Pub Date : 2016-09-01DOI: 10.1109/ICLP.2016.7791346
Kazuo Yamamoto, T. Nakashima, S. Sumi, A. Ametani
On the website of the Japan Meteorological Agency, various weather data are shown. This paper has surveyed the hundred years data of the surface temperatures of Japan Sea and the number of lightning days in cities along the Japan Sea coast. The sea surface temperatures have increased by 1.2 °C to 2.2 °C in the last hundred years, and correspondingly the number of lightning days has increased by 20 to 45 days in the last hundred years. The correlation coefficient for winter lightning shows rather high dependence of the lightning days on the sea temperature in the cities located in a high latitude.
{"title":"About 100 years survey of the surface temperatures of Japan sea and lightning days along the coast","authors":"Kazuo Yamamoto, T. Nakashima, S. Sumi, A. Ametani","doi":"10.1109/ICLP.2016.7791346","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791346","url":null,"abstract":"On the website of the Japan Meteorological Agency, various weather data are shown. This paper has surveyed the hundred years data of the surface temperatures of Japan Sea and the number of lightning days in cities along the Japan Sea coast. The sea surface temperatures have increased by 1.2 °C to 2.2 °C in the last hundred years, and correspondingly the number of lightning days has increased by 20 to 45 days in the last hundred years. The correlation coefficient for winter lightning shows rather high dependence of the lightning days on the sea temperature in the cities located in a high latitude.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121427193","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}
Pub Date : 2016-09-01DOI: 10.1109/ICLP.2016.7791457
S. Correia, Â. Lourenço, João Rio, V. Prior, N. Moreira
The Portuguese Meteorological Institute (IPMA) has been exploiting a Lightning Detection Network (LDN) since June 2002, with 4 sensors in mainland Portugal operating in integration with 5 more Spanish sensors since January 2003, in cooperation with the Agencia Estatal de Meteorologia (AEMET, Spain). A study based on 13 years of lightning data is presented using Cloud-to-Ground (CG) flash density maps on a 0.2°×0.2° resolution grid, as well as intra and inter-annual distributions. Thunderstorm events in mainland Portugal result primarily from frontal systems approaching in the winter/spring season and convective instability in the summer/autumn season, especially due to diurnal surface heating particularly observed during the months of May to September. Two case studies representative of summer convection and a frontal system type are presented. A forecast method based on a logistic regression model using 4 stability indexes, as predictors, is computed for a specific thunderstorm event.
{"title":"Portuguese lightning detection network, applications and developed products","authors":"S. Correia, Â. Lourenço, João Rio, V. Prior, N. Moreira","doi":"10.1109/ICLP.2016.7791457","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791457","url":null,"abstract":"The Portuguese Meteorological Institute (IPMA) has been exploiting a Lightning Detection Network (LDN) since June 2002, with 4 sensors in mainland Portugal operating in integration with 5 more Spanish sensors since January 2003, in cooperation with the Agencia Estatal de Meteorologia (AEMET, Spain). A study based on 13 years of lightning data is presented using Cloud-to-Ground (CG) flash density maps on a 0.2°×0.2° resolution grid, as well as intra and inter-annual distributions. Thunderstorm events in mainland Portugal result primarily from frontal systems approaching in the winter/spring season and convective instability in the summer/autumn season, especially due to diurnal surface heating particularly observed during the months of May to September. Two case studies representative of summer convection and a frontal system type are presented. A forecast method based on a logistic regression model using 4 stability indexes, as predictors, is computed for a specific thunderstorm event.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128349318","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}
Pub Date : 2016-09-01DOI: 10.1109/ICLP.2016.7791358
D. Kind, M. Kurrat, T. Kopp
With the first application of HV-power lines at the early 20th century the protection of electric components against lightning strokes became a crucial problem. Albeit the overhead insulators were designed to withstand high ac-voltages above the operating level, they failed under stress of high impulse voltages with unknown shape. The need to generate short-time HV-impulses was solved in the 1920th by the invention of the “Marx-Generator”. At least it was observed that the flashover voltage of an insulator is higher for shorter than for longer pulses. During the following decades HV-power networks expanded worldwide rapidly and with it grew the need of HV-impulse tests in laboratories. Progress in short time measurement techniques allowed to reproduce impulses of defined shape and amplitude. In order to establish compatibility of discharge tests in the Megavolt-range, standard pulse shapes were internationally agreed upon. Of special interest for an effective coordination of various insulation structures became data of spark-over values of air gaps with very short time lags. However, a great number of measurements did not lead to satisfying results for non-standard test-voltages. Attempts to derive formulae for good results were neither easy to use nor reliable. Finally, an approach starting from the first principle of discharge in an air gap assuming the speed of leader growth being proportional to the instant voltage above the withstand value led to a simple and generally applicable criterion. Further development of physical models for the leader propagation process leads to self-reliant calculation methods, which are simply coupled to average field calculations.
{"title":"Voltage-time characteristics of air gaps and insulation coordination — Survey of 100 years research","authors":"D. Kind, M. Kurrat, T. Kopp","doi":"10.1109/ICLP.2016.7791358","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791358","url":null,"abstract":"With the first application of HV-power lines at the early 20th century the protection of electric components against lightning strokes became a crucial problem. Albeit the overhead insulators were designed to withstand high ac-voltages above the operating level, they failed under stress of high impulse voltages with unknown shape. The need to generate short-time HV-impulses was solved in the 1920th by the invention of the “Marx-Generator”. At least it was observed that the flashover voltage of an insulator is higher for shorter than for longer pulses. During the following decades HV-power networks expanded worldwide rapidly and with it grew the need of HV-impulse tests in laboratories. Progress in short time measurement techniques allowed to reproduce impulses of defined shape and amplitude. In order to establish compatibility of discharge tests in the Megavolt-range, standard pulse shapes were internationally agreed upon. Of special interest for an effective coordination of various insulation structures became data of spark-over values of air gaps with very short time lags. However, a great number of measurements did not lead to satisfying results for non-standard test-voltages. Attempts to derive formulae for good results were neither easy to use nor reliable. Finally, an approach starting from the first principle of discharge in an air gap assuming the speed of leader growth being proportional to the instant voltage above the withstand value led to a simple and generally applicable criterion. Further development of physical models for the leader propagation process leads to self-reliant calculation methods, which are simply coupled to average field calculations.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123666993","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}
Pub Date : 2016-09-01DOI: 10.1109/ICLP.2016.7791462
Koji Michishita, S. Kurihara, Koji Takano
The authors have carried out measurement of the current waveforms associated with lightning strokes to wind turbines at south Kyushu. In this paper measured waveforms on summer in 2013 are reported and it is shown that the return strokes with steep rate of rise and/or with high energy are observed in summer. This result is of practical importance for the insulation design of the wind turbine at the area of high lightning activity on summer.
{"title":"Measurement and modeling of lightning current at wind turbine in summer","authors":"Koji Michishita, S. Kurihara, Koji Takano","doi":"10.1109/ICLP.2016.7791462","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791462","url":null,"abstract":"The authors have carried out measurement of the current waveforms associated with lightning strokes to wind turbines at south Kyushu. In this paper measured waveforms on summer in 2013 are reported and it is shown that the return strokes with steep rate of rise and/or with high energy are observed in summer. This result is of practical importance for the insulation design of the wind turbine at the area of high lightning activity on summer.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124366695","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}
Pub Date : 2016-09-01DOI: 10.1109/ICLP.2016.7791461
J. Birkl, E. Shulzhenko, Johannes Kolb, Michael Rock
Wind turbines are increasingly becoming an important source of energy for many power systems worldwide. Reliable and safe operation of the turbines is becoming more and more important. Due to their height and exposed location wind turbines are defined as very exposed structures to lightning. A reliable lightning protection system (LPS) for wind turbines is therefore essential. Designing the overvoltage protection system of a wind turbine the lightning current distribution and overvoltages inside the turbine needs to be analyzed. For this purpose the real structure of a specific standard wind turbine is considered. Based on the geometry and material parameters an equivalent circuit model is developed in EMTP-ATP. Using this model, the current distribution and overvoltages can simply be calculated. In the following paper this model is used to investigate the voltage stresses occurring inside the turbine due to direct lightning strike into a rotor blade. Based on the simulation results different overvoltage concepts for the electrical and IT systems are analyzed including the investigation of the power electronic converter of a full converter wind turbine. Ultimately an overvoltage protection concept is suggested that reduces voltage stresses for the electrical and IT system as well as the power converter according to standard [1].
{"title":"Approach for evaluation of lightning current distribution on wind turbine with numerical model","authors":"J. Birkl, E. Shulzhenko, Johannes Kolb, Michael Rock","doi":"10.1109/ICLP.2016.7791461","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791461","url":null,"abstract":"Wind turbines are increasingly becoming an important source of energy for many power systems worldwide. Reliable and safe operation of the turbines is becoming more and more important. Due to their height and exposed location wind turbines are defined as very exposed structures to lightning. A reliable lightning protection system (LPS) for wind turbines is therefore essential. Designing the overvoltage protection system of a wind turbine the lightning current distribution and overvoltages inside the turbine needs to be analyzed. For this purpose the real structure of a specific standard wind turbine is considered. Based on the geometry and material parameters an equivalent circuit model is developed in EMTP-ATP. Using this model, the current distribution and overvoltages can simply be calculated. In the following paper this model is used to investigate the voltage stresses occurring inside the turbine due to direct lightning strike into a rotor blade. Based on the simulation results different overvoltage concepts for the electrical and IT systems are analyzed including the investigation of the power electronic converter of a full converter wind turbine. Ultimately an overvoltage protection concept is suggested that reduces voltage stresses for the electrical and IT system as well as the power converter according to standard [1].","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114835170","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}
Pub Date : 2016-09-01DOI: 10.1109/ICLP.2016.7791482
D. Okano
This paper presents our investigation of the properties of lightning impulse discharges and the extent to which they depend on the pressure of air entering concrete material soaked in salt water. The experimental results determined that 1) the discharge through a concrete wall including a junction structure displays distorted voltage waveforms in the first half cycle; 2) these distorted waveforms also cause high-frequency noise exceeding 100 kHz; 3) a gap in which the air pressure exceeds 2 atm is capable of suppressing the amount of high-frequency noise above 100 kHz by one third; 4) for air pressures exceeding 2 atm, subjecting the discharge waveforms to Fourier transform makes it possible to specify the dependency of the impedance on the frequency, and to estimate the impedance elements and their circuit in the frequency bands of conventional lightning currents.
{"title":"Lightning transient impedance analysis of a junction concrete gap soaked in salt water under varying air pressure conditions","authors":"D. Okano","doi":"10.1109/ICLP.2016.7791482","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791482","url":null,"abstract":"This paper presents our investigation of the properties of lightning impulse discharges and the extent to which they depend on the pressure of air entering concrete material soaked in salt water. The experimental results determined that 1) the discharge through a concrete wall including a junction structure displays distorted voltage waveforms in the first half cycle; 2) these distorted waveforms also cause high-frequency noise exceeding 100 kHz; 3) a gap in which the air pressure exceeds 2 atm is capable of suppressing the amount of high-frequency noise above 100 kHz by one third; 4) for air pressures exceeding 2 atm, subjecting the discharge waveforms to Fourier transform makes it possible to specify the dependency of the impedance on the frequency, and to estimate the impedance elements and their circuit in the frequency bands of conventional lightning currents.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"85 16","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120820747","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}
Pub Date : 2016-09-01DOI: 10.1109/ICLP.2016.7791447
V. March, J. Montanyà, Ferran Fabró, O. A. van der Velde, David Romero, G. Sola, Modesto Freijó, N. Pineda
The paper presents winter lightning maps on specific regions in the northern hemisphere. Four different degrees of winter lightning activity are defined based on information derived from Japanese case. Based on this reference case it is possible to determine regions where winter lightning can be a threat to specific structures. Guidance on risk assessment to tall structures and wind turbines are described as well.
{"title":"Winter lightning activity in specific global regions and implications to wind turbines and tall structures","authors":"V. March, J. Montanyà, Ferran Fabró, O. A. van der Velde, David Romero, G. Sola, Modesto Freijó, N. Pineda","doi":"10.1109/ICLP.2016.7791447","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791447","url":null,"abstract":"The paper presents winter lightning maps on specific regions in the northern hemisphere. Four different degrees of winter lightning activity are defined based on information derived from Japanese case. Based on this reference case it is possible to determine regions where winter lightning can be a threat to specific structures. Guidance on risk assessment to tall structures and wind turbines are described as well.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122628636","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}
Pub Date : 2016-09-01DOI: 10.1109/ICLP.2016.7791349
Yao Yao, Li Jian, Zhou Xue-ming, Tang Ze-yang, Li Han, Zhou Wen-jun
The operating experience of power system suggests that the development of mountain lightning leader is certainly attracted by the mountain terrain for electric field distortion affection, resulting in increased CG lightning density in transmission line corridor area. This paper presents a simulation model applicable to lightning strike probability of transmission lines on abstract mountainous terrain. By a conformal mapping function, which has a similar shape as mountain, the abstracted 2D mountainous terrain will be mapped to the horizontal plane, then the image method is used to calculate electrical-potential field and Development Track of the lightning downward leader on mountainous terrain by LPM (leader progression model). The Striking Distance of EGM (electro-geometric model) is adopted as an important parameter to simply determine lightning strike point on lightning lead's last-jump. The simulation results show that the lightning distribution in some typical mountain terrain performs good agreement with the lightning location statistics in mountainous terrain area. Compared with the results calculated through EGM model, the shielding failure flashover probability of the edge phase of a 220 kV transmission line in Three Gorges area increases significantly through the new model, which considers the attraction effects on the lightning leader of mountain terrain. Therefore, the higher lighting flashover probability in mountain terrain can be well explained by the model.
{"title":"Research of lightning leader development in mountainous terrain based on conformai mapping","authors":"Yao Yao, Li Jian, Zhou Xue-ming, Tang Ze-yang, Li Han, Zhou Wen-jun","doi":"10.1109/ICLP.2016.7791349","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791349","url":null,"abstract":"The operating experience of power system suggests that the development of mountain lightning leader is certainly attracted by the mountain terrain for electric field distortion affection, resulting in increased CG lightning density in transmission line corridor area. This paper presents a simulation model applicable to lightning strike probability of transmission lines on abstract mountainous terrain. By a conformal mapping function, which has a similar shape as mountain, the abstracted 2D mountainous terrain will be mapped to the horizontal plane, then the image method is used to calculate electrical-potential field and Development Track of the lightning downward leader on mountainous terrain by LPM (leader progression model). The Striking Distance of EGM (electro-geometric model) is adopted as an important parameter to simply determine lightning strike point on lightning lead's last-jump. The simulation results show that the lightning distribution in some typical mountain terrain performs good agreement with the lightning location statistics in mountainous terrain area. Compared with the results calculated through EGM model, the shielding failure flashover probability of the edge phase of a 220 kV transmission line in Three Gorges area increases significantly through the new model, which considers the attraction effects on the lightning leader of mountain terrain. Therefore, the higher lighting flashover probability in mountain terrain can be well explained by the model.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"213 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116755759","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}
Pub Date : 2016-09-01DOI: 10.1109/ICLP.2016.7791369
Rui Han, Qing Yang, W. Sima, Shangpeng Sun, Tong Liu, Hongwen Liu, Ke Wang
In this paper, a type of sensor for the non-contact monitoring of lightning and switching overvoltage in power grid is presented. It is designed based on Pockels effect and stray-capacity coupling theory. Double-crystal structure is utilized to restrain the unwanted influence caused by natural birefringence. The transmission of the data is achieved by optical fibers which are immune to the electromagnetic interference in substation. This type of sensor is applied to an EHV transformer substation for on-line monitoring.
{"title":"Research and application of a non-contact optical voltage sensor for the monitoring of lightning and switching overvoltage in EHV power grid","authors":"Rui Han, Qing Yang, W. Sima, Shangpeng Sun, Tong Liu, Hongwen Liu, Ke Wang","doi":"10.1109/ICLP.2016.7791369","DOIUrl":"https://doi.org/10.1109/ICLP.2016.7791369","url":null,"abstract":"In this paper, a type of sensor for the non-contact monitoring of lightning and switching overvoltage in power grid is presented. It is designed based on Pockels effect and stray-capacity coupling theory. Double-crystal structure is utilized to restrain the unwanted influence caused by natural birefringence. The transmission of the data is achieved by optical fibers which are immune to the electromagnetic interference in substation. This type of sensor is applied to an EHV transformer substation for on-line monitoring.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122330534","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}
Pub Date : 2016-09-01DOI: 10.1109/ICLP.2014.6973366
Y. Naito, Kazuo Yamamoto, S. Yanagawa
We applied impulse voltages to an electric vehicle using an impulse voltage generator. The results provide insight into the phenomenological aspects of lightning strikes and characteristics of electric discharge between the wheels and ground.
{"title":"High voltage impulse experiment on electric automobiles and its verification part2","authors":"Y. Naito, Kazuo Yamamoto, S. Yanagawa","doi":"10.1109/ICLP.2014.6973366","DOIUrl":"https://doi.org/10.1109/ICLP.2014.6973366","url":null,"abstract":"We applied impulse voltages to an electric vehicle using an impulse voltage generator. The results provide insight into the phenomenological aspects of lightning strikes and characteristics of electric discharge between the wheels and ground.","PeriodicalId":373744,"journal":{"name":"2016 33rd International Conference on Lightning Protection (ICLP)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128081925","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}
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