Microchemical Engineering: Components,Plant Concepts User Acceptance – Part I

Over the last five years, many activities have focused on the unexploited field of carrying out reactions on small scales. Due to the rapid development of new components, this paper deals with recent developments only in a compressed form. An important point is the analysis of possible plant concepts for microreactors and whether these are a sensible option. Due to the enormous difference in size between the microchannels and the fluid periphera of possible components this is not just a technical question. It touches on the microtechnology concept as a whole. The direction in which the field should be developed and which measures can be taken to influence its development are questions that are addressed here with respect to the big industrial interest in microreactors.     

Study of liquid injection impact on the performance of new refrigerant mixtures

In this paper, the test results of liquid injection impact on the performance of new alternative refrigerant mixtures such as: R-410A, R-507, R-407C and R-404A are discussed, analysed and presented. The test results were obtained using an air-source heat pump set-up with enhanced surface tubing under various liquid injection ratios. Performance tests were conducted according to the ARI/ASHRAE standards. The performance data demonstrated that as liquid injection ratio increases, compressor head pressure and discharge temperature decrease. This has a positive effect in protecting the compressor. The effect of liquid injection on mixture behaviour varies from one mixture to another depending upon the mixture's composition. Furthermore, liquid injection appears to have a significant influence on R-410A behaviour compared to the other mixtures in question. Copyright © 2002 John Wiley & Sons, Ltd.     

新取代苯基荧光酮试剂的合成及其性质的研究Ⅱ．新型取代苯基荧光酮与金属离子显色反应的研究

研究了３，５－二溴－４－氨基苯基荧光酮、３，５－二溴－４－偶氮变色酸等８种苯基荧光酮在酸性介质中与高价金属离子Ｚｒ（Ⅳ）、Ｍｏ（Ⅵ）、Ｗ（Ⅵ）、Ａｌ（Ⅲ）、Ｇａ（Ⅲ）等的显色反应。３，５－位二溴取代的试剂的灵敏度高于未取代的灵敏度，摩尔吸光系数绝大多数在１０５Ｌ·ｍｏｌ－１·ｃｍ－１以上。     

Practical method for generation expansion planning based on dynamic programming

This paper presents an efficient method which provides the optimal generation mix and the optimal generation construction process. The approximation method in which the dynamic programming technique and gradient method are combined is applied to determine the optimal generation mix with hydropower generation technologies. The successive approximations dynamic programming (SADP) technique, which is very suitable for high-dimensional multistage decision process problems, is used for obtaining the optimal generation construction process. The effectiveness and feasibility of the developed technique are demonstrated on a practical power system model which has five types of generation technologies including a hydropower generation technology.     

New Engineered Particles from Spray Dryers: Research Needs in Spray Drying

This article reviews developments in the simulations of spray dryer behavior, including the challenges in modeling the complex flow patterns inside the equipment, which are often highly transient and three-dimensional in nature. There appears to be considerable scope for using CFD simulations for investigating methods to reduce the rates of wall deposition and of thermal degradation for particles by modifying the air flow patterns in the chamber through small changes in the air inlet geometry. Challenges include building particle drying kinetics and reaction processes, as well as agglomeration behavior, into these simulations. The numerical simulations should be valuable supplements to pilot-scale testing, enabling more extensive and accurate optimization to be carried out than hitherto possible. New understanding of reaction processes and materials science, in combination with recent knowledge of the application of CFD to these problems, may enable new engineered powder products to be developed from the one-step spray-drying process.     

Work-oriented development of knowledge-based systems: a case for multiple perspectives

System development is strongly influenced by the perspectives used by system developers. Current development methods for knowledge-based systems are based on an information processing perspectives of experts and users which has been criticized by a number of researchers. The paper argues that work-oriented development of knowledge-based systems requires the parallel use of multiple perspectives (including the information processing perspective), and that the use of any single perspective is potentially dangerous. As an example of the importance of using multiple perspectives, thepaper presents the situated action perspective, and shows how it complements the information processing perspective.     

进一步增强整体开放意识开创我市对外开放工作的新局面

九十年代是中国社会主义现代化建设进程的关键时期。作者从宏观角度提出了青岛市如何进一步增强整体开放意识,开创对外开放工作的设想。对我市今后更好适应我国的经济振兴和社会进步意义重大。