High temperature low cycle fatigue

Fatigue at high temperature is a complex phenomenon as it is influenced by a number of time-dependent processes which become important at elevated temperatures. These processes include creep, oxidation, phase instabilities and dynamic strain ageing (DSA), acting either independently or synergistically influence fatigue behaviour, often lowering the fatigue life. Current design approaches employ linear summation of fatigue and creep damage with suitable factors on permissible damage to take care of uncertainties in interaction between cyclic and time-dependent processes. It is, therefore, important to develop a deeper understanding of the processes that occur during high temperature fatigue so that realistic life predictions could be made. Results on the high temperature fatigue behaviour of austenitic stainless steels, ferritic steels and nickel base alloys are presented here. The important mechanisms of interaction of high temperature time-dependent processes with fatigue under various conditions are discussed in detail. Emphasis is placed on cyclic stress response, fatigue life, deformation substructure and fracture behaviour. This is followed by a review of important life prediction techniques under combined creep-fatigue loading conditions. Life prediction techniques considered here include linear damage summation, strain range partitioning, ductility exhaustion approach, frequency modified and frequency separation methods, techniques based on hysteresis energy and damage rate models, and methods based on crack-cavitation interation models.     

中央空调系统变频节能改造方案

在我国经济快速发展的大背景下,能源（水、电、油）的消耗在企业中所占的比重越来越高,也受到愈来愈大的重视。同时也由于房地产的快速发展需求,中央空调的市场需求呈现强劲的增长。在市场容量不断增大的吸引下,越来越多的厂家加入到商用中央空调的领域。变频技术应用于中央空调系统,对提升中央空调自动化水平、降低能耗.减少对电网的冲击,延长机械及管网的使用寿命,都具有重要的意义。     

严格环境管理提高环境意识

环境伴随着经济的发展越来越体现了它的重要性,全社会应重视环境、保护环境,以预防为主,加强综合治理,使我们的天更蓝、水更净、草更绿,到处充满着春的意境.     

火电仿真技术研究

在电力行业中，计算机仿真一直是不可缺少的工具，它在减少损失、节约经费、提高效率、确保安全经济运行等方面发挥了巨大作用。主要介绍了计算机仿真技术在660MW火电站中的具体应用情况。以邯峰发电厂^#1机为对象，采用STAR-90仿真支撑系统，建立起660MW火电机组1：1仿真机，并在机组投产前建成，取得了良好的培训效果。论述了火电站仿真机未来的发展趋势，包括开发高精度机理性仿真数学模型以及真实的DCS仿真模型、进行性能计算与故障诊断、应用于热工人员培训及机组调试等。     

地基基础与上部结构共同作用和结构次生应力问题

本文考虑到上部结构与地基基础共同作用的事实,着重分析上部结构参与共同作用导致的内力重分布——次生应力问题。通过多个理论与实验的结果,对不同地基和基础条件下的次生应力进行了定量分析,探讨了造成次生应力的各种因素以及对建筑结构带来的危害。     

底板翻面机及其液压系统设计

本文介绍了底板翻面机及其液压系统的工作原理和设计特点。该机结构紧凑、运行平稳、工作可靠、能耗低，其成功的设计经验对同类设备的设计改造具有一定的参考价值     

行列式制瓶机的使用与维护

本文以国产单滴行列式制瓶机为研究对象,对行列式制瓶机使用技术、维修技术进行较为全面的论述,探讨以提高行列式制瓶机完好率和利用率,降低故障停机时间,提高企业经济效益为目的的行列式制瓶机技术管理模式。     

Adaptive control of permanent magnet synchronous machines with disturbance estimation

In this paper,an adaptive control scheme is introduced for permanent magnet synchronous machines (PMSMs)as an alternative to classical control techniques.The adaptive control strategy capitalizes on the machine’s inverse dynamics to achieve accurate tracking by using an observer to approximate disturbance in the form of friction and load torque.The controller’s output is then fed to a space vector pulse width modulation(SVPWM)algorithm to produce duty cycles for the inverter.The control scheme is validated through a set of simulations on an experimentally validated PMSM model.Results for different situations highlight its high speed tracking accuracy and high performance in compensating for friction and load disturbances of various magnitudes.     

网络对抗训练混合虚拟化平台设计研究

讨论了虚拟化技术实现原理及其在网络对抗教学中的应用上,分析了各类虚拟化技术的优缺点和构建网络对抗训练环境存在的问题。提出了一种混合虚拟化平台设计,该平台利用Libvirt虚拟化的应用程序编程接口（API）调用两种虚拟化技术同时运行在同一物理主机上。并详细叙述了混合虚拟化平台的实现过程和方法,并在多个虚拟机内同时运行测试基准,分析其可扩展性。多种虚拟化技术在同一物理机上的混合,实现了复杂实验环境的创建,对构建大规模的网络实验平台具有一定的参考价值。     

大型立式玻璃磨边机整机动态特性分析

大型立式玻璃磨边机的动态特性影响玻璃磨边质量和磨边效率。利用Solidworks软件建立某大型立式玻璃磨边机三维实体模型,导入ANSYS软件中,对整机结构有限元动力学分析,得到该磨边机前六阶模态参数,分析了各阶振型对磨边机动态特性的影响,为磨边机结构的改进设计提供了理论依据。