基于AODV且考虑拓扑信息的节能路由算法

提出了一种基于AODV的节能路由算法EBF-AODV.该算法在路由发现过程中,源节点设置一个阈值,中间节点根据本节点拓扑变化情况决定如何处理路由请求分组,目的节点综合考虑路径上的可用能量和路由跳数,选择最佳路径.通过仿真证明了该算法的有效性.     

基于无线传感器网络的一种改进Dv-Hop算法

无线传感器网络中的Dv-Hop算法是一种无需测距的节点定位算法,经仿真观察,该算法在信标节点密度较低时节点平均误差较大且稳定性不好.提出了一种改进Dv-Hop算法,即在一个网络区域的边缘设置信标节点.经仿真验证,该算法在和Dv-Hop同等信标节点密度的情况下,在定位精度、节点定位的稳定性以及能源消耗方面都有所改善.     

一种用于紫外光通信网络的改进蚁群算法

由于紫外光通信网络信道时变性强,需要对应的自适应路由来解决组网过程中出现的网络传输时延大和节点能量消耗不均衡等问题。基于蚁群优化（ACO）算法,提出了一种用于紫外光通信网络中的改进ACO算法。该算法将网络节点能量引入到ACO算法状态转移概率公式中,并通过Mat l ab软件仿真分析了算法在不同收发角度、发射功率和数据传输速率条件下的时延性能。仿真结果表明：与ACO算法相比,当收发仰角为50°时,所提算法的时延降低了1 s,收敛速度提升了28%,收敛路径的平均剩余能量也明显提高,有效地延长了网络的生存周期。     

用于紫外光通信组网的改进加权算法

针对已有加权算法在紫外光通信组网运用中存在的结构划分不均衡、不稳定和不准确等问题,提出一种改进的加权算法。改进算法基于能量损耗模型确定合理的小区数划分,并将节点间的相对移动性考虑到功率变化因素中计算通信连接时间。仿真分析表明,改进算法提高了网络的稳定性,中心节点的选择更趋于均衡化,可以进一步改善紫外光通信网络的性能。     

紫外光通信协作蜂群无人机网络动态能效均衡算法

针对蜂群无人机在复杂战场环境下的能效均衡需求,提出一种紫外光通信协作蜂群无人机网络动态能效均衡算法。该算法结合紫外光抗干扰、高保密的优点,为蜂群无人机提供一种可靠的通信方式,并通过引入自适应节点度、无人机能效和距离稳定度参数加权分簇来选举簇首,使算法更加适用于动态场景。最后结合无线紫外光通信及能量消耗模型,在高斯马尔可夫移动模型下对蜂群无人机进行了仿真分析,结果表明,本算法相比LEACH算法可以将网络生存周期提升16%,同时可将平均簇首数量降低57%,数据传输量提升近两倍。     

紫外光空分复用自组织网络路由协议

为了改善紫外光(UV)点对点通信中传输距离有限、覆盖范围小的问题,组建了UV自组织(Ad Hoc)网络。结合UV通信的信道特性,提出了一种UV组网通信收发装置设计方案。基于该方案,给出了UV Ad Hoc网络节点定位算法,该算法利用节点间的通信距离和扇区信息求得节点间的相对位置。以无线Ad Hoc网络多播按需距离矢量路由协议为基础,提出了一种UV空分复用Ad Hoc网络路由协议,并对该路由协议进行了仿真,给出了不同节点数和运动区域下的仿真结果。结果表明:在满足发包数、时延和丢包率等通信要求的前提下,在一定运动区域内,应选择较少的节点;当节点数一定时,应选择较小的运动区域。     

一种基于车载自组网的停车位协作发现算法

在停车位发现问题中,车辆节点快速变化的拓扑结构使停车位的选择和分配变得非常复杂.车载自组网多跳通信的特点使车辆节点容易产生抢占式不良竞争,从而造成无效的车辆行驶.基于OAPS算法和模拟退火算法,提出了一种停车位协作发现算法（COAPS）,综合考虑当前节点与邻居节点的整体开销,进而实现停车位资源在车辆节点间的协作分配.通过在VanetMobisim平台上仿真比较,验证COAPS算法具有较短的停车位发现时间和车辆协作性.     

信号强度和运动向量结合的无线传感器网络移动节点定位

无线传感器网络的定位是近年来无线传感器网络研究的重要课题.本文首先介绍了无线传感器网络的来源、重要性以及无线传感器网络定位的分类.然后提出了一种全新定位算法,信号强度和运动向量结合的无线传感器网络移动节点定位,简称SSMV算法,在外围布置四个锚节点,得用信号强度和未知节点在运动中向量的变化,对锚节点在内的未知节点进行定位,并对该算法进行了仿真和总结.通过与凸规划法进行比较,仿真结果表明,该算法有更高的定位精度.     

一种能耗均衡的无线传感器网络路由算法

为了延长采用电池供电的无线传感器网络的生命周期,提出了一种综合考虑单个节点能耗和节点传输信息至汇集节点所需总能耗的路由算法.该算法首先根据网络中节点到汇集节点从小到大的距离顺序选择待规划节点,然后计算各对应候选节点的评价参数,该参数由单节点能耗和节点传输信息至汇集节点所需总能耗加权得到,最后选择评价参数最小的候选节点作为待规划节点的中继节点.仿真结果表明,该算法的生命周期明显长于LEACH(Low Energy Adaptive Clustering Hier-archy)算法.     

无线传感器网络中基于映射扩散的节点定位算法

提出了一种基于映射扩散的无线传感器网络节点定位算法,适用于规模较大、参考节点较少的无线传感器网络.该算法在传感器网络中首先随机选择一个节点作为"起始节点",然后根据扩散算法选择3个"一级节点",然后以每个一级节点为中心,逐级外推,直至覆盖网络中的所有节点.仿真结果证明,该算法可以快速准确进行定位,可降低和均衡所有节点的能耗,提高定位精度.     

聚对苯撑苯并双(口恶)唑发光及其器件制备

采用光谱技术,研究了聚对苯撑苯并双(口恶)唑(PBO)溶液的光敏发光特性,并用相对法估算出溶液发光效率在50%范围.结合光谱技术、半导体电学和电化学等研究手段,具体研究了以PBO为发光层的单层电致发光器件,研究结果显示,电致发光与薄膜的光致发光有具有相同的发光中心,峰值位于510 nm左右.同时发现,由于存制备过程中不同处理条件使得不同厚度薄膜残留的掺杂物质浓度不同,从而引起薄膜的导电性的不同.使得器件的阈值场强随PBO厚度的减小而逐渐增加.     

系统级封装新型埋入式电源滤波结构的研究

在高密度小尺寸的系统级封装(SiP)中,对供电系统的完整性要求越来越高,多芯片共用一个电源网路所产生的电压抖动除了会影响到芯片的正常工作,还会通过供电网路干扰到临近电路和其他敏感电路,导致芯片误动作,以及信号完整性和其他电磁干扰问题.这种电压抖动所占频带相当宽,几百MHz到几个GHz的中频电源噪声普通方法很难去除.结合埋入式电容和电源分割方法的特点,提出一种新型高性能埋入式电源低通滤波结构直接替代电源/地平面.研究表明,在0.65～4GHz的频带内隔离深度可达-40～75 dB,电源阻抗均在0.25ohm以下,实现了宽频高隔离度的高性能滤波作用.分别用电磁场和广义传输线两种仿真器模拟,高频等效电路模型分析这种低通滤波器的工作原理以及结构对隔离性能的影响,并进行了实验验证.     

Emerging interconnects: a state-of-the-art review and emerging solutions

Aluminium was a primary material for interconnection in integrated circuits (ICs) since their inception. Later, copper was introduced as interconnect material which has better metallic conductivity and resistance to electromigration. As the aggressive technology scaling continues, the copper resistivity increased because of size effects, which causes increase in delay, power dissipation and electromigration. The need to reduce the resistor-capacitor??????? delay, dynamic power utilisation and the crosstalk commotion is as of now the fundamental main impetus behind the presentation of new materials. The purpose of this paper is to do a survey of interconnect material used in IC from introduction of ICs to till date. This paper studies and reviews new materials available for interconnect application which are optical interconnects, carbon nanotube (CNT), graphene nanoribbons (GNRs) and silicon nanowires which are alternatives to copper. While doing a survey of interconnect material, it is found that multiwalled CNTs, multilayer GNR and mixed CNT bundles are promising candidates and are ultimate choice that can strongly address the problems faced by copper but on integration basis copper would last for coming years.     

Arsenic deposition as a precursor layer on silicon (211) and (311) surfaces

We investigate the properties of arsenic (As) covered Si(211) and Si(311) surfaces by analyzing data from x-ray photoelectron spectroscopy (XPS) and low-energy electron diffraction (LEED) images. We then create a model using total surface energy calculations. It was found that both Si(211) and Si(311) had 0.68±0.08 surface As coverage. Si(211) had 0.28±0.04 Te coverage and Si(311) had 0.24±0.04 Te coverage. The Si(211) surface replaces the terrace and trench Si atoms with As for a lower surface energy, while the Si edge atoms form dimers. The Si(311) surface replaces all terrace atoms and adsorbs an As dimer every other edge site. These configurations imply an improvement in the mean migration path from the bare silicon surface by allowing the impinging atoms for the next epitaxial layer, tellurium (Te), to bind at every other pair of edge atoms, and not the step terrace sites. This would ensure a nonpolar, B-face growth.     

光子晶体微腔发光二极管

光子晶体微腔因其具有增强自发辐射、定向输出和单模工作的能力而受到广泛关注。介绍了光子晶体微腔发光二极管的基本原理、设计、特性、制作及其典型器件。     

Comparative study of maximum power point tracking techniques for hybrid renewable energy system

The power generation demand is increasing day-by-day throughout the world, therefore, the use of hybrid systems becomes a significant solution. The hybrid renewable energy system (HRES) is used for delivering power in various regions in order to overcome intermittence of wind and solar resources. Because of increasing environmental problems, for example, greenhouse gas emission and energy cost have interested novel research into substitute methods in favour of electrical power generation. Maximum Power Point Tracking (MPPT) control method is a vast deal of novel research used for enhancing the efficiency of HRES. The authors have revealed that the hybrid techniques i.e. Global MPPT, fuzzy-neuro systems, Adaptive Neuro-Fuzzy Inference System (ANFIS), Perturbed and Observe (P&O) + Adaptive Neural Network (ANN) etc. can provide best results as compared to other MPPT control methods. This paper offering a state of art review of MPPT control techniques for HRES.     

用于单光子TOF测量的时间-幅度变换器

基于新型共源共栅电流源的积分方法,设计了一种用于单光子飞行时间(TOF)测量的时间-幅度变换器(TAC).该方法有效简化了 TAC电路结构,减小了 TAC占用面积,显著提高了TOF的满量程范围(FSR).采用0.18 μm标准CMOS工艺设计.集成TAC的单光子探测器像素单元的填充因子可达到26.8％.后仿真结果表明,...     

超宽带脉冲信号的光学生成方法研究

近年来超宽带(UWB)通信技术迅猛发展,在测量、雷达技术、民用和军事无线通信中有着重要的应用,UWB-over-fiber技术已经成为目前研究的热点,其中就包括UWB脉冲信号的产生方法。区别于传统的电子学方法,光子学产生方法不受电子瓶颈制约,可以实现很高的带宽,并且具有抗电磁干扰、重量轻、结构紧凑的优点。通过对比国内外本领域研究成果,讨论及总结了以下三种原理的UWB脉冲信号的光学生成方法:1)相位调制-强度调制转换(PM-IM);2)半导体光放大器(SOA)的非线性效应;3)频谱塑形和色散所致频域-时域映射,然后对各种方案进行了对比分析。     

Joint estimation of TOA and DOA in IR-UWB system using a successive propagator method

Impulse radio ultra-wideband (IR-UWB) ranging and positioning require accurate estimation of time-of-arrival (TOA) and direction-of-arrival (DOA). With receiver of two antennas, both of the TOA and DOA parameters can be estimated via two-dimensional (2D) propagator method (PM), in which the 2D spectral peak searching, however, renders much higher computational complexity. This paper proposes a successive PM algorithm for joint TOA and DOA estimation in IR-UWB system to avoid 2D spectral peak searching. The proposed algorithm firstly gets the initial TOA estimates in the two antennas from the propagation matrix, then utilises successively one-dimensional (1D) local searches to achieve the estimation of TOAs in the two antennas, and finally obtains the DOA estimates via the difference in the TOAs between the two antennas. The proposed algorithm, which only requires 1D local searches, can avoid the high computational cost in 2D-PM algorithm. Furthermore, the proposed algorithm can obtain automatically paired parameters and has better joint TOA and DOA estimation performance than conventional PM algorithm, estimation of signal parameters via rotational invariance techniques algorithm and matrix pencil algorithm. Meanwhile, it has very close parameter estimation to that of 2D-PM algorithm. We have also derived the mean square error of TOA and DOA estimation of the proposed algorithm and the Cramer-Rao bound of TOA and DOA estimation in this paper. The simulation results verify the usefulness of the proposed algorithm.     

多孔硅发光机制的分析

从量子力学的基本理论出发讨论了量子限制效应，推导出多孔硅有效禁带宽度增量并用量子限制效应和表面态及其物质在发光中作用的理论解释了ＰＳ光致发光的实验现象。