脉冲Nd:YAG激光蚀刻牙齿硬组织的临床研究

目的:观察脉冲Nd:YAG激光蚀刻牙硬组织后增加与复合树脂结合力的临床效果方法:观察组采用脉冲Nd:YAG激光照射窝洞后进行光固化治疗,对照组以常规酸处理后光固化治疗。结果:观察组115个牙齿成功105,有效6个,失败4个;对照组成功76,有效21,失败18个。两组间有非常显著性差异(P<0.01)。结论:脉冲Nd:YAG激光代替酸处理蚀剂牙硬组织进行光固化治疗上一种可行的方法。     

厄米-高斯型短脉冲在光纤中传输的理论研究

从含高阶色散的非线性薛定谔方程出发 ,用矩法研究了厄米 高斯型短脉冲在光纤中的传输 ,获得了脉冲各参量在光纤中演化的耦合微分方程组 ,再利用龙格 库塔法得到此微分方程组的解 ,并与数值模拟进行了比较 ,两者吻合较好。     

光电双向负阻晶体管的研制及特性分析

首次对双向负阻晶体管(BNRT)进行了光敏化,设计并研制出既有光敏特性又有“S”型负阻特性的一种新型光电开关器件——光电双向负阻晶体管(PBNRT)。介绍了器件的设计和研制过程;测量分析了其J—V特性与光强和栅极电压的关系;测量了光电开关的时间常数并进行了分析讨论。     

基于修正素数码的双OHL同步OCDMA性能分析

基于单硬限幅器(OHL)的同步光码分多址 (OCDMA) 系统不能完全消除信道串扰,引入了双OHL结构来优化系统传输性能.文章给出地址码的码重、光谱强度、用户数与误码率及同异步系统归一化吞吐量间的关系,结果表明:在用户数与地址码重相差较大的情况下,双OHL同步OCDMA系统误码率下降明显且比异步系统的归一化吞吐量大.     

Performance analysis of cooperative spatial multiplexing networks with AF/DF relaying and linear receiver over Rayleigh fading channels

Cooperative spatial multiplexing (CSM) system has played an important role in wireless networks by offering a substantial improvement in multiplexing gain compared with its cooperative diversity counterpart. However, there is a limited number of research works that consider the performance of CSM systems. As such, in this paper, we have derived exact performance of CSM with amplify‐and‐forward and decode‐and‐forward relays in terms of outage capacity and ergodic capacity. We have shown that CSM systems yield a unity diversity order regardless of the number of antennas at the destination and the number of relays in the networks, which is the direct result of diversity and multiplexing gain trade‐off. Our analytical expressions are corroborated by Monte‐Carlo simulations. Copyright © 2013 John Wiley & Sons, Ltd.     

热敏打印机与高速数字处理器DSP的接口应用

分析了仪器仪表领域的发展趋势，详细介绍了微型热敏打印机的工作原理及应用。给出了热敏打印机同DSP的简单接口方法以及相应的打印机初始化程序。     

ESM系统与低截获概率雷达之争

阐述了低截获概率(LPI)雷达和ESM系统截获接收机的现状,讨论了ESM系统如何增加灵敏度和截获距离,以及如何采取措施使得ESM系统对雷达信号的截获更加困难。结论为任何一方都不可能长期占有优势。     

实现小波变换图像识别的光电混合实验系统

本文依据联合变换相关器,设计一套实现小波变换图像识别的光电混合实验系统,联合变换功率谱及相关输出强度分布分别用CCD采集并输入计算机进行处理,证明小波变换可以明显改善光学图像相关识别能力;同时,该系统提高了光学相关识别实验的灵活性和可操作性。     

Discrimination of Smoke Particles Using Infrared Photoelectrical Detection

A method of discrimination of smoke particles using infrared photoelectrical detection is proposed in this paper. Principle of the method is that smoke particles of different materials have different scattering light intensities at same scattering angle according to Mie Theory. Facility used to realize the method includes an infrared laser as light source and an array of avalanche photodiodes distributed at assigned angles as sensing devices. Scattered light signal at these angles are collected and processed. Categories of smoke particle are discriminated by signal processing results. Experiments show that by using this method cigarette smoke, kerosene smoke and water vapor can be discriminated with rate of discrimination of greater than 95%. Application of this technology in the field of fire detection will eliminate some effects of human activities such as cigarette smoking and steam on smoke detection, and improve sensitivity as well as reliability of smoke detection.     

光通信系统中偏振模色散克服技术

由于光通信系统的速率不断提升 ,克服偏振模色散已成为高速光通信系统中急需解决的问题。现仅对国内外现有的偏振模色散克服技术作一回顾和分析