无源标签技术在井下人员定位系统中的应用

由于煤矿作业环境的特殊性,以及矿难的不断发生,井下安全生产以及人员的管理和营救一直是困绕人们的重大难题。利用射频识别技术对井下人员定位系统进行研究,在射频识别技术基础上,设计井下人员定位系统的应用方案。介绍RFID系统的组成、特点,阐述电子标签的结构、工作原理及应用,同时介绍了井下人员定位系统设计方案和工作原理。     

基于RFID的定位系统综述

RFID技术被广泛地用于电子身份识别和跟踪定位。首先,介绍RFID定位系统构成及应用场景,回顾了主流的RFID定位算法以及采用这些算法的定位系统,并对这些定位系统进行比较分析;然后,指出影响RFID系统定位精度的因素,并根据当前RFID定位技术应用领域,给出RFID定位系统的发展趋势。结论:与其它定位技术相比,RFID定位具有极强的发展潜力;虽然RFID技术是可用于从低频到微波的各个频率,但在到具体应用时,关键还是要选择一个正确的工作频率,以更好地适应不同的应用场景。     

基于RFID的井下人员定位系统设计

井下人员定位系统是煤矿井下安全避险"六大系统"之一。本文在概述射频识别技术的基础上,提出了一种基于RFID系统设计的井下人员定位系统的设计方法。系统的读写器和标签均采用低功耗射频芯片nRF24LE1作为核心器件,采用VS2008+QT构建井下人员定位软件系统。该系统主要有硬件、下位机软件和上位机软件三个部分组成。应用于井下人员定位的RFID系统,可以实现对井下人员的实时定位,在人员的管理调度和事故发生时的搜救工作上起到辅助作用,对井下安全生产管理有着重要的现实意义。     

基于RFID的井下人员定位系统设计

井下人员定位系统是煤矿井下安全避险"六大系统"之一。本文在概述射频识别技术的基础上,提出了一种基于RFID系统设计的井下人员定位系统的设计方法。系统的读写器和标签均采用低功耗射频芯片nRF24LE1作为核心器件,采用VS2008+QT构建井下人员定位软件系统。该系统主要有硬件、下位机软件和上位机软件三个部分组成。应用于井下人员定位的RFID系统,可以实现对井下人员的实时定位,在人员的管理调度和事故发生时的搜救工作上起到辅助作用,对井下安全生产管理有着重要的现实意义。     

物联网技术在道路运输领域中的应用研究

研究如何依托RFID技术对车辆身份进行有效识别,并形成车辆的电子身份管理系统,实现客运站自动报班管理与服务、出租车动态执法管理与服务、货运车辆的管理与服务、智能停车场管理、党政机关人员及车辆的自动化出入管理,以此规范道路运输市场秩序、加大安全监管力度,整治假牌、套牌车现象,提高停车场使用效率并实现党政机关人员车辆进出管理的安全防范水平。     

基于射频技术与智能动作识别的人员身份认证方法研究

针对大部分身份认证方法存在认证方式单一、认证准确性低等问题,文中在医用场景下开展了基于射频技术与智能动作识别的人员身份认证方法研究.在详细论述无线射频识别技术(RFID)及其系统构成后,基于深度学习网络中的t-SNE降维处理、支持向量机动作分类等技术,设计实现了智能动作识别方法.将通过RFID和智能动作识别方法获得的身...     

井下人员超声波测距定位系统

在煤矿井下发生安全事故后,及时准确地获知井下作业人员的位置信息是至关重要的。文章提出了将超声波技术应用于煤矿井下人员无线定位系统,并结合先进的多步长搜索定位技术,对人员进行高精度定位、身份识别;为查询矿井中的人员分布情况提供了依据及高效救援;系统适用于各类环境下煤矿的安全管理。     

基于RFID的无线监控技术在电力系统中的应用

首先介绍了射频识别技术,然后具体探讨了射频识别技术在电力企业人员及设备智能安全管理系统中的应用,最后展望了RFID技术在电力系统安全管理中的应用前景。本文针对目前电力系统行业安全管理存在的问题,利用射频识别(RFID)技术、数据库管理技术和计算机网络技术相结合提出了一种新的解决方案。     

RFID技术在井下人员定位系统中的应用研究

井下人员定位系统是井下安全避险六大系统的重要组成部分。本文介绍了RFID技术在浙江绍兴平水矿业公司井下人员定位系统中的应用,详细描述了系统工作原理、硬件配置和软件功能设计。井下人员定位系统实际运行结果表明,保障了井下工作人员的安全,提高了企业的管理水平和安全生产效率。     

RFID技术及其所面临的挑战

无线射频识别(RFID)是利用射频通信实现的非接触式自动识别技术,可工作于各种恶劣环境,通过附着在物体上的标签,能迅速识别多个高速运动的物体。由于它的快速识别的特点,RFID技术越来越受到各大厂商的青睐,它在仓储物流、产品防伪、产品流通及产品维护追踪等领域有着极大的应用潜力。文章分析了RFID技术的基本原理,介绍了它在供应链管理、安全与身份识别及移动追踪等领域的应用。RFID技术也面临很多挑战,有待进一步研究。     

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.     

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.     

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.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Call for Papers

正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its