Resilient metal spring network silicone-matrix composite for separable interconnections

Resilient metal spring silicone-matrix conducting composites for separable interconnections in electronics were fabricated by the impregnation of silicone into a preform comprising randomly oriented C-shaped Cu-Be springs and a small proportion of Sn-Pb solder, which served to connect the springs at some of their intersections. Composites containing 6.1-9.8 vol.% total filler exhibited volume electrical resistivity 0.5-1.0 mΩ.cm and contact resistivity (with copper) 11-17 mΩ.cm². A compressive stress of about 30 kPa was needed for the low contact resistivity to be reached. The volume 17-26% and the contact resistivity increased by 5% after heating in air at 130-150°C for seven days. Composites containing <9 vol.% total filler showed no stress relaxation for seven days at 6.0% strain.     

粉末布法制备SiC/Ti基复合材料

用粉末布法制备了低成本SiC/Ti基复合材料.结果表明,采用合适的轧制参数即可容易地获得厚度合适、均匀的粉末布;热失重分析和热解残余物分析指出用来制备粉末布的有机粘结剂的去除过程分成两个阶段,合理除气后,基本没有残余物.使用真空热压工艺制备的SiC/Ti基复合材料,纤维分布基本均匀,纤维与基体的界面结合良好.     

OFDM系统信道盲估计的一种新算法

利用循环前缀（CP）引入的信息冗余，在利用接受信号的二阶统计特性实现正交频分复用（OFDM）系统信道盲估计的子空间算法基础上，采用矩阵变换的方法，改善信息序列的非周期相关函数，推导出信道估计的新算法。     

Chemical Interactions in Diboride-Reinforced Oxide-Matrix Composites

Thermochemical analyses of interfacial reactions in titanium, zirconium, and hafnium diboride reinforced oxidematrix composites have been carried out to evaluate the chemical compatibility. The chemical reactivity of these diborides with oxygen and the high volatility of B₂O₃( l ) at reduced oxygen pressures are concerns during processing and operating conditions. The thermochemical stability and the vaporization behavior of B₂O₃( l ) are discussed in terms of partial pressures of dominant gaseous species of the boron-oxygen system at 1700 and 2300 K. The TiB₂/ZrO₂ and TiB₂/HfO₂ systems are thermodynamically stable in a limited oxygen pressure range. The TiB₂/Al₂O₃ system is stable, but the reactions in this system may apparently be accompanied by formation of gaseous products (B₂O₃, AlO, Al₂O, and lower boron oxides) in the presence of elemental oxygen. These thermochemical considerations are very useful in evaluating the effectiveness of oxides as diffusion barrier coatings on diboride reinforcements.     

预测控制算法的统一格式及其在电加热炉的应用

本文根据常用的两类预测控制算法推出一种新型预测控制算法。并将其应用于一双输入/双输出的力学持久机电加热炉的温度控制系统上,获得了满意的结果:控温精度为±1.5℃/300℃,且适用于非最小相位系统。     

利用增量矩阵辨识确定型ARMA模型的新算法

本文提出了一种无偏辨识确定型ARMA模型参数及阶次的新方法。和其他辨识算法不同的是在这里我们构造了关于系统开环阶跃响应的增量矩阵,并且通过分析该增量矩阵子矩阵的代数性质而得到了辨识系统阶次的一种简单方法。仿真的结果说明了本文理论的正确性。     

示例学习的扩张矩阵理论

本文提出示例学习的一种计算理论,扩张矩阵论.根据这个理论,示例学习中一些主要最优化问题被证明是NP难题,并给出这些难题的近似解法及下界的估计.     

On the mechanical behavior of aluminum alloys reinforced by long or short alumina fibers or SiC whiskers

This study was initiated to examine the dispersion of longitudinal and transverse waves in metal matrix composites in order to obtain the dynamic elastic modulus and to evaluate various models for predicting the composite's macroscopic elastic constants from the properties of its constituents. The materials chosen for this investigation were alumina continuous fibers on the one hand and alumina and SiC short fibers on the other hand, all embedded in an aluminum alloy matrix. In addition, some indications have been obtained experimentally for the acoustoelastic effect in the composite.     

点阵汉字无级变倍算法

本文给出了由一种汉字字库得到任意大小汉字点阵的算法.该算法能对任意二值点阵图像进行放大平滑.简单放大是按字节进行运算,速度快;最佳平滑操作不是对简单放大后的点阵按位操作,而是根据原点阵的特性,在需要平滑的地方进行操作,需操作的位数不会超过图像总点数的5％.用该方法输出的汉字质量和速度都令人满意.     

Onr-partition designs in hamming spaces

The concept of the combinatorial matrix of an unrestricted code and the notion of anr-partition design admitted by a code are introduced and discussed in detail. The theory includes a characterization of completely regular codes, and a combinatorial interpretation of the fact that the distinct rows of the distance distribution matrix of a code are linearly independent. In general, it is possible to compute the distance distribution matrix of any code admitting a given partition design by solving a well-defined system of linear equations; this is an efficient technique provided the number of classes in the partition is relatively small.