Rotor blades are widely used in large turbine equipment such as aero-engines and gas turbines. The stable operation of these machines is largely dependent on the condition of the blades. In gas turbines and compressors, blade failure is mostly caused by foreign object damage (FOD), manufacturing defects and material defects. To ensure the rationality of blade design and the stability of the whole system, reliable blade on-line monitoring is the foundation [1]. Blade tip timing (BTT) is a potential method of blade vibration monitoring. It does not need to contact the blade, which can realize the whole-stage blade vibration monitoring by a few numbers of probes. The traditional method of vibration monitoring with strain gauges requires the complex telemetry system and even adjustment of the rotor structure. In contrast, the BTT method is simple and efficient; however, the disadvantage is that the signal is under-sampled. Various methods have been developed in recent decades to overcome undersampling. In this article, you will see how to sample blade tip displacement using the BTT method, what constitutes a BTT measurement system, and how to overcome undersampling and extract the vibration parameters from BTT signals.
{"title":"Measurement Methodology: Blade Tip Timing: A Non-Contact Blade Vibration Measurement Method","authors":"Haoqi Li, Shuming Wu, Zhibo Yang, Ruqiang Yan, Xuefeng Chen","doi":"10.1109/MIM.2023.10328672","DOIUrl":"https://doi.org/10.1109/MIM.2023.10328672","url":null,"abstract":"Rotor blades are widely used in large turbine equipment such as aero-engines and gas turbines. The stable operation of these machines is largely dependent on the condition of the blades. In gas turbines and compressors, blade failure is mostly caused by foreign object damage (FOD), manufacturing defects and material defects. To ensure the rationality of blade design and the stability of the whole system, reliable blade on-line monitoring is the foundation [1]. Blade tip timing (BTT) is a potential method of blade vibration monitoring. It does not need to contact the blade, which can realize the whole-stage blade vibration monitoring by a few numbers of probes. The traditional method of vibration monitoring with strain gauges requires the complex telemetry system and even adjustment of the rotor structure. In contrast, the BTT method is simple and efficient; however, the disadvantage is that the signal is under-sampled. Various methods have been developed in recent decades to overcome undersampling. In this article, you will see how to sample blade tip displacement using the BTT method, what constitutes a BTT measurement system, and how to overcome undersampling and extract the vibration parameters from BTT signals.","PeriodicalId":55025,"journal":{"name":"IEEE Instrumentation & Measurement Magazine","volume":" 16","pages":"12-20"},"PeriodicalIF":2.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138615919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1109/MIM.2023.10328673
Richard Davis
The International System of Units (SI) [1] was inaugurated in 1960, following years of discussions interrupted by world wars. At that time, a consensus did not yet exist on whether the SI unit of plane angle, the radian (symbol: rad), should be treated as a base unit with its own dimension A, independent of all other base dimensions, or as a unit derived from the meter (m). Provisionally, either interpretation could be used as needed. Thirty-five years later, it was finally decided that the radian should be defined as a derived unit equal to 1. Mathematically, then, $1 text{rad} =1 mathrm{m}/mathrm{m}=1$. Reference [1] notes that some ambiguities have arisen from this choice. For instance, a general rule that “the unit symbol 1 or unit name ‘one’ are not explicitly shown” can be problematic. Therefore, rad can be used for clarity when helpful, i.e., rad can be written explicitly with the understanding that 1 rad = 1.
{"title":"Fundamentals in Measurement: Looking Out for Number 1","authors":"Richard Davis","doi":"10.1109/MIM.2023.10328673","DOIUrl":"https://doi.org/10.1109/MIM.2023.10328673","url":null,"abstract":"The International System of Units (SI) [1] was inaugurated in 1960, following years of discussions interrupted by world wars. At that time, a consensus did not yet exist on whether the SI unit of plane angle, the radian (symbol: rad), should be treated as a base unit with its own dimension A, independent of all other base dimensions, or as a unit derived from the meter (m). Provisionally, either interpretation could be used as needed. Thirty-five years later, it was finally decided that the radian should be defined as a derived unit equal to 1. Mathematically, then, $1 text{rad} =1 mathrm{m}/mathrm{m}=1$. Reference [1] notes that some ambiguities have arisen from this choice. For instance, a general rule that “the unit symbol 1 or unit name ‘one’ are not explicitly shown” can be problematic. Therefore, rad can be used for clarity when helpful, i.e., rad can be written explicitly with the understanding that 1 rad = 1.","PeriodicalId":55025,"journal":{"name":"IEEE Instrumentation & Measurement Magazine","volume":" 20","pages":"5-11"},"PeriodicalIF":2.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138609736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1109/MIM.2023.10328669
Aatha Mohin Shaikh, R. Patel, M. Vinchurkar, Rajul S. Patkar, A. Adami, Flavio Giacomozzi, Leandro Lorenzelli, M. Baghini
Gold interdigitated electrode (IDE) structure is one of the commonly-used platforms for sensing. The response of IDE-based sensors is measured in different ways, of which non-faradaic electrochemical impedance spectroscopy (nf-EIS) is specially used to extract the analytes impedance characteristics without redox labels. Many research projects across various disciplines need students from different domains, such as Electrical Engineering, Chemistry, and/or Biology, to experience electrical measurements that can easily go wrong without notice. It is crucial to evaluate the intrinsic and extrinsic constraints that need to be resolved to get reliable and high-quality nf-EIS measurements, which are also reproducible in the presence of noise and other sources of error. This article provides examples and summarizes how to systematically address the effect of the commonly existing non-idealities to enable any student to get confidence in the interpretation and reliability of nf-EIS measurements they perform. As part of our experimental analysis demonstration, various conditions and volume optimization for adequate measurements are performed.
{"title":"Addressing Non-Idealities and EIS Measurement: From Inspection to Implementation","authors":"Aatha Mohin Shaikh, R. Patel, M. Vinchurkar, Rajul S. Patkar, A. Adami, Flavio Giacomozzi, Leandro Lorenzelli, M. Baghini","doi":"10.1109/MIM.2023.10328669","DOIUrl":"https://doi.org/10.1109/MIM.2023.10328669","url":null,"abstract":"Gold interdigitated electrode (IDE) structure is one of the commonly-used platforms for sensing. The response of IDE-based sensors is measured in different ways, of which non-faradaic electrochemical impedance spectroscopy (nf-EIS) is specially used to extract the analytes impedance characteristics without redox labels. Many research projects across various disciplines need students from different domains, such as Electrical Engineering, Chemistry, and/or Biology, to experience electrical measurements that can easily go wrong without notice. It is crucial to evaluate the intrinsic and extrinsic constraints that need to be resolved to get reliable and high-quality nf-EIS measurements, which are also reproducible in the presence of noise and other sources of error. This article provides examples and summarizes how to systematically address the effect of the commonly existing non-idealities to enable any student to get confidence in the interpretation and reliability of nf-EIS measurements they perform. As part of our experimental analysis demonstration, various conditions and volume optimization for adequate measurements are performed.","PeriodicalId":55025,"journal":{"name":"IEEE Instrumentation & Measurement Magazine","volume":" 9","pages":"45-52"},"PeriodicalIF":2.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138610048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1109/MIM.2023.10328621
V. Isaiev
This paper presents an approach to the ac-dc difference determination of precision current shunts by dual-using one voltage converter. It can reduce the number of intrinsic uncertainty sources due to the exclusion of one voltage converter and one voltmeter from the set of equipment. In addition, such modification in the measurement setup causes a transformation in the measurement method. Therefore, dual-using one ac-dc transfer standard can be an alternative for checking the correctness of the calibration results of current shunts. Also, the proposed method allows us to avoid the collapse of the entire calibration system caused by the failure of one of the reference voltage converters or one of the voltmeters. Most of the results presented in the paper were obtained analytically and mathematically.
{"title":"Dual-Using AC-DC Transfer Standard for Characterization of Precision Shunt","authors":"V. Isaiev","doi":"10.1109/MIM.2023.10328621","DOIUrl":"https://doi.org/10.1109/MIM.2023.10328621","url":null,"abstract":"This paper presents an approach to the ac-dc difference determination of precision current shunts by dual-using one voltage converter. It can reduce the number of intrinsic uncertainty sources due to the exclusion of one voltage converter and one voltmeter from the set of equipment. In addition, such modification in the measurement setup causes a transformation in the measurement method. Therefore, dual-using one ac-dc transfer standard can be an alternative for checking the correctness of the calibration results of current shunts. Also, the proposed method allows us to avoid the collapse of the entire calibration system caused by the failure of one of the reference voltage converters or one of the voltmeters. Most of the results presented in the paper were obtained analytically and mathematically.","PeriodicalId":55025,"journal":{"name":"IEEE Instrumentation & Measurement Magazine","volume":" 22","pages":"53-59"},"PeriodicalIF":2.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138620596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1109/MIM.2023.10328618
S. Engelberg
When making measurements, it is often important to have a signal generator that outputs accurate sine waves that can be used as inputs to the system under test. One nice, conceptually simple way to implement such an instrument is to make use of direct digital synthesis. Synthesizers that use this technique, described below, have many nice features. For example, they can switch between different frequencies quickly, and they produce very nice output. Unfortunately, their output contains small spectral components at frequencies other than the desired one. There are, for example, components due to the nonlinearity of the digital to analog converter used as part of the synthesizer, components due to clock feedthrough, and components due to phase truncation spurs [1], [2]. In this lecture/lab note we examine phase truncation spurs.
{"title":"Education I&M: Seeing Phase Truncation Spurs in the Output of Direct Digital Synthesizers","authors":"S. Engelberg","doi":"10.1109/MIM.2023.10328618","DOIUrl":"https://doi.org/10.1109/MIM.2023.10328618","url":null,"abstract":"When making measurements, it is often important to have a signal generator that outputs accurate sine waves that can be used as inputs to the system under test. One nice, conceptually simple way to implement such an instrument is to make use of direct digital synthesis. Synthesizers that use this technique, described below, have many nice features. For example, they can switch between different frequencies quickly, and they produce very nice output. Unfortunately, their output contains small spectral components at frequencies other than the desired one. There are, for example, components due to the nonlinearity of the digital to analog converter used as part of the synthesizer, components due to clock feedthrough, and components due to phase truncation spurs [1], [2]. In this lecture/lab note we examine phase truncation spurs.","PeriodicalId":55025,"journal":{"name":"IEEE Instrumentation & Measurement Magazine","volume":" 102","pages":"38-44"},"PeriodicalIF":2.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138620420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1109/MIM.2023.10328674
Veronica Scotti
This paper aims at providing some food for thoughts related to unexpected effects of AI originated in its design, its features or even the data used to “feed” the AI itself.
本文旨在为AI的设计、功能甚至是用于“喂养”AI本身的数据所产生的意想不到的影响提供一些思路。
{"title":"Women Inengineering: AI and the Empowerment of Gender Equality","authors":"Veronica Scotti","doi":"10.1109/MIM.2023.10328674","DOIUrl":"https://doi.org/10.1109/MIM.2023.10328674","url":null,"abstract":"This paper aims at providing some food for thoughts related to unexpected effects of AI originated in its design, its features or even the data used to “feed” the AI itself.","PeriodicalId":55025,"journal":{"name":"IEEE Instrumentation & Measurement Magazine","volume":"7 3","pages":"32-37"},"PeriodicalIF":2.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138626664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1109/MIM.2023.10328670
S. Romaniuk, Zdzisław Gosiewski
Lateration-based systems use distance measurements for position estimation. Since distance measurement is critical to positioning accuracy, it is necessary to ensure its quality. One of the main sources of bias error in distance measurement is caused by non-line-of-sight (NLOS) conditions which occur when a signal propagates through other objects or materials. NLOS measurements should be properly handled; otherwise, they can cause significant errors in navigation.
{"title":"Evaluation and Identification of Non-Line of Sight Conditions in UWB Systems","authors":"S. Romaniuk, Zdzisław Gosiewski","doi":"10.1109/MIM.2023.10328670","DOIUrl":"https://doi.org/10.1109/MIM.2023.10328670","url":null,"abstract":"Lateration-based systems use distance measurements for position estimation. Since distance measurement is critical to positioning accuracy, it is necessary to ensure its quality. One of the main sources of bias error in distance measurement is caused by non-line-of-sight (NLOS) conditions which occur when a signal propagates through other objects or materials. NLOS measurements should be properly handled; otherwise, they can cause significant errors in navigation.","PeriodicalId":55025,"journal":{"name":"IEEE Instrumentation & Measurement Magazine","volume":" 21","pages":"60-65"},"PeriodicalIF":2.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138613017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1109/mim.2023.10292625
Yuansheng Cheng, Zufeng Zhang, Grzegorz M. Królczyk, Sifa Zheng, Zhixiong Li
The machine vision-based non-contact vibration measurement is currently one of the hottest research topics in the instrumentation and measurement field. Single-frequency experiments are usually used to evaluate the non-contact measurement quality; however, in reality, it is difficult/impossible to quantify the non-contact vibration measurement using a single-frequency excitation. To bridge this research gap, this work designs and tests a low-cost platform to produce multi-frequency vibrations for evaluating the non-contact vibration measurement. In this platform, a double-rail sliding mechanism is designed to convert the circular motion of a servo motor into linear motion. The pulse+ direction control method is applied to the servo motor to produce multi-frequency and multi-amplitude vibration excitations. Thanks to the simplicity of the sliding mechanism, common and inexpensive mechanical and instrumentation devices can be used to construct the testing platform, and the low-cost feature of the developed platform make it ubiquitously applicable for practice. Lastly, the vibration characteristics of the platform are analyzed, and three sets of vibration tests using different frequency bands are performed. The experimental results verify that the vibration responses of the platform are well consistent with the theoretical results, which can be used as a new solution that allows non-contact vibration quantification.
{"title":"A LOW-Cost Multi-Frequency Testing Platform for Non-Contact Vibration Measurement","authors":"Yuansheng Cheng, Zufeng Zhang, Grzegorz M. Królczyk, Sifa Zheng, Zhixiong Li","doi":"10.1109/mim.2023.10292625","DOIUrl":"https://doi.org/10.1109/mim.2023.10292625","url":null,"abstract":"The machine vision-based non-contact vibration measurement is currently one of the hottest research topics in the instrumentation and measurement field. Single-frequency experiments are usually used to evaluate the non-contact measurement quality; however, in reality, it is difficult/impossible to quantify the non-contact vibration measurement using a single-frequency excitation. To bridge this research gap, this work designs and tests a low-cost platform to produce multi-frequency vibrations for evaluating the non-contact vibration measurement. In this platform, a double-rail sliding mechanism is designed to convert the circular motion of a servo motor into linear motion. The pulse+ direction control method is applied to the servo motor to produce multi-frequency and multi-amplitude vibration excitations. Thanks to the simplicity of the sliding mechanism, common and inexpensive mechanical and instrumentation devices can be used to construct the testing platform, and the low-cost feature of the developed platform make it ubiquitously applicable for practice. Lastly, the vibration characteristics of the platform are analyzed, and three sets of vibration tests using different frequency bands are performed. The experimental results verify that the vibration responses of the platform are well consistent with the theoretical results, which can be used as a new solution that allows non-contact vibration quantification.","PeriodicalId":55025,"journal":{"name":"IEEE Instrumentation & Measurement Magazine","volume":"401 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135111838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1109/mim.2023.10292592
Gabriele Patrizi
In the last few years, reliability assessment acquired a fundamental role in many advanced technology applications. System downtime and unexpected failures massively affect the productivity of a system/product/plant. As a consequence, the Reliability, Availability, Maintainability, and Safety (RAMS) disciplines, together with diagnostics and prognostics tools are becoming more and more essential for several application fields, especially in case of complex industrial systems where environment, personnel, and equipment safety are mandatory features.
{"title":"IMS Awards: An Innovative Data-Driven Reliability Life Cycle for Complex Systems","authors":"Gabriele Patrizi","doi":"10.1109/mim.2023.10292592","DOIUrl":"https://doi.org/10.1109/mim.2023.10292592","url":null,"abstract":"In the last few years, reliability assessment acquired a fundamental role in many advanced technology applications. System downtime and unexpected failures massively affect the productivity of a system/product/plant. As a consequence, the Reliability, Availability, Maintainability, and Safety (RAMS) disciplines, together with diagnostics and prognostics tools are becoming more and more essential for several application fields, especially in case of complex industrial systems where environment, personnel, and equipment safety are mandatory features.","PeriodicalId":55025,"journal":{"name":"IEEE Instrumentation & Measurement Magazine","volume":"402 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135112056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1109/mim.2023.10292619
Xinbo Huang, Zhicheng Liu, Long Zhao, Peng Yuan, Ye Zhang
The transmission line is the key facility of power grid systems all over the world. The transmission tower is an important part of the transmission line. Vibration response analysis can be applied to structural health monitoring, since environmental factors and external excitation will have a certain impact on the accuracy of mode. Tower 126 of the Xinjiang Guangfang line is close to the train track, and external excitation will be generated when the train passes, so it is important to study the influence of the train on the tower. This study conducts dynamic response experiments on the transmission tower. To identify the modal parameters of the tower under different states, an automatic modal identification method of the tower is used to process the vibration acceleration signal. It is found that train excitation will stimulate high order modes. The tower mode will decrease as the train passes, and the third and eighth natural frequencies change obviously. The influence of train excitation on the mode of transmission tower leads to the misjudgment of the structural health of the transmission tower by the monitoring device. After the train passes through the transmission tower, if the tower is not permanently damaged due to train excitation, the structure can still be restored to its original state after a certain time. Therefore, the authors design and optimize the vibration monitoring device of the Guangfang line tower to avoid power safety accidents.
{"title":"Research on Vibration Analysis and Online Monitoring Technology of Transmission Tower Near Railway","authors":"Xinbo Huang, Zhicheng Liu, Long Zhao, Peng Yuan, Ye Zhang","doi":"10.1109/mim.2023.10292619","DOIUrl":"https://doi.org/10.1109/mim.2023.10292619","url":null,"abstract":"The transmission line is the key facility of power grid systems all over the world. The transmission tower is an important part of the transmission line. Vibration response analysis can be applied to structural health monitoring, since environmental factors and external excitation will have a certain impact on the accuracy of mode. Tower 126 of the Xinjiang Guangfang line is close to the train track, and external excitation will be generated when the train passes, so it is important to study the influence of the train on the tower. This study conducts dynamic response experiments on the transmission tower. To identify the modal parameters of the tower under different states, an automatic modal identification method of the tower is used to process the vibration acceleration signal. It is found that train excitation will stimulate high order modes. The tower mode will decrease as the train passes, and the third and eighth natural frequencies change obviously. The influence of train excitation on the mode of transmission tower leads to the misjudgment of the structural health of the transmission tower by the monitoring device. After the train passes through the transmission tower, if the tower is not permanently damaged due to train excitation, the structure can still be restored to its original state after a certain time. Therefore, the authors design and optimize the vibration monitoring device of the Guangfang line tower to avoid power safety accidents.","PeriodicalId":55025,"journal":{"name":"IEEE Instrumentation & Measurement Magazine","volume":"402 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135112058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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