Testing multi-characteristic product capability indices

Recently, studies associated with testing the quality and performance of each process for a product with multi-characteristics are proposed more often. However, most studies are limited to discussing one single type of quality characteristic. Practically, a multi-characteristic product is potentially composed of three types: smaller-the-better, larger-the-better, and nominal-the-best. In this paper, we propose an integrated product capability index which considers these three different types of quality characteristics. According to the theory of testing hypothesis, we develop a testing procedure for the product capability index to judge whether the process capabilities of total quality characteristics meet the customers’ demands. In addition, the relationship between the product capability index and the yield of the entire product will be introduced. Finally, an example is provided as a practical application.     

胶凝砂砾石坝材料特性研究及工程应用

本文阐述了胶凝砂砾石坝的起源和发展情况。根据福建街面水电站下游围堰的施工要求，即施工期作为挡水堰，运行期作为量水堰，设计了围堰坝体的断面，对堰体的应力、稳定和渗流进行了分析，提出了材料的性能参数要求，并探讨了胶凝砂砾石材料的渗透溶蚀性能。研究结果表明，采用当地天然砂砾石，掺入水泥和粉煤灰各40kg/m3，其180d龄期抗压强度等级可达到C7.5，并满足围堰的力学、稳定、防渗和抗溶蚀要求，缩短了工期，降低了造价。     

柳钢100t转炉冶炼工艺优化实践

通过分析100t转炉冶炼工艺中存在的问题，对冶炼工艺进行优化，提高转炉过程控制能力和一倒炉命中率，结果表明：过程喷溅可降低至9％，冶炼终点命中率提高到63％ 以上。[第一段]     

X射线三轴晶衍射法测量半绝缘GaAs单晶的化学配比

采用X射线三轴晶衍射法,根据As间隙原子对作为过量As在GaAs单晶材料中存在的主要形式的模型,可以无损、高精度测量半绝缘GaAs单晶的化学配比.并探讨了引起晶格变化的原因及其与熔体组分的关系,对于制备高质量GaAs单晶及其光电器件具有重要的意义.     

进口VPSA制氧装置的流程特点及配置

详细介绍了进口的VPSA制氧装置的流程特点、工艺参数及主要设备的配置。实际运转证明 ,该制氧装置具有运行可靠、启动时间短、部分负荷性能优越、负荷转换速度快等优点 ,能满足金隆铜业有限公司的实际生产要求。     

Interaction bounds in multivariable control systems

Time-domain limitations due to right half-plane zeros and poles in linear multivariable control systems are studied. Lower bounds on the interaction are derived. They show not only how the location of zeros and poles are critical in multivariable systems, but also how the zero and pole directions influence the performance. The results are illustrated on the quadruple-tank process, which is a new multivariable laboratory process.     

静水压力下混凝土双K断裂参数试验测定

本文主要研究混凝土在机械荷载和水压力的双重作用下，裂缝的起裂、扩展和失稳断裂情况。试验采用楔入劈拉试件，试验时每间隔一定的机械荷载，施加一个循环的一定数值的水压力，直至试件断裂。试验采用“恒定裂缝张开位移”和“恒定荷载”两种加载方式，恒定裂缝张开位移是对水压力作用下的试件进行的定性对比分析，恒定荷载是对固定水压力作用下的试件，通过表面粘贴应变片的方法监测裂缝的起裂和扩展长度。采用混凝土裂缝扩展的双K断裂准则计算了粘聚韧度、失稳韧度和起裂韧度，并与试验测定结果进行了比较。结果表明，随着水压力的逐渐增大，试件的可承受最大荷载逐渐减小，裂缝的起裂提前。     

Development of Low-Oxide MCrAlY Coatings for Gas Turbine Applications

Advanced high-energy plasma systems are being used to achieve the benefits of the high-velocity oxy-fuel (HVOF) system without losing the inherent advantages of plasma for coating of gas turbine parts. MCrAlY coatings play a very important role in the performance and reliability of gas turbine components. One of the important considerations for next generation of gas turbines, which have more demanding conditions and need to withstand ever increasing operating temperatures, is that they should possess very low oxygen content levels in the coating. Low oxygen content coatings are applied by the expensive low-pressure plasma spray (LPPS)/vacuum plasma spray (VPS) technique for critical components in aero- and land-based gas turbines. This work deals with the development of low-cost LPPS equivalent coatings (having low oxygen content) using the high-energy high-velocity plasma spray (HEHVPS) gun and inert gas shroud. A comparison has also been made with CoNiCrAlY coatings by HVOF.     

Time and Temperature Factors in Construction of Rock Strength Criteria

Using the synthesis of the kinetic concept on solid strength and the Coulomb - Mohr strength theory as the base, the failure conditions taking into account the time and temperature factors are obtained.     

Ultrasonic properties of hexagonal ZnS at nanoscale

Higher order elastic constants have been calculated in ZnS at 300 K and 500 K following the interaction potential model. Ultrasonic attenuation, velocity and other related parameters have been calculated using the higher order elastic constants for the different size of the material at 500 K. The size dependency of the ultrasonic properties is discussed in correlation with elastic, thermal and electrical properties. It has been found that the thermal conductivity is the main contributor to the behaviour of the ultrasonic attenuation as a function of the size and the responsible cause of attenuation is phonon-phonon interaction. The semiconducting nature of ZnS film has been achieved with the study of size variation of thermal relaxation time and ultrasonic attenuation.