A bi-objective DC-optimal power flow model using linear relaxation-based second order cone programming and its Pareto Frontier

The DC optimal power flow (DC-OPF) plays an important role in the operation and planning of modern power systems. In this paper, a bi-objective DC-OPF model minimizing both network losses and generation costs is introduced, which can further be converted into a single objective model via the weighted sum method. Furthermore, the Pareto Frontier is employed to solve this problem. In the mathematical view, the model is a special non-convex quadratic constraints quadratic programming problem. In order to obtain a continuous Pareto Frontier, the original non-convex feasible region is relaxed to its convex hull using a linear relaxation-based second order cone programming method. Compared with the semi-definite relaxation method, the proposed method can greatly reduce the number of dummy variables and the complexity of solutions. Finally, simulations on eight small systems and four practical, large systems are performed, in addition to the comparison of a Monte Carlo simulation. The results verify the effectiveness of the proposed algorithm.     

无捕收剂浮选的半导体能带理论讨论

用量子力学计算得到了方铅矿(PbS)和黄铁矿(FeS_2)的半导体能带图,以及分子氧和HS-离子的HOMO和LUMO的能量。计算结果画成方铅矿和黄铁矿半导体与分子氧和HS-离子作用的能级图,从电子转移微观层次上解释这两类矿物的无捕收剂浮选机理(包括自诱导浮选和硫化钠诱导浮选)。结果表明,P型半导体(以黄铁矿为典型代表)具有良好硫化钠诱导浮选行为,N型半导体(以方铅矿为典型代表)具有良好自诱导浮选行为。电子载流子浓度(n_e)与空穴载流子浓度(n_p)之比值可以作为一个参数来判断无捕收剂浮选行为:n_c/n_p值大,自诱导浮选行为好;n_p/n_e值大,硫化钠诱导浮选行为好。     

绿色房产创新战略的思考

为落实国家倡导的绿色建筑战略，提出立足本地，设计先行，应用前沿科技来创新绿色房产的战略思路。     

The persistence of efficiency

Profits can persist in the resource-based view (RBV) of the firm because of heterogeneity of inputs combined with resource immobility. The firm-efficiency interpretation of the RBV posits that heterogeneity in, for example, technology or know-how, leads to inter-firm efficiency differences which can persist because of imperfect imitability. Thus the persistence of efficiency leads to the persistence of profitability. There has been no empirical research into the firm-efficiency view, and this paper therefore fills that gap by utilizing a panel of 4280 firms in the manufacturing sector over the period 1983–2003. Efficiency scores are derived using data envelopment analysis (DEA) and these are then modelled in a random parameter framework where one determinant of current period efficiency is the firm’s own lagged efficiency. The estimated coefficient of efficiency persistence is found to be around 0.7, thereby offering support for the firm-efficiency view, and this varies by country and by industry.     

Fullerene Production in Tons and More: From Science to Industry

In the last decade, application of fullerenes has been proposed actively in a wide range of areas, and recent developments suggest that many of those applications are to be practical technologies. However, there has been no large-scale production enterprise for commercial usage of fullerenes. High production cost and limited availability of fullerenes have been the main obstacle in the development of the Fullerene Market. Improved flame-based technology leads to the most feasible process for mass production of fullerenes, since it is a continuous process and uses inexpensive hydrocarbons as its starting materials. In May 2003, we started fullerene production in tons and more to supply fullerenes with reasonable price as practical materials for industries.     

大雅和顺：来自一个古典聚落的报告

文章展示了云南省腾冲县和顺乡－－幅亚热带密林中汉文化聚落的五彩画面。在这里让人们看到了一个历史、文化、军事、经济挽成一个文化内圈的、互为完善缺一不可的特殊情结以及由此情结展现出来的和顺人自下而上发展的生态链。建筑可谓是此链上重要的一环，是为和顺文化的载体。     

基于多目标决策方法的反应离子刻蚀机约束环优化设计研究

从反应离子刻蚀设备腔室内部结构细节角度出发,研究腔室约束环对以450 mm为代表大晶圆尺寸刻蚀机流场影响。与同类研究相比,本文旨在突出研讨仿真模型的精确性与边界条件比较设置准则的重要性。本文首先介绍刻蚀机腔室约束环的结构及其功能并提出高精度粘度修正的实现方法并计算腔室流体气压分布。提出了腔室气压分布的多目标问题,采用遗传算法求解,并通过多目标决策对优化结果进行评价和排序,得到最适合的优化结果。最后,给出约束环设计结果并得出约束环可以优化腔室内气流分布轮廓的结论。     

A quantitative method used in negotiation support systems

It is important for small and medium sized business to enter international market with an electronic international trade network-the Marketplace, which is a large and synthetic computer-based network to enable an organization to engage in buying and selling products and services across national borders almost as easily as one can conduct such business locally. As one of its necessary components, Negotiation Support Systems(NSS) aid negotiators to bargain and reach agreement in negotiation process. On the basis of discussing the framework and capabilities of the Marketplace and the theory of negotiation, this paper introduces a quantitative method used in negotiation support system, which systematically analyses trade-offs between variables and is an additive scoring method to get to the efficient frontier in order to recommend high quality alternatives near it. The principle and techniques of this approach are also suggested.     

氢气在硫化钼分子簇上解离的DFT研究

A DFT study of H2 dissociation on a series of Mo x S y clusters was performed, including homolytic and heterolytic dissociation. The preference for the two pathways on these models show much difference, as the Mo coordination number increases, the homolytic dissociation becomes easier, whereas the heterolytic dissociation becomes more difficult. Furthermore, frontier orbital theory was used to analyze the dissociation mechanisms of these two pathways. It was found that the symmetry and energy gap of Mo x S y’s HOMO and H2’s LUMO are the decisive factors in H2 activation.     

机械强度学科发展趋势

综述2005年中国机械强度学科前沿研讨会所得出的学科发展趋势。根据30位与会专家学者的意见,归纳出5个前沿方向。它们分别是重大与先进机械结构及系统的强度可靠性与安全性、微一纳结构系统的强度与失效、复杂载荷与环境下结构的强度与失效、微细观结构强度与失效理论和先进智能的无损检测与早期诊断技术。