A Review of Researches on the Self-organization Issue Concerning Complex Engineering Systems

With the development of science and technology, engineering practices have become more and more complex, which have resulted in a great deal of complex engineering systems. The elements of such systems are so numerous and jumbled, and the nonlinear interaction between the elements is so strong that traditional engineering methodology is no longer suitable to cope with such kind of engineering practices. Under such circumstances, some thoughts from complexity science, especially those of self-organization theory, have been drawn to solve the complex engineering problems. And some new ideas and methods have thus sprung out. Based on the literature review, the authors of this thesis clarify the concept of complex engineering system and its features. Besides, they also discuss the latest progress of the research on self-organization issue concerning complex engineering system from three aspects: on the self-property of complex engineering system, on the self-organizing mechanism of complex engineering system and on the relationship between self-organization and hetero-organization in complex engineering system. The effectiveness of the research from simulation still needs to be tested through the real engineering practice. The general principles and laws of constructing complex engineering system still need to be explored. The research on self-property of complex engineering system could not satisfy the need of engineering practice. And the problem of how to balance the relationship between self-organization and hetero-organization in constructive process of complex engineering system needs to be further studied. Dealing with all these problems requires not only the advancement in engineering science, but also the contribution of engineering philosophy, which is especially useful to the development of engineering methodology.     

水平管道油水两相流流型研究综述

油水两相流动现象作为多相流领域的重要分支,普遍存在于石油工业各个环节中.水平管道油水两相流流型的相关研究对于解决石油生产中的重要技术问题具有重要意义.简述了国内、外水平管道油水两相流流型研究的现状和发展方向,介绍了流型划分的方法.分析了影响流型的各种因素和参数,包括流速和相含率、油相黏度、管道直径和材质、入口形状、添加剂等.介绍了流型参数的测量方法和流型的识别方法,分析了现有测量手段存在的不足.针对流型影响因素、测量方法、内部结构的研究,指出了当前研究存在的问题和未来的研究方向,为进一步开展水平管道油水两相流流型研究工作提供了参考.     

长江三峡库区突发性溢油事故环境风险及对策研究

本研究从溢油敏感资源、油品种类、装卸码头、油品吞吐量及其变化趋势、船舶流量与船舶类型、三峡工程蓄水等影响因素出发,分析了长江三峡库区突发性溢油事故环境风险.采用计算机数值模拟的方法,本研究对三峡库区长寿段溢油事故情景进行了模拟预测,分析了不采取围控措施和采取围控措施的不同效果.结合突发性溢油事故环境风险分析和事故情景预...     

Important Effect of the Organic Fertilizer on Soil Fertility and Yield of Crop : a Case Study in Zhende Organic Farm, Henan, China

Using organic fertilizer can effectively improve soil structure,enhance soil organic matter content, and increase the yield of crop, which is the only way for the development of sustainable eco- agriculture. Our study mainly introduces the China's application of organic fertilizer, its important effect on soil fertility and the yield of the crops. An organic farm in Henan was chosen as research object. Calculation of the nitrogen input and output in this agro-ecosystem was done under the routine managements, and the best fertilizing scheme was investigated. The results showed that the least input of the organic fertilizer was 25.5t/hm, which could maintain nitrogen balance of this agro-ecosystem. It is of significance to use organic fertilizer scientifically, reduce production costs, increase crop yields, and develop the sustainable ecological agriculture.