磁控溅射法制备AZO薄膜的工艺研究

用XRD测试仪、分光光度计、四探针等测试仪器,探讨了制备气氛、退火温度和退火环境对AZO薄膜光电性能及结构的影响。结果表明:氧气和氩气的体积流量比为2∶1时,薄膜透光率最高(95.33%);退火有利于薄膜结晶;低于400℃退火时,温度越高薄膜电阻越小,超过400℃后,真空中退火温度再升高电阻变化不大,而空气中退火温度再升高电阻反而变大。     

基于有线电视网和IP网的视频会议系统设计与实现

设计并实现了一种结合有线电视网和IP网的视频会议系统.该系统以会议服务器为中心单元,协调各会场间的数据流和控制流传递,利用双向IP网,实现会议服务器和各会场间的会议控制等交互操作,以及上传各会场的音视频至会议服务器.它基于多播协议,利用有线电视网稳定可靠的高速下行带宽,将上载的音视频高质量地传送至各会场.     

SIPv6 analyzer: an analysis tool for 3GPP IMS services

The 3rd Generation Partnership Project (3GPP) defines IP Multimedia Core Network Subsystem (IMS) to support IP‐based multimedia services. IMS utilizes protocols such as IP version 6 (IPv6), Session Initiation Protocol (SIP), and Real‐time Transport Protocol (RTP) to deliver the multimedia content. This paper proposes an analysis tool referred to as SIPv6 Analyzer to investigate the IMS‐related protocols during IMS service deployment. The SIPv6 Analyzer not only dissects the protocol headers but also provides user‐friendly functions such as message flow generation and audio/video replay for IPv6, SIP, and RTP. We describe the design of the SIPv6 Analyzer and use examples to illustrate how it works. Copyright © 2006 John Wiley & Sons, Ltd.     

基于3G无线网络的视频监控系统前端设计

介绍了一种以ARM926-EJS微处理器为主控制器、Linux为操作系统、WCDMA网络为传输网络的视频监控系统前端。给出了视频监控系统前端的硬件设计、软件设计。重点介绍了视频采集、压缩编码、无线发送过程。将视频监控系统前端输出的H.264视频流封装成大小合适的RTP数据包,然后通过IEEE 802.11g无线传输模块发送到3G传输网络。经实验证明,该系统具有较好的实时性和可靠性,在抢险救灾等领域得到了较广泛的应用。     

Observation and characterization of near-interface oxide traps in 3C-SiC MOS structures by quasi-static I-V method

The electrical properties of oxides grown on 3C-SiC by rapid thermal processing in various oxidizing and annealing atmospheres are investigated using a quasi-static method. According to the anomalous capacitance hump, the existence of two types of traps, interface and near interface oxide traps, is observed in quasi-static. By monitoring the sweep-rate measurement of the quasi-static current related to electron tunneling from interface traps to near-interface oxide traps, a profile of the traps in response time can be obtained. Based on the extracted parameters of the carrier traps, we demonstrate that the near SiO₂/3C-SiC interface is significantly improved when using 100% N₂O compared to 100% O₂ or even N₂-O₂ dilution as oxidizing gas. Also, we show that incorporating N₂ during the oxidation in O₂ is not favourable for the reduction of the near-interface oxide traps.     

678 nm RTP electro-optical Q-switched ceramic laser

The RTP electro-optical Q-switched ceramic laser at the wavelength of 678 nm with narrow pulse width is studied. We used the laser diode arrays side-pumped Nd:YAG ceramic crystal with 1.1 at% Nd doping and dimensions of Φ3 mm × 50 mm, designed folding cavity parameters, and discussed the variation of the beam radius in the ceramic crystal and frequency doubling crystal with the thermal focal length of ceramic crystal or KTP crystal. By using double RTP crystals as electro-optic Q-switch and KTP crystal type II phase matching for intracavity frequency-doubling, a narrow pulse width electro-optical Q-switched Nd:YAG ceramic laser was obtained. The output energy of 0.9 mJ and the pulse width of 41.6 ns at 678 nm are obtained at the repetition rate of 1000 Hz and pumped power of 144 W. The results formed the basis for the further development of the high power and high efficiency ceramic red laser.     

LD抽运腔内和频571.6 nm连续波黄光激光器

报道了全固态连续波571.6 nm黄光激光器.黄激光是分别由两片Nd∶YAG的1 444 nm和946 nm谱线非线性和频产生,两条谱线在各自晶体对应能级跃迁分别为4F3/2-4I15/2和4F3/2-4I9/2.实验中采用复合腔结构,利用RTP晶体II类临界相位进行内腔和频,当注入到两片Nd∶YAG晶体的抽运功率分别为25 W和14.8 W时,获得562 mW的连续波571.6 nm黄激光输出,4 h功率稳定度优于±2.9％.     

基于流媒体技术的移动视频服务器的设计

针对3G无线互联网技术的迅猛发展和人们生活、工作中对手机实时视频的需求,应用MPEG-4视频编码标准和RTP/RTCP流媒体传输协议为基础,设计了一个流媒体传输的解决方案的移动实时视频服务器,服务器完成了对实时视频数据的采集和压缩,对实时源Filter传输和处理过程和服务器与客户端RTP/RTCP通信过程,实现服务器视频实时传输的编码设计和对视频传输的测试.     

RoIP关键技术及其应用研究

主要介绍了RoIP关键技术及其应用,通过回顾RoIP的发展现状,了解RoIP的技术优势,分析其技术原理与关键技术组成,最后指出其应用场合,为构建低成本、全覆盖的无线电台通信网络提供了思路。     

快速热处理对PECVD氮化硅薄膜性能的影响

利用PECVD在硅片上沉积了氮化硅(SiNx)薄膜,将沉积膜后的样品放在N2气氛中进行快速热处理(RTP),研究了不同快速热处理对PECVD氮化硅薄膜件能的影响.采用原子力显微镜(AFM)检测薄膜的表面形貌,利用椭圆偏振仪测量样品膜厚和折射率,利用准稳态光电导衰减法(QSSPCD)测鼋样品的少子寿命.实验结果表明随着RTP温度的升高,薄膜厚度迅速减小,折射率迅速增大;低于500℃热处理时,少子寿命基本不变;高于500℃热处理时,随着温度的升高,少子寿命急剧下降.氮化硅薄膜经热处理后反射率基本不变.