基于ARM处理器的现场总线协议转换网关的研究与开发

对Profibus-DP总线和CAN总线的协议帧结构以及数据传输方式进行了研究,提出现场总线协议转换的方法,并在此基础上进行协议转换网关的硬件和软件开发。为降低设计难度,提高系统性能,该网关采用基于ARM9内核的高性能处理器AT91RM9200作为主控芯片,并使用了专用的总线协议芯片SPC3与控制芯片SJA1000。实验结果表明,CAN总线设备可以成功接入到Profibus-DP总线中,各项性能指标都能达到设计要求,具有较高的实时性和可靠性。     

自适应多采样扫描转换算法

随着片元着色器的可编程能力不断提高和新型图元的出现,扫描转换必须加强多采样时的处理能力.经典的边方程扫描转换算法便于实现多采样,但采样点测试的计算量大并且存在冗余测试,为此提出一种自适应多采样扫描转换算法.该算法的多采样集中在"边界片元",并结合点采样和区域采样技术根据自适应细分规则细分边界片元进行采样点的测试;避免了边方程算法中进行采样点测试时的乘法运算,减少了采样点的冗余测试,提高了多采样时扫描转换的性能.实验结果表明,文中算法在较小代价下达到或接近有相同采样点数的超采样反走样能力.     

基于S5PV210的矿井综合接入网关的设计

针对现有矿井接入网关的专用网关存在可重用性差的问题,提出了一种基于S5PV210的矿井综合接入网关设计方案,介绍了网关的硬件结构和软件的设计,详细分析了多种协议之间的转换原理。该网关采用S5PV210微处理器、嵌入式操作系统和Socket软件技术实现了无线网络、现场总线网络、控制设备与工业以太网的互联,完成了多种协议之间的互转。     

应用于矿井LED电子显示牌的点阵式绘图软件设计

针对矿井LED电子显示牌采用矢量图技术绘图存在的图形绘制不精确、可视性差等问题,提出一种可应用于不同型号电子显示牌的点阵式绘图软件设计方案,介绍了该软件的总体设计及BMP图像的灰度化步骤。点阵式绘图软件基于组件的设计理念,实现了所见即所得的绘图功能、文字点阵转换功能、BMP图片导入/转换功能、ICO图标导入/导出功能、模拟显示功能及对外通用接口功能。比较发现,采用点阵式绘图软件绘制的原始图形及实际显示效果均明显好于采用矢量图技术绘制的图形。     

SVG的3D实现

针对SVG在3D图形的描述与绘制上存在局限性的问题,提出了一种SVG的3D实现方法;详细介绍了SVG的2D坐标系到3D坐标系的转换原理,给出了转换到3D坐标系后的SVG-3D图形的绘制与操控流程,并以在3D场景中绘制一个正立方体和圆球体为例,介绍了在HTML页面中采用JavaScript创建3D场景和绘制与操控这2个图形的实现。     

Report on a new OED project: A study of the history of new words in the new OED

The study of the history of new words in theNewOED described in this paper was undertaken in 1986-87, and is based on the material then available. Since then, theNewOED has been finished, and PAT, the inquiry system developed at the University of Waterloo for the investigation of theNewOED data base, has been much altered and improved. Nevertheless, this report should prove useful in indicating the potentiality for analyzing the computerizedNewOED and some of the problems. This project is a study of the ways in which new words are created in English at various periods of time. A chronological dictionary 's created listing words introduced into the language over 50 year increments. These words are then classified by the processes used in forming them to show, in proportional terms, if certain processes are more common at some times than at others.H. M. Logan, Associate Professor, Department of English, University of Waterloo, Waterloo, Ontario, Canada, has written The Dialect of the Middle English Life of St. Katherine (Mouton, 1973), making use of the computer in a study of medieval dialectology. He has also written articles on computer stylistics and literary analysis inCHum, ALLC Journal, Language and Style, College Literature, and on the dictionary inDictionaries.     

Photocatalytic syngas synthesis from CO2 and H2O using ultrafine CeO2-decorated layered double hydroxide nanosheets under visible-light up to 600 nm

The rational design of photocatalyst that can effectively reduce CO₂ under visible light(l>400 nm),and simultaneously precise control of the products syngas(CO/H2)ratio is highly desirable for the Fischer-Tropsch reaction.In this work,we synthesized a series of CeO₂-decorated layered double hydroxides(LDHs,Ce-x)samples for photocatalytic CO₂ reduction.It was found that the selectivity and productivity of CO and H₂ from photoreduction of CO₂ in conjunction with Ru-complex as photosensitizer performed an obvious“volcano-like”trend,with the highest point at Ce-0.15 and the CO/H₂ ratio can be widely tunable from 1/7.7 to 1/1.3.Furthermore,compared with LDH,Ce-0.15 also drove photocatalytic CO₂ to syngas under 600 nm irradiation.It implied that an optimum amount of CeO₂ modifying LDH promoted the photoreduction of CO₂ to syngas.This report gives the way to fully utilize the rare earth elements and provides a promising route to enhance the photo-response ability and charge injection efficiency of LDH-based photocatalysts in the synthesis of syngas with a tunable ratio under visible light irradiation.     

先进控制技术在波浪发电系统中的应用

由于波浪储量丰富,具有随机性,如何控制波能转换系统捕获最大波能和控制并网电能质量成为波浪发电的核心问题。简述了波能转换装置实现最大波能捕获的方法,综述了滑模变结构控制、自适应控制、最优控制、智能算法、模糊控制、无源控制在控制最大波能捕获以及改善电能质量方面的研究成果。并提出未来的控制算法应是多种先进控制算法相结合。     

Studying the formation process of chromate conversion coatings on aluminium using continuous electrochemical noise resistance measurements

A unique electrochemical technique, namely continuous noise resistance calculation (CNRC), was used to obtain electrochemical kinetic information from the formation process of chromate conversion coatings (CCC) on aluminium electrodes. It was found that the noise resistance (R_n) of aluminium electrodes remained almost unchanged during electrodes' immersion in a chromate containing acidic solution where the CCC films were supposed to form rapidly. This result indicates that the formation of CCC was associated with continuous corrosion of the aluminium electrodes and that the CCC films formed on aluminium surface were not intact barrier films, but most likely porous layers. The CCCs became protective only after they were aged in the environment. Based on these findings, the formation and inhibition mechanisms of CCC have been discussed.