Insight - Non-Destructive Testing and Condition Monitoring最新文献

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Arrival-time detection with histogram distance for acoustic emission signals 基于直方图距离的声发射信号到达时间检测
Insight - Non-Destructive Testing and Condition Monitoring Pub Date : 2023-06-01 DOI: 10.1784/insi.2023.65.6.327
Zhensheng Yang, Handong Xu, Bang-ping Gu
{"title":"Arrival-time detection with histogram distance for acoustic emission signals","authors":"Zhensheng Yang, Handong Xu, Bang-ping Gu","doi":"10.1784/insi.2023.65.6.327","DOIUrl":"https://doi.org/10.1784/insi.2023.65.6.327","url":null,"abstract":"Arrival-time picking is a fundamental step in time-of-arrival (TOA)-based localisation in current and future acoustic emission (AE), microseismic and seismic localisation systems. The accurate detection of TOA is of great importance for high localisation accuracy. This work presents\u0000 a histogram distance-based method for TOA detection of elastic wave signals. The authors treat an original elastic waveform that includes the arrival as two different locally stationary segments, namely the intervals following and preceding arrival. To determine the optimal separation of these\u0000 two stationary segments, ie the arrival time, histograms of these intervals are calculated and a measure of the distance between them modified from the Bhattacharyya coefficient is proposed. The performance of the proposed method is evaluated using TOA picking for AE. The method is shown to\u0000 provide accurate and robust picks on AE signals under various signal-to-noise ratios. To evaluate the adaptability of the method to other TOA picking scenarios, it is applied to detect the seismic P-phase. The detection accuracy is adequate and errors are constrained to within a few seconds.\u0000 Factors that influence the detection accuracy are discussed. The results suggest that the proposed method has the potential to detect TOA in various fields.","PeriodicalId":344397,"journal":{"name":"Insight - Non-Destructive Testing and Condition Monitoring","volume":"526 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133988997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Parameter measurement of cable lead sealing using an eddy current system 用涡流系统测量电缆引线密封参数
Insight - Non-Destructive Testing and Condition Monitoring Pub Date : 2023-06-01 DOI: 10.1784/insi.2023.65.6.306
Qianqiu Shao, Songhai Fan
{"title":"Parameter measurement of cable lead sealing using an eddy current system","authors":"Qianqiu Shao, Songhai Fan","doi":"10.1784/insi.2023.65.6.306","DOIUrl":"https://doi.org/10.1784/insi.2023.65.6.306","url":null,"abstract":"Lead sealing is one of the key accessories for high-voltage cables and its quality directly affects the security and stability of such cables. In order to reduce the accident rate in power processing caused by lead sealing issues, it is necessary to carry out non-destructive testing\u0000 and evaluation. Due to the bending surface of lead sealings, it is difficult to detect their conductivity and thickness accurately using existing eddy current (EC) testing methods. In this paper, measurements of conductivity and thickness for curved specimens are analysed and an accurate method\u0000 is subsequently proposed. Firstly, the measurement methods of conductivity and thickness are established based on the transformer model. It is found that the conductivity and thickness can be detected using phase signature at high and low frequencies, respectively. Secondly, the influence\u0000 of curvature on the phase signature is analysed and the conductivity and thickness measurements of lead sealing are corrected using curvature correction coefficients. Finally, an EC system is built and experiments are carried out to evaluate the novel methods. The results show that the methods\u0000 achieve a good level of accuracy in detecting the conductivity and thickness of curved lead sealings.","PeriodicalId":344397,"journal":{"name":"Insight - Non-Destructive Testing and Condition Monitoring","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130288114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Research on a DS-class X-ray film digitisation device and an image enhancement algorithm with 12-bit RAW data ds级x射线胶片数字化装置及12位RAW数据图像增强算法研究
Insight - Non-Destructive Testing and Condition Monitoring Pub Date : 2023-06-01 DOI: 10.1784/insi.2023.65.6.313
Zhigang Lv, Liangliang Li, Peng Wang, Hongxi Wang, Xiaoyan Li
{"title":"Research on a DS-class X-ray film digitisation device and an image enhancement algorithm with 12-bit RAW data","authors":"Zhigang Lv, Liangliang Li, Peng Wang, Hongxi Wang, Xiaoyan Li","doi":"10.1784/insi.2023.65.6.313","DOIUrl":"https://doi.org/10.1784/insi.2023.65.6.313","url":null,"abstract":"Automatic evaluation of the X-ray films of welds is an important area of study in the field of non-destructive testing (NDT). A digitising device for the X-ray film is the key to realising automatic evaluation and its image quality directly determines the quality of the automatic evaluation\u0000 system. At present, the imaging quality of most mature digitising systems on the market cannot meet the DS-class requirements of international standard EN 14096. In order to solve the problems of low visual contrast, detailed information that is difficult to distinguish and low visual resolution\u0000 in existing digitising systems, a high-quality embedded X-ray film digitising device, processing films with adjustable width, is developed in this paper. The device uses a 12-bit camera and has the characteristics of small size, simple operation and easy maintenance. In order to improve the\u0000 imaging quality, an optical visual enhancement model is constructed for the generated 12-bit RAW data, which can improve the display of the data. The MTF20% values of the device in the horizontal and vertical directions are 7.544 and 7.460, respectively, and the optical density range is 0.5-4.5\u0000 D, the comprehensive index of which can reach DS class. The device has been initially applied by non-destructive testing companies.","PeriodicalId":344397,"journal":{"name":"Insight - Non-Destructive Testing and Condition Monitoring","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132483568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Research on magnetic inversion in alternating current magnetic flux leakage testing 交流漏磁检测中磁反转的研究
Insight - Non-Destructive Testing and Condition Monitoring Pub Date : 2023-06-01 DOI: 10.1784/insi.2023.65.6.319
Gang Wang, Ce Liang, Huadong Song, Qiong Xiao, Yuan Zhong
{"title":"Research on magnetic inversion in alternating current magnetic flux leakage testing","authors":"Gang Wang, Ce Liang, Huadong Song, Qiong Xiao, Yuan Zhong","doi":"10.1784/insi.2023.65.6.319","DOIUrl":"https://doi.org/10.1784/insi.2023.65.6.319","url":null,"abstract":"Defects bring significant security risks to pipelines, which are essential carriers in oil and gas transportation. However, when alternating current magnetic flux leakage (AC-MFL) testing is applied to pipeline defect detection, the morphological reversal of the detection signal under\u0000 specific parameters has adverse effects on defect identification and quantification. This paper identifies and explains the phenomenon of detection signal morphological reversal in AC-MFL testing, which is defined as magnetic inversion (MI). Based on the AC-MFL testing mechanism, the causes\u0000 of MI are analysed. The influence of the excitation current frequency, excitation current intensity and defect depth on MI is numerically analysed using the finite element method. The excitation current frequency and the defect depth are important factors causing MI, but the excitation current\u0000 density is not. MI only occurs when deep defects are detected under low-frequency excitation. The boundary conditions of AC-MFL testing are further clarified.","PeriodicalId":344397,"journal":{"name":"Insight - Non-Destructive Testing and Condition Monitoring","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115746737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Study and Application on the Early Damage Signal Characteristics of Ultra-Low-Speed and Heavy-Load Rolling Bearings of Large Amusement Machinery 大型游乐机械超低速重载滚动轴承早期损伤信号特征研究与应用
Insight - Non-Destructive Testing and Condition Monitoring Pub Date : 2023-05-01 DOI: 10.1784/insi.2023.65.5.270
Yuan Liu, Yaguang Jin, Gaoyu Cui, Gongtian Shen
{"title":"Study and Application on the Early Damage Signal Characteristics of Ultra-Low-Speed and Heavy-Load Rolling Bearings of Large Amusement Machinery","authors":"Yuan Liu, Yaguang Jin, Gaoyu Cui, Gongtian Shen","doi":"10.1784/insi.2023.65.5.270","DOIUrl":"https://doi.org/10.1784/insi.2023.65.5.270","url":null,"abstract":"Ultra-low-speed and heavy-load bearings are widely used in large amusement machinery. Their breakdown results in great economic losses and possibly even personal injuries. Using their damage signal characteristics to quickly identify early damage is an effective means of preventing\u0000 accidents. In this study, to determine the early damage signal characteristics of the ultra-low-speed and heavy-load slewing mechanism, a typical ultra-low-speed and heavy-load bearing rotation experimental platform and signal testing system are designed and built, so as to simulate the operation\u0000 of the rolling bearings of large amusement machinery with ultra-low speed and heavy load. Next, by constructing different bearing damage sizes and operating conditions, the vibration signal characteristics of different degrees of crack damage are analysed, along with the signal variation law\u0000 of the same damage under different operating conditions. The effectiveness and practicability of this method are verified through the application analysis of a slewing bearing of a typical piece of large amusement machinery. The results of this study provide a reference for quickly identifying\u0000 early damage in similar equipment and determining the damage state.","PeriodicalId":344397,"journal":{"name":"Insight - Non-Destructive Testing and Condition Monitoring","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132589344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Progress in the Reliable Detection of Near-Surface Reflectors when Inspecting Anisotropic and Isotropic Material Using the Total Focusing Method 全聚焦法检测各向异性和各向同性材料时近地表反射物可靠检测的研究进展
Insight - Non-Destructive Testing and Condition Monitoring Pub Date : 2023-05-01 DOI: 10.1784/insi.2023.65.5.248
L. Bergbreiter, J. Grager, A. Narr, H. Mooshofer, C. Grosse
{"title":"Progress in the Reliable Detection of Near-Surface Reflectors when Inspecting Anisotropic and Isotropic Material Using the Total Focusing Method","authors":"L. Bergbreiter, J. Grager, A. Narr, H. Mooshofer, C. Grosse","doi":"10.1784/insi.2023.65.5.248","DOIUrl":"https://doi.org/10.1784/insi.2023.65.5.248","url":null,"abstract":"Load-bearing components made of composite laminates of several centimetres in thickness, for example those used in wind turbine blades, are frequently used in the energy sector. These components are usually tested using conventional ultrasound techniques. A typical approach to increase\u0000 the energy penetration depth is testing with lower frequencies. This leads to a decrease in sensitivity and consequently to reduced detectability of small defects compared to higher frequencies, especially for defects close to the surface. Another possibility is to use high excitation voltage\u0000 or gain to improve penetration, but this also leads to a much more pronounced initial pulse with saturated or clipped A-scans, resulting in a loss of information. Consequently, the defects close to the surface are often indistinguishable to the initial pulse and are not detected. In comparison\u0000 to conventional ultrasonic testing, the total focusing method (TFM) shows higher resolution of near-surface defects using the same frequencies. The TFM can be adapted to anisotropic media by consideration of the direction-dependent wave propagation. Therefore, sound paths not perpendicular\u0000 to the surface, which show less clipping, can be used for imaging. In this paper, approaches for improving the detectability of defects close to the surface in carbon fibre-reinforced plastic (CFRP) and aluminium using full matrix capture (FMC) and the TFM are discussed. As a result, defects\u0000 in CFRP with a depth of 0.9 mm and above can be detected. The presented methods also improve the signal-to-noise ratio (SNR) of near-surface defects in the TFM reconstructions up to 4 dB. The first approach filters the FMC pulses in the wavenumber-frequency domain, which reduces the aforementioned\u0000 disturbances in the time-domain signals and thus improves the detectability of near-surface defects. The second approach is based on a maximum angle in the reconstruction step, which reduces the entries of the information matrix based on location. This procedure is similar to taking the directivity\u0000 function of each array element into account. Therefore, only time signals with a high signal-to-noise ratio are considered.","PeriodicalId":344397,"journal":{"name":"Insight - Non-Destructive Testing and Condition Monitoring","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115560726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Non-Linear Ultrasonic Testing of the Long-Period Stacking Ordered Phase Volume Fraction in Magnesium Alloys 镁合金长周期堆积有序相体积分数的非线性超声检测
Insight - Non-Destructive Testing and Condition Monitoring Pub Date : 2023-05-01 DOI: 10.1784/insi.2023.65.5.254
Xiang-hong Wang, Huibing Yang, Sheng Yang, Hong-wei Hu, Xiaoqiang Xu, Duo Lyu
{"title":"Non-Linear Ultrasonic Testing of the Long-Period Stacking Ordered Phase Volume Fraction in Magnesium Alloys","authors":"Xiang-hong Wang, Huibing Yang, Sheng Yang, Hong-wei Hu, Xiaoqiang Xu, Duo Lyu","doi":"10.1784/insi.2023.65.5.254","DOIUrl":"https://doi.org/10.1784/insi.2023.65.5.254","url":null,"abstract":"\u0000 The content of the long-period stacking ordered (LPSO) structure strengthening phase has an important influence on the tensile strength, compressive strength, ductility and other mechanical properties of magnesium (Mg) alloys. Therefore, effective detection of the volume fraction\u0000 of the LPSO phase plays an important role in understanding the properties of the alloy. Focused on the problem that the accuracy of the non-destructive testing method for the LPSO phase precipitates with micron or nanometer scale is not sufficient, this paper studies the non-linear ultrasonic\u0000 testing of the Mg alloy LPSO phase volume fraction. Based on the non-linear ultrasonic testing theory, the non-linear ultrasonic simulation of the simulation models with different LPSO phase contents was carried out using finite element simulation. The relationship between the volume fraction\u0000 of the LPSO phase and the non-linear coefficient of ultrasonic simulation was studied and a non-linear ultrasonic testing system was established to test the Mg alloy specimens with different LPSO phase volume fractions. The results show that the non-linear ultrasonic testing method is sensitive\u0000 to changes in the LPSO phase volume fraction. Thus, this method is an effective way to detect the LPSO phase volume fraction.\u0000","PeriodicalId":344397,"journal":{"name":"Insight - Non-Destructive Testing and Condition Monitoring","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123808189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Matlab-Based Fault Diagnosis of Industrial Rotor-Bearing Systems 基于matlab的工业转子-轴承系统故障诊断
Insight - Non-Destructive Testing and Condition Monitoring Pub Date : 2023-05-01 DOI: 10.1784/insi.2023.65.5.278
Mahesh Joshi, K. Pujar
{"title":"Matlab-Based Fault Diagnosis of Industrial Rotor-Bearing Systems","authors":"Mahesh Joshi, K. Pujar","doi":"10.1784/insi.2023.65.5.278","DOIUrl":"https://doi.org/10.1784/insi.2023.65.5.278","url":null,"abstract":"Continuous monitoring of critical rotor-bearing systems is crucial in order to prevent machine downtime, which would otherwise lower the overall output and quality. Complex modern machinery demands an upgraded intelligent fault diagnosis method that leaves minimal room for human error.\u0000 This paper presents a MATLAB-based condition monitoring and fault diagnosis method for rotating machines used in sugar factories. The vibration responses are acquired through the use of data acquisition and the fast Fourier transform (FFT) analyser on real industrial machines. These signals\u0000 are supplied as the input to a specially developed MATLAB program for processing in order to detect the fault and help to suggest remedies. The simple and user-friendly approach saves time and increases the effectiveness of condition monitoring in the reduction of downtime and the avoidance\u0000 of catastrophic failure in industrial machines.","PeriodicalId":344397,"journal":{"name":"Insight - Non-Destructive Testing and Condition Monitoring","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116050727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Automatic Classification of Weld Defects From Ultrasonic Signals Using WPEE-KPCA Feature Extraction and an ABC-SVM Approach 基于WPEE-KPCA特征提取和ABC-SVM的超声信号焊缝缺陷自动分类
Insight - Non-Destructive Testing and Condition Monitoring Pub Date : 2023-05-01 DOI: 10.1784/insi.2023.65.5.262
Yuan Chen, Shaonan Liang, Zhongyang Wang, H. Ma, M. Dong, Dengxue Liu, Xiang Wan
{"title":"Automatic Classification of Weld Defects From Ultrasonic Signals Using WPEE-KPCA Feature Extraction and an ABC-SVM Approach","authors":"Yuan Chen, Shaonan Liang, Zhongyang Wang, H. Ma, M. Dong, Dengxue Liu, Xiang Wan","doi":"10.1784/insi.2023.65.5.262","DOIUrl":"https://doi.org/10.1784/insi.2023.65.5.262","url":null,"abstract":"The classification of weld defects is very important for the safety assessment of welded structures and feature extraction of ultrasonic defect signals is vital for defect classification. A novel approach based on wavelet packet energy entropy (WPEE) and kernel principal component analysis\u0000 (KPCA) feature extraction and an artificial bee colony optimisation support vector machine (ABC-SVM) classifier is proposed in this paper. Firstly, the WPEE method is adopted to extract ultrasonic signal features of weld defects and KPCA is used for feature selection. Secondly, an ABC-SVM\u0000 classifier is employed to perform defect classification. Finally, experiments involving defect feature extraction, selection and classification are carried out using four types of weld defect. The results demonstrate that the performance of the proposed feature extraction method based on WPEE\u0000 is superior to that of wavelet packet energy (WPE). In addition, the WPEE-KPCA method achieved a higher accuracy rate of defect classification than WPEE.","PeriodicalId":344397,"journal":{"name":"Insight - Non-Destructive Testing and Condition Monitoring","volume":"28 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114040033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Simulation analysis and experimental investigation of wire rope leakage magnetic field detection 钢丝绳漏磁场检测的仿真分析与实验研究
Insight - Non-Destructive Testing and Condition Monitoring Pub Date : 2023-04-01 DOI: 10.1784/insi.2023.65.4.203
Hongyao Wang, Jie Tian, Z. Tian, H. Guo, Jian-Wu Ma, Yang Wang
{"title":"Simulation analysis and experimental investigation of wire rope leakage magnetic field detection","authors":"Hongyao Wang, Jie Tian, Z. Tian, H. Guo, Jian-Wu Ma, Yang Wang","doi":"10.1784/insi.2023.65.4.203","DOIUrl":"https://doi.org/10.1784/insi.2023.65.4.203","url":null,"abstract":"As a key bearing component, steel wire ropes suffer from partial wire breakage, broken strands and other types of damage during long-term continuous use. In this study, a magnetic flux circuit was constructed around a wire rope, an excitation detection device and an air gap. The relationship\u0000 between the direction and angle of the magnetic line of force on the damaged end face was analysed and the waveforms of the inverted U-shaped and M-shaped leakage flux signals and their transition intervals were determined. Following this, focusing on the influence of factors such as the length\u0000 of the damage, the cross-sectional area and the lift-off value on the magnetic flux leakage signal, the changes in the wave width and the peak value under different variables were analysed and the distribution law of the leakage magnetic field around the wire rope damage under different control\u0000 variables was determined.","PeriodicalId":344397,"journal":{"name":"Insight - Non-Destructive Testing and Condition Monitoring","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131217444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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