基于LabVIEW的单片机温度自动测试系统

冷库的温度是在实际应用中的一个重要指标,为此笔者设计开发了此单片机巡回测试系统,使其能对冷库的各冷冻室的温度巡回测试并加以处理。该系统由AT89C51单片机和温度传感器组成室温的数据采集系统,利用PC机上的RS 232串行口实现数据的串行通讯,使用LabVIEW虚拟仪器软件完成上位机串行通讯程序和前面板程序的编写。实验证明此系统取得良好的测试效果。     

基于LabVIEW的声波采集系统

为降低传统测井仪器成本,实现命令传送以及波形显示,该文设计了一套基于LabVIEW的数据采集与分析系统。通过LabVIEW数据采集实时采集信号,利用LabVIEW图形化编程语言开发了上位机界面来实现仪器与地面系统的通讯分析仪软件系统。结果表明,该界面能完成基本波形数据采集通讯功能,可广泛应用于测井领域。     

基于TCS230与LabVIEW的颜色测量系统

TCS230是TAOS(Texas Advanced Optoelectronic Solutions)公司推出的可编程彩色光到频率的转换器.本系统利用TCS230和单片机组成颜色采集小系统进行颜色采集,然后将采集的数据通过单片机串行通信传送给上位机,位机串口通信利用LabVIEW的VISA节点来完成.同时LabVIEW实现对所采集数据的处理、显示和保存.     

多路同步串口的FPGA传输实现

为适应多路数据接收的需要,设计了一种基于FPGA的多路同步串行数据采集及发送系统.详细讨论了FPGA数据采集部分及发送部分的控制逻辑;FPGA与DSP的通讯,FPGA与ARM的通讯的设计和实现.本系统已成功用硬件实现,其性能和指标均达到应用要求.     

基于LabVIEW的远程数据采集终端通信接口的设计与实现

对LabVIEW的串行通信接口驱动进行了研究,对用VISA编程进行了初步的尝试,设计并实现了基于LabVIEW的上位机控制程序,以及基于MCS-51单片机控制的数据采集终端的数据存储与控制,完成了基于8051单片机的远程数据采集终端的上位机串口通信接口部分程序,并且通过了测试.     

基于AVR单片机的负荷缸多路遥控开关编解码实现

利用AVR单片机对发电机负荷缸的多路远程遥控开关量进行采集,对采集到的开关量信号进行数字信号编码,通过RS 232/RS 485串行通信转换芯片实现了串行通信信号的远距离传送,在信号的传输和通讯中采用了握手和数据校验的方法保证了数据的可靠传输和控制。该方法也可用于其他开关状态信号的采集和自动化控制场所,实现设备的智能化监控。     

基于STM32的微生物发酵自动控制系统设计与实现

本文设计了一种基于STM32F407的微生物发酵过程自动控制系统。该系统由现场传感器、监控中心计算机、现场执行器等硬件组成。现场传感器将采集的数据传递给STM32控制板,处理器对数据进行分析处理;一方面将数据传递给监控中心上位机实时显示,上位机测控软件采用美国NI公司的LabVIEW软件平台设计开发;另一方面将控制信号传递给现场执行设备,使发酵过程达到优化控制的效果。实验测试表明,所设计的微生物发酵自动控制系统达到了设计要求,实现了对微生物发酵过程的自动控制。     

基于LabVIEW的水温虚拟测量系统的设计

本文介绍了一种基于LabVIEW的水温虚拟测量系统。介绍水温的数据采集和温度值的计算;介绍如何利用LabVIEW软件实现PIC单片机与PC机的串行通讯; 最后给出了本系统的前面板设计和实验结果。     

基于LabVIEW的多种通讯方式数采系统

在数据采集过程中,采集系统的稳定、高速和远距离可控制等性能是非常重要的。针对该多功能性的要求,对以LabVIEW为软件开发平台的数据采集系统进行了研究。通过以太网和无线两种通讯方式完成了上位机与多路采集系统的数据传输和对采集系统的远程控制,并且系统能够对数据进行预览、存储、回放、预处理等操作。系统还具有自检、复位、存储体擦除等功能。实际应用证明系统可以准确的完成各项功能。     

基于LabVIEW串行通信系统的开发

虚拟仪器是由软件实现的,其软件开发平台是LabVIEW。VISA是在所有LabVIEW工作平台上控制VISA、GPIB、RS-232以及其他种类仪器的单接口程序库,通过LabVIEW平台中的VISA模块编写控制程序．可以进行仪器控制。本文以串行通信为例,用LabVIEW构建仪器控制进行串行设备通信,在虚拟环境中使用VISA功能模块向串行设备读写数据．缩短了项目开发周期,提高了开发效率。     

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.     

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