抑制CATV系统重影干扰的实践

本文仅从实践的角度探讨分析影响图像质量的三种因素,并提出了一些具体的抑制方法。     

激光二极管自混合干涉和微振动的实验观测

介绍了利用LabView软件虚拟示波器和信号源,对激光二极管自混合干涉和微振动进行的实验观测.该实验可以作为本科低年级学生的综合设计实验.     

IPA模型对Hopfield模型神经网络的改进

考虑Ｈｏｐｆｉｅｌｄ模型中假态之间的布尔逻辑关系，提出利用ＩＰＡ模型对神经网络中的假态进行抑制，并和原网络的性能进行了比较，结果表明：改进后的网络性能比Ｈｏｐｆｉｅｌｄ模型和ＩＰＡ模型均有较大提高。     

Modulation of Particle Concentrations in the Interference Laser Radiation Field

Spatial redistribution of microparticles in a suspension on exposure to the interference laser field depending on the parameters of the particles and the field characteristics has been analyzed theoretically. Results of experimental investigations are presented that illustrate the capture of an ensemble of polymeric small spheres and also of the lymphocytes of human blood and other microparticles in a liquid in the interference radiation bands of the He–Ne laser.     

Transmit Diversity Schemes for WCDMA

Previous work on transmitter antenna diversity has shown that the use of multiple transmitter antennas at the base station results in improved performance due to increase of diversity (path diversity). This happens with no bandwidth cost, even when the signal quality along several paths is poor, but the receiver estimates the channel with accuracy. This paper evaluates the effects of channel estimation errors in the performance of the schemes designated as Space-Time Transmitter Diversity (STTD) and Selective Transmitter Diversity (STD). We consider low to medium signal to noise ratios characteristic of Wideband Code Division Multiple Access (WCDMA) networks. Different fading channel models are considered for comparison between the two schemes. The improvement due to convolutional coding associated with these techniques is also evaluated.     

激光探针监测半导体器件内自由载流子浓度调制效应

介绍了基于自由载流子对介质折射率调制作用,而建立的监测半导体器件内自由载流子变化情况的实验装置,该装置能实时反映自由载流子变化情况,且对原电路无任何影响。本方法适用于硅和砷化镓材料的电子和光电子器件,也显示了在测量集成电路内部有源器件特性方面的潜在应用前景。     

带有块间串扰MC-CDMA的时域信道估计和多用户检测

本文把带有IBI的MC-CDMA系统等效解释为特殊的直接序列码分多址（DS-CDMA）系统，并给出了相应的时域信道估计方法和时域线性最小均方误差（MMSE）多用户检测方法。仿真实验表明了本文方法的性能。     

基于偏振光干涉仪的Interleaver解复用器实验研究

为实现更窄信道间隔的密集波分复用 ,提出了一种基于偏振光干涉仪的新型Interleaver解复用器 ,分析了结构组成与基本工作原理 ,对其进行了初步的测试实验 ,该器件所分开的DWDM系统两组波长功率均衡 ,隔离度分别为 1 0 6dB和 1 4 6 4dB ,- 1dB带宽分别为 0 7nm和 0 4nm。     

Phenol biosensor based on electrochemically controlled integration of tyrosinase in a redox polymer

An amperometric biosensor for the detection of phenolic compounds was developed based on the immobilization of tyrosinase within an Os-complex functionalized electrodeposition polymer. Integration of tyrosinase within the redox polymer assures efficient catechol recycling between the enzyme and the polymer bound redox sites. The non-manual immobilization procedure improves the reproducibility of fabrication process, greatly reduces the desorption of the enzyme from the immobilization layer, and, most importantly prevents fast inactivation of the enzyme by its substrate due to fast redox cycling. A two-layer sensor architecture was developed involving ascorbic acid oxidase entrapped within an electrodeposition polymer in a second layer on top of the redox polymer/tyrosinase layer. Using this sensor architecture it was possible to eliminate the current interference arising from direct ascorbate oxidation up to a concentration of 630 μM ascorbic acid. The effects of the polymer thickness, the enzyme/polymer ratio, and the applied potential were evaluated with respect to optimal sensor properties. The sensitivity of the optimized sensors for catechol was 6.1 nA μM⁻¹ with a detection limit of 10 nM, and for phenol 0.15 nA μM⁻¹ with a detection limit of 100 nM.     

电子镇流器的电磁兼容问题研究

电磁兼容是目前电子镇流器最需要解决的问题之一。介绍了电子镇流器产生的辐射干扰、传导干扰及电流谐波畸变干扰的形成和所造成的影响,分析了产生这些干扰的原因,并分别给出了抑制这些干扰的方法,最后就电子镇流器设计制造中的难点问题作了简要说明。