低差错平底特性的非规则LDPC码的设计

介绍了非规则LDPC码的发展并给出了其优势及缺点，重点论述用ACE算法来构造非规则LDPC码从而降低其差错平底特性。对降低非规则LDPC码的差错平底特性的其它方法提出了展望。     

Properties of high reinforcement-content aluminum matrix composite for electronic packages

Aluminum matrix composites reinforced by a high volume fraction of ceramic particles provide a novel solution to electronic packaging technology, because of their high thermal conductivity, compatible and tailorable coefficient of thermal expansion (CTE) with chips or substrates, low weight, enhanced specific stiffness, and low cost. In this paper, SiC-particle-reinforced aluminum matrix composites are fabricated by the cost-effective squeeze-casting technology, and their microstructure characteristics, thermo-physical, and mechanical properties are investigated. The reinforcement volume fraction is as high as 70% and composites with linear CTE of 6.9–9.7×10^–6 °C^–1 and thermal conductivity of 120–170 W m^–1 °C^–1 are produced. The composites can be electric-discharge machined, ground, and electric-spark drilled. An electroless nickel layer is plated on the composite by the conventional procedures. Finally, their potential applications in electronic packaging and thermal management are illustrated via prototype examples.     

防腐蚀涂料的性能与选择

介绍并比较几种常用的防腐蚀涂料的品种、组成和性能特点，提出防腐蚀涂料的选择原则。     

一种单片机控制的指令转换器的设计

采用89C51单片机，串口扩展芯片8251、中断扩展芯片8259等器件设计了一种指令格式转换器。     

共面波导有限金属厚度效应的研究

用保角变换法对共面波导金属厚度效应进行了理论分析，编制了相应的计算机程序，给出了数值解，并对此进行了多元曲线拟合，导出了考虑金属厚度后的形状比k、有效介电常数、特征阻抗、损耗的闭定表达式。用此修正表达式求得特征阻抗及损耗的数值解，并与K．C．格普塔的修正值及实验测量值进行了详细比较，结果表明此修正公式与实验值相符较好。     

激光抛光技术的发展与展望

介绍激光抛光技术的发展历史,阐明激光抛光的应用现状及未来的发展前景,论述了激光抛光的工艺特点和作用机理,将激光抛光技术与其它抛光技术进行了全面的对比,指出激光抛光的优势及其存在的问题。     

Control of stroma-dependent hematopoiesis by basic fibroblast growth factor: stromal phenotypic plasticity and modified myelopoietic functions

The immunological agglutination reactions of physically absorbed F(ab')2 molecules onto anionic and cationic latex particles have been investigated by means of optical absorbance measurements. These measurements have been conducted under different conditions to determine the most influential factors. Surface F(ab')2 and BSA densities, particle concentration in the reaction medium and polyethylene glycol concentration are some of these factors. Sensitized cationic and anionic latexes differ considerably with respect to their colloidal stability and reactivity. As a general rule, the sensitized cationic latex has a relatively higher colloidal stability and hence, it provides reagents with a better optical response. Less than 0.025 microgram/ml of C-reactive protein has been detected using this particle enhanced optical immunoassay.     

THE STATISTICAL DISTRIBUTION OF EXTREME VALUES OF WAVE-CURRENT FORCES ACTING ON SLENDER CIRCULAR CYLINDER IN IRREGULAR WAVES

Based on model test,the statistical distribution of extreme values of wave-current in-line forces acting on vertical circular cylinder is analyzed in this paper.It is shownthat the results calculated by the simplified method,proposed by authors,agree well with the testdata;Weibull distribution is also adoptable in the region of high KC number, and the shapeparameter a and scale parameter β are related well with KC number respectively.     

广东省智能网工程建设

本文介绍了广东省智能网的组网方案及所能提供的业务,并论述了智能网工程建设,安装维护以及与广东省现有移动通信网联网中存在的一些问题。     

Applications of a super element model for non-linear analysis of stiffened box structures

Numerical investigations are carried out to verify the new super element model developed in Reference 1 for non-linear analysis of stiffened box structures. The results presented here are obtained from a variety of examples which are chosen to illustrate the accuracy and convergence of the model in various applications. Good agreement is obtained for most of the problems considered and the present formulation is found to be accurate and economical for preliminary engineering design.