机械零件刚度的模糊可靠性设计

介绍了机械零件刚度模糊可靠性设计变形分布参数和刚度隶属函数的确定,导出了零件刚度模糊可靠度的计算公式,并通过机床主轴模糊可靠性设计实例说明机械零件模糊可靠性的计算方法.     

小方坯粘结漏钢的检验与分析

粘结漏钢严重影响铸机生产率提高.对粘结漏钢残留坯壳进行检验分析,发现其具有外表面振痕紊乱、坯壳厚度从上向下逐渐变薄等特点.分析原因,制定相应的解决措施,取得了较好的效果.     

(Short communication) Degradation of corrosion resistance of Zircaloy-4 in LiOH aqueous solution

To investigate the degradation of corrosion resistance of Zircaloy-4 in LiOH aqueous solution, SIMS (secondary ion mass spectrometry) analysis was performed to examine the profiles of Li~ , K~ , and OH~- in oxide layers formed in the same concentration (0.1 mol/L) LiOH and KOH solutions. Even though the oxide layers have an equal thickness, the penetration depth of K~ is shallower than that of Li~ , and the penetration depth of OH~- corroded in KOH solution is also shallower than that corroded in LiOH solution. It shows that the diffusion of OH~- into oxide layer is accompanied by the corresponding cation. The difference of degradation effect of LiOH and KOH solutions on the corrosion resistance of Zircaloy-4 was discussed.     

Influence of electroplating conditions on magnetic properties of Fe-36wt.% Ni alloy film

A Fe-Ni soft magnetic film was prepared in sulphate solution by electroplating. The influences of the molar ratio of n [Fe2+ ]/ n [Ni2+ ], current density, bath temperature, pH and L-ascorbic acid concentration on magnetic properties of Fe-Ni alloy film were investigated. The results show that the saturated flux density(BS) of the film increases initially and decreases after it reaches the specific value with the increase of n [Fe2+ ]/ n [Ni2+ ] molar ratio, current density, bath temperature and pH. However, the relationship between L-ascorbic acid concentration and B S keeps linear. It is observed that the coercive force( Hc) is enhanced with the increase of n [Fe2+ ]/ n [Ni2+ ] molar ratio, current density and pH. By comparison, when the bath temperature increases, Hc always decreases. With the increase of L-ascorbic acid concentration, the coercive force increases initially and then decreases.     

Effect of grain size on high-temperature oxidation behavior of Cu-80Ni alloy

1　INTRODUCTIONTheoxidationofunalloyedcopperandnickelhasalreadybeenstudiedindetail.Whilethehigh tem peratureoxidationofCu Nialloys ,alsostudiedanumberoftimestodate[13] ,isanexampleofarela tivelysimpleclassofscalingofbinaryalloysbyasin gleoxidant,becausethemetalsformacontinuousse riesofsolidsolutions ,whiletheiroxides ,CuO ,Cu2 OandNiO ,exhibitsmallmutualsolubilitiesandshowsignificantdifferencesinthethermodynamicstabilityandparabolicgrowthrates .Thus ,copper richalloysformexternalscales…     

全球铝轧制工业概览系列综述之九——日本神户钢铁公司真冈铝板带轧制厂

对日本神户钢铁公司枥木县真冈轧制厂的方方面面作了较全面的介绍，并对神户钢铁公司与美国铝业公司的合资企业－－神钢－美铝铝业有限公司作了附带的描述。这两家企业都是从上世纪70年代以来新建的高起点、高水平、高标准、高质量的世界级的铝板带轧制厂，前者的建设时间历20余年，是一步一步壮大的，原来（1＋3）式热连轧生产线，后改为（1＋4）式的，还有进一步改为（1＋5）式的余地。这是一个综合性强的铝板带加工厂，除生产罐料处，还可生产各种热处理可强化的硬合金板带材。该厂可作为中国今后建设全新的大型现代化铝板带轧制工程的模式。     

CNC设备跟踪误差大故障排除

本文主要介绍了在一fagor数控系统中伺服系统的电流反馈、速度反馈、转子位置信号处理及开关电源等环节的元件失效、元件参数变值所引起的跟踪误差大故障的排除和CNC跟踪误差大的概要分析。     

基于Apache Shiro的站群角色管理

在站群角色管理中,易出现权限管理复杂、角色分配多样,访问效率低下等问题,因此,设计实现一种基于Apache Shiro开源框架的RBAC管理系统来解决站群角色管理中的不足;首先全面概述Shiro原理,然后以Shiro 为基础设计实现站群权限角色管理功能。最终使用户可以定制不同的角色与权限功能,且整个过程操作简单便捷。     

2010年长江流域暴雨洪水初步分析

分析2010年长江流域暴雨洪水,有利于更全面认识长江流域暴雨洪水特性,可为今后更好开展长江流域防汛水情保障工程。从主汛期长江流域暴雨及气候特征、干支流主要洪水过程及洪水特性等方面,进行了初步的总结和分析。2010年长江主汛期洪水发生范围广、持续时间长且局部地区洪水量级大,通过与三峡水库蓄水前后几次大的历史洪水分析对比,初步认为,2010年长江流域主汛期出现的洪水为长江上中游区域性较大洪水。     

Second-order terminal sliding mode control for hypersonic vehicle in cruising flight with sliding mode disturbance observer

This paper focuses on the design of nonlinear robust controller and disturbance observer for the longitudinal dynamics of a hypersonic vehicle (HSV) in the presence of parameter uncertainties and external disturbances. First, by combining terminal sliding mode control (TSMC) and second-order sliding mode control (SOSMC) approach, the secondorder terminal sliding control (2TSMC) is proposed for the velocity and altitude tracking control of the HSV. The 2TSMC possesses the merits of both TSMC and SOSMC, which can provide fast convergence, continuous control law and hightracking precision. Then, in order to increase the robustness of the control system and improve the control performance, the sliding mode disturbance observer (SMDO) is presented. The closed-loop stability is analyzed using the Lyapunov technique. Finally, simulation results illustrate the effectiveness of the proposed method, as well as the improved overall performance over the conventional sliding mode control (SMC).