机电一体化交流接触器动态控制技术与特性计算

介绍以单片机控制的交流接触器动态控制技术的原理与线路，给出了利用有限元法计算其起动过程特性的新方法，该法具有计算时间大为缩短等优点。     

高电压大容量真空灭弧室电弧特性的测量与研究

以线圈式纵磁结构63kV、40kA真空灭弧室为实验对象,在4种定弧隙燃弧情况下(10、20、30、40mm),测量了电流峰值时对应弧压值与电流的关系、开距对噪声分量电压的影响、弧压特性与主屏蔽罩电位特性的异同。在变弧隙燃弧情况下,测量刚分电流对电弧特性的影响。最后对实验结果进行了分析。     

垂直柔性梁固有频率的计算与测试

航天结构系统属于重量轻、尺寸大的柔性结构,加之运行条件复杂,因此研究这类结构的振动特性及其控制就成为发展航天事业的重要课题之一。本文研究了作为构成航天结构系统基本构件——柔性梁的固有频率的理论计算与实验测试,结果表明,考虑重力影响的计算值与测试值十分接近,从而证明,在计算垂直柔性梁的固有频率时,不可忽视重力的影响。     

推覆体下13—1煤层综放开采水文地质特征及“三带”高度的探讨

探讨煤层开采的“三带”高度 ,确定 13- 1煤层综放开采的上限 ,正确指导 13- 1煤层安全回采     

Flow Characteristics of Metal with Phase Transformation and Prediction of Its Microstructure

We propose a flow-stress characteristic of SUS430F steel that takes in account the effects of temperature, strain rate and their deformation history. In the framework of this characteristic, the history effects of strain rate and temperature are estimated through the plastic strain energy stored. The formulated characteristic () may be shown as a function of temperature (), strain rate ((), and the stored energy W or the reference stress (_st). The energy is stored through plastic deformation and released during annealing process. The energy is also referred by the yield flow stress (_st), which is measured under the reference condition. The discussion on the characteristic is extended to the material at high temperature (1073–1473 K) with the + gamma phase of a given phase ratio. The equilibrium ratio of ()- or ()-phase at a given temperature can be estimated on the basis of an equilibrium phase diagram. In order to introduce the flow-stress characteristic with phase transformation using the proposed formulation, we also analyze the phase transformation rate from () to + with temperature elevation, and from () to > + in the cooling process on the basis of the time–temperature–transformation diagram that includes the quenching process as well. The flow stress characteristic and phase ratio are estimated simultaneously for a hot forging process.     

The order structure of fuzzy numbers based on the level characteristics and its application to optimization problems

Ranking and comparing fuzzy numbers is an important part in many fuzzy optimization problems such as intelligent control and manufacturing system production line scheduling with uncertainty environments. In this paper, based on the level characteristic function and α-average of level cut sets of fuzzy number, we establish the IMα-metric method for measuring fuzzy number as a whole, and introduce the concept of IDα-difFerence that describes the reliability of IMα-metric value. Further, the basic properties and the separability of IMα-metric and IDα-difference are discussed. Finally, we give a mathematical model to solve fuzzy optimization problems by means of IMα-metric.     

中值滤波器对信号相位和形状影响的研究

中值滤波器具有许多优点,已经在VSP等地震资料处理中得到较为广泛的应用。由于中值滤波器是一种非线性滤波器,对尖脉冲的响应是零,在傅氏域没有“真正”的振幅普和相位谱,所以了解其特性比了解线性滤波器特性要困难得多。然而许多简单的数值方法可合理、直观地了解这种滤波器在地震资料中的作用。其中,通过研究它对各种信号的响应来了解其性质是一种有效而实用的方法。在此方法基础上分析了中值滤波器的特性。     

双语法律文本的自动对齐

基于实例的机器翻译系统需要双语句对的支持。为大量获取双语句对,则需要以篇章对齐的双语文本为输入,实现句子的自动对齐。通过分析汉英双语法律文本的特征,提出了法律文本对齐假设。首先识别出法规源文和译文中的结构标识和句子,然后在句子一级对齐法律文本。该方法在150篇汉英法律文本语料上,取得了80.98%的对齐准确率。     

Study on softening melting characteristics of iron bearing material in oxygen blast furnace

The softening melting characteristics of sinter, pellet and mixed ore in oxygen blast furnace and traditional blast furnace were studied by using load softening and dropping equipment. It is found that, compared with the traditional blast furnace under the softening starting temperature of sinter, pellet, and their mixture decreases, the softening ending temperature increases in oxygen blast furnace atmosphere. Under the condition of oxygen blast furnace, the dropping temperature of sinter decreases, the dropping temperature of pellets and their mixture increases, and dropping zone becomes narrow and even disappears. Through the analysis of the data of the soft melting process, it is found that the mixed ore has a certain interaction effect in the oxygen blast furnace atmosphere, which improves the gas permeability of the charge.     

基于小波子带统计特性的图像量化及质量可分级编码研究

随着数字电视、网上会议和在线点播的出现，越来越多的图像信息需要在网上进行传输，而此时人们不仅要求编码技术具有较好的压缩效果，还要求信息的传输能够满足渐进传输、多质量服务以及图像数据库浏览等一系列的要求。本文提出了一种基于位平面的图像质量可分级编码方法，结合小波子带图像的系数分布特性，利用样本标准差作为量化的依据，对各分辨率级进行分级量化，并且采用了位平面编码和算术编码，使得在解码时可以根据给定解码的数率不同对位平面进行重构以实现图像的质量可分级性。实验结果表明，本文提出的方法实现简单，编解码速度快，在保证具有很好的编码效果的前提下，可以实现图像的质量可分级编码。