小方坯的二冷计算

二次冷却系统的设计计算参数较多,使用电子表格进行设计,简化计算过程,便于工艺分析和改进.     

基于数据融合的核动力管道腐蚀速率预测研究

在分析了数据融合技术的基础上,建立了基于数据融合的腐蚀速率预测模型,并对核动力管道的腐蚀速率进行预测.结果表明,利用数据融合技术对腐蚀速率进行预测所得到的结果是有效的,且精度比单一预测模型高,同时所得的预测结果对核动力管道的维护具有一定的指导意义.     

无模拉伸汽车后视镜支杆数学模型

介绍了新型无模拉伸加工汽车后视镜支杆的成型方法及生产工艺。通过对支杆无模拉伸变形机制的研究,分析了拉伸速度的变化规律,并建立了无模拉伸支杆的数学模型。实验证明,该数学模型结构简单、实用、可靠。     

汽车用灯头的注射模设计

针对汽车用塑料灯头的结构特点与工作环境,分析了灯头结构的复杂性、材料性能、注射工艺条件。合理地设计了注射成型模具,采用了组合式动模型芯来完成内孔的复杂成型,同时采用组合式侧抽芯来完成外侧面的卡钩与上面的穿线孔的成型,简化了模具的结构。     

锅炉用焊接钢管的制造技术

简述了锅炉用焊接钢管的优势,国内外锅炉用焊接钢管的生产发展概况以及我国焊接钢管用于锅炉制造的情况。详细介绍了锅炉用焊接钢管的质量要求、品种和规格,锅炉用焊接钢管的几种生产工艺方法,典型的制管工艺流程和生产关键技术。对锅炉用焊接钢管生产提出了几点建议。     

Numerical design for cathodic protection systems for concrete

Cathodic protection (CP) has become a successful method for the rehabilitation of concrete structures affected by chloride-induced corrosion of reinforcing steel. CP involves applying an electrical current from an external anode through the concrete to the reinforcement. The current causes steel polarisation, electrochemical reactions and ion transport. Normally the anode is placed over relatively large surface areas, including those where the steel is passive. Conventional views assume that protection current will not significantly flow outside the anode area. In many cases this results in a conservative design. This paper presents principles and first results of numerical calculations for design of an example CP system by finite element modelling. The final objective is to develop a tool for more economical CP system design. In particular, a CP system for the protection of local damage in bridges (e.g. at leaking joints) has been simulated. The corroding area with respect to the size of the anode is varied. Current and potential distributions and depolarisation values are predicted, both close to and more distant from the anode. It appears that current densities required to achieve sufficient polarisation are much higher than those usually found in the field. Neglecting time-dependent repassivation processes is likely to be the main cause and further work is needed to include them. The present model can be used with reasonable confidence for preventive application to passive steel.     

钢结构用高强度垫圈的淬火工艺

高强度垫圈是GB1231钢结构摩擦型高强度螺栓连接副的重要零件之一,由45钢板材冲制而成。该垫圈淬火时易开裂。经过试验,采用亚硝酸钠水溶液淬火解决了这一问题。     

车灯模NC编程及刀具选用的若干原则及技巧

在对机加工刀具切削性能和参数进行理论分析的基础上,结合车灯模具生产实践,研究了机加工刀具的选用原则及编程技巧,针对数控加工大刀、小刀分别进行了分析。从大刀方面,对深腔粗加工、刀具拔长及立卧式机床的编程特点和技巧进行了总结,并给出了实例。从小刀方面,对刀具选用原则、特殊夹头的采用以及车灯花纹等关键部位如何用刀也做了论述,着重给出了花纹加工编程的实用原则,具有一定的参考价值。     

A framework for international location decisions for manufacturing firms

The purpose of this paper is to address current shortcomings in international location decisions (ILD), which were identified through an exploratory study, by developing a model that addresses previous limitations in research and encapsulate an adequate theories and frameworks. Based on insights from an exploratory study on 17 Danish manufacturing firms and a literature review of over a 100 publications, the scope model was developed with the MECE principles in mind in order to encompass all aspects as identified, while being supplemented by adequate tools and models in different phases of the ILD process. This paper presents an application-oriented model for facilitating ILDs in manufacturing firms, which is unique in its way of being exhaustive and yet able to decompose the ILD problem in different aspects and abstraction levels to assist firms in balancing and aligning their efforts with strategic goals and organizational values.     

铸钢件凝固过程计算机模拟技术应用研究

介绍清华大学开发的计算机三维数值凝固模拟软件FT—Star的功能及其在二重集团公司的工艺性试验和应用研究。解决了软件实际应用于铸钢件凝固过程中出现的一些问题,摸索出一些计算经验和规律。对不同铸钢件如何恰当地剖分网格、确定缩孔缩松判据参数、优化补贴工艺设计等都进行了深入研究,保证了计算机数值模拟结果的精确、可靠。实现了铸造缩孔缩松缺陷的预测,避免过去靠经验来进行铸造工艺设计,使工艺设计更具有科学性,大大降低了铸造生产成本。     

张力卷取过程卷筒压力的有限元分析

用有限元方法对张力卷取过程进行了数值模拟 ,分析了卷取过程中带卷内的压力和应力分布情况 ,并对影响卷筒压力的几个主要因素 (张力、摩擦力、带卷外径 )进行了分析 ,得出了卷筒压力和张力、摩擦力、带卷直径之间的关系。根据计算结果 ,得出一适于工程计算的卷筒压力计算公式 ,对实际生产具有一定的参考价值     

孔用弹性挡圈多工位级进模设计

介绍1副用于制造孔用弹性挡圈的模具,对冲压工艺、工艺方案以及模具结构形式、排样和压力中心等作了详细分析,并设计了孔用弹性挡圈模,模具结构合理,具有一定的参考价值。     

Method for supporting conflict resolution for efficient PSS development

A method is proposed to enable service designers to identify existing conflicts in design solutions and to develop basic strategies to solve them. For this purpose, two different approaches for detecting conflicts are introduced: one entails the use of lexical expressions of functions, and the other involves the ranges of design parameters. In the remainder of this paper, the authors describe a detailed process to identify conflicts in design solutions and to develop strategies for resolving them by applying the proposed methods in an actual service case. The proposed method is expected to lead to an improvement in the efficiency of PSS development.     

Strategies for designing composite materials for high temperature application

A clear understanding of the factors controlling reproducible composite processing is critical for high temperature application. One approach to obtain stable phase combinations (i.e. compatibility) is to use a controlled interface reaction (in-situ layer design). An effective approach to control the reaction products and diffusion pathway by adding an extra component layer has been practiced and analyzed based upon the relative component fluxes. At the same time, the observed diffusion pathway has been examined in terms of a chemical potential framework, which can provide in assistance interpreting kinetic data in multicomponent systems. While component chemical potential values can increase and decrease through the interdiffusion reaction layers, the total free energy value will be decreased during the interdiffusion reaction. In order to examine the operating principles involved in the synthesis of in-situ composites, model ternary systems including potential materials such as TiAl and SiC have been investigated. This article based on a presentation made in the symposium “The 1999 KSEA Materials Symposium in Honor of Professor Sang Joo Kim’s 70th Anniversary“, held at UCLA, Los Angeles, CA, USA, August 12–14, 1999 under the auspices of Korea—US American Scientists and Engineers Association.     

立式刻槽和扩孔电解加工装置设计

针对刻槽和扩孔需提高加工效率和改善表面粗糙度的问题,采用固定阴极立式布局方式设计电解加工装置.通过设计聚液套和分液锥帽保证流场均匀;采用杠杆使导电板在弹簧的作用下紧紧压住工件保证接电可靠;采用带动定心功能的锥形夹具装夹保证工件和阴极;夹具中采用垫块粗调和螺纹细调配合使用,使该装置具有一定的加工范围;根据加工对象的槽宽、槽深确定阴极工作条的宽度,设计了刻槽和扩孔阴极各一套.通过更换夹具和阴极,可完成多种口径和长度零件的刻槽和扩孔加工.     

New technology for heat treating leaf-spring sheets for trucks

Conclusion New technology and automatic equipment for heat treating leaf-spring sheets based on using induction heating, rapid cooling by a stream of water, and a specially developed steel with controllable hardenability have been developed.The new technology makes it possible for one production example to obtain a highstrength hardened layer (_f2500 N/mm²), a strengthened core (_f1200 N/mm²), and compressive residual stresses in surface layers which in combination provide high service properties for leaf springs and the possibility of reducing their weight by 15–25%.The new technology also makes it basically possible to automate the heat treatment process for leaf-spring sheets, to improve working conditions, and as a result of this, to exclude the use of quenching oil to improve the ecological atmosphere of the heat treatment workshop and also to exclude the work hardening operation with shot.Scientific Production Association "Tekhmash." Sinel'nikov Leaf Spring Factory. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 2, pp. 11–14, February, 1992.     

气门锻模渗硼工艺研究

针对3Cr2W8V钢制造的锻模,常规热处理后因变形或模腔起皱而失效,效率低、成本高等缺点,提出对气门成型锻模进行渗硼强化工艺研究,找到了适合于锻模渗硼的热处理工艺。锻模使用结果表明,使用寿命是原淬火+回火的2倍,社会效益与经济效益明显提高。     

有线分配器压铸模具CAD

介绍了有线电视分配器压铸模具CAD的过程，进行了零件工艺性分析，对模具成型零件也进行了分析并提出了解决方案。     

基座类注射模型芯定位方法

分析了基座成型的特殊性 ,从多年的工作实践中总结了一套利用制件特征解决此类模具型芯定位的方法。所举的实例对其它类型产品的型芯以至于扩展到各种定、动模镶件的定位结构具有一定的参考意义。     

临床试验机构研究者培训的标准操作规程

合格的研究者是保证临床试验质量的关键。临床试验机构对研究者的培训, 是研究者获得参加其所承担试验项目资格的必备条件。本操作规程是依据GCP 以及我院对研究者培训的实践制订的。内容包括制定培训计划, 研究者的岗位培训, 临床试验项目开始前的研究者培训, 培训原则, 培训技巧,培训评估, 培训者资格审定, 以及文件和档案的建立等。