ASON 中RSVP-TE可靠性和生存性机制研究

基于流量工程扩展的资源预留协议(RSVP-TE)作为自动交换光网络(ASON)中最重要的信令协议之一被广泛应用.RSVP-TE的可靠性和生存性机制直接影响到ASON的可靠性.文章具体分析了RSVP-TE的可靠性机制和支撑RSVP-TE生存性的软状态机制,阐述了影响生存性的两种基本故障类型--控制信道失效和平面节点失效,并深入研究了它们相应的恢复机制.     

DCXRD分析Ge/Si(001)多层纳米岛材料

结合透射电镜与原子力显微镜实验,用双晶X射线衍射方法分析了Ge/Si多层纳米岛材料.衍射的卫星峰可以被分解为两个洛仑兹峰,它们分别源于材料的浸润层区和纳米岛区.利用透射电镜得到Si和SiGe层的厚度比,估算出浸润层区与岛区的Ge组分分别为0.51和0.67.这是一种简单估算Ge/Si多层纳米岛材料中Ge组分的方法.     

EDGE技术的测试和研究

对EDGE技术进行了介绍，并对EDGE技术的现网测试进行了说明，对于EDGE技术的功能特点及现网应用的模型、性能指标进行了研究和探讨。     

LCD触控感应技术发展趋势(英文)

作为直接和界面友好的输入装置,触摸屏被广泛地应用于移动显示产品。在过去几年中,触控技术的发展也是多种多样的。文章主要介绍了传统式触控技术及内嵌式触控技术的特点,并讨论了触控技术的发展趋势。     

环形腔氦氖激光器加速寿命试验分析

为了找到特定条件下使用环形腔氦氖气体激光器寿命估计理论模型与寿命试验方法,文中假设环形腔氦氖激光器的工作寿命分布规律,在大电流应力下满足威布尔分布,选取电流作为加速应力,对环形腔氦氖激光器进行加速寿命试验。通过最小二乘法对试验数据进行处理,试验结果验证了假设的正确性,得出了环形腔氦氖激光器在正常工作电流下的特征寿命,可以通过大电流应力下的特征寿命来计算,有效缩短了试验时间。     

抑制空间行波管三阶交调失真的信号注入技术

为了抑制空间行波管非线性特性产生的交调失真,本文通过理论分析、计算机仿真和实验验证,分别研究了谐波、交调和混合信号注入技术对空间行波管三阶交调（IM3）分量的抑制情况。实验结果表明：IM3注入技术能够得到25.2 dB的IM3最大抑制量,明显大于谐波注入技术的12.7 dB,两者对IM3失真分量的抑制效果都很良好,且就窄带空间行波管而言IM3注入技术比谐波注入技术更具优势。通过进一步仿真实验,证明双IM3注入技术可以在两个IM3频率处分别产生46 dB和53 dB的最佳抑制量,且混合注入谐波和交调信号也能最大抑制36.9 dB。     

透紫玻璃与蓝宝石的热压粘结工艺研究

透射式GaN阴极组件是GaN紫外日盲型探测器的最关键部件之一。介绍了制备透射式GaN阴极组件的工艺难点,主要报道了透紫玻璃与蓝宝石的热压粘结工艺的原理和研制过程,并着重分析了热压粘结工艺中出现的问题,同时提出了拟定的解决方案。     

Synthesis of Self‐Supported Ordered Mesoporous Cobalt and Chromium Nitrides

Herein, we demonstrate an ammonia nitridation approach to synthesize self‐supported ordered mesoporous metal nitrides (CoN and CrN) from mesostructured metal oxide replicas (Co₃O₄ and Cr₂O₃), which were nanocastly prepared by using mesoporous silica SBA‐15 as a hard template. Two synthetic routes are adopted. One route is the direct nitridation of mesoporous metal oxide nanowire replicas templated from SBA‐15 to metal nitrides. By this method, highly ordered mesoporous cobalt nitrides (CoN) can be obtained by the transformation of Co₃O₄ nanowire replica under ammonia atmosphere from 275 to 350 °C, without a distinct lose of the mesostructural regularity. Treating the samples above 375 °C leads to the formation of metallic cobalt and the collapse of the mesostructure due to large volume shrinkage. The other route is to transform mesostructured metal oxides/silica composites to nitrides/silica composites at 750–1000 °C under ammonia. Ordered mesoporous CrN nanowire arrays can be obtained after the silica template removal by NaOH erosion. A slowly temperature‐program‐decrease process can reduce the influence of silica nitridation and improve the purity of final CrN product. Small‐angle XRD patterns and TEM images showed the 2‐D ordered hexagonal structure of the obtained mesoporous CoN and CrN nanowires. Wide‐angle XRD patterns, HRTEM images, and SAED patterns revealed the formation of crystallized metal nitrides. Nitrogen sorption analyses showed that the obtained materials possessed high surface areas (70–90 m² g^?1) and large pore volumes (about 0.2 cm³ g^?1).     

卫星定位中伪距的广义延拓外推

GPS当丢失部分伪距不能正常定位时,采用广义延拓外推法外推伪距来实现对用户位置的定位.仿真结果和理论推理表明,这种伪距外推法在外推步数一定的条件下能满足用户接收机定位的要求.     

A direct digital frequency synthesizer with fourth-order phase domain /spl Delta//spl Sigma/ noise shaper and 12-bit current-steering DAC

This paper presents a direct digital frequency synthesizer (DDFS) with a 16-bit accumulator, a fourth-order phase domain single-stage /spl Delta//spl Sigma/ interpolator, and a 300-MS/s 12-bit current-steering DAC based on the Q/sup 2/ Random Walk switching scheme. The /spl Delta//spl Sigma/ interpolator is used to reduce the phase truncation error and the ROM size. The implemented fourth-order single-stage /spl Delta//spl Sigma/ noise shaper reduces the effective phase bits by four and reduces the ROM size by 16 times. The DDFS prototype is fabricated in a 0.35-/spl mu/m CMOS technology with active area of 1.11mm/sup 2/ including a 12-bit DAC. The measured DDFS spurious-free dynamic range (SFDR) is greater than 78 dB using a reduced ROM with 8-bit phase, 12-bit amplitude resolution and a size of 0.09 mm/sup 2/. The total power consumption of the DDFS is 200mW with a 3.3-V power supply.