噪声监测中前景噪声与背景噪声分离方法的研究

为了能够有效的区分前景噪声和背景噪声,本文搭建了一种噪声采集的系统,采用数字噪音计VC824B为噪声采集传感器,单片机作为初级处理端并将噪声数据传输给ARM主控板,再通过通讯板传输给上位机主机。本文提出了在总体噪声的数据中用声强法进行噪声分离。经过实验验证了该方法的可行性,同时为以后提供大规模的噪声采集提供了合理的硬件平台和分析方法。     

远程电网电流数据采集系统的设计

介绍一个由数据采集终端和数据处理主机组成的远程电网电流数据采集系统设计,采集终端对电网电流进行实时数据采集,通过GPRS/互联网发送至云端的数据处理主机,数据处理主机对数据接收及处理。数据采集终端由STM32完成对A/D采集和GPRS数据发送的控制。     

基于嵌入式操作系统的工业采集板设计

工业采集板广泛应用于各种工业级设备,主要实现工业现场的数据采集、监控、处理功能。伴随着互联网+和工业4.0时代的到来,传统形式的工业采集板已经不能满足各种工业场合对工业参数采集速率,数据处理性能以及通讯接口管理资源日益增多的需求。文中介绍如何采用工业级ARM处理器配合嵌入式操作系统设计一种多接口资源,高速采集,高效处理数据的工业采集板。     

基于AD7738的高精度、多通道数据采集系统设计

介绍了基于AD7738的高精度数据采集系统,系统采用C8051F320单片机、高速光耦,开发出高精度的数据采集系统,通过USB接口实现主机与单片机之间的通信。实验结果表明,在转化速率为1kHz/s时,数据精度可达到19bit。     

基于MATLAB的室内温度数据采集

介绍了基于MATLAB的PC与USB数据采集板之间的串行通信,利用热敏电阻温度传感器对室内温度进行采集和对传感器进行加温和降温来控制室内温度。将采集的温度送到USB数据采集板上,接着利用该采集板能直接支持Simulink进行硬件在线仿真的特点,在Simulink中进行建模仿真,同时可以将仿真后的温度数据在PC界面上以曲线的方式显示,由于温度传感器的特点,该数据是温度变化相对应的电压曲线,具有良好的直观性和可视性。     

一种通用雷达信号处理机的设计

在基于VME总线或CPCI总线的雷达信号处理机中，板与板之间的数据传输速率受限于总线的速率。针对现有的雷达信号处理机板间的数据传输速率较低的问题，本文提出了一种新的设计方法，即采用DSP和FPGA相结合的设计方法，利用FPGA提供的高速串行收发通道进行板间的数据传输，使板间的数据传输速率获得大幅度的提升，同时也有效地改善了板内DSP间的数据传输问题。     

基于LabWindows/CVI多点无线温度数据采集系统设计

给出了一种基于C8051F020单片机实现无线温度采集的系统方案。将AT24C16数据储存电路、AD590温度采集电路、实时时钟电路、无线收发模块和C8051F020控制电路置于采集环境中,采集到的数据可根据用户需要通过无线模块向主机发送,主机只需发送不同的控制命令,即可完成多点无线温度采集,然后主机再将接收的数据通过串口发给PC机,用户在LabWindows/CVI实现的PC机数据处理界面下,完成系统操作。实验结果表明,该设计很好地达到了设计目的。     

用CPLD设计EPP数据采集控制器

基于增强并行口 (EPP)的数据采集系统与基于SPP和RS2 32接口的数据采集系统相比具有更高的数据传输速率。用CPLD开发的基于EPP接口的数据采集控制器 (以下简称为EPP数据采集控制器 )具备多项优点 :高速度、灵活、功能齐全 (得益于CPLD丰富的内部资源 ) ,引脚自定义为设计PCB板提供极大方便。文章介绍使用CPLD设计的EPP数据采集控制器的原理 ,并附有应用实例     

基于单片机的井场仪表参数无线传输系统设计

应用STC单片机和无线通信模块FC211设计开发了钻井井场仪表数据无线传输系统。本系统可以采集直流4~20 mA模拟量、直流1~5 V模拟量、开关量、脉冲,并可以输出开关控制量对井场电机等进行无线控制。系统具体分为主机和从机两部分,从机主要负责将分布在现场的仪表采集的数据无线发送至控制室内的主机,主机再把数据传到计算机内进行处理和显示。经过实际现场运行检验效果是令人满意的。     

基于USB接口的电化学沉积仪器数据采集系统的研究

数据采集系统是试验仪器的重要组成部分.介绍电化学沉积试验仪器的原理及其数据采集系统部分的设计.该采集系统中采用AVR单片机AT90USB1287处理器实现与终端PC的数据通信.USB外设把采集到的数据信号发往主机,从而在主机上实现了数据图像的实时显示.实验结果表明该USB接口的数据采集系统数据传输速率快、性能稳定.     

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.     

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.     

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.     

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.     

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     

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