LaCrMnNiO系热敏陶瓷的微观结构控制

通过对不同配方、工艺下的ＬａＣｒＭｎＮｉＯ系热敏陶瓷的微观结构研究，指出材料的相组成对其宏观电性能的影响，并提出了通过复合工艺利用“过渡相”的形成，对材料的“最终相”加以控制的方法。文中列出了使用ＸＲＤ及ＸＰＳ手段对材料微观结构的分析结果及有关电性能的测试数据。     

Li2O在保护渣中的作用

采用在不同玻璃性的两种基渣中加入Ｌｉ２Ｏ为研究Ｌｉ２Ｏ对保护渣粘度，熔化温度及玻璃性能的影响，并对Ｌｉ２Ｏ改善保护渣玻璃性的机理进行了探讨，提出了寻找高速连铸保护渣中Ｌｉ２Ｏ的代用物的一种方法。     

A numerical model for the dissolution of spherical particles in binary alloys under mixed mode control

A general numerical model is described for the dissolution kinetics of spherical particles in binary systems for any combination of first order reactions at the particle-matrix interface and long distance diffusion within the matrix. The model is applicable to both finite and infinite media and handles both complete and partial particle dissolution. It is shown that interfacial reactions can have a strong effect on the dissolution kinetics, the solute concentration at the particle-matrix interface and the solute concentration profile in the matrix.     

ZnO陶瓷材料的负阻特性

介绍了ＺｎＯ陶瓷的负阻特性，主要研究了ＭｎＯ２掺杂和Ｎｉ２Ｏ３掺杂对ＺｎＯ陶瓷负阻特性的影响。     

对洪水分级的浅见

洪水的等级划分应考虑流量、水位、防洪能力及灾害等因素,综合这些因素把洪水分成5个等级。1、2级洪水,洪水流量小,水位低,基本无灾;3级洪水,洪水流量较大或水位较高,有一定灾害;4级洪水,为大洪水或高水位,有较大灾害;5级洪水,为特大洪水或高水位,灾情严重。     

A sensorless brushless dc motor system

This paper describes a brushless dc motor system without position or speed sensor. The brushless motor consists of a permanent magnet synchronous motor and a voltage-source inverter capable of controlling the amplitude and frequency of voltage. The rectangular-shaped stator current with a conducting interval of 120° (electrical) is controlled to be in phase with the trapezoidal back electromotive force. This results in producing maximum torque. Variable speed is achieved by adjusting the average motor voltage similarly to chopper control of dc motors. In this paper, two sensorless position detecting methods, i.e., an “indirect method” suited for the lower-speed range and a “direct method” suited for the higher-speed range are proposed. The combination of the two makes it possible to detect the rotor position over a wide-speed range. Furthermore, a speed-sen-sorless PLL control is proposed in applying the principle of the direct method. Experimental results obtained from a prototype brushless dc motor are shown to confirm the validity of the sensorless drive. The starting procedure of the motor also is discussed because it is impossible to detect the rotor position at a standstill.     

A bidding decision index for construction contractors

Results from applying the model on a sample of contractors, the majority of whom were international and operating in Egypt, reinforces the credibility of the developed methodology, claim the authors.     

基于STEP的零件加工工艺计划模型

为了满足ＣＩＭＳ环境下工艺系统与其它系统集成的需要，建立了标准工艺计划模型具十分重要的意义。本文描述了一个基于ＳＴＥＰ的零件加工工艺计划模型，介绍了建立这一模型的关键技术，给出了参照ＳＴＥＰ建立工艺计划模型的方法。     

微量Ag对CP276合金性能和组织的影响

研究添加不同含量的Ａｇ对ＣＰ２７６合金的拉伸性能和时效组织的影响。对拉伸强度、延伸率测试及透射电镜观察表明：０．１１ｗｔ％加入可促进Ｔ１相析出，使合金强度值升高；０．３５ｗｔ％Ａｇ的加入可在时效前期生成富Ａｇ、Ｍｇ的稳定的ＧＰ区，从而降低合金中Ｃｕ的固溶度，阻碍Ｔ１相析出，时效后期，ＧＰ区分解，生成大量Ｔ１相，使合金强度值显著升高。     

转炉炼钢静态模型的初步探讨

根据转炉炼钢的物理化学反应机理，从质量平衡和能量平衡的计算出发，通过小参数变动，导出了增量式静态模型中矿石方程和供氧方程的系数。所得结论与新日铁资料基本相符。同时，还进行了炉料和产物的计算，分析了改变废钢比对生产的影响。