1 江苏科技大学土木工程与建筑学院, 镇江 212114
2 香港理工大学土木及环境工程学系, 香港 999077
裂缝自修复效果是评价材料功能恢复水平的重要依据。为实现水泥基材料裂缝全断面修复效果的综合评定, 开展了基于接触电阻理论的裂缝自修复评价方法研究, 包括导电材料选择与优化、测试参数优化和计算方法推导等。结果表明, 0.3%体积掺量碳纤维能有效降低水泥基材料电阻率, 并同步改善力学性能。测量电压对电阻率测试结果无显著影响, 电阻率随接触压力的增加逐渐降低。自修复过程即裂缝面接触形式变化的过程, 同时伴随接触电阻的变化, 从而可以构建接触电阻与自修复效果的定量计算公式。该方法仅与修复产物在裂缝面的分布数量有关, 不受空间分布形式影响。研究结论为水泥基材料自修复效果定量表征提供借鉴。
裂缝修复率 电阻率 接触电阻 定量表征 自修复混凝土 产物分布 crack repair rate resistivity contact resistance quantitative characterization self-healing concrete product distribution
Author Affiliations
Abstract
1 State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-intense Laser Science, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
3 Department of Physics, College of Arts and Science, University of Colorado Boulder, Boulder, CO 80309, USA
4 College of Physics, Guizhou University, Guiyang 550025, China
5 Department of Physics, Shanghai Normal University, Shanghai 200234, China
6 Physics Faculty, Lomonosov Moscow State University, Moscow 119991, Russia
Laser polarization and its intensity inside a filament core play an important role in filament-based applications. However, polarization dependent clamping intensity inside filaments has been overlooked to interpret the polarization-related filamentation phenomena. Here, we report on experimental and numerical investigations of polarization dependent clamping intensity inside a femtosecond filament in air. By adjusting the initial polarization from linear to circular, the clamping intensity is increased by 1.36 times when using a 30 cm focal length lens for filamentation. The results indicate that clamping intensity inside the filament is sensitive to laser polarization, which has to be considered to fully understand polarization-related phenomena.
femtosecond laser filamentation clamping intensity polarization Chinese Optics Letters
2021, 19(10): 103201
西安石油大学 陕西省油气井测控技术重点实验室, 西安 710065
为了便于检测液体pH值, 通过将多模光纤剥除涂覆层后, 经过化学腐蚀, 在腐蚀区域涂覆对pH敏感的溶胶-凝胶膜, 从而制作了一种基于纤芯失配的马赫-曾德尔干涉pH检测传感器。使用光谱仪来检测该传感结构对pH样品溶液的响应光谱, 并对响应光谱数据进行分析。实验结果表明: 当样品溶液pH值在4.02~10.01范围时, 响应光谱波长漂移量与pH值变化呈良好的线性变化规律, pH值每变化1个单位, 所检测波谷中心波长向短波方向漂移567 pm。该传感结构经过涂敷之后具有良好的机械强度, 可更好地应用于液体的pH检测。
纤芯失配 溶胶-凝胶 core mismatch sol-gel pH pH
1 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室, 上海 201800
2 中国科学院大学材料与光电研究中心, 北京 100049
研究了飞秒激光成丝过程中钳制光强对脉宽的依赖关系。对不同脉宽成丝钳制光强进行直接实验测量,发现当脉宽逐渐展宽(由45 fs展宽至177 fs)时,对应的钳制光强逐渐减小。实验结论与通过求解非线性薛定谔方程得到的数值模拟结果一致。依赖于脉宽的钳制光强的分析结果可为深入理解与脉宽相关的光丝应用提供科学依据和新思路。
激光器 飞秒现象 飞秒激光成丝 钳制光强 啁啾
Author Affiliations
Abstract
College of Physics and Electronic Engineering, Sichuan Normal University, Chengdu 610101, China
The impacts of Brillouin pump depletion and nonlinear amplification in coded long-range Brillouin optical time-domain analysis (BOTDA) based on distributed Brillouin amplification (DBA) were studied. The error of Brillouin frequency shift (BFS) due to Brillouin pump depletion was compared for DBA-BOTDA using non-cyclic and cyclic coding. For non-cyclic coding, significant over- and under-shoots of BFS were found in the range with larger BFS variation, such as hot spot. The impact of Brillouin pump depletion can be reduced considerably by cyclic coding. Furthermore, to compensate the BFS error due to nonlinear amplification, a simple and effective log linearization was proposed and demonstrated.
060.2370 Fiber optics sensors Chinese Optics Letters
2018, 16(9): 090604
Author Affiliations
Abstract
1 Department of Physics, Shanghai University, Shanghai 200444, China
2 State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
3 Centre d’Optique, Photonique et Laser (COPL) and Département de physique, de génie physique et d’optique, Université Laval, Québec, Québec G1V 0A6, Canada
We report on a systematic study of the laser polarization effect on a femtosecond laser filamentation in air. By changing the laser’s ellipticity from linear polarization to circular polarization, the onset position of laser filament formation becomes farther from the focusing optics, the filament length is shorter, and less laser energy is deposited. The laser polarization effect on air filaments is supported by a simulation and analysis of the polarization-dependent critical power and ionization rates in air.
320.2250 Femtosecond phenomena 260.5430 Polarization Chinese Optics Letters
2018, 16(7): 073201
1 西安石油大学 理学院, 西安710065
2 西北大学 物理系, 西安 710069
在色散补偿光纤上刻写光栅, 形成全光纤复合传感结构, 将干涉结构和光栅结构集成在同一段光纤内.分析了干涉包层模式和布拉格谐振峰对纵向拉力以及温度的响应机理.通过监测包层模式和布拉格谐振峰的波长漂移量, 建立矩阵方程, 实现对纵向拉力和温度双参量的同时测量.实验结果表明, 包层模式和布拉格谐振峰对温度的响应灵敏度分别为49.4 pm/℃和11.0 pm/℃, 包层模式对纵向拉力的响应灵敏度为1.05 pm/με, 布拉格谐振模式对纵向拉力的响应灵敏度为0.651 pm/με, 且这四个参数均表现出良好的线性度.该传感器结构采用低阶包层模式和纤芯基模模式, 对外界环境折射率不敏感, 能较好地应用于纵向拉力和温度的同时测量中.
光纤传感 光纤布拉格光栅 全光纤拉力传感器 全光纤温度传感器 双参量测量 Fiber optics sensors Fiber Bragg grating All-fiber strain sensor All-fiber temperature sensor Double-parameter-measurement
合肥鑫晟光电科技有限公司, 安徽 合肥 230012
Panel污渍是TFT-LCD生产中一种常见的不良, 它直接影响到产品的画面品质和出售价格, 降低产品竞争力。本文通过研究发现大量panel污渍是摩擦产生的含Si元素杂质导致。实验表明: 降低制品膜面的粗糙度, 使杂质更易去除; 通过提升摩擦后的清洗能力, 也能有效去除杂质, 一定程度降低了panel污渍发生率; 而最后通过导入C系列摩擦布, 使摩擦过程中产生极少杂质。通过导入以上3种改善措施, 最终将55UHD产品的panel污渍发生率从8.2%降至0.2%。
面板 panel污渍 清洗 摩擦布 杂质 panel panel stain clean rubbing cloth impurities
1 西安石油大学 理学院, 西安 710065
2 中国科学院国家授时中心 时间频率重点实验室, 西安 710600
基于相位共轭稳相方法研制微波频率传递系统, 简化传递系统光路, 实现光纤微波频率传递链路噪声的实时补偿, 完成50 km光纤9.2 GHz超稳微波频率传递实验.该系统采用模块化设计, 由微波参考信号生成模块、相位补偿模块、光纤传递模块组成.在实验室环境下经过9 d的连续测试, 结果表明, 自由运转时频率传递的稳定度(标准阿伦方差)为4.2E－13@1 s, 4.3E－14@1 d; 补偿后频率传递系统的稳定度达到5.8E－14@1 s, 1.9E－17@1 d.该系统能够满足百公里范围内的超稳微波原子钟频率传递需求.
微波频率 光纤 相位共轭 频率传递 Microwave frequency Fiber link Stabilization by phase conjugation Frequency transmission
