一种轻量级无线传感网络网关设计

在基于Zig Bee技术和GPRS的区域环境远程监控系统设计中,需要实现数据从Zig Bee网络到GPRS的转换。针对系统中多种无线通信技术之间互联的需要,设计实现了一种轻量级无线通信网关。该网关主要由CC2430无线射频芯片和嵌入TCP/IP协议的GPRS模块组成,通过软、硬件设计,实现了数据从Zig Bee网络到GPRS网络的传输。实际应用表明:网关满足了远程无线监控系统中协议转换的需要。     

基于ZigBee无线传感器网络的远程数据监测的设计

将无线传感网络技术与Zig Bee技术进行融合,使用Zig Bee技术搭建无线传感网络,并建立基于Zig Bee无线传感器网络的远程数据监测系统。以楼宇供暖远程监测系统为例,对基于Zig Bee无线传感网络的远程数据监测系统设计进行说明。对Zig Bee节点的核心组件PIC18LF4620处理器和CC2420无线射频模块引脚连接电路进行设计;对Zig Bee无线传感网络中处理器和模块的软件程序以及上位机组态监测软件进行设计。通过在目标楼宇内成功安装调试该文研究的楼宇供暖远程数据监测系统,使得全天候各个供暖时段的室温均在要求的18℃以上,基本能够达到室温均衡,节约了供暖公司的成本和资源。     

基于ZigBee无线网络的室内温度监测系统

针对传统温度监测系统需要布线,可扩展性差等缺点,该文设计了一种利用Zig Bee无线网络实现的室内温度监测系统。系统以ARM9为主控平台,采用Zig Bee技术组建了一个室内无线传感网络。网络终端节点负责实时采集室内监测区域的温度数据,并通过网络协调器将温度数据发送给系统的网关服务器。用户可以通过Web浏览器访问网关服务器来实时查看室内温度数据。经测试,系统运行稳定,实现了预期功能,具有一定的应用价值。     

无线传感器网络组网设计

无线传感器网络是一种集成了计算机技术、通信技术、传感器技术的新型智能监控网络。本文分析了Zig Bee无线传感器网络的结构,并研究了采用Zig Bee技术如何建立无线传感器网络,及实现终端节点和协调节点的通信。     

铁路机车各参数监测无线传感器网络研究

论文首先介绍了无线传感器网络体系结构。接着,论文阐述了Zig Bee技术的优点,本文采用无线Zig Bee技术作为无线传感器网络的传输载体。以这个思路为基础,论文详细分析了Zig Bee无线传感器网络的架构,包括网络节点类型和网络拓扑结构等,并对Zig Bee技术的组网原理作了详细的研究。     

面向智能家居的嵌入式传感网网关的研究与设计

为了实现家庭内部网路与Internet以及GSM网的互联,提出了一种嵌入式无线智能家居网关系统的设计方案。该网关系统的硬件平台以ARM920T核处理器S3C2440为主处理器,采用ZigBee协议建家庭内部网络,而且通过以太网模块和GSM模块接入外部网络。软件平台采用Linux操作系统,通过交叉编译设计网关的应用程序。最后,以Qtopia Core为嵌入式GUI,进行家庭网关监测应用软件的功能需求分析,设计图形用户界面,实现家庭内部信息的查询。基于ARM9和Linux的嵌入式网关系统,可扩展性强,数据处理速度快,使用简单,能够对家庭网络内部多项环境信息进行监测。     

基于ZigBee的无线组网技术研究

在阐述Zig Bee技术特点的基础上,介绍Zig Bee网络的功能类型设备与节点类型,并提出Zig Bee协议下的网络拓扑结构,着重从组网流程方面对基于Zig Bee的无线组网技术进行相应研究。     

基于Arduino的XBee与Yeelink结合的温湿度监控网络的搭建

以Arduino为开发平台,借助XBee模块完成Zig Bee局域网组网,利用Yeelink互联网开放平台搭建了一个远程温湿度监控系统。系统以Arduino UNO为控制板,在局域网内利用XBee模块无线传输温湿度传感器所采集的数据,以W5100以太网模块作为Zig Bee无线网络网关,实现数据从Zig Bee网络向互联网传输。该系统可以实现对温度、湿度等数据的实时采集;通过互联网访问Yeelink可以获取信息,进行在线监测;在数据监测出现异常情况时通过Yeelink向终端发出报警信息,使终端蜂鸣器发出声响,从而提醒周围人,达到报警效果,实现系统的远程实时监控。     

物联网ZigBee网关的设计与实现方法

随着传感器、无线通信等技术的迅速的不断发展,物联网在仓库物理、智能电网等领域都得到了广泛的应用。作为计算机网络及移动通讯设备之后的又一次信息革新,如何设计与实现物联网Zig Bee网关成为我们研究的热点。因为物联网中的Big Zee网关的协议与广泛的TCP/IP协议并不一致,这就为实现两种不同的网络的融合带来了难题。本文就主要对此进行深入的探讨。本文主要从网关的内部构造及Zig Bee在以太网中与其他模块之间的交互作用角度出发,探索如何实现异构网络的融合,以达到数据顺利传输和有效处理。     

基于ZigBee的移动物联网温度采集系统设计与实现

为了实时准确获取特定环境下的温度值,设计并实现了一种温度采集系统。系统基于Zig Bee技术,采集平台利用自带Zig Bee协调器获取Zig Bee终端节点温度值,通过4G移动网络上传至远程服务器My SQL数据库;同时提供Android客户端APK供手机用户查看温度,以及搭建B/S架构网站供PC用户访问,实现了温度数据采集并多方式呈现。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.