Soft polymer optical fiber(SPOF)has shown great potential in optical-based wearable and implantable biosensors due to its excellent mechanical properties and optical guiding characteristics.However,the multimodality c...Soft polymer optical fiber(SPOF)has shown great potential in optical-based wearable and implantable biosensors due to its excellent mechanical properties and optical guiding characteristics.However,the multimodality characteristics of SPOF limit their integration with traditional fiber optic sensors.This article introduces for the first time a flexible fiber optic vibration sensor based on laser interference technology,which can be applied to vibration measurement under high stretch conditions.This sensor utilizes elastic optical fibers made of polydimethylsiloxane(PDMS)as sensing elements,combined with phase generating carrier technology,to achieve vibration measurement at 50−260 Hz within the stretch range of 0−42%.展开更多
准确掌握浅层土体含水率及其变化过程对于岩土工程、环境工程地质等多个领域具有重要意义。利用自然温度信息反演含水率是一种适用于长距离、大范围含水率监测的新方法。针对常规自然温度信息法中土体温度测试及重建精细程度低导致含水...准确掌握浅层土体含水率及其变化过程对于岩土工程、环境工程地质等多个领域具有重要意义。利用自然温度信息反演含水率是一种适用于长距离、大范围含水率监测的新方法。针对常规自然温度信息法中土体温度测试及重建精细程度低导致含水率估算精度低等问题,以分布式光纤测温(fiber optic distributed temperature sensing,简称FO-DTS)技术为基础,引入显式有限差分算法和马尔科夫链蒙特卡洛(Markov chain Monte Carlo,简称MCMC)算法,提出了浅表土体温度重建及含水率反演的新方法,并开展了原位试坑试验验证。结果表明:(1)基于FO-DTS的高时空分辨率温度,显式有限差分算法可以有效重建土体不同深度的温度分布,重建温度场拟合残差约为0.2℃。(2)MCMC反演优化算法能准确估算土体热扩散系数,由此土体含水率的估算误差仅为7%;(3)浅表土体含水率估算结果能够很好地反映天气变化导致的土体水分迁移变化。新方法实现了土体含水率的精细化估算,适用场景广泛。展开更多
文摘Soft polymer optical fiber(SPOF)has shown great potential in optical-based wearable and implantable biosensors due to its excellent mechanical properties and optical guiding characteristics.However,the multimodality characteristics of SPOF limit their integration with traditional fiber optic sensors.This article introduces for the first time a flexible fiber optic vibration sensor based on laser interference technology,which can be applied to vibration measurement under high stretch conditions.This sensor utilizes elastic optical fibers made of polydimethylsiloxane(PDMS)as sensing elements,combined with phase generating carrier technology,to achieve vibration measurement at 50−260 Hz within the stretch range of 0−42%.
文摘准确掌握浅层土体含水率及其变化过程对于岩土工程、环境工程地质等多个领域具有重要意义。利用自然温度信息反演含水率是一种适用于长距离、大范围含水率监测的新方法。针对常规自然温度信息法中土体温度测试及重建精细程度低导致含水率估算精度低等问题,以分布式光纤测温(fiber optic distributed temperature sensing,简称FO-DTS)技术为基础,引入显式有限差分算法和马尔科夫链蒙特卡洛(Markov chain Monte Carlo,简称MCMC)算法,提出了浅表土体温度重建及含水率反演的新方法,并开展了原位试坑试验验证。结果表明:(1)基于FO-DTS的高时空分辨率温度,显式有限差分算法可以有效重建土体不同深度的温度分布,重建温度场拟合残差约为0.2℃。(2)MCMC反演优化算法能准确估算土体热扩散系数,由此土体含水率的估算误差仅为7%;(3)浅表土体含水率估算结果能够很好地反映天气变化导致的土体水分迁移变化。新方法实现了土体含水率的精细化估算,适用场景广泛。
