填充柱使用尾吹气对FID检测器灵敏度的影响

本文研究气相色谱填充柱在不同柱流量和不同浓度的苯系物样品,使用尾吹气对FID检测器灵敏度的影响,以确定分析仪器的最佳灵敏度。     

基于 MEMS 的量热式传感器气体流量测量的模型研究

气体流量测量广泛应用于呼吸监测、管道运输等领域。本研究细致分析了MEMS量热式传感器温度一维分布模型中的热边界层参数,进行了相应的经验修正。并且在温度一维分布模型的基础上,针对具有两对上下游测温电阻芯片结构的MEMS量热式传感器,提出了一种新的传感器输出电压关于气体流量的半修正理论模型。该理论模型能够适用于不同类型的单介质气体。同时,开展了N₂、CO₂流量测量实验,与理论模型进行对比,证明所提出的理论模型可以正确预测不同气体介质的流量,其中针对CO₂测量介质的均方根误差为0.15%。此外,结合理论分析,提出了一种高精度,拟合形式简单、针对确定气体适用性更好的测量模型,其中针对CO₂测量介质的均方根误差为0.05%。     

A novel compact design of calibration equipment for gas and thermal sensors

A novel design of calibration equipment has been developed for static and dynamic calibrations of gas and thermal sensors. This system is cheap, compact, and easily adjustable, which is also combined with a plasma surface modification source for tailoring the surface of sensors to ensure the sensitivity and selectivity. The main advantage of this equipment is that the operating temperature, bias voltage, types of plasma source (for surface modification), types of feeding gases, and gas flow rate (for calibrations), etc., can be independently controlled. This novel system provides a highly reliable, reproducible, and economical method of calibrations for various gas and thermal sensors.     

DATA ACQUISITION SYSTEM FOR ARC-DRIVEN HF/DF CHEMICAL LASERS

The article focuses on the development of a data acquisition system (DAS) working in a noisy and hostile environment for an arc-operated hydrogen fluoride/deuterium fluoride (HF/DF) chemical laser. PC-based DAS has been configured using Advantech plug and play modules with fiber link connectivity. This article also focuses on implementation of an orifice-based precise gas flow control system. The plasma arc discharge in an arc heater/generator is essentially employed for inducing thermal dissociation of sulfur hexafluoride SF₆ for production of fluorine atoms, and DAS has been used for performance optimization of the composition of the lasing mixture by independently varying the flow rate, pressure, and temperature of its constituents. Since arc load is complex with high voltage transients and electromagnetic noise, an optical fiber link has been implemented for data transmission. This article also discusses digital output interface circuitry for various electro-pneumatic actuators/solenoid valves. The developed DAS has been used for monitoring and performance evaluation of parameters for 50 kW arc tunnel.     

气固两相流超声过程层析成像系统研究

研究了一种应用于气固两相流过程监测的超声波层析成像系统。为利用少数传感器实现较精确成像,研制了一套测试系统:传感器阵列由8个扇形空气耦合传感器组成,每个传感器均为收发一体式并且发射扇形波束角度可达150°;设计了基于单片机的切换装置以改善系统实时性;发展了改进二值逻辑反投影图像重建算法,通过设置双阈值改善边缘效应提高了图像重建精度。对四氟乙烯棒进行的静态实验与对煤粉进行的动态测试实验中,系统获得了足够多的有效信号数据,实现了气固两相流横断面的二维图像重建。静态实验中重建图像的最小空间成像误差(SIE)为3.2%,表明系统具有较好成像精度,可实现气固两相流流动监测。     

电火花机床计算机数控系统的设计

这里简要介绍了电火花加工(EDM)的原理,为满足其加工要求,将PC机强大的软硬件资源、友好的人机界面和单片机优秀的实时控制功能、灵活的编程能力有机的结合起来,开发出电火花机床计算机数字控制系统(CNC),并实现了对电火花加工过程的模糊控制。实验表明该系统具有运行可靠、加工稳定、加工效率高和可视化图形操作界面、操作简单等特点。     

气相色谱电子流量/压力控制模块研制和应用

为了提高气相色谱仪气路控制自动化水平,研制了电子流量/压力控制模块.该模块在基于闭环控制的方式上,通过小流量比例电磁阀、小流量和压力传感器、微型可调限流装置、颗粒过滤网、集成流路块体的优化设计,以放大基准电路、A/D转换、单片机控制系统PID、D/A转换、功率驱动电路来达到控制气体流量/压力的目的.再以单气路控制为最小...     

基于PLC的液压机控制系统设计

针对传统液压机控制系统的不足,为使其拥有更好的性能和人性化操作界面,构建了基于PLC与工业触摸屏的电气控制系统整体结构,设计采用三菱FXIN PLC作为主控核心,实现的功能分别为与上位机的数据交换,对液压机外围硬件电路以及内部阀体控制和对压力、位移、温度的数据检测.并给出相应的PLC程序及部分上位机界面设计.应用结果表明,与传统设计相比,该系统既可以实现自动优化运行,又可以满足手动控制的操作要求,提高了工作效率,是机电一体化的典型应用.     

Fluid Level Sensor‐Controlled,Fully Automatic Spectrophotometry System

Abstract

This study deals with a new, relatively economical, and fully automatic spectrophotometer. The most difficult part when working with automatic spectrophotometers is that the same quantities of sample to be analyzed and reagent have to be prepared for each measurement to maintain the reproducibility and accuracy of the measurements. This generally requires the use of very expensive systems (pumps, selection valves, etc.). In the system proposed here, the flow is gravitational and quantities of sample and reagent are kept constant using level sensors. Simple electrical solenoid valves are used for these processes. The PIC 16F877 microcontroller serves to control the solenoid valves and to save the analytical results. These results are saved on an EEPROM on the electronic card, and may be read directly on an LCD or saved on a PC from the EEPROM. In order to obtain data from remote stations in real time, the results are transmitted as SMS via GSM operators. The system analyzes the Fe(II) ions in the rainwater. By small modifications, it may be used to measure other parameters.     

基于HT46R23的智能排气扇的研制

介绍了研制的智能排气系统的构成及检测主机的硬件与软件设计,该智能排气系统运用传感器技术、电子技术与微机技术对化工仓库中有毒有害气体的含量、空气的温度、湿度3个关键技术参数进行了动态检测,基于化工企业的实际情况,采用气敏传感器、热敏电阻、湿敏传感器分别精确检测有毒有害气体含量、温度、湿度和压力值,试验结果表明:该系统具有稳定性好,精度和灵敏度高,响应速度快等特点.     

负载敏感多路阀测试系统研究

设计负载敏感多路阀液压测试回路,建立以负载敏感多路阀为测试对象的测试系统。通过STM32单片机为核心的硬件电路,将压力、位移和流量等传感器采集所得数据进行处理;以LabVIEW为软件控制平台,通过高性能以太网芯片W5500,实现对阀数据的在线采集、输出、保存及打印。以某种农机专用且已知性能完好的负载敏感多路阀为测试对象,根据测试结果判断测试系统性能及被测负载敏感多路阀具体参数。系统测试结果表明,所设计测试系统稳定可靠,为多路阀测试系统研究提供一些有价值的参考。     

气敏元件自动测试系统的设计

介绍了一套气敏元件自动测试系统的设计方案,该系统能够自动控制气敏元件的工作温度、时间及测试气体的流量和浓度,能够自动采集气敏元件的动态响应,并通过测试系统软件实现数据处理与图像分析.改善了系统在数据采集与图像处理方面的不足.     

分布式远程无线巡回测温系统的研究

为提升对不同地点温度变化情况的监测水平 ,可采用多个温度传感器进行分布式布置 ,并采用无线巡回通信技术实现对多个测温点的遥测遥控。有鉴于此 ,本文构建了一种远程分布式无线巡回测温系统 ,并采用一台个人PC机充当系统主控中心 ,通过基站对多个从站进行分布式无线巡回测温及其控制 ,控制关系简单 ,测温效果良好。所采用的系统设计方案和工作流程具有一定的参考意义和实用价值     

基于VC＋＋的钻机起升综合实验装置监测系统设计

设计了一种基于VC＋＋编程环境的钻机起升实时监测系统。该系统主要由传感器、数据采集部件、通信接口电路、PC机及相应的系统软件构成。系统软件在Microsoft Visual C＋＋6．0集成环境下开发,采用模块化的设计思想,主要包括数据采集模块、报警模块、数据保存模块、数据处理和分析模块。     

Simulation and experimental study of phase segregation in helical pipes: A new method for flow conditioning

The aim of the present study is to contribute some knowledge of phase separation phenomena of gas–liquid turbulent flow in curved pipe and provide a basis for the development of an in-line gas–liquid separator and flow pattern conditioning device. A systematic study of gas–liquid three-phase flow in 3D helical pipes was numerically performed. Gas phase distribution in the flow through the helical pipe was analyzed for various flow parameters conditions and different pipe geometries. Experimental qualitative results show that a helical pipe can, successfully, be used to condition a bubble flow into a stratified (stratified wavy flow). The main idea is to put it just upstream of sensors that are flow regime dependent; ensuring that the sensor, once calibrated to work in this flow pattern, suffers no reduction in its performance and, consequently, avoid additional sources of error.     

基于LabVIEW及DAQ的光电检测系统

基于NI USB-6009数据采集卡、上位机及Lab VIEW为基础构建了光电检测系统。系统适用于光电传感器性能检测以及简单的实时信号监控。系统中数据采集由数据采集卡实现,其他功能,包括数据存储、触发、控制、显示、用户界面等,均在上位机中用软件(Lab VIEW 2013)实现。由于采用USB数据线,采集卡与上位机之间连接方便,并且提高了可扩展性、可维护性,降低了成本。实验结果表明,对于不同的光电传感器,系统都能够进行准确的检测。     

超临界二氧化碳气体端面密封阻塞效应研究

为了分析超临界二氧化碳气体临界状态大幅度物性参数变化和偏离理想气体的真实气体效应对干气密封性能的影响,建立螺旋槽干气密封端面微尺度三维流动模型,分别采用Fluent软件中二氧化碳的实际气体模型和理想气体模型求解密封端面流动方程。数值模拟结果表明:考虑超临界二氧化碳实际气体效应时,端面更容易发生阻塞工况;气膜间隙和转速增大,阻塞效应增强,但温度升高,阻塞效应减弱;在阻塞工况下,密封开启力和泄漏量均随着气体温度、转速增加而降低。     

分析测试实验室集中供气系统的设计应用

比较了分析检测实验室仪器载气的传统供气方式和集中供气方式的优缺点，从管阀件的选材、供气压力稳定性、安全性及维护的方便快捷等多方面考虑，提出了集中供气设计方案及日常维护注意事项。集中供气是由双侧汇流排系统手动或自动切换供气，采用两级减压方式，通过316L不锈钢干路长距离管道输送将载气输送至仪器前端，具有供气稳定、经济、美观、便于维护及管理的特点。     

High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m∕Δm > 2500. The system design is superior to conventional batch and flow reactors with accompanying product detection by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0-5000 amu in the current configuration). As a demonstration of the system performance we present data from ammonia oxidation on a Pt thin film showing resolved spectra of OH and NH(3).     

三参数灌浆自动记录仪

介绍了研制的LJ型三参数灌浆自动记录仪，仪器运用传感器技术、电子技术与微机技术对灌浆过程中的压力、流量和水灰比3个关键技术参数进行了动态检测，设计了传感器与主机的接口，研制了数据转存器与灌浆资料管理软件。实验结果表明：该仪器具有稳定性好、精度和灵敏度高、响应速度快等特点，在高温、潮湿、高灰尘的恶劣施工现场能正常工作。