一种估计TSD信道的扩展时间的方法

复本相关器，复本相关积累器和分段复本相关器分别是理想信道，时间扩展信道和频率扩展信道的最佳似然比检测器。针对实际中信道扩展时间未知的问题，提出了一种简单的，易操作的估计目标回波时间扩展长度的方法，解决了复本相关积累器的严重失配问题，最后对该方法进行了仿真计算，表明该估计方法是可行的。     

用DSC法研究潜伏性二酰肼固化环氧粉末涂料

用ＤＳＣ法研究了以潜伏性二酰肼为固化剂的环氧粉末涂料的固化行为，探讨了固化剂用量与固化度、固化温度与固化时间的关系，对固化工艺条件进行了选择。     

基于PSO改进的OTSU图像分割方法

阈值的选取对图像分割后的效果起着至关重要的作用,本文针对图像分割过程中阈值选取的问题,提出了一种基于PSO优化的改进OTSU图像分割算法.该算法以最大类间方差作为PSO算法适应度函数,以当前分割阈值组合作为粒子的当前位置,阈值更新速度作为粒子的当前速度.通过迭代计算更新粒子位置和速度,最后确定图像分割的最佳阈值.与传统OTSU图像分割算法及基本遗传算法图像分割算法相比,该算法稳定性更好,算法效率更高.     

液相共沉淀法合成浸渍阴极用Ba5CaAl4O12

Ba5CaAl4O12是浸渍阴极电子发射最主要的活性物质。采用液相共沉淀法，通过调节共沉淀反应的金属盐溶液浓度、溶液的pH、沉淀剂的加入方式及洗涤方式，制备出分散良好的超细碳酸钡、碳酸钙、氢氧化铝的混合前驱体粉末，经1200℃煅烧2h，得到超细粉末。采用XRD，SEM分析产物粉末的物相组成、颗粒形貌，结果表明产物为具有Ba5CaAl4O12结构的结晶颗粒，粒径在0．2～0.5μm。     

广义的自适应相干累积算法

根据最小均方误差(LMS)算法、自适应相干累积(ACI)算法及推广的自适应相干累积(GACI)算法在原理上的相关性和推广关系，提出了广义的自适应相干累积(IGACI)算法。它是在GACI的基础上，在算法的权系数迭代公式中引入更多的动量因子，即利用权系数的更多的历史信息，使被检测的单频或调频脉冲信号，在脉冲期间，实现自适应相干累积，从而完成低输入信噪比条件下的信号检测，而无需或很少需要知道信号的先验信息。理论分析和仿真结果证明在低信噪比的情况下，其性能要优于GACI算法。     

基于高阶累积量的自适应IIR线谱增强器

将四阶累积量的递推算法推广到求正弦信号的四阶混合累积量，并提出了一种基于四阶混合累积量切片的自适应IIR结构的线谱增强器算法。该线谱增强器通过自适应前向线性预测法求得滤波器的系数，从而使带噪信号的线谱成份得到增强。仿真结果表明，在平稳或非平稳输入信号情况下，该算法从色噪声中提取正弦信号的能力优于基于二阶自相关函数的自适应IIR线谱增强器。     

A fast algorithm forn-D discrete cosine transform

A generalized fast computational algorithm for then-dimensional discrete cosine transform (n-D DCT) of lengthN=2 ^m (m≥2) is presented. The developed algorithm is theoretically proved and its efficiency is evaluated. The theoretical results show that compared with the conventional method to compute the 1-D DCTs inn directions, the number of multiplications needed by this algorithm is only 1/n of that required by the conventional method; for the total number of additions, it is a bit more whenN≤8 and much less whenN≥16 than the coventional one. To validate the proposed algorithm, the case whenn=3 is taken as an example and applied to the motion picture compression. The results show that the proposed method is superior to MPEG-2. Project supported by the Climbing Programme—National Key Project for Fundamental Research in China.     

Blind separation of slow waves and spikes from gastrointestinalmyoelectrical recordings

Myoelectrical recordings of the gut contain slow waves (slow rhythmicity) and spikes (fast rhythmicity). While the slow wave determines the frequency and propagation of gastrointestinal contractions, spike activities are directly associated with the contractions. Traditionally, spikes are extracted from the myoelectrical recording using high-pass/bandpass filters. Due to the sharp rising edge (high-frequency component) of the slow wave, the conventional method is not accurate in the separation of the slow wave and spikes, although it has been used for years. In this paper, a novel and fast blind source separation algorithm is developed. Experimental results show that the proposed method was able to accurately extract spike activities from the myoelectrical recordings obtained in dogs and that its performance was not affected by the high-frequency components of the slow wave     

地名和宅名标志牌的探寻

中国的地名、宅名标志牌的历史悠久。早在远古时代，人们上山打猎就知道在树干、石头上刻上标记，以提示回来的路线。随着社会生产的发展，人们告别了石器时代，进入青铜器时代，……，现又进入电子时代。经济与技术的发展促进了地名、宅名标志牌的不断发展，其品种日益增多，制作更加精美。无论在帝王时代还是在现代社会，地名、宅名标志牌不只是传统意义上的指示、装饰标牌，