Frame size adaptation for indoor wireless networks

An optimal frame size predictor for indoor wireless networks is proposed and studied. Kalman filtering is employed to predict the optimal frame size in order to obtain a guaranteed channel utilisation. Through simulation, it is shown that the proposed algorithm can substantially lower the estimation error     

On a multivariable extension of Jacobi matrix polynomials

The classical Jacobi matrix polynomials only for commutative matrices were first studied by Defez et al. [E. Defez, L. Jódar, A. Law. Jacobi matrix differential equation, polynomial solutions and their properties, Comput. Math. Appl. 48 (2004) 789–803]. The main aim of this paper is to construct a multivariable extension with the help of the classical Jacobi matrix polynomials (JMPs). Generating matrix functions and recurrence relations satisfied by these multivariable matrix polynomials are derived. Furthermore, general families of multilinear and multilateral generating matrix functions are obtained and their applications are presented.     

OPGW温升上限的确定及其测量

影响OPGW温升上限的因素较多，本文简要分析了这些因素，并介绍了几种OPGW短路电流和温升的测量方法。     

砒砂岩地区沟道植物"柔性坝"拦沙试验

通过对原型和室内模型试验资料的分析，证明了在黄土高原砒砂岩地区的支毛沟中，垂直于水流方向种植沙棘灌木植物作为拦沙的坝型框架材料是可行的，其机理在于利用植物干、枝、叶的分流、阻滞性能，分散了沟通集中的股流，降低了水流对沟床的剪切应力，拦截了洪水挟带的大量粗沙，形成了植物“柔性坝”，同时又根据原型和室内试验资料得出的物理图形，初步建立了植物拦沙的理论架构。     

对当前监理工作的认识

对当前监理工作存在的问题进行了分析,指出了监理工作的主要任务、监理单位的权利及当前监理工作应解决的问题。     

电站柴油机双机并联调速系统的仿真研究

建立了电站柴油机双机并联调速系统的模型 ,对柴油机的调速控制、负荷前馈控制、负荷均衡控制进行了 MATL AB仿真研究。结果表明 :采用负荷前馈控制可明显提高柴油机电子调速器的调速性能 ,引入负荷均衡控制后 ,可以在零稳态调速率条件下实现双机之间的负荷均匀分配     

LB单分子膜中电荷密度的确定

本文介绍了一种新的测定单层LB膜中电荷密度的C-V方法,解决了常规C-V方法的不精确问题。通过对硬脂酸C20H40O2膜中电荷密度的测定,表明此方法实用可行。     

基于傅立叶变换的岩屑纹理特征提取及岩性识别方法研究

针对在PDC钻头条件下石油录井过程中的岩屑岩性难以用肉眼识别,以及人工分类速度较慢的问题,该文利用傅立叶周向谱能量法原理,将岩屑图像在频域中按照频率由低到高对周向谱能量进行分级,将各级能量占总能量的比率作为该图像的特征量,然后应用Bayes分类器对其进行分类处理,将所得结果与人工分类结果做比较,并验证了方法的可靠性。实验证明,这种方法能更好的分析岩屑的岩性,对泥岩的分类准确率高达99.44%。     

Continuous carbon nanotube reinforced composites

Carbon nanotubes are considered short fibers, and polymer composites with nanotube fillers are always analogues of random, short fiber composites. The real structural carbon fiber composites, on the other hand, always contain carbon fiber reinforcements where fibers run continuously through the composite matrix. With the recent optimization in aligned nanotube growth, samples of nanotubes in macroscopic lengths have become available, and this allows the creation of composites that are similar to the continuous fiber composites with individual nanotubes running continuously through the composite body. This allows the proper utilization of the extreme high modulus and strength predicted for nanotubes in structural composites. Here, we fabricate such continuous nanotube polymer composites with continuous nanotube reinforcements and report that under compressive loadings, the nanotube composites can generate more than an order of magnitude improvement in the longitudinal modulus (up to 3,300%) as well as damping capability (up to 2,100%). It is also observed that composites with a random distribution of nanotubes of same length and similar filler fraction provide three times less effective reinforcement in composites.