相移光纤光栅横向受力传感特性研究

对相移光纤光栅(PS-FBG)的横向受力特性进行了理论和实验研究.采用传输矩阵法分析了PS-FBG的传输特性,并建立了光栅横向受力数学模型.理论分析表明,光栅透射谱阻带中的透射窗口在横向受力时会产生光谱分裂,且分裂距离与所受横向压力的大小成正比关系.实验在0~1 N的横向压力条件下,获得了1.4×10-3N/mm的灵敏度,实验结果与理论模拟相符.     

基于电涡流传感器的智能公交投币机性能改进

公交投币机在市场上得到广泛应用,但是现有智能公交投币机存在一些不足之处。研究通过应用微型直流电机,对现有的智能公交投币机进行改进,利用LM317控制投入的硬币通过电涡流传感器时的速度,并对软件进行修改,使智能公交投币机的硬币辨识率得到很大的提高。     

基于R-17MED化学传感器的氧气体积分数检测仪设计与实现

介绍一种基于R-17MED化学传感器的氧气体积分数检测仪设计与实现。系统可实现矿井等特殊环境中氧气体积分数的检测,保证特殊环境中工作人员的健康与安全。采用R-17MED化学传感器作为数据采集前端,将氧气体积分数转变成电压信号并直接送至TLC2543的采集通道(AIN4)进行A/D转换,转换后,通过和AT89C51连接的LCD编程实现氧气体积分数显示。将不同环境中得到的测试数据与理论数据相比较,系统测试精度达到97.78%,符合工业生产需求。     

基于多智能体协同的无线传感网络水产养殖监控系统

基于现有监控系统在自学习能力和监控范围方面的局限,将多智能体技术引入到规模化水产养殖监控系统中,提出了一种基于多智能体协同的无线传感网络水产养殖监控系统。系统由信息采集智能体、信息汇聚智能体、环境调节智能体、现场监控智能体和远程监控智能体组成。通过多智能体间的协作,使系统的监控能力得以增强,便于适应多变的养殖环境。试验结果表明,系统能够根据养殖环境因子的变化对养殖环境进行调节,精度满足要求,能够适应规模化水产养殖环境监控的需要。     

一种基于结构相似性的图像质量评价指标

图像质量评价方法是控制传输、压缩和处理对图像质量影响的关键技术,也是多媒体系统中不可或缺的一部分。提出一种基于结构相似理论的图像质量评价指标,首先将待评价的图像分割成若干互不相交的图像块;然后分别计算图像块的显著性和结构相似度;最后以每个图像块的相对显著性作为权重,计算整幅图像的结构相似度。该模型时间复杂度低,同时实验表明该指标的性能明显优于传统指标。     

基于AndroidPN技术的Zigbee无线网络的物联网数据采集

为了实现对体温和脉搏长时间的监测并形象地展示出温度和脉搏随时间变化的趋势,设计了一款基于AndroidPN技术的Zigbee无线网络温度、脉搏实时采集器,通过传感器采集人体实时的体温和脉搏信息,经过蓝牙或通过在PC上配置Android PN服务将采集到的信息传送到Android手机客户端,由手机实现对数据的显示和处理并生成实时的动态图表信息,再由手机的GSM等上网模块将数据上传到云端,实现数据的云存储,便于用户查看、管理。这种实时监测仪提供了一种便捷、低成本的温度和脉搏记录方式,在日常生活中有着广泛的应用。     

一种能量均衡的无线传感器网络分簇算法*

为了延长网络的生存时间,提出了一种能量均衡的无线传感器网络分簇算法（EBCA）,该算法优先选择剩余能量较多的节点作为簇首,以平衡节点的能量消耗。仿真实验结果表明：无论同构网还是异构网,该算法都能显著地推迟网络第一个节点的死亡时间,其性能明显优于LEACH算法。     

Thermal stability and performance of optimized ZrCx diffusion barriers in ceramic coating systems for ATF applications

Surface-modified Zr alloy claddings with advanced ceramic coatings are promising materials for accident-tolerant fuel (ATF) systems to meet stringent safety regulations concerning light water reactors. The applications of ceramic coatings are, however, limited as a result of inferior thermal stability when used in conjunction with Zircaloy-4 (Zry-4) substrates. Herein, the thermal stability of sub-stoichiometric zirconium carbide barrier layers as a function of composition was studied. Integrated ceramic coatings comprising ZrC_0.55 diffusion barriers and a Cr₂AlC top layer were synthesized via a magnetron sputtering method. After rapid thermal annealing, the ZrC_0.55 barrier layer having a thickness of 0.5 μm effectively prevented the inter-diffusion between Cr₂AlC and the Zry-4 substrate, thereby ensuring retention of the structural integrity of the integrated ceramic coating system for ATF applications.     

A review on microwell and microfluidic geometric array fabrication techniques and its potential applications in cellular studies

The ability to trap precise quantities of cells or particles into confined areas has numerous applications for biological purposes. In particular, single cell trapping has received considerable attention because it permits the study of heterogeneity in a population, while trapping larger groups of cells have been used to form aggregates. Among several methods, the use of microwell offers a simple platform to capture cells or particles using hydrodynamic forces. This review examines the use of microwells in both static and microfluidic environments, and the application of microfluidic geometric arrays for trapping. This paper discusses the design and fabrication methods of microwells and compares the trapping and release techniques used in both static and microfluidics‐integrated microwells. Finally, we will summarize novel microfluidic geometric arrays used to capture cells or particles through hydrodynamic trapping.