【摘 要】
：
We propose and demonstrate an all-fiber liquid-level sensor using an in-line multimode-single-mode-multimode(MSM)fiber structure.A piece of single-mode fiber(SMF)is spliced to two sections of equivalent multimode fiber(MMF)which are used as both mode spli
【机 构】
：
School of Optoelectronic Engineering and Instrumentation Science,Dalian University of Technology,Dal
论文部分内容阅读
We propose and demonstrate an all-fiber liquid-level sensor using an in-line multimode-single-mode-multimode(MSM)fiber structure.A piece of single-mode fiber(SMF)is spliced to two sections of equivalent multimode fiber(MMF)which are used as both mode splitter and mode coupler.The cladding mode will be excited when the light propagates from MMF to SMF,and then it will be combined with fundamental mode to form a Mach-Zehnder interferometer(MZI)when the light propagates from SMF to the other MMF.The liquid level is detected by the selected resonant dips shift of the transmission spectrum.A sensing sensitivity of 264.6 pm/mm is achieved for the proposed sensor with an SMF length of 26 mm.Due to its compact structure,easy fabrication,and high sensitivity,the proposed liquid-level sensor is attractive for practical applications in a variety of fields,such as marine detection and chemical processing.
其他文献
为解决当前长距离引水工程存在的巡检手段相对落后、信息传递慢、统计查询难、巡检维护工作不易监管的问题,基于NFC和云计算技术,结合移动互联网、地理信息技术、可视化技术,提出一套适用于长距离引水工程的巡检控制体系.首先对工程巡查隐患进行分级分类,通过移动巡检系统结合NFC标签进行巡检数据采集.巡检数据实时同步到云平台数据库,保证数据的准确与效力.通过云计算技术,建立基于“云+NFC”的引水工程智能巡检系统,实现工程区域建筑物、设备及环境的全方位管控,可为维护和管理人员提供协同工作技术支持.经某引水工程现场应用
随着现货市场的改革和发展,发电商将面临更加复杂的市场环境,通过组建报价单元可达到对冲市场风险的 目的.为解决流域水电现货市场报价单元组建问题,基于各单元报价策略和单元间的竞价行为,梳理了影响报价单元组建的因素,分析了各因素对单元报价的影响机理,并对水电报价单元组建行为进行态势分析,运用层次分析法建立了电站报价单元组建决策模型.算例应用结果表明,该模型可行、实用,对参与电力现货市场的发电商组建报价单元具有实际指导意义.
对于高扬程泵后设置空气罐防护的输水工程,水泵断电时输水系统的倒流动力往往很大.针对输水系统倒流动力过大而导致所需空气罐体积剧增的问题,提出了一种泵后球阀兼作泄压阀的水锤防护方案,建立了泵后球阀的数学模型,并分析了泵后球阀“先关后开再关”操作方案的可行性.结合实际长距离供水工程,对比分析了泵后球阀一段直线关闭、球阀两段折线关闭与泵后球阀“先关后开再关”操作方式的水锤防护效果,并对泵后球阀开启阶段的目标开度进行了敏感性分析.结果表明,泵后球阀采用“先关后开再关”的操作方式能够解决输水管道超压问题,有效减小所需
为揭示水工沥青混凝土在不同温度和应变率下的细观能量演化规律,基于离散元颗粒流程序(PFC3D),根据试件中骨料级配建立三维细观随机骨料模型,利用该模型对不同温度范围应变率条件下的水工沥青混凝土单轴受压试验进行离散元研究.分析水工沥青混凝土破坏全过程中细观能量演化特征,探讨温度和应变率对应变能和耗散能演化特征的影响,从细观层次研究能量演化的机制.研究结果表明,在破坏过程中粘结应变能和线性应变能随变形增大而增大,摩擦耗散能和阻尼耗散能随变形增大而增大;应变率为10-4s-1时,温度从10 ℃降低至-20℃,应
为了充分挖掘电力负荷数据中的有效信息、提高超短期负荷预测精度,提出一种基于多重聚类分析(MAC)、小波分解(WD)、卷积神经网络(CNN)和多路卷积神经网络(MCNN)的超短期负荷预测模型MAC-WD-CNN-MCNN.通过MAC方法筛选训练集样本,并采用WD算法对负荷进行频段分解,提取负荷细节特征,然后提出了MCNN网络结构,采用CNN网络和MCNN网络分别预测高低频负荷信号,最后通过小波重构输出负荷预测值.试验仿真结果表明,与CNN-GRU模型和MAC-WD-CNN-GRU模型相比,所提超短期负荷预测
针对风电波动性和随机性及电网调节能力不足的问题,在分析风电波动特性的基础上对风电波动过程进行划分,基于聚类算法以风电波动量和持续波动时间为特征向量划分风电波动类型,并提出一种源荷优化调度策略.针对不同类型的风电波动,日前优化模型以系统运行成本最优为 目标安排高载能可连续、可离散负荷进行消纳;日内优化模型以风电消纳量最大为 目标,通过调节可连续调节负荷来追踪风电波动.最后通过自适应惯性权重粒子群算法求解模型,验证了所提调度策略的有效性.
In this paper,a graphene-coated surface plasmon resonance sensor is designed for the examination of Rodent urine which is responsible for Leptospirosis bacteria.Rodent urine is considered as sensing medium.Graphene surface is activated by phosphate-buffer
A Mach-Zehnder interferometer(MZI)for high temperature(1 000℃)sensing based on few mode fiber(FMF)was proposed and experimentally demonstrated.The sensor was fabricated by fusing a section of FMF between two single-mode fibers(SMFs).The structure was prov
Utilizing polarization maintaining photonic crystal fiber(PM-PCF)with the low temperature coefficient of birefringence,a two-dimensional tunable and temperature-insensitive Lyot filter aiming to compensate the frequency modulation to amplitude modulation(
This paper describes how the maximum blur radius affects the depth results by depth from the defocus(DFD)method based on liquid crystal(LC)lens.Boundary frequency is determined by the maximum blur radius.It is found that if the maximum blur radius used in