基于ICCD的高分辨率汤姆逊散射系统分析

本文介绍了一套针对EAST托卡马克上的高分辨汤姆逊散射诊断系统(简称TVTS).设计采用了Littrow型平面光栅谱仪和带三代的像增强器的ICCD相机,同时测量整个等离子体中心弦的电子温度和密度.本文概述了该系统的意义和原理,分析了系统各部分的设计方案并对系统性能进行了估算.可测的电子温度范围和电子密度范围分别是250ev～2key和2×1019 m-3～5×1019 m-3,空间分辨率为10mm,时间分辨率约为几个毫秒.     

EAST汤姆逊散射诊断定位控制系统的设计

设计了一种激光光路定位控制系统,用于EAST汤姆逊散射诊断的光路准直和测量区域的定位,其精确性对于该诊断的测量尤为重要,该诊断用于测量EAST装置放电时等离子体的电子温度和密度;为节约宝贵的实验时间,结合该系统给出一种快捷的激光光路定位方法;重点描述该系统中基于单片机PIC16F874A设计的靶板控制器,与传统步进电机控制器相比,具有故障恢复、支持光纤通信、体积小等优点。该系统已在2010年度的EAST实验中投入使用,运行可靠,定位精确,大幅缩短了光路准直所需时间。     

EAST技术诊断系统监控子系统分析和设计

EAST是为科学研究建造的全超导核聚变实验装置。根据EAST的实验特点和性能要求,技术诊断系统数据监控子系统采用管理层、控制层和现场设备层3 层网络结构完成对装置的监控,通过采集卡和以太网实现信号采集及数据的传送。在EAST工程调试实验和两轮放电实验中,该数据监控系统成功实现了对EAST装置的运行状态和故障诊断的实时监控,表明该系统具有性能稳定、可靠等特点。     

EAST等离子体剖面数据可视化

EAST已经初步建立较为完善的分析数据数据库,相较于存储原始采集信号的一级数据库,科研人员称这个包含EAST各个子系统（诊断、加热、加料等）具体物理信息的数据库为EAST二级数据库.为了便于科研人员从EAST二级库中查看和分析等离子体剖面数据,采用Python及PyQt开发了数据可视化图形用户软件.它可以分析比较来自不同诊断系统的剖面数据,具有将剖面数据用图形表示出来并改变图形属性等功能.同时在等离子体放电实验期间,提供了炮间分析等离子体剖面数据可视化的功能.本文介绍了EAST剖面数据可视化系统的设计方案与实现方法,同时也给出了系统的初步测试结果.     

虚拟EAST系统的设计与实现

虚拟EAST系统能三维再现EAST装置,并提供360度全方位浏览EAST内部结构及点击访问相关信息的功能.交互式虚拟EAST的建立使用了3ds Max和虚拟现实建模语言(VRML)技术,3ds Max提供了良好的可视化开发环境,可以利用其产生高质量的3D模型;VRML是Web上建立三维虚拟模型的标准语言,可以构造虚拟场景并实现用户与虚拟场景的互动.初步构建了虚拟EAST系统,可以动态交互地再现EAST装置,为全面虚拟EAST的三维物理实验建立了基础.     

LHCD高压电源诊断

本文介绍了EAST低杂波高压电源系统的诊断,在低杂波系统中高压电源系统的正常运行意义非凡。我们通过对一般的抽象的故障分析专家系统具体化建立一个高压电源故障分析专家系统并把它做成一个可被计算机识别的数学模型存储在计算机当中。在低杂波高压电源诊断系统中,根据采集到的高压电源的参数通过存储在计算机中的高压电源故障分析专家系统来推断高压电源系统中哪个部分出现了问题,这个问题会带来什么影响以便去寻找针对具体故障的解决办法。     

最精品的便携式多媒体播放器——法国汤姆逊PMP2516

在法国汤姆逊THOMSON进入中国前,国内已经有同样一家主打音/视频产品的深圳汤姆逊TMS;时至今日,这两家“汤姆逊”都仍然在市场上存在。也因此,当THOMSON跟我们联系时,一再强调自己是法国汤姆逊,生怕给混淆了。尽管都叫“汤姆逊”,但法国汤姆逊与深圳汤姆逊走了一条不同的发展道路。近期法国汤姆逊以“薄”为特色,推出了一系列PMP产品。前段时间高光玛瑙灰丝质不锈钢外壳的FMP2008吸引了不少眼球,现在法国汤姆逊继续秉承“薄”理念,推出PMP2516。外观PMP2516跟PMP2008一样,都采用了卡位式结构设计,正反两片机壳以卡扣形式紧密结…     

实时交互式虚拟EAST系统

实时交互式虚拟EAST(全超导托卡马克)系统能够三维重现EAST装置,在线获取EAST实验工程数据,实时显示等离子放电位形等三维物理实验成果。该系统采用B/S(浏览器/服务器)结构框架,结合了VRML(虚拟现实建模语言)和Java3D两种虚拟现实技术。利用VRML建立EAST三维仿真模型,结合Java3D实现用户与场景的交互,最终实现一个实时、动态的三维物理实验系统,从而推动EAST实验的进行。     

EAST托卡马克实时数据系统

全超导托卡马克装置EAST的设计目标之一是实现1 000 s的可控等离子体放电,与此相对应,需要构建具有实时数据传输、存储和发布的高速分布式实时数据系统。该文从功能结构和实现方法2个方面,论述了EAST实时数据系统的硬件结构,对基于时间片机制的实时数据系统接口和实现方法进行分析。     

基于XMPP的EAST实验通信系统的设计与实现

为满足EAST实验中实验信息交互对象的多样性和实验人员远程控制的需求,提出了基于可扩展消息处理现场协议XMPP的即时通信系统方案;该系统是基于可扩展消息处理现场协议,采用C/S模式实现,用于EAST实验信息交流的即时通信系统;在基本通信功能模块实现的基础之上,重点研究设计了EAST实验数据可视化,实验信息共享白板等功能模块;该系统为EAST实验提供了一个良好的即时信息交流平台,为实验数据资源的交流和实验的远程控制提供了方便,在EAST实验中得到广泛的应用.     

James Clerk Maxwell's Glasgow manuscripts: extracts relating to control and stability

Four of Maxwell's letters which were written to William Thomson, and are currently held by Glasgow University Library, are reproduced and discussed. Some of the material relates to control, and leads to possible explanations of certain points which were treated enigmatically in Maxwell's 1868 paper on governors.     

基于PPP-80TDA分布式光纤温度传感技术的数值模拟

基于脉冲预泵浦布里渊光时域分析法的分布式光纤温度传感技术是近年来出现的一种新型温度传感技术.本文采用有限差分法对一维瞬态受激布里渊散射的耦合波方程进行了数值求解,分别模拟了传感器在不同温度情况下的布里渊散射三维频谱图,得到了布里渊散射谱的中心频率、布里渊频移以及功率随温度变化的趋势.仿真结果表明,理论模拟与实际相符,并...     

Application of the Polynomial Chaos Expansion to the simulation of chemical reactors with uncertainties

In this paper we consider the simulation of probabilistic chemical reactions in isothermal and adiabatic conditions. Models for reactions under isothermal conditions result in advection equations, adiabatic conditions yield the reactive Euler equations. In order to treat with scattering data, the equations are projected onto the polynomial chaos space. Scattering data can largely affect the estimation of quantities in the system, including variable optimization. This is demonstrated on a selective non-catalytic reduction of nitric oxide.     

Multitaper perceptual linear prediction features of voice samples to discriminate healthy persons from early stage Parkinson diseased persons

The performance of multitaper perceptual linear prediction (PLP) features of speech samples to discriminate healthy and early stage Parkinson diseased subjects is investigated in this paper. The PLP features are conventionally obtained by computing the power spectrum using a single tapered Hamming window. This estimated spectrum exhibits large variance which can be reduced by computing the weighted average of power spectra obtained using a set of tapered windows, leading to multitaper spectral estimation. In this investigation, two multitaper techniques namely Sine wave taper and Thomson multitaper along with the conventional single taper windowing are investigated. Artificial Neural network is then used to classify the PLP features extracted by applying the three types of window tapers on the speech signals of healthy and early stage Parkinson affected people and their respective performances are compared. The results show more accuracy using the multitaper techniques when compared with the conventional single taper technique. It is seen that the accuracy obtained using Sine wave tapers as well as Thomson multitaper is maximum for five tapers. An improvement in the recognition accuracy by 7.5% using the Sine tapers and by 6.9% using the Thomson tapers is obtained when compared with the conventional method. An improvement in other performance measures like Equal error rate, False positive rate, False negative rate, Sensitivity and Specificity is also observed in the multitaper techniques.     

分布式光纤滑动传感监测技术研究

基于光时域反射技术和瑞利散射原理,将高精度的自动力-光耦合测试系统与土工大三轴剪切试验仪相结合,完成了光纤滑动监测的力-光本构关系模型试验.结果表明,传感光纤的初始损耗达30～50dB,动态范围达3.0～3.5 mm,又利用试验测试数据,经曲线拟合,得出滑动损耗的半经验公式.     

Thomson问题的数值解及应用计算化学

提出一种能精确而有效的计算方法,用于计算分子各种表面积如容剂可及性表面积、范德华表面积和体积,对计算蛋白质溶剂化能、表征分子形状、计算药物分子在蛋白质分子表面的对接及预测有机小分子生物活性均有重要意义.本文针对n个单位点电荷在单位球面上均匀分布问题-Thomson问题,采用Metropolis Monte Carlo模拟退火方法数值求解,得到了与其它方法一致的结果,并用于小分子和大分子的容剂可及性表面积及范德华表面积和体积的快速计算,提出采用高时斯定理计算分子体积的新方法,结果很好.     

Modelling precipitation kinetics: Evaluation of the thermodynamics of nucleation and growth

Modelling of (solid-state) precipitation kinetics in terms of particle nucleation and particle growth requires evaluation of the thermodynamic relations pertaining to these mechanisms, i.e. evaluation of the nucleation barrier and of the Gibbs–Thomson effect. In the present work, frequently occurring problems and misconceptions of the thermodynamic evaluation are identified and a practical approach with regard to kinetic modelling is proposed for combined and unified analysis of the thermodynamics of nucleation and growth, based on the fundamental thermodynamic equilibrium consideration in a particle–matrix system. A computationally efficient method for numerical determination of the thermodynamic relations is presented which allows an easy and flexible implementation into kinetic modelling.     

Underwater image dehazing using joint trilateral filter

This paper describes a novel method to enhance underwater images by image dehazing. Scattering and color change are two major problems of distortion for underwater imaging. Scattering is caused by large suspended particles, such as turbid water which contains abundant particles. Color change or color distortion corresponds to the varying degrees of attenuation encountered by light traveling in the water with different wavelengths, rendering ambient underwater environments dominated by a bluish tone. Our key contributions are proposed a new underwater model to compensate the attenuation discrepancy along the propagation path, and proposed a fast joint trigonometric filtering dehazing algorithm. The enhanced images are characterized by reduced noised level, better exposedness of the dark regions, improved global contrast while the finest details and edges are enhanced significantly. In addition, our method is comparable to higher quality than the state-of-the-art methods by assuming in the latest image evaluation systems.     

基于Web UI的软件自动化测试的研究

随着软件产品使用范围的提高和先进组建设备的出现．软件产品的复杂性也越来越强．这就需要对软件产品实施更加深入和透彻的测试。自动化测试以其覆盖率大．测试效率高．精度准等多个优点．越来越被人们重视和使用。而轻量级测试程序的开发．不仅具备自动化测试的全部优点．还能够减少对测试环境的要求和弥补对测试工具使用熟悉度较低所产生的工作效率问题．使自动化测试更快更经济的投入到日常工作中。基于汤森路透公司（Thomson Reuters、的Common Platform Searchand Navigation项目对Reference Data的测试需求设计一个轻量级测试程序．