有线电视双向网接入技术方案分析比较

本文通过搭建网络模型,对当前主流有线电视双向网用户接入技术"EPON+EOC和CMTS"进行简要分析,并对两种接入技术方案投资、带宽进行比较。     

Passively Q -switched Ytterbium-Doped Double-Clad Fiber Laser With a Cr4+:YAG Saturable Absorber

A high-power and high-repetition-rate passively Q -switched ytterbium-doped single-mode double-clad fiber laser was built using a Cr⁴⁺:YAG saturable absorber (SA). Two different SAs with initial transmissions of T_omicron = 30% and T_omicron = 50% were studied. At the maximum coupled pump power of 9.8 W, an output power of 4.7 W, pulse duration of 143 ns, pulse repetition rate of 253 KHz, pulse energy of 18.5 muJ, and slope efficiency of 49% were obtained with the T_omicron = 30% SA.     

火控雷达认知抗干扰技术研究

认知雷达技术通过对周围环境的学习,实时调整雷达的工作参数,最优化雷达在特定场景下的工作性能,发挥雷达最大性能。火控雷达认知抗干扰技术是一种基于认知技术的雷达抗干扰设计方法,将认知技术融入火控雷达设计中。 文中针对火控雷达面临的复合干扰特别是主瓣干扰威胁问题,研究火控雷达认知抗干扰技术,智能化调整火控雷达工作参数,选择工作频率,优化发射波形,有效提升火控雷达抗干扰的能力。     

Observation of whispering-gallery mode splitting in spherical resonator

We report the observation of the splitting of whispering-gallery mode in the silica spherical resonator. To characterize the fused-silica spherical resonator,an evanescent fiber taper coupling technique is employed. The coupling system consists of a fiber taper with a diameter of about 2.8 microns and a fused-silica spherical resonator with a diameter of about 143 microns. By injecting the laser power into the fiber taper,a number of narrow absorption peaks with equal peak spacing of 3.7 nm are observed in a wide spectral range. After replacing the resonator by the other one with the shape being slightly modified,whispering-gallery mode splitting in the spherical resonator is observed. The wavelength spacing between adja-cent peaks is 0.32 nm,much smaller than that of the previous one.     

基于CPLD的LCD显示缓冲驱动器设计

DSP具有较高的数字信号处理速度,为电机及其他运动控制领域的应用提供了性能优异的设计平台,通常一个完整的控制方案需要利用液晶屏输出显示各种控制参数,这种传统的慢速设备往往与DSP的高速处理能力及实时控制的要求产生矛盾,文章介绍了一种利用复杂可编程逻辑器件CPLD设计的显示缓冲驱动器,解决了DSP芯片的高速运算能力与LCD液晶显示模块显示速度较低这一矛盾的有效方法,同一行字符,通过该缓冲驱动器控制LCD显示比直接用DSP控制LCD显示节省至少9 ms,降低了DSP耗费在LCD上的等待时间,提高了DSP的效率,优化了系统。     

基于免疫算法的空战目标分配

目标分配是现代空战系统对抗中要首先面对的问题,它是一个组合优化问题.首先用优势函数来表明敌我态势,建立机群对抗优势函数矩阵.然后将一种新型的启发式算法--免疫算法用于解决目标分配问题.免疫算法具有很好的全局搜索能力和收敛性,能够很好地解决这类问题,实例也证明了该方法是可行和有效的.     

瞬态激光全息干涉计量与测试设备的研制与开发

文中论述了瞬态激光全息干涉计量的基本理论和在工程测量时需要解决的关键技术;简要地介绍了几种瞬态激光全息干涉计量的应用实例,对新近研制、开发的瞬态激光全息干涉计量的测试设备作了详细介绍。文音共分四部分：1）离轴光全息的物理过程和简要数学描述;2）瞬态激光全息干涉计量的关键技术;3）介绍几种典型的测试设备;4）讨论。     

An Inter-domain Routing and Signaling Scheme for Optical Mesh Networks

An inter-domain routing and signaling scheme based on the OBGP protocol for WDM networks with a mesh topology is proposed in the paper. For mesh networks with wavelength conversion, inter-domain routing and signaling are realized by introducing a new message based on an optimal path identifier (OPI) and by establishing the corresponding message-exchange procedures. Considering the wavelength continuity constraint, a strategy called improved destination wavelength assignment (IDWA) combined with the OPI-based message is presented to establish a lightpath dynamically. The scheme is verified on the NSFNET and the CERNET by simulation. Results show that the blocking performance of a non-wavelength-conversion network is even a little lower than that of a wavelength-conversion network.     

利用40kVA移动油机对交换机供电的解决方案

本文介绍了市电停电后主用油机故障,临时将40kVA移动发电机接到交流供电系统,向重要负荷(交换机)供电,利用这种方式进行实验,得出在应急情况下的解决方案.