Photoacoustic(PA)imaging has been widely used in biomedical research and preclinical studies during the past two decades.It has also been explored for nondestructive testing and evaluation(NDT/E)and for industrial app...Photoacoustic(PA)imaging has been widely used in biomedical research and preclinical studies during the past two decades.It has also been explored for nondestructive testing and evaluation(NDT/E)and for industrial applications.This paper describes the basic principles of PA technology for NDT/E and its applications in recent years.PA technology for NDT/E includes the use of a modulated continuous-wave laser and a pulsed laser for PA wave excitation,PA-generated ultrasonic waves,and all-optical PA wave excitation and detection.PA technology for NDT/E has demonstrated broad applications,including the imaging of railway cracks and defects,the imaging of Li metal batteries,the measurements of the porosity and Young’s modulus,the detection of defects and damage in silicon wafers,and a visualization of underdrawings in paintings.展开更多
Earthen sites are widely distributed throughout China, and most of them belong to archaeological sites with significant values, which not only directly witness the origin, formation and development of Chinese civiliza...Earthen sites are widely distributed throughout China, and most of them belong to archaeological sites with significant values, which not only directly witness the origin, formation and development of Chinese civilization, but also possess important values for conservation and exhibition. Many researches and practices on their conservation and consolidation have been carried out; however, the consolidation effect is mainly judged by visual observation and expert evaluation. Scientific assessment of conservation and consolidation effects is a challenging issue. Many instruments in other fields cannot be directly applied to the conservation of cultural relics due to their peculiarity. In order to assess the effects of field conservation experiments, this paper tries to understand the consolidation effects at Liangzhu site using nondestructive or micro-damage methods, including thermo-physical parameters testing, infrared thermal imaging, high-density microelectrode resistivity testing, portable microscope observation, and hydrophilic and hydrophobic testing, and thereby explores the practicable methods for evaluating the properties of consolidation materials for earthen sites treatment.展开更多
In order to pay more attention to the quality of construction concrete and accurately judge whether concrete material meets the standard,a nondestructive testing algorithm of building concrete material defects based o...In order to pay more attention to the quality of construction concrete and accurately judge whether concrete material meets the standard,a nondestructive testing algorithm of building concrete material defects based on machine learning is proposed.Through the ray tracing algorithm of Snell’s theorem,the shortest path between two random punctuation marks of building concrete is calculated.The original coordinate system and grid size were set,the trend and length of the line in the grid were calculated,and the coordinates between the grid corner points and the transmitting probe were calculated so as to obtain the position of the intermediate refractive points of the two probes.Finally,the vector dot product of the local defects is obtained by the optimal hyperplane calculation of the binary classification in the support vector machine.Experimental results show that the proposed method has the advantages of high precision.展开更多
Terahertz (THz) waves, whose frequencies range between microwave and infrared, are part of the electromagnetic spectrum. A gap exists in THz literature because investigating THz waves is difficult due to the weak char...Terahertz (THz) waves, whose frequencies range between microwave and infrared, are part of the electromagnetic spectrum. A gap exists in THz literature because investigating THz waves is difficult due to the weak characteristics of the waves and the lack of suitable THz sources and detectors. Recently, THz nondestructive testing (NDT) technology has become an interesting topic. This review outlines several typical THz devices and systems and engineering applications of THz NDT techniques in composite materials, thermal barrier coatings, car paint films, marine protective coatings, and pharmaceutical tablet coatings. THz imaging has higher resolution but lower penetration than ultrasound imaging. This review presents the significance and advantages provided by the emerging THz NDT technique.展开更多
A new nondestructive test method-Impact Echo Scanning was introduced. Application of this method on pavement structure test was discussed. A method to increase the measurement accuracy of the test on multi-layers was ...A new nondestructive test method-Impact Echo Scanning was introduced. Application of this method on pavement structure test was discussed. A method to increase the measurement accuracy of the test on multi-layers was proposed, and was verified by field test. The test results show that the basic structural information can obtained rapidly and accurately by 3-D scanning of the impact echo system.展开更多
含盐量是衡量咸鸭蛋品质的重要指标。为了利用机器视觉技术实现高压脉动腌制咸鸭蛋含盐量的无损检测。该研究采用工业相机和透射光源搭建咸鸭蛋的透射图像采集装置。采用图像整体特征和长轴截面光强度特征两种特征提取方法,利用多元线...含盐量是衡量咸鸭蛋品质的重要指标。为了利用机器视觉技术实现高压脉动腌制咸鸭蛋含盐量的无损检测。该研究采用工业相机和透射光源搭建咸鸭蛋的透射图像采集装置。采用图像整体特征和长轴截面光强度特征两种特征提取方法,利用多元线性回归、支持向量机回归两种算法,建立对蛋清、蛋黄及全蛋含盐量以及蛋黄指数的定量预测模型。结果表明,随着咸鸭蛋腌制时间的增加,其透光性显著提高。同时,透射图像蛋黄的所在视野区域会随着含盐量的增加而呈现规律性的变化。基于图像整体特征建立的蛋清、蛋黄、全蛋含盐量模型较优,在蛋黄指数预测下基于长轴截面光强度特征所建模型较优。其中,基于图像整体特征所建立的蛋黄含盐量支持向量机回归(support vector regression,SVR)模型最优,测试集相关系数(test set correlation coefficient,Rp)、测试集均方根误差(root mean square error of prediction,RMSEp)、相对分析误差(residual predictive deviation,RPD)分别达到0.8460、0.3416、1.898;基于长轴截面光强度特征建立的蛋黄指数多元线性回归(multiple linear regression,MLR)模型最优,测试集相关系数Rp、均方根误差RMSEp、相对分析误差RPD分别为0.8318、0.0743、1.916。该研究结果为咸鸭蛋含盐量的快速检测提供理论依据和技术支持。展开更多
基金S.-L.Chen acknowledges funding from the National Natural Science Foundation of China,No.61775134C.Tian acknowledges funding from the National Natural Science Foundation of China,No.61705216the Anhui Science and Technology Department,No.18030801138.
文摘Photoacoustic(PA)imaging has been widely used in biomedical research and preclinical studies during the past two decades.It has also been explored for nondestructive testing and evaluation(NDT/E)and for industrial applications.This paper describes the basic principles of PA technology for NDT/E and its applications in recent years.PA technology for NDT/E includes the use of a modulated continuous-wave laser and a pulsed laser for PA wave excitation,PA-generated ultrasonic waves,and all-optical PA wave excitation and detection.PA technology for NDT/E has demonstrated broad applications,including the imaging of railway cracks and defects,the imaging of Li metal batteries,the measurements of the porosity and Young’s modulus,the detection of defects and damage in silicon wafers,and a visualization of underdrawings in paintings.
基金supported by the National"12th Five-Year"Plan for Science and Technology Support(Grant No.2014BAK16B02)the Key Project of the State Administration of Cultural Heritage(Grant No.20120207)the Project on Basic Research of Gansu Province's Innovation Group(Grant No.145RJIF336)
文摘Earthen sites are widely distributed throughout China, and most of them belong to archaeological sites with significant values, which not only directly witness the origin, formation and development of Chinese civilization, but also possess important values for conservation and exhibition. Many researches and practices on their conservation and consolidation have been carried out; however, the consolidation effect is mainly judged by visual observation and expert evaluation. Scientific assessment of conservation and consolidation effects is a challenging issue. Many instruments in other fields cannot be directly applied to the conservation of cultural relics due to their peculiarity. In order to assess the effects of field conservation experiments, this paper tries to understand the consolidation effects at Liangzhu site using nondestructive or micro-damage methods, including thermo-physical parameters testing, infrared thermal imaging, high-density microelectrode resistivity testing, portable microscope observation, and hydrophilic and hydrophobic testing, and thereby explores the practicable methods for evaluating the properties of consolidation materials for earthen sites treatment.
文摘In order to pay more attention to the quality of construction concrete and accurately judge whether concrete material meets the standard,a nondestructive testing algorithm of building concrete material defects based on machine learning is proposed.Through the ray tracing algorithm of Snell’s theorem,the shortest path between two random punctuation marks of building concrete is calculated.The original coordinate system and grid size were set,the trend and length of the line in the grid were calculated,and the coordinates between the grid corner points and the transmitting probe were calculated so as to obtain the position of the intermediate refractive points of the two probes.Finally,the vector dot product of the local defects is obtained by the optimal hyperplane calculation of the binary classification in the support vector machine.Experimental results show that the proposed method has the advantages of high precision.
基金National Natural Science Foundation of China (Grant No. 51675103)Fujian Provincial Excellent Young Scientist Fund (Grant No. 2014J07007)+1 种基金Shanghai Natural Science Fund (Grant No. 18ZR1414200)Research Project of State Key Laboratory of Mechanical System and Vibration (Grant No. MSV201807).
文摘Terahertz (THz) waves, whose frequencies range between microwave and infrared, are part of the electromagnetic spectrum. A gap exists in THz literature because investigating THz waves is difficult due to the weak characteristics of the waves and the lack of suitable THz sources and detectors. Recently, THz nondestructive testing (NDT) technology has become an interesting topic. This review outlines several typical THz devices and systems and engineering applications of THz NDT techniques in composite materials, thermal barrier coatings, car paint films, marine protective coatings, and pharmaceutical tablet coatings. THz imaging has higher resolution but lower penetration than ultrasound imaging. This review presents the significance and advantages provided by the emerging THz NDT technique.
基金Funded by the National Natural Science Foundation of China(No.50472042) Doctoral Base Fund of Ministry of Education of China(No.20050497010)
文摘A new nondestructive test method-Impact Echo Scanning was introduced. Application of this method on pavement structure test was discussed. A method to increase the measurement accuracy of the test on multi-layers was proposed, and was verified by field test. The test results show that the basic structural information can obtained rapidly and accurately by 3-D scanning of the impact echo system.
文摘含盐量是衡量咸鸭蛋品质的重要指标。为了利用机器视觉技术实现高压脉动腌制咸鸭蛋含盐量的无损检测。该研究采用工业相机和透射光源搭建咸鸭蛋的透射图像采集装置。采用图像整体特征和长轴截面光强度特征两种特征提取方法,利用多元线性回归、支持向量机回归两种算法,建立对蛋清、蛋黄及全蛋含盐量以及蛋黄指数的定量预测模型。结果表明,随着咸鸭蛋腌制时间的增加,其透光性显著提高。同时,透射图像蛋黄的所在视野区域会随着含盐量的增加而呈现规律性的变化。基于图像整体特征建立的蛋清、蛋黄、全蛋含盐量模型较优,在蛋黄指数预测下基于长轴截面光强度特征所建模型较优。其中,基于图像整体特征所建立的蛋黄含盐量支持向量机回归(support vector regression,SVR)模型最优,测试集相关系数(test set correlation coefficient,Rp)、测试集均方根误差(root mean square error of prediction,RMSEp)、相对分析误差(residual predictive deviation,RPD)分别达到0.8460、0.3416、1.898;基于长轴截面光强度特征建立的蛋黄指数多元线性回归(multiple linear regression,MLR)模型最优,测试集相关系数Rp、均方根误差RMSEp、相对分析误差RPD分别为0.8318、0.0743、1.916。该研究结果为咸鸭蛋含盐量的快速检测提供理论依据和技术支持。
