强韧包装纸板用落叶松半化学浆的研究

主要研究一种可以替代传统硫酸盐化学木浆，来生产强韧包装纸板或瓦楞纸箱箱板纸的落叶松碱性亚硫酸盐－蒽醌半化学浆。这种采用碱性亚硫酸盐添加蒽醌助剂的制浆方法研制的落叶松半化学浆，当纸浆得率为５６．９％时，在低打浆度情况下纸浆强度性能可以达到我国２号未漂硫酸盐化学木浆的标准，而且有可能达到１号未漂硫酸盐化学木浆的标准，纸浆得率比落叶松硫酸盐木浆得率实际指标（４３％）绝对值提高１３％以上。用于制作强韧包装纸板或瓦楞纸箱箱板纸的落叶松碱性亚硫酸盐－蒽醌半化学浆，蒸煮终点宜于控制在得率约６２％、卡伯值１００左右。     

液相对流对固液界面稳定性的影响

以模型合金丁二腈－乙醇的强制性晶体生长为基础，利用自行研制的液相对流驱动装置，详细考查了液相自然对流及强迫对流作用下，模型合金平界面失稳的动态生长过程，证实了液相的流动加快了液相温度与浓度分布的均匀化，从而增强了液／固界面的稳定性。并且随流动速度的增加，界面稳定性提高。     

Valid parameter range analyses for chemical reaction kinetic models

The present work quantifies the relations between the structure of a chemical reaction kinetic model, its valid parameter range, and the truncation error tolerance of the model. General methods are presented to solve the three important problems of valid parameter range analysis: (1) identification of the valid parameter range of a kinetic model, (2) estimation of the error tolerance required when applying a kinetic model over a specified parameter range, and (3) improvement of existing model generation algorithms to construct more robust models. Finally, the relationship between a model's structure, its valid parameter range, and the truncation error tolerance are illustrated by the flexibility-tolerance-model graph. The new methods are applied to pyrolysis of methane/ethane mixtures.     

先进控制在环管法聚丙烯装置中的应用

以九江石油化工总厂70kt/a聚丙烯装置产率控制为例,介绍先进过程控制系统在石油化工装置上的应用情况。     

露采边坡渗流的有限元分析及其实例

介绍了应用有限元法求解渗流问题的原理及其实例。     

Coupling of reaction and separation at the microscopic level: esterification processes in a H-ZSM-5 membrane reactor

A catalytically active zeolite membrane has been used to displace equilibrium by selective water permeation during ethanol esterification. Unlike previous works in which water separation was carried out by zeolitic membranes that did not take part in the reaction, the H-ZSM-5 membrane used in this work had sufficient catalytic activity to carry out the esterification of ethanol with acetic acid, and at the same time was selective for water permeation. As a consequence, the reaction and separation functions could be coupled very efficiently, and the conversion obtained at the same feed rate and catalyst loading was greater than in conventional fixed bed reactors, or in reactors where the zeolite membrane was kept separated from the catalyst.     

Investigation of the stability of tablets prepared from sucrose and citric acid anhydride utilizing response surface methodology

Inversion of sucrose is a stability problem particularly of candies with acidic taste that contain sucrose and small amounts of organic acids such as citric acid, since the free d-fructose produced by hydrolysis is hygroscopic. The following possibilities were investigated for preventing the hydrolysis of sucrose in tablets containing sucrose and citric acid: Adding various amounts of tri-sodium citrate to the formulation to neutralize the citric acid, (Hot) melt coating of citric acid and tri-sodium citrate with a vegetable fat at different coating ratios, variation of the ratio of coated citric acid and tri-sodium citrate in formulations, and compressing the formulations with different compression forces. After tablet processing and storage of tablets, the concentration of d-fructose was determined on the basis of enzymatic reactions. A response surface central composite design was used. The above-mentioned variations were chosen as independent variables and the amount of d-fructose was chosen as response variable. The lowest rates of inversion could be achieved by increasing the content of tri-sodium citrate and the ratio of coating material and decreasing the ratio of coated citric acid and tri-sodium citrate in the tablet formulations. The compression force had no significant effect on the inversion of sucrose.     

What is a free name in a process algebra?

There are two popular approaches to specifying the semantics of process algebras: labelled transition semantics and reaction semantics. While the notion of free name is rather unproblematic for labelled transition semantics this is not so for reaction semantics in the presence of a structural congruence for unfolding recursive declarations.We show that the standard definition of free name is not preserved under the structural congruence. We then develop a fixed point approach to the set of free names and show that it is invariant under the structural congruence.     

SYNTHESIS OF CHEMICAL REACTION PATHS: ECONOMIC AND SPECIFICATION CONSTRAINTS

The synthesis of alternative reaction paths leading to a desired chemical has received increasing attention in the recent past. A procedure to develop new reaction schemes in a systematic manner was reviewed by the authors ( [ 1 -3] ). The algorithm presented in these earlier papers implied the generation of an infinite number of reaction paths. The thermodynamic feasibility is a preliminary screening which reduces the number of chemical production schemes. Further screening is necessary, taking into account considerations which are related to economics, processing, safety and so on. Some constraints related with role specification, gross added value and demand/supply requirements are analysed in this paper. Examples illustrate the application of the screening procedure, showing that the addition of a few constraints results in a dramatic decrease of alternative reaction paths.     

油脂氢化理论研究进展

本文从下列几个方面阐明油脂氢化理论的研究状况：（１）氢化机理的研究；（２）氢化反应动力学处理；（３）氢化反应活化能的确定；（４）氢化选择性的研究。