江汉平原农村饮用水净化工艺研究

针对江汉平原农村地表水污染情况和农村水生疾病的状况,设计了农村饮用水的净化方案与工艺,以满足农村居民的基本饮水需求。工艺设计兼顾了集成式装置对结构紧凑的要求和净化功能;预处理选用臭氧预氧化和混凝沉降进行,常规处理选用可靠的石英砂过滤,深度处理选用紫外线杀菌和膜分离。在水处理工艺的基础上,设计了一套集混合、絮凝、沉降于一体的旋流强化混凝设备。该水处理系统采用模块化组合,结构紧凑,安装、使用方便,为农村饮用水的净化提供了新的方法。     

基于物联网的公路网传感设备故障信息系统设计

针对我国高等级公路严重的管理滞后问题,分析公路网传感设备的特点、实际使用情况及故障诊断常用方法,研究了基于FTP传输协议及Windows服务程序的公路网传感设备数据采集传输方法,通过实验表明该方法解决了公路网多种传感设备的异构数据的采集传输的问题;采用Visual Studio 2008及SQL Server 2005作为开发工具,设计开发了基于B/S结构的公路网传感设备故障信息系统,实现对各类型公路网传感设备基本信息的管理、故障记录的管理及传感设备的数据采集传输,通过实际测试证明该系统可以正确运行,实现了设计的功能。     

多媒体教学设备使用课件的设计

目前各高等院校多媒体教学系统设备种类繁多,教师在教学过程中,由于对多媒体教学系统各类设备功能及使用方法不熟悉,经常会出现多媒体设备的使用操作故障,从而影响正常的教学工作。为了培训教师掌握多媒体教学系统设备的使用技能,充分发挥多媒体教学设备的功效,更好地服务于现代化教学,提出利用PPT软件设计多媒体教学设备使用课件。     

试谈光缆通信的应用和发展

光纤通信因其具有损耗低、传输频带宽、容量大、体积小、重量轻、抗电磁干扰、不易串音等优点,备受业内人士青睐,发展非常迅速。目前,光纤光缆已经进入了有线通信的各个领域,包括教育卫生、邮电通信、广播通信、电力通信、石油通信和军用通信等领域。在此主要讲述我国光缆通信在网络中的应用。     

The segmented presentation of visually structured texts: Effects on text comprehension

The effects of a segmented presentation applied to a visually structured text were examined in the context of the explosion of small-screen devices. Empirical research investigating the influence of text signaling on text processing suggests that the text visual structure may influence comprehension by facilitating the construction of a coherent text representation. Undergraduate students were asked to read a text under different segmented conditions varying on the type of information provided about the text visual structure and on the segmentation unit. When the segmented presentation did not supply any information or when it only offered local information about the text visual structure, text comprehension depended on the segmentation unit. When the segmentation unit did not fit the text visual structure, an erroneous text representation was constructed, whereas the compatible segmentation unit led to a correct text comprehension. When the segmented presentation rendered the global text visual structure, the segmentation unit had no effect on comprehension and more readers constructed a correct and close text representation. Thus, the text visual structure seems to play a role in text comprehension and this role has to be taken into account for text segmented presentation.     

Synchronized switch harvesting applied to self-powered smart systems: Piezoactive microgenerators for autonomous wireless receivers

This paper introduces the conceptual architecture of a fully integrated, truly self-powered structural health monitoring (SHM) scheme. The challenge here is to power an array of numerous distributed actuators and sensors as well as wireless data transmission modules without recurring to heavy and costly wiring. Based on microgenerators which directly convert ambient mechanical energy into electrical energy, using the synchronized switch harvesting (SSH) method, the proposed solution allows avoiding the periodic replacement or reloading of batteries. This addresses environmental and economic issues at the same time, knowing that such elements are heavy, polluting and might be installed in rather inaccessible locations. Indeed, especially in airborne structures saving weight and maintenance cost is of priority importance.Previous work showed that such microgenerators provide a stand-alone power source, whose performances meet the requirements of autonomous wireless transmitters (AWTs) that comprise an acoustic Lamb wave's actuator and a radio frequency (RF) emitter (D. Guyomar, Y. Jayet, L. Petit, E. Lefeuvre, T. Monnier, C. Richard, M. Lallart, Synchronized switch harvesting applied to self-powered smart systems: Piezoactive microgenerators for autonomous wireless transmitters, Sens Actuators A: Phys. 138 (1) (2007) 151–160, doi:10.1016/j.sna.2007.04.009). Following this work, the present contribution presents a further step towards the integration of the SHM technique. It shows the ability of our microgenerators to provide enough energy to give logical autonomy to each self-powered sensing node, named autonomous wireless receiver (AWR), and thus to provide some local (decentralized) pre-processing ability to the SHM system.A preliminary design of the device using off-the-shelf electronics and surface mounted piezoelectric patches will be presented. Since the existence of a positive energy balance between the harvesting capabilities of the SSH technique and the energy requirements of the proposed device will be proved, the system formed by the combination of the AWR with the previously developed AWT, is a proof of concept of truly self-powered smart systems for damage detection in simple structures, setting apart application-specific optimization or miniaturization concerns that will be addressed in future works.     

Line patterning of graphite and the fabrication of cheap, inexpensive, “throw-away” sensors

A new simple method (“line patterning technique”) using only standard office equipment is described whereby clearly defined, electrically conducting patterns of graphite can be deposited on polymer (plastic) or paper substrates. The properties of the conductive patterns have been characterized by electrical conductivity and SEM measurements. Sensors were constructed by using interdigitated patterns of graphite deposited on plastic and paper, and coated with a thin film of conducting electronic polymer, e.g. polyaniline emeraldine salt.     

Transaction Management for Flash Media Databases in Portable Computing Environments

Flash memory is becoming a major database storage in building embedded systems or portable devices because of its non-volatile, shock-resistant, power-economic nature, and fast access time for read operations. Flash memory, however, should be erased before it can be rewritten and the erase and write operations are very slow as compared to main memory. Due to this drawback, traditional database management schemes are not easy to apply directly to flash memory database for portable devices. Therefore, we improve the traditional schemes and propose a new scheme called flash two phase locking (F2PL) scheme for efficient transaction processing in a flash memory database environment. F2PL achieves high transaction performance by exploiting the notion of the alternative version coordination which allows previous version reads and efficiently handles slow write/erase operations in lock management processes. We also propose a simulation model to show the performance of F2PL. Based on the results of the performance evaluation, we conclude that F2PL scheme outperforms the traditional schemes.     

Calculation of photosensitivity of porous silicon with the cylindrical geometry of pores

The paper theoretically investigates a model of the photosensitivity of porous silicon with cylindrical pores in the condition of homogeneous generation of photocarriers. Dependences of the photoconductivity of a porous semiconductor on the velocity of recombination of nonequilibrium carriers at the surfaces of pores, radius of pores and average distance between them are analyzed. At large velocities of surface recombination the photoconductivity of porous semiconductor is shown to linearly decrease with increasing the pore’s radius. The article is published in the original.     

移动设备中基于J2ME技术游戏的开发与实现

J2ME是一种针对开发移动设备平台的Java语言,它的应用极大地扩展了手机、个人数字助理等小型移动设备的应用范围。介绍了J2ME的体系结构和J2ME技术开发游戏的新特性,结合一个实际例子着重分析了基于J2ME手机游戏开发的过程,通过总结和分析手机游戏的开发流程和代码框架的设计,详细描述了移动设备的游戏开发和实现过程,最后展示了手机游戏的运行效果。