固体力学有限元体系的结构拓扑变化理论

本文是文[1]的继续.文[1]提出了杆件系统的结构拓扑变化理论和拓扑变化法本文将这一理论和方法推进到连续体有限元体系;且在此基础上揭示出有限元体系的一个新性质,称为基本位移之梯度的正交性定理,从而给出一套设计敏度的显式表达式,可直接用于计算.     

A simple method improving the analyzing accuracy of circular groove guide

A simple method is introduced to improve the analysing accuracy of circular groove guide. With this method, the characteristic equation of circular groove guide is derived and its solution is given and discussed.The Project Supported by National Natural Science Foundation of P.R.China     

COATES GRAPH APPROACH FOR GENERATING SYMBOLIC NETWORK FUNCTION

In this paper, symbolic code matrix ,constant matrix and count matrix are defined .The first twomatrices are used to describe the elemental expression of augmented matrix and the nede admittance equa-tion is thus obtained. The third matrix is used to obtain the incoming degree matrix, and according to thematrix all the 1- factors of the Coates graph are given. By using the data code, the determinant is expandedand the same items in the expansion are merged. Thus the symbolic network function in which no term can-cellation occurs is generated.     

Scanning tunnelling microscope studies of growth of RuO2（110） thin layer on Ru（0001）

This paper reports that the growth of RuO_x(110) thin layer growth on Ru(0001) has been investigated by means of scanning tunnelling microscope (STM). The STM images showed a domain structure with three rotational domains of RuO_x(110) rotated by an angle of 120℃. The as-grown RuO_x(110) thin layer is expanded from the bulk-truncated RuO_x(110) due to the large mismatch between RuO_x(110) and the Ru(0001) substrate. The results also indicate that growth of RuO_x(110) thin layer on the Ru(0001) substrate by oxidation tends first to formation of the Ru-O (oxygen) chains in the [001] direction of RuO_x(110).     

DS1620实现的X射线采集板温度自动控制

DR是目前非常先进的X射线成像技术，将其X射线采集板工作温度控制在最佳工作范围可采集更好的图像。本系统采用PC和单独控制双模块分别控制温度，利用半导体传感器DS1620进行四路温度采集，通过单片机和PC串口通信，用PC通过半导体制冷芯片来控制X射线采集板的工作温度，在通信故障时也可以通过单独控制模块来控制采集板的温度。     

基于多传感器数据融合方法的火灾模拟实验炉温度采集系统

基于多传感器算术平均值与分批估计的数据融合方法在火灾模拟实验炉上温度数据采集中的应用，用VB6．0开发了相应的实际应用系统。     

一种高效的硬布线控制CPU的设计方法

文章提出了一种硬布线逻辑CPU的设计流程，即以CPU设计工具软件LDF为核心的设计方法，其主要目的的提高硬布线逻辑CPU的设计效率。定义了一种用于描述硬布线控制逻辑的语言-MCDL，对总线优化问题进行了研究，并且给出了解决总线优化问题的近似算法。     

LDPC-based space-time coded OFDM systems over correlated fadingchannels: Performance analysis and receiver design

We consider a space-time coded (STC) orthogonal frequency-division multiplexing (OFDM) system with multiple transmitter and receiver antennas over correlated frequency- and time-selective fading channels. It is shown that the product of the time-selectivity order and the frequency-selectivity order is a key parameter to characterize the outage capacity of the correlated fading channel. It is also observed that STCs with large effective lengths and ideal built-in interleavers are more effective in exploiting the natural diversity in multiple-antenna correlated fading channels. We then propose a low-density parity-check (LDPC)-code-based STC-OFDM system. Compared with the conventional space-time trellis code (STTC), the LDPC-based STC can significantly improve the system performance by exploiting both the spatial diversity and the selective-fading diversity in wireless channels. Compared with the previously proposed turbo-code-based STC scheme, LDPC-based STC exhibits lower receiver complexity and more flexible scalability. We also consider receiver design for LDPC-based STC-OFDM systems in unknown fast fading channels and propose a novel turbo receiver employing a maximum a posteriori expectation-maximization (MAP-EM) demodulator and a soft LDPC decoder, which can significantly reduce the error floor in fast fading channels with a modest computational complexity. With such a turbo receiver, the proposed LDPC-based STC-OFDM system is a promising solution to highly efficient data transmission over selective-fading mobile wireless channels     

分布式光纤喇曼放大技术及其在WDM系统中的应用

介绍了分布式光纤喇曼放大技术的原理、特点和应用 ,并从受此影响的 WDM传输系统的信噪比、噪声指数和品质因数三个方面讨论了光纤喇曼放大技术在提升光纤通信系统性能方面的重要作用。     

对位酚类衍生物作为化学发光分析的增强剂研究

在化学发光分析中，常常要用到碱性条件下鲁米诺与过氧化氢的反应系统，通过催化剂辣根过氧化物酶使反应顺利进行。如果再加入适当的增强剂，则灵敏度提高且发光时间延长，可改善测定的重现性。实验证明，对位酚类衍生物，如：对叔丁基苯酚，对甲苯酚的发光增强作用明显，其发光效率可上升几十倍，发光时间也获得有效延长。