基于ZigBee的煤矿监控系统的设计

针对恶劣的煤矿生产环境和事故救援的需求,提出了一种基于ZigBee的安全监控系统。该监控系统主要以CC2530和NRF24LE1为核心,集矿井人员定位和瓦斯检测于一体。该系统性能稳定,技术可靠,设计简单实用。能够满足当前矿山检测和监控需要。     

基于ZigBee的矿井环境监测系统的设计

针对矿井内部环境复杂、人员活动频繁的特点,提出了基于ZigBee的矿井环境监测系统。该系统以STM32单片机为主控单元,采用传感器技术和ZigBee技术相结合实现对井下环境参数的采集与控制,实现了数据的实时监测与分析处理,从而达到实时监控煤矿内环境要素变化情况、及时准确地了解生产,可以为煤矿生产提供全方位实时动态信息服务。     

矿井无线定位导航与安全监控系统研究

针对当前国内煤矿坍塌爆炸等安全事故问题，本文对井下导航与安全监控系统进行了分析研究，提出了一种基于ZigBee短距离无线通信技术的矿井定位导航与安全监控系统。文中讨论分析了ZigBee的特点，详细介绍了井下定位导航、环境信息采集与传输的过程，并针对单片机的控制系统方案、工作原理以及实现过程进行了全面介绍。实验表明，通过该系统可实时了解井下安全生产作业情况，并切实保证矿井工作人员人身安全。     

基于无线传感网的矿井环境监测系统设计

由于ZigBee无线通信技术具有低功耗、低成本、应用简单等特点,提出了基于ZigBee无线通信技术的矿井环境监测系统方案,采用在井下主巷道RS-485有线通信和采掘巷道ZigBee无线通信相结合的网络结构,ZigBee采用网型网络拓扑结构,井上部分上位机和井下监测节点采用标准的Modbus协议进行通信,上位机采用hbview进行数据接收、显示和存储。本文进行了监测节点的硬件设计,编程实现了监测系统ZigBee无线通信和ModbuS协议通信过程。测试结果显示,该系统能够准确可靠显示环境监测信息,证实了该方案可行。     

基于ZigBee的矿井安全管理系统设计

安全是煤矿生产的前提,是现代化矿井建设的主要目标,井下人员定位管理和瓦斯实时监控是安全管理的重要组成部分。本文设计了一种基于ZigBee技术的安全管理系统,该系统通过井下无线通讯和地面监控,可以实现对井下作业人员的考勤定位,以及对井下的温度、湿度、瓦斯浓度等的实时监测,为矿井安全生产提供有效保障。     

基于ZigBee技术的精准农业中监控网络

精准农业是当今世界农业发展的新潮流,是未来农业发展的必然趋势。将ZigBee技术运用到精准农中,与传统的精准农业系统相比,ZigBee监控系统具有维护方便、运行费用低、实时在线监控、无线采集和传输的特点。首先介绍了ZigBee技术及ZigBee协议栈,并给出了精准农业监控网络的总体设计。     

基于ZigBee技术的矿井人员管理系统设计

基于无线通信技术的快速发展及人们对现代化煤矿的需求,提出了一种基于ZigBee的短距离无线通信技术在矿井人员管理系统中应用的设计。将低功耗的ZigBee技术用于矿井下的无线传输系统中,用CAN总线实现数据的双向通信,并可通过GPRS网络及因特网实现信息共享。该系统组成的井下无线传感器网络,实现了井下人员的跟踪定位、考勤管理、安全检测,为矿业的安全生产提供了科学依据。     

无线传感器技术在变压器安全状态监测系统中的应用

目前无线传感器技术主要方向是ZigBee技术,ZigBee技术建立在802.15.4协议基础上,本文主要研究WSN技术在变压器状态监控系统中的应用,重点论述了基于ZigBee协议的硬件设计以及软件控制。     

基于无线传感网的矿井监控系统设计与研究

煤矿安全问题一直是制约煤矿发展的关键因素,解决该问题的办法之一就是建立一套可靠的监控系统,实现智能化管理。本文利用高性能微处理器S3C2440A采集矿井下重要环境点的图像、有害气体等数据。进行相关的算法处理后传送给附近的ZigBee节点,然后通过ZigBee节点组成的传感网络进行无线传输,最终在控制端实现对每个节点的实时监控。结果表明,本文设计的智能化矿井监控系统能大大提高矿井的管理力度,降低矿井下的事故发生率,提高工作效率。     

矿井高压电缆接头状态的无线网络监测系统

针对矿井高压电缆接头爆炸事故频发及在线监控技术具有局限性的问题,提出了一种基于ZigBee技术的矿井高压电缆接头状态的无线网络监测系统.通过构建网状拓扑结构、设置网络节点和无线自组网完成通信网络建设,通过X-CTU和ZigBee Operator应用软件实现整个网络的控制和配置,再结合基于单片机的下位机电流、温度和湿度数据采集以及PC机的上位机数据分析处理.模拟实验证明,该系统实用有效,可靠性好.     

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.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.