三元复合驱合理井网、井距分析

在深入总结大庆油田杏五区、杏二区、北一区断西等三元复合驱先导性矿物试验的基础之上,结合非均质岩心室内物理模拟实验,进行了综合研究及数值模拟理论计算工作。针对大庆油田萨中以北地区及杏北地区现有井网的实际,给出了不同地区三元复合驱合理井网、井距的原则。     

支持复杂建设工程"精准建造"的项目持续分解模型

持续的项目计划与控制,是复杂建设工程推行“精准建造”(Lean Construction)的本质要求,与之相适应的工程项目分解也是一个持续动态的过程．分析了执行效能控制在复杂建设工程持续计划与控制中的核心地位,探讨了在以协同为特征的项目执行效能控制体系中采用本体论建模进行信息分解的必要性与可行性,提出了以效用本体论为中心的复杂建设工程项目分解结构体系构建策略,为进一步研究复杂建设工程本体论开发方法和持续计划与控制机制奠定了基础．     

Shoe Last Machining Using Virtual Digitising

Shoe lasts are the moulds used in the footwear industry in order to mount the shoe. Most of the machines used in the sector to make lasts are simply mechanical copiers. CAD/CAM systems have just arrived in the shoe last market but their accuracy and efficiency is no better than traditional machines, and so it is difficult to persuade the industry to adopt new systems. A tool-path generation algorithm that takes advantage of traditional copier systems that do not fulfil the CNC standards is presented in this paper. The tool path is computed from a "virtually digitised" model of the last surface. The algorithm is then analysed in terms of computing cost and accuracy, and refined by applying a series of optimisations. Some computer architectures are proposed in order to reduce the computation time. The proposed algorithm has been successfully implemented in a commercial CAD/CAM system specialised for shoe-last making. Finally, some illustrative examples are given.     

粉末冶金摩擦材料在高速列车制动中的应用

本文介绍了高速列车摩擦制动和粉末冶金闸瓦及闸片材料的成份、性能和国内外研究概况,并对我国高速列车制动材料的发展提出了建议.     

磁浮列车用铜基受电靴滑块材料的研究

研究了一种新型Cu-Sn-Pb-Cr-C受电靴滑块材料,并进行了性能测定和组织观察.结果表明:受电靴滑块材料具有优良的综合性能,其抗拉强度为138.1MPa,断口局部范围内有韧断特征;摩擦系数为0.38,其摩擦性能大大优于纯Cu;材料的电导率可达74%IACS,明显高于纯Al(60%IACS).从其微观结构可以发现,试样材料中Cu基体以连续网状形式分布,加入的石墨比较均匀地分布在网络空隙内,充分发挥了材料的导电性能及石墨的自润滑性能.     

主动知识辅助系统中制动蹄设计知识库的构建

针对高额的设计成本和对人才资源的竞争影响高端CAE技术使用的现状,用汽车制动系统中制动蹄的设计为例,将专家设计领域的知识结构化分层,用产生式规则表示法和框架表示法相结合的混合表达方式构建相应设计领域知识库。通过"主动的机-人知识辅助系统"为设计人员快速提供欠缺的经验知识,使设计人员能够快速地利用知识,而不是学习知识,实现设计知识和经验的高效利用,缩短设计人员的预学习过程,降低了CAE的应用门槛,达到高端CAE技术低起点应用的目的。     

Optimal periodic and random inspections with first,last and overtime policies

It has been assumed for a standby unit that periodic inspection is performed more easily to detect failures, but such a strict periodic mode would be impractical if the unit is executing some procedures without stops. From the above viewpoint, this paper first optimises a random inspection policy in accordance with random procedure times, compares it with periodic inspection and computes a modified checking cost for random inspection to determine the case where such a random inspection would be adopted. Second, this paper proposes three new inspection models in which inspections with deterministic policies are scheduled strategically while their performances need to be limited by completion times of operation procedures. These policies are called inspection first, inspection last and inspection overtime. The total expected inspection and downtime costs of each model until failure detection are obtained, and optimal policies which minimise them are derived analytically. Furthermore, the three inspection policies are compared with periodic inspection, inspection first and last are compared with each other, and a modified checking cost for inspection overtime is discussed when the policy would be better than periodic inspection.     

新型精密冷挤成形脱模装置设计与应用

分析了旋转顶出脱模方法的原理,并计算重要参数螺旋升角,设计出合理旋转顶出脱模装置,最后通过工艺试验证明旋转顶出脱模装置具有脱模阻力小,成形精度高等优点。     

空间下弦式液压滑模在小孤山水电站调压井的应用

文中论述了在张掖小孤山电站洞压井的竖井井筒部位采用空间下弦式液压滑模进行衬砌施工的过程,该技术的应用减少了钢材的消耗量,降低了爬升系统的运行难度,整体抗变形能力加强,保证了工程质量.     

基于携因素语义距离的定制西服订单聚类方法

为解决定制西服订单多样性和生产高效性的矛盾,利用大规模定制思想,结合定制西服订单商业特征到过程特征的映射建立了多段多级柔性西服物流编码系统,提出一种携因素语义距离订单聚类方法,该方法运用多级层次分析法确定了影响因素的权重,分析了编码属性的值域,将其分为有序属性和无序属性,并概念化得出了语义距离计算方法,采用改进的聚类识别算法对距离设计结构矩阵模型进行分割,实现了订单的聚类。通过实例计算表明了该方法能有效解决西服订单聚类问题。