W18Cr4V高速钢激光相变强化层的残余应力

利用Ｘ射线衍射法对Ｗ１８Ｃｒ４Ｖ高速钢激光相变强化层的残余应力进行了测定和分析。试验结果表明，相变强化层表面的残余应力为压应力，内部为拉应力，近似按正弦函数分布。其大小和分布状态随工艺参数的变化而改变。当改变工艺参数使表面熔化时，表面为拉应力。     

EFFECTS OF TWO－STEP HEAT－TREATMENT ON MICROSTRUCTURE AND PROPERTIES OF TiAl INTERMETALLICS

ＥＦＦＥＣＴＳＯＦＴＷＯ－ＳＴＥＰＨＥＡＴ－ＴＲＥＡＴＭＥＮＴＯＮＭＩＣＲＯＳＴＲＵＣＴＵＲＥＡＮＤＰＲＯＰＥＲＴＩＥＳＯＦＴｉＡｌＩＮＴＥＲＭＥＴＡＬＬＩＣＳ￥Ｋｏｎｇ，Ｇａｏｎｉｎｇ；Ｈｕａｎｇ，Ｂａｉｙｕｎ；Ｑｕ，Ｘｕａｎｈｕｉ；Ｌｅｉ，Ｃｈａ...     

CALCULATING ACTIVITIES USING Δ_(fus) H_((A_η)( B_ξ)) AND CALCULATION OF ACTIVITIES IN Ga-As, Ga-Sb AND In-Sb SYSTEMS

ＣＡＬＣＵＬＡＴＩＮＧＡＣＴＩＶＩＴＩＥＳＵＳＩＮＧΔｆｕｓＨＡηＢξＡＮＤＣＡＬＣＵＬＡＴＩＯＮＯＦＡＣＴＩＶＩＴＩＥＳＩＮＧａＡｓ，ＧａＳｂＡＮＤＩｎＳｂＳＹＳＴＥＭＳ①ＬｉＷｅｎｃｈａｏ，ＺｈｏｕＧｕｏｚｈｉ，ＬｉＸｉｎｇｋａｎｇ，Ｄｉｎ...     

大型厚断面球墨铸铁机架的铸造

大型厚断面球墨铸铁件在铸造过程中极易产生缩孔、缩松、石墨漂浮及球化衰退等铸造缺陷。在合理分析了机架铸件的工艺结构的基础上,设计了合适的铸造工艺并确定了有效防止各类铸造缺陷的措施,成功地生产出了球墨铸铁机架,满足了用户的使用要求。     

高铝锌基合金直齿圆锥齿轮的挤压铸造工艺

利用挤压铸造技术生产高铝锌基合金直齿圆锥齿轮，齿面精度能够得到保证。适用于工作环境较好，载荷不是很大条件下的高铝锌基合金直齿圆锥齿轮，可减少设备投资、减少工序工时，从而大大降低生产成本，具有很高的经济效益和社会效益。     

炼油厂酮苯装置空冷器腐蚀原因分析

炼厂酮苯装置空冷器因空冷管束腐蚀穿孔被迫停工检修，经取样分析和现场调查，得出结论：溶解氧含量偏高，设备本身存在震动，无盐水质量不稳定及空冷管束选材不当是造成空冷器管束腐蚀穿孔的主要原因，提出有效大的防腐措施。     

对学术权力的再审视

近年来 ,有的学者对学术权力进行了重新界定 ,提出新的看法。本文从新观点提出的依据、专用术语与普通用语的区别、历史的内涵、概念的定义等角度 ,对这些新观点进行了深入的分析 ,说明了新观点存在的误区 ,指出学术权力这个概念并未超出原来的意义     

A study of the passive films on chromium by capacitance measurement

Using capacitance measurement and Mott-Schottky analysis, the semiconducting properties of passive films formed on chromium within the passive potential range under different conditions were investigated. The study reveals a p-type behavior of the passive layers. Two semiconductive parameters, i.e., the acceptor density (N_A) and the flatband potential (E_FB), which are mainly related to composition and surface charges of the passive films, have been measured. The effect of film formation potential, passivation time, pH and composition of solutions on the parameters are discussed. N_A increases either with lowering film formation potentials or with prolonging passivation times. This is attributed to the transformation of a less hydrated oxide film into a more hydrated form. The changes of E_FB are discussed as a function of adsorptive anions and pH values of electrolyte solution.     

Robust non‐fragile H ∞ ∕ L2 − L ∞ control of uncertain linear system with time‐delay and application to vehicle active suspension

This paper presents an approach to design robust non‐fragile H _∞ ∕ L₂ ? L _∞ static output feedback controller, considering actuator time‐delay and the controller gain variations, and it is applied to design vehicle active suspension. According to suspension design requirements, the H _∞ and L₂ ? L _∞ norms are used, respectively, to reflect ride comfort and time‐domain hard constraints. By employing a delay‐dependent Lyapunov function, existence conditions of delay‐dependent robust non‐fragile static output feedback H _∞ controller and L₂ ? L _∞ controller are derived, respectively, in terms of the feasibility of bilinear matrix inequalities. Then, a new procedure based on LMI optimization and a hybrid algorithm of the particle swarm optimization and differential evolution is used to solve an optimization problem with bilinear matrix inequality constraints. Simulation results show that the designed active suspension system still can guarantee their own performance in spite of the existence of the model uncertainties, the actuator time‐delay and the controller gain variations. Copyright © 2014 John Wiley & Sons, Ltd.