基于GSM技术的冻土区土壤温度监测系统

将GSM技术应用到冻土区土壤温度自动监测中,以满足恶劣气候条件下的无人值守、长时间、多点监测需求.详细阐述了系统结构、施工过程及实验结果分析.结果表明,该系统测量精度高、可靠性好、功耗低,可实现较大范围内的多点测温及超远距离无线监测.     

通信电源的发展现状及趋势

开关电源的发展经历了从线性电源、相控电源到开关电源的发展历程,由于开关电源具有功率转换效率高、稳压范围宽、功率密度比大、重量轻等优点,从而取代相控电源,成为通信电源的主体,并向着高频小型化、高效率、高可靠性的方向发展。计算机控制、计算机通信和计算机网络技术的快速发展源监控系统的发展和完善提供了外部条件,使其逐步实现了少人值守值守。为通信电直至无人值守。     

基于云终端的UPS电池远程监测系统软件设计

针对目前"有人值守"UPS电池监测系统的缺陷,提出了以云终端技术为基础的远程在线监测新方法,从而改变原有的"有人值守"为"无人值守"。系统基于ADO数据库访问技术及C++编程完成数据管理、人机交互和系统控制,由云终端实现监测系统下位机与上位机之间的数据传输。实践证明,该技术安全稳定,具有很好的实用和推广价值。     

钢轨应变实时监测节点研究

为了实现对钢轨应变的远距离、实时监测,以MSP430F149单片机为主控制器,结合ZigBee技术,设计了实时监测节点,完成了钢轨应变、温度的采集及数据无线传输。将节点进行了实验室测试和标定并将其安装在某铁路路段进行了实际测试,实际测得的数据与理论分析相符,节点安装简单、运行稳定、速度快、功耗低,适用于户外无人值守的恶劣监测环境。     

一种远程控制的广播频段监测接收机的设计

为了对目标区域的广播信号进行监测,评估信号的接收效果,提出一种远程控制的广播频段监测接收机设计方案。接收机在远程控制中心的指令控制下,接收广播信号,对解调出的声音信号进行录音,根据信号场强、信噪比等指标评估接收效果,然后把监测结果上报给远程控制中心,实现广播频段信号的远程监测和效果评估。实际应用中,该接收机可大量部署于目标区域进行无人值守,避免外派很多人员进行实地监测,大大降低了工作难度和人力成本,具有较好的工程推广价值。     

基于海上无人平台的低功耗实时智能监测系统

针对海上无人值守的监测平台对功耗、实时性、识别率等方面的要求,设计并实现了基于人工智能技术的综合目标识别系统。该系统提出了目标框定预处理算法,大大降低了神经网络的输入数据量;通过神经网络模型优化降低了计算复杂度,并能适应不同尺寸的输入图片。该系统具有良好的性能功耗比,能较好地满足实际应用场景的需求。     

电气设备过温红外远程在线监测系统在变电站的应用

为了实现智能电网要求的管理信息化、智能化的目标,提出了解决变电站电气设备自动不间断温度状态监测的应用方案。应用方案采用安装在全方位云台上的网络型红外在线式热成像仪,对无人值守变电站电气设备关键节点进行连续不间断的远程温度状态监测,并将监测数据实时传输到工作网络中,同时实时对监测到的目标温度数据进行分析处理,生成数据报告。实际运行表明,系统输出的温度异常信息可以为预先排除电力设备故障隐患提供有力依据,实现了电网管理从维护运行到状态运行的重大提升。     

变电站蓄电池在线监测系统设计与实现

蓄电池是变电站的重要设备之一,随着电力系统和通讯系统的不断改善和发展,对蓄电池组的可靠性,对无人值守站、机房后备电源的监测与监控等要求也相应提高,蓄电池的运行监测及其运行维护问题成为研究热点。文中论述了变电站蓄电池在线监测系统的工作原理和一些常见问题,如蓄电池好坏的判断、蓄电池容量的测试、快速查找电压过低的单节或多节蓄电池的方法等。     

电子核查与遥测

本文通过国外核查技术的两个实例，说明现代遥测技术与电子核查技术的密切关系和军备控制电子学新概念。并且简要地介绍了活动目标电子核查装置与无人值守监测系统两个研究课题的进展情况和研究的意义。     

刍议大盘卷高速设备振动远程监测的实现

本文主要简述了现应用于华菱湘钢大盘卷高速轧机的德国FAG在线振动监测系统,介绍了其监测对象及软/硬件构成和常规数据采集和频谱分析,在此基础上嵌入局域网办公系统实现办公自动化,进而讨论实现大范围、低延误、高密度地监控高速轧机振动的可行性。     

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