器的时间开销得到缩减，提高了性能。     

花博园景观规划设计研究——以漳州花博园为例

文章通过对漳州花博园的总体布局、功能分区与景点规划、园路系统等方面的研究，分析评价了漳州花博园的整体景观规划与设计，指出其存在的主要问题，并提出相应的改进措施，实现可持续发展．     

Hankel矩阵的生成函数

画Ｈａｎｋｅｌ矩的生成函数，进而给同此类矩阵的相应多项式参数表示与核空间。     

英语成语汉译浅析

英语成语在英文原著中占有一定的比例，对中国读者来说，如何理解和翻译英语成语，对准确把握原著精粹往往起到举足轻重的作用。本文从英汉成语对比及文化差异的角度分别讨论了三种基本的成语翻译技巧。     

组织激励冲突问题研究

激励是组织行为学的核心问题．激励期望理论又是管理学的重要组成部分．对激励理论的深入研究,就会触及到激励冲突的复杂问题．本文提出激励冲突的概念,并分析其所具有的多重特性．在对传统的激励期望理论作进一步探讨后．对一个完整的组织“目标—激励”体系,得出相应的激励冲突状态,明晰地揭示出激励冲突的复杂性．     

Dielectric constants of fluid mixtures over a wide range of temperature and density

A new expression is presented for estimating the dielectric constant of a fluid mixture as a function of temperature, density and composition. The estimated dielectric constants (and their derivatives) are required for phase-equilibrium calculations, based on an equation of state, for systems containing electrolytes and nonelectrolytes. The new expression holds for the entire range of fluid densities, from zero to liquid-like densities. Mixing of components is performed on a volume-fraction basis at constant temperature and constant reduced density. For polar components where data are not available at the temperature and/or reduced density of interest, the well-characterized behavior of water is used to extrapolate the available pure-component data. The importance of using the correct density of the mixture is shown. Using one adjustable parameter for each nonideal binary subsystem, predicted results can be significantly improved.