Effects of crack size and weld metal mismatch on the has cleavage toughness of wide plates

The heat affect zone (HAZ) is in many cases considered to be the most critical part of a weldment. In this paper, the effect of crack size and weld metal mismatch on the HAZ cleavage toughness of wide plate specimens with X-groove has been investigated by the J-Q-M theories and a simple micromechanism for cleavage fracture. Two crack sizes have been studied (a/w = 0.1 and 0.3). In the analyses, the HAZ yield strength is assumed to be higher than the base metal. For each crack size, weld metal local overmatch and local evenmatch with respect to the HAZ are considered. For a given global strain, the results indicate that weld metal overmatch and evenmatch yield the same crack tip loading in terms of J-integral for a/w = 0.3. For a/w = 0.1, overmatch gives lower crack tip loading than evenmatch. For a given crack tip loading, weld metal local evenmatch in general results in less effective crack tip loading than the overmatch. Overmatch is detrimental to HAZ toughness, but this detrimental effect becomes less significant when the crack size decreases.     

石灰竖窑工作衬砖蚀损机理的探讨

阐述了石灰竖窑的预热带、煅烧带和冷却带工作衬砖蚀损机理，并讨论了如何根据耐火砖性能和石灰竖窑不同区域的蚀损机理，选择耐火材料。     

超高纯铜的制备方法和应用

简要介绍了超高纯铜(UHPC)的几种精炼方法，以及它在工业方面的应用。并对超高纯铜的研究开发趋势及应用前景进行了展望。     

浅论水电规划工作思路

在水电的前期设计阶段，规划专业的重要性显而易见。由于水电规划工作涉及专业很多，如果仅停留于规划专业本身，未必能解决问题。在规划工作中，既有定量的计算，也有定性的分析；既要站在国家的角度进行评价，也要进行企业的财务效益分析；既要考虑目前的现实情况，也要对未来的发展做出预测；既有企业的主观意志，也有自然、社会历史的限制。总之，规划专业是涉及多目标、多量纲的综合判断，若以局部来通观全体，则一定要流于片面的谬误。因此，水电规划工作须进行辩证的综合研究。     

Multi-plant production scheduling in SMEs

Traditionally, companies used to view themselves as separate entities and did not devote efforts to collaborate with other echelons of the extended enterprise. This even happened at multi-site companies owning different plants that belonged to the same supply chain. However, manufacturing facilities of the same supply chain should intensively share information and coordinate planning and scheduling tasks in order to get a globally optimized solution. This paper discusses some specific characteristics of the planning and scheduling problem in the extended enterprise including an analysis of a case study, and reviews the available state-of-the-art research studies in this field. Most studies suggest that integrated approaches can have a significant impact on the system performance, in terms of lower production costs, and less inventory levels. The paper provides some conclusions and suggestions of future works.     

A visual tool for computer supported learning: The robot motion planning example

We introduce an effective computer aided learning visual tool (CALVT) to teach graph-based applications. We present the robot motion planning problem as an example of such applications. The proposed tool can be used to simulate and/or further to implement practical systems in different areas of computer science such as graphics, computational geometry, robotics and networking. In the robot motion planning example, CALVT enables users to setup the working environment by creating obstacles and a robot of different shapes, specifying starting and goal positions, and setting other path or environment parameters from a user-friendly interface. The path planning system involves several phases. Each of these modules is complex and therefore we provide the possibility of visualizing graphically the output of each phase. Based on our experience, this tool has been an effective one in classroom teaching. It not only cuts down, significantly, on the instructor’s time and effort but also motivates senior/graduate students to pursue work in this specific area of research.     

上海市松江新城突进式发展的体制创新与探索

本文用理论和现实的案例分析详细阐述了“经营城市”的六项特征和“三赢”的理念 ,简要介绍了松江新城在财政不出一分钱的情况下为取得突进式发展所采取的制度创新和探索 ,并总结了两点如何树立规划权威性的经验。     

价格不确定情况下炼厂生产计划的优化

生产计划的编制是炼油企业生产经营管理中的一个关键环节，然而由于市场变化的不确定性，使企业制度长远规划受到限制，笔者将多目标规划应用于炼厂价格不确定情况下生产计划的制定，使所得到的生产计划在一定程度上反映市场的变化并能使企业的生产效益最优，为企业管理决策者进行长远规划给予指导。通过实例验证了该方法的可行性。