A VUV-UV gas-discharge lamp on a low-pressure mixture of argon and xenon with bromine vapors

The characteristics of a lamp operating on a low-pressure (0.5–1.5 kPa) Ar-Xe-Br₂ mixture and excited with a longitudinal glow discharge have been studied. A cylindrical lamp has a 10-cm interelectrode distance and a 1.4-cm-diameter discharge tube. The lamp radiates in the spectrum range 150–300 nm. Its emission spectrum is represented by a wide continuum formed on the basis of the 282-nm XeBr(B-X) and 220-nm XeBr(D-X) bands and the 163.3-nm spectral line of atomic boron. The emission power of the lamp reaches 5–7 W at a power of up to 40 W injected into the discharge tube. The service life of the lamp on a single working mixture reaches 500 h.     

A UV source on hydroxyl molecules operating in a pulsed-periodic mode

The emission and energy characteristics of a UV source based on water vapors, which was excited by a longitudinal pulsed-periodic discharge, are presented. The emission in the spectral range 280–340 nm was studied. The average emission power of gas-discharge plasma of low-pressure (∼130 Pa) water vapors in the UV region was 75 mW.     

Development of micro-stereolithography technology using a UV lamp and optical fiber

Micro-stereolithography technology makes it possible to fabricate free-form three-dimensional (3D) microstructures using a focused UV beam with a very small focal diameter to solidify a UV-curable liquid photopolymer. Generally, expensive UV lasers and complex optical systems are required. However, in this study, we developed a more economical and simpler micro-stereolithography technology using a UV lamp as a light source and optical fiber as the light delivery system. We conducted photopolymer solidification experiments to examine the characteristics of the developed micro-stereolithography apparatus. To achieve an adequate solidification width and depth, a photostabilizer was mixed with a conventional photopolymer and then tested. The developed apparatus could be used to fabricate 3D microstructures by modifying the fabrication conditions for a given photopolymer. Several 3D microstructures were fabricated.     

基于模型预测控制的灯光调节系统设计

高压钠灯是人工温室常用的光源，控制比较困难。结合模型预测控制策略，设计了高压钠灯连续调光二级控制系统。实验结果表明，在存在干扰情况下，系统仍能获得满意的控制效果。     

基于PSoC的紫外荧光法水中藻类检测系统设计

近年来我国多次大面积爆发湖泊水华,利用紫外荧光法可快速检测水中叶绿素的含量,进而监测水体中富营养化程度。本文依据叶绿素荧光检测的基本原理,设计和完成基于可编程片上芯片(PSoC)的荧光检测系统。提取湖泊中的水样,经丙酮溶液萃取后制成不同标准浓度的叶绿素溶液,实验测定其对应荧光值。实验证明,本系统可较好地应用于水质中叶绿素的检测。     

I^2C总线在数据采集器的FPGA实现

基于Altium Designer开发平台。采用原理图实现顶层模块及主电路图．VHDL语言实现控制电路和各部分接口电路两级设计的方法实现数据采集器．其中A／D、D／A转换芯片与系统主控电路采用I^2C总线方式实现。文章给出了主体硬件图和I^2C总线的部分实现程序。     

基于STM32智能氘灯电源的设计与实现

为了满足分析仪器智能化的发展需求,本研究提出了一种基于STM32的智能氘灯电源。通过STM32微处理器控制氘灯电源的预热、启辉和恒流电路,并将恒流电路的输出电流分为3个档位可调。根据氘灯的发光强度,智能电源自动调节恒流电路档位大小,控制氘灯发光强度保持在一个相对固定的水平。进一步通过实验验证,设计的氘灯电源可自动实现新灯使用低电流档位,保证发光强度的同时降低不必要的浪费;旧灯使用高电流档位,在发光效率降低的情况下保证发光强度,延长使用寿命。     

基于声—光传感技术的楼道灯的研制

根据楼道灯在实际应用中的特点,提出了系统的控制方式和整体方案。详细说明了关键部件的工作原理,双话筒的选用、差分放大电路、带通滤波电路、光敏电路、强电输出电路;并对程序流程图进行了分析。     

氙灯和发光二极管作光源的积分球太阳光谱模拟器

设计了一种由氙灯和发光二极管(LEDs)作光源的积分球太阳光谱模拟器来提高太阳光谱的光谱匹配精度.引进模拟退火算法研究光谱匹配技术,设计了氙灯模块及LEDs模块的结构和控制系统.LEDs采用环带摆放和恒流驱动方式,并通过多机通信系统控制.氙灯模块上安装截止滤光片和程控衰减器,滤光片用来滤去氙灯红外波段的尖峰,衰减器则用来调整氙灯入射到积分球的辐射通量.仿真实验表明:Epitex公司的53种单色LEDs和氙灯完全可以模拟380～1000 nm波段的AM 1.5标准太阳光谱,光谱的平均相对误差为5.67％.分析讨论了该太阳光谱模拟器的光谱失配误差、出光面的辐照非均匀度和辐照不稳定度,三者均可以控制在±3％以内.     

基于GPRS／GSM的路灯监控系统研究

针对国内外路灯监控系统的特点,结合现有路灯监控系统,提出了一种基于GPRS／GSM的路灯监控系统,该系统集移动通信技术、软件开发、传感器技术及控制技术于一体,在通信方面做出了较为先进的改进。该系统较之现有路灯监控系统无论在功能上还是在稳定性方面都有了显著的提高。     

基于ECPR的紫外探测器绝对光谱响应测试系统

在研制电定标热释电辐射计(electrically calibrated pyroelectric radiometer,ECPR)的基础上,设计和研制了紫外探测器绝对光谱响应测试系统.系统由紫外光源、光栅单色仪、移动探测器平台、弱信号检测仪器以及计算机和软件组成.测试采用参考探测器和待测探测器的光谱响应度比较的方法完...     

基于Fluent的UV杀菌器结构设计和仿真

随着紫外线(Ultraviolet,简称UV)杀菌技术在船舶压载水处理方面的应用日趋成熟,对UV杀菌器的结构设计要求越来越高,其设计核心就是确定UV照射剂量。根据杀灭不同微生物所需UV剂量大小确定杀菌器辐照剂量,应用经验公式进行UV杀菌器结构设计,对流场进行了仿真。根据仿真结果的不足,提出在进出口加一旋向相反的导流叶片,对改进后的杀菌器的流场进行再仿真。最后,对两次的结果进行比对,并统计了二者的过流时间,得出在优化后,流速分布变得均匀,从而保证了杀菌效果,说明该优化结构是可行的。     

基于单片机的I2C总线系统设计

目前比较流行的串行扩展总线中,I2C总线以其严格的规范和众多支持I2C接口的外围器件而获得了广泛的应用.它适合于较复杂单片机应用系统中元件与芯片之间的短距离通信,主要应用于板级的IC通信.文章中介绍了基于单片机的I2C总线系统设计过程,其中包括了硬件和软件的设计.     

基于I2C总线的64×8Bits EEPROM芯片的设计与实现

本文主要阐述了一款基于l2C总线的64×8 Bits EEPROM芯片的设计与实现.首先介绍了l2C总线的特点及其工作原理.然后,对整个设计的框架,每个部分的功能做了说明.其中重点介绍了总线控制模块的设计与实现,并给出了该模块的主状态机.最后,对测试验证的方法,及验证结果做了介绍.     

Staining of DNA-phosphate groups with a mixture of azure A and acridine yellow.

This paper deals with staining of DNA-phosphate groups with a mixture of an equal parts of aqueous solution of azure A and acridine yellow in a 1:1 proportion and also embodies a study of the absorption properties of the stained nuclei. It also embodies results of sequential staining of nuclei stained first with azure A followed by staining with acridine yellow and vice versa, after extraction of RNA with cold phosphoric acid. The results indicate that the absorption peaks of nuclei differ from those of nuclei stained for DNA-aldehyde molecules with azure A-SO2 or acridine yellow-SO2. The in vitro absorption characteristics of an aqueous solution of azure A and those of an aqueous solution of acridine yellow are also presented herein. The conclusion obtained from this study is that all the phosphate groups of DNA do not take part in the staining process when staining is carried out with azure A or acridine yellow alone after after RNA has been extracted. This is because the nuclei stained with these dyes sequentially show the presence of acridine yellow-DNA and azure A-DNA complex.     

Simulation and analysis of grinding wheel based on Gaussian mixture model

This article presents an application of numerical simulation technique for the generation and analysis of the grinding wheel surface topographies. The ZETA 20 imaging and metrology microscope is employed to measure the surface topographies. The Gaussian mixture model (GMM) is used to transform the measured non-Gaussian field to Gaussian fields, and the simulated topographies are generated. Some numerical examples are used to illustrate the viability of the method. It shows that the simulated grinding wheel topographies are similar with the measured and can be effective used to study the abrasive grains and grinding mechanism.     

Machine fault diagnosis based on Gaussian mixture model and its application

This paper presents a simple and efficient machine fault diagnosis approach based on Gaussian mixture model (GMM). After feature vectors that represent different machine conditions are extracted, a GMM for each of the machine conditions is built based on the corresponding extracted feature vectors, machine fault diagnosis can be accomplished through finding out the GMM whose posteriori probability for a given testing feature vector is the maximum of all. Experimental results based on the application on bearing fault diagnosis have shown that GMM can reliably diagnose not only the type of bearing faults, but also the degree of fault severity that are associated with incipient faults, moderate faults, and severe faults. Meanwhile, GMM has better diagnostic performance as compared to the multilayer perceptron neural networks.     

A numerical prediction on the reduction of microorganisms with UV disinfection

This paper investigates the three dimensional flow field and organism concentration in a UV disinfection channel. The modified P-1 model is newly adopted to solve the UV intensity field. This modified P-1 model for radiative transfer can yield an accurate light intensity for even complicated geometries. The effect of UV light intensity on the disinfection of microorganisms has been considered in the species equation. Differently from existing literatures, this study has used the Euler method for the calculation of both the flow field and the concentration of organisms. The CFD modeling results are compared with existing experimental data [1] for a UV channel, which shows outstanding agreement. The effects of inlet velocity, absorption coefficients of lamps quartz and water on the disinfection efficiency are investigated. With a smaller inlet velocity and smaller absorption coefficients, higher disinfection efficiency has been obtained. The current CFD model has the capability to predict the performance of UV disinfection channels.     

A study on radial spreading of a resin droplet with varying viscosity under UV curing process

One-dimensional axisymmetric fluid dynamics of a resin droplet was studied when it is squeezed between two parallel plates under the influence of UV (Ultraviolet) radiation curing. The radial spreading of different level of resin viscosity and its spreading speed are developed from the previous framework for viscous fluid dynamics of Newtonian fluid with negligible capillary number and Reynolds number. Then the final equations for spreading radius and spreading speed under the influence of UV curing are related with each other for the given spreading radius, viscosity at the corresponding elapsed time. The elapsed time increment could be assessed from the incremental elapsed time calculated from the incremental radius, assuming negligible viscosity change when the incremental radius is controlled to be small enough. The spreading of resin droplet is highly restricted by rapid viscosity rise due to crosslinking polymerization from UV curing. The theory was verified through droplet spreading tests with resin samples of different initial viscosities and of the same viscosity under different UV power. The theoretical prediction was in good agreement with the experimental results for both spreading radius and spreading speed. The same theoretical approach was then applied to the prediction of spreading boundary size and time to reach to it for a slow curing resin with different UV power intensity.     

烟气颗粒物浓度激光测量仪光电传感器运算处理电路设计

设计了一种烟气颗粒物激光检测仪的激光信号处理电路,检测系统应用激光Mie散射原理.信号处理电路采集散射光的光强信号,采用双光路结构消除干扰噪声,将微弱电流信号转换成便于测量或转换的0-10V电压信号,输出稳定,反应灵敏,能够对输入的变化快速反应产生可信输出.