以钼酸钠、硝酸铁、磷酸和三亚乙基四胺为原料, 采用水热合成法成功制备了一种还原型磷钼酸盐与FeⅡ构筑的超分子化合物, 其化学式为［C8H24N4］1.5［C6H22N4］1.5{Fe［Mo6O12(OH)3(PO4)3(HPO4)］2}·5H2O (1), 并通过单晶X射线衍射、粉末X射线衍射(PXRD)和红外光谱(FT-IR)对其结构进行了表征。结果表明, 该化合物是由{Fe［P4MoV6O31］2}22- (记为{Fe(P4Mo6)2})、质子化的三亚乙基四胺和质子化的N, N′-二(氨乙基)-哌嗪通过氢键相互作用连接形成的三维超分子结构。电催化性能的研究表明, 化合物1对铬离子(CrⅥ)、铁离子(FeⅢ)、溴酸钾(KBrO3)和抗坏血酸(AA)具有良好的电化学传感性能和低检测限(LOD)。

在InGaAs/GaAs表面量子点(SQDs)的GaAs势垒层中引入Si掺杂层，以研究Si掺杂对InGaAs/GaAs SQDs光学特性的影响。荧光发光谱(PL)测量结果显示，InGaAs/GaAs SQDs的发光强烈依赖于Si掺杂浓度。随着掺杂浓度的增加， SQDs的PL峰值位置先红移后蓝移； PL峰值能量与激光激发强度的立方根依赖关系由线性向非线性转变；通过组态交互作用方法发现SQDs的PL峰位蓝移减弱；时间分辨荧光光谱显示了从非线性衰减到线性衰减的转变。以上结果说明Si掺杂能够填充InGaAs SQDs的表面态，并且改变表面费米能级钉扎效应和SQDs的荧光辐射特性。本研究为深入理解与InGaAs SQDs的表面敏感特性关联的物理机制和载流子动力学过程，以及扩大InGaAs/GaAs SQDs传感器的应用提供了实验依据。

提出了应用于周界安防的基于后向瑞利散射光空间差分干涉的光纤分布式振动传感监测方案。环境振动信号引起传感光纤的相位变化, 含有相位信息的后向瑞利散射信号注入到非平衡迈克尔逊干涉仪, 实现了后向瑞利散射信号的空间差分干涉, 光纤分布式振动传感监测完成相位信号的解调, 提高了系统的灵敏度。该系统能够实时监测入侵者的行走路线和速率以及模拟挖掘的距离的判断, 实现了15 dB的信噪比以及35 m的探测距离。

An in-line fiber Fabry-Perot interferometer (FPI) based on the hollow-core photonic crystal fiber (HCPCF) for refractive index (RI) measurement is proposed in this paper. The FPI is formed by splicing both ends of a short section of the HCPCF to single mode fibers (SMFs) and cleaving the SMF pigtail to a proper length. The RI response of the sensor is analyzed theoretically and demonstrated experimentally. The results show that the FPI sensor has linear response to external RI and good repeatability. The sensitivity calculated from the maximum fringe contrast is –136 dB/RIU. A new spectrum differential integration (SDI) method for signal processing is also presented in this study. In this method, the RI is obtained from the integrated intensity of the absolute difference between the interference spectrum and its smoothed spectrum. The results show that the sensitivity obtained from the integrated intensity is about –1.34×10⁵ dB/RIU. Compared with the maximum fringe contrast method, the new SDI method can provide the higher sensitivity, better linearity, improved reliability, and accuracy, and it’s also convenient for automatic and fast signal processing in real-time monitoring of RI.

提出一种在线型光纤法布里-珀罗折射率传感器。传感器由空芯光子晶体光纤两端熔接单模光纤而成。理论分析并实验验证了其折射率传感特性。结果表明, 干涉条纹对比度随溶液折射率的增加而减小, 与理论模拟一致。提出利用标准差解调方法对干涉谱进行分析, 标准差解调方法具有更好的线性度和准确性, 可靠性更高, 便于编程实现自动化、快速的数据分析和溶液折射率的实时检测。

The distributed acoustic sensing (DAS) has been extensively studied and widely used. A distributed acoustic sensing system based on the unbalanced Michelson interferometer with phase generated carrier (PGC) demodulation was designed and tested. The system could directly obtain the phase, amplitude, frequency response, and location information of sound wave at the same time and measurement at all points along the sensing fiber simultaneously. Experiments showed that the system successfully measured the acoustic signals with a phase-pressure sensitivity about –148 dB (re rad/μPa) and frequency response ripple less than 1.5 dB. The further field experiment showed that the system could measure signals at all points along the sensing fiber simultaneously.

文中提出了一种光纤分布式声波传感方案。作用在传感光纤上的声波信号导致后向瑞利散射光的相位变化, 将含有声波信息的后向瑞利散射信号注入到迈克尔逊干涉仪, 并采用相位载波解调算法解调出相位信息。实验中采用压电拉伸器模拟声波振动, 分布式声波传感系统实现了10 m的空间分辨率以及平坦的频响。

We demonstrate a distributed optical fiber sensing system based on the Michelson interferometer of the phase sensitive optical time domain reflectometer (φ-OTDR) for acoustic measurement. Phase, amplitude, frequency response, and location information can be directly obtained at the same time by using the passive 3×3 coupler demodulation. We also set an experiment and successfully restore the acoustic information. Meanwhile, our system has preliminary realized acoustic-phase sensitivity around 150 dB (re rad/μPa) in the experiment.

地埋式入侵监测系统具有隐蔽性强、受自然因素影响小、误报率低、识别概率高等特点, 在入侵监测中具有重要作用。介绍了将光纤传感用于入侵监测的主要技术方案, 阐述了光纤分布式振动传感(DVS)系统和光纤布拉格光栅(FBG)振动传感系统的工作原理。对这两种系统进行了人员入侵监测实验。结果表明, DVS系统的有效探测范围可达到10~15 m, 空间分辨率约为20 m; FBG振动传感系统的最大有效探测距离超过75 m。对比和评估了这两种系统的关键性能, 展望了地埋式光纤入侵监测系统的应用方向。

为提高石油生产中原油采收率,需对原油采集时的流量进行实时监测。提出一种基于管壁振动频率的光纤流量监测系统,通过对缠绕在油管外壁的传感光纤感应流体经过管壁时由湍流产生的振动,从而实现流量监测。通过实验总结出管壁的振动频率特性,并在此频率特性范围内确定出平均流量与管壁振动加速度脉动值的标准方差的量化关系,求解出相应的流量。