Electromagnetic properties of ferroelectric-ferrite ceramic composites

The NiFe₂O₄ and Pb(Zr_0.52Ti_0.48)O₃ ceramic composites are prepared by conventional solid state reaction method. The microstructural and morphological properties of the composites are studied by X-ray diffraction analysis and scanning electron microscopy. Results indicate that the ferrite and piezoelectric phases can co-exist in the composites. The relationship between the dielectric constant and frequency (40 Hz–40 MHz) as well as temperature is also investigated. It is noted that the transition temperature of the composites is about 380 °C. A double electric hysteresis loop is observed in our composites. The magnetic properties are relatively weak according to the magnetic hysteresis loop. With increase in the content of the ferrite phase, the permeability increases. The electromagnetic properties of the as-prepared composites are tunable according to the content of the NiFe₂O₄ phase.     

基于神经网络的模糊自适应PID控制方法

提出一种基于BP神经网络的模糊自适应PID控制器。该控制器综合模糊控制、神经网络与PID调节各自的优点，既具有模糊控制的简单和有效的非线性控制作用，又具有神经网络的学习和适应能力，同时具备PID控制的广泛适应性，仿真实验表明该控制器对模型、环境具有较好的适应能力和较强的鲁棒性。     

石油化工蒸汽系统顶层分析研究与应用

介绍石油化工蒸汽系统顶层分析，并通过实例分析阐明，在顶层分析的指导下进行蒸汽系统优化可以给工厂带来可观的经济效益。     

10.6μm线性声光调制器研究

本文讨论的１０．６μｍ线性声光调制器，采用Ｇｅ单晶作为声光介质，工作中心频率为８０ＭＨｚ，３ｄｂ带宽为７ＭＨｚ。在驱动射频源输出功率８Ｗ的条件下，得到器件衍射效率峰值达３６％，该器件已作为激光束强度调制器件应用于视频／红外动态图象转换装置中。     

A Type-Safe Embedding of XDuce into ML

We consider the problem of integrating XDuce into ML. This is difficult because of incompatible type and value representations. Our solution is a type-driven translation scheme from XDuce to ML based on a structured representation of XDuce values. XDuce type inference guides the insertion of appropriate coercion functions to translate regular expression pattern matching and uses of semantic subtyping. We can extend our translation scheme to include ML function calls and patterns into XDuce. Thus, we can embed XDuce into ML. Our results allow to enrich the ML language with support for dealing with semi-structured data.     

基于BP神经网络的心电图ST段的模式识别

心电图ST段对心脏疾病的诊断具有重要意义.在正确读取采集于郑州大学一附院的运动心电图数据基础上,利用小波变换更准确地确定其ST段的起始和终止位置,初步探讨了BP神经网络用于心电图ST段识别的方法,并用此方法识别出心电图ST段的三种类型-正常、水平压低和抬高.实验结果较好.     

桌面式天线虚拟实验系统

将天线数值仿真技术与虚拟现实技术结合,构建一个桌面式天线虚拟实验系统,可以解决天线实验课开设成本高、场地受限等问题.     

Hastelloy B-2封头加工

HastelloyB - 2是哈氏合金中最难制造和加工的镍基合金之一 ,尤其是化工容器中的封头 ,其制作工艺过程较复杂 ,这种材料较昂贵 ,目前在国内化工行业应用很少 ,因此掌握这种材料的制造技术具有重要的意义 ,本文阐述了HastelloyB - 2封头的坯料焊接、旋压成形、固溶处理及酸洗等工艺过程。