Pub Date : 2018-05-20DOI: 10.23919/IPEC.2018.8507986
K. Wada, M. Ando
Recently, high-speed switching circuits using SiC power modules have been developed for using the next-generation power converter circuits. The stray inductances inside the converter circuit caused by among DC capacitors, bus bars, and power module package are one of the most critical parameters, which influence not only the over-voltage but also the switching loss. This paper proposes a quantitative design procedure for the switching losses depending the stray inductances. This paper focuses on the effects of stray inductance on both the turn-on and turn-off losses, and the quantitative analyses are explained using a stray inductance scaling method. To verify the design procedure, experimental results rated at 500 V and 160 A are demonstrated using an all-SiC power module.
{"title":"Switching Loss Analysis of SiC-MOSFET based on Stray Inductance Scaling","authors":"K. Wada, M. Ando","doi":"10.23919/IPEC.2018.8507986","DOIUrl":"https://doi.org/10.23919/IPEC.2018.8507986","url":null,"abstract":"Recently, high-speed switching circuits using SiC power modules have been developed for using the next-generation power converter circuits. The stray inductances inside the converter circuit caused by among DC capacitors, bus bars, and power module package are one of the most critical parameters, which influence not only the over-voltage but also the switching loss. This paper proposes a quantitative design procedure for the switching losses depending the stray inductances. This paper focuses on the effects of stray inductance on both the turn-on and turn-off losses, and the quantitative analyses are explained using a stray inductance scaling method. To verify the design procedure, experimental results rated at 500 V and 160 A are demonstrated using an all-SiC power module.","PeriodicalId":6610,"journal":{"name":"2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia)","volume":"239 1","pages":"1919-1924"},"PeriodicalIF":0.0,"publicationDate":"2018-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74528384","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 : 2018-05-20DOI: 10.23919/IPEC.2018.8507630
R. Schwendemann, S. Decker, M. Hiller, M. Braun
For academic research it is mandatory that the theoretical evaluation and modelling of new control methods, modulation schemes, electrical machines, power electronic topologies, etc. is validated with accurate measurements. To guarantee a high quality and high performance research it is necessary to have a modular, scalable, user-frsiendly, adaptable and affordable system. This allows to put the focus on the research topics themselves rather than spending a high effort on the pure implementation of the theoretical research results. The system described in this paper consists of a software environment/toolchain and a hardware platform. The hardware platform can be subdivided into a power electronics platform and a System on Chip based signal processing system. Besides the hardware platform also a user-friendly software environment/toolchain for model-based research is developed and illustrated in this paper. This new system enables rapid-prototyping of new algorithms, hardware and topologies.
{"title":"A Modular Converter- and Signal-Processing-Platform for Academic Research in the Field of Power Electronics","authors":"R. Schwendemann, S. Decker, M. Hiller, M. Braun","doi":"10.23919/IPEC.2018.8507630","DOIUrl":"https://doi.org/10.23919/IPEC.2018.8507630","url":null,"abstract":"For academic research it is mandatory that the theoretical evaluation and modelling of new control methods, modulation schemes, electrical machines, power electronic topologies, etc. is validated with accurate measurements. To guarantee a high quality and high performance research it is necessary to have a modular, scalable, user-frsiendly, adaptable and affordable system. This allows to put the focus on the research topics themselves rather than spending a high effort on the pure implementation of the theoretical research results. The system described in this paper consists of a software environment/toolchain and a hardware platform. The hardware platform can be subdivided into a power electronics platform and a System on Chip based signal processing system. Besides the hardware platform also a user-friendly software environment/toolchain for model-based research is developed and illustrated in this paper. This new system enables rapid-prototyping of new algorithms, hardware and topologies.","PeriodicalId":6610,"journal":{"name":"2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia)","volume":"42 1","pages":"3074-3080"},"PeriodicalIF":0.0,"publicationDate":"2018-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76191631","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 : 2018-05-20DOI: 10.23919/IPEC.2018.8507873
H. Ayano, Akira Fujimura, Y. Matsui
This paper proposes a new high-frequency reactor with a wire guide for small-size toroidal core. In theory, reactor size can be reduced in proportion to switching frequency. However, practically, as the switching frequency is increased, the reactor is affected by the parasitic capacitance existing between the windings and between the winding and the core, and the inductance characteristic of the reactor is deteriorated. As a result, there is a limit to increase the switching frequency. This paper proposes two kinds of wire guides with two-layer winding and three-layer winding to reduce the parasitic capacitance. The effects of the wire arrangement and the material of the guide are also evaluated. With the proposed guides, the parasitic capacitance decreases by 0.73 times and 0.66 times compared with the conventional reactor. Moreover, the linear regions of the impedance which can be regarded as a pure inductance are enlarged.
{"title":"Evaluation of a High-Frequency Reactor with a New Wire Guide for a Toroidal Core","authors":"H. Ayano, Akira Fujimura, Y. Matsui","doi":"10.23919/IPEC.2018.8507873","DOIUrl":"https://doi.org/10.23919/IPEC.2018.8507873","url":null,"abstract":"This paper proposes a new high-frequency reactor with a wire guide for small-size toroidal core. In theory, reactor size can be reduced in proportion to switching frequency. However, practically, as the switching frequency is increased, the reactor is affected by the parasitic capacitance existing between the windings and between the winding and the core, and the inductance characteristic of the reactor is deteriorated. As a result, there is a limit to increase the switching frequency. This paper proposes two kinds of wire guides with two-layer winding and three-layer winding to reduce the parasitic capacitance. The effects of the wire arrangement and the material of the guide are also evaluated. With the proposed guides, the parasitic capacitance decreases by 0.73 times and 0.66 times compared with the conventional reactor. Moreover, the linear regions of the impedance which can be regarded as a pure inductance are enlarged.","PeriodicalId":6610,"journal":{"name":"2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia)","volume":"7 1","pages":"1080-1086"},"PeriodicalIF":0.0,"publicationDate":"2018-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82886150","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 : 2018-05-20DOI: 10.23919/IPEC.2018.8507676
Takehiro Jikumaru, G. Kuwata
This paper presents high speed motor for electric turbo blowers used in aircraft. In this application, equipment specifications such as light weight and high power density are strongly required. Therefore, it is necessary to increase the rotational speed of motors. We have developed 1.2kW/100krpm high speed motor. This paper also shows experimental results in the prototype.
{"title":"1.2kW 100,000rpm high speed motor for aircraft","authors":"Takehiro Jikumaru, G. Kuwata","doi":"10.23919/IPEC.2018.8507676","DOIUrl":"https://doi.org/10.23919/IPEC.2018.8507676","url":null,"abstract":"This paper presents high speed motor for electric turbo blowers used in aircraft. In this application, equipment specifications such as light weight and high power density are strongly required. Therefore, it is necessary to increase the rotational speed of motors. We have developed 1.2kW/100krpm high speed motor. This paper also shows experimental results in the prototype.","PeriodicalId":6610,"journal":{"name":"2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia)","volume":"1 1","pages":"177-180"},"PeriodicalIF":0.0,"publicationDate":"2018-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85064866","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 : 2018-05-20DOI: 10.23919/IPEC.2018.8507671
Lei Gu, K. Surakitbovorn, J. Rivas-Davila
Applying RF circuit design techniques to dc-dc power conversion has pushed the switching frequency of power converters using discrete components well beyond 10 MHz. This paper proposes a simple solution to implement synchronous rectification for resonant dc-dc power converters operating at above 10 MHz, by using a symmetric bandpass matching network between the inverter and rectifier. The bandpass matching network enables the synchronous switch to be driven by the same clock signal as the inverter switch. Furthermore, this family of high frequency converter is able to maintain zero-voltage-switching operation over a wide load range. A 200 W 13.56 MHz 210 V-to-30 V bidirectional converter with a peak efficiency of 90% is demonstrated.
{"title":"High-Frequency Resonant Converter with Synchronous Rectification for High Conversion Ratio and Variable Load Operation","authors":"Lei Gu, K. Surakitbovorn, J. Rivas-Davila","doi":"10.23919/IPEC.2018.8507671","DOIUrl":"https://doi.org/10.23919/IPEC.2018.8507671","url":null,"abstract":"Applying RF circuit design techniques to dc-dc power conversion has pushed the switching frequency of power converters using discrete components well beyond 10 MHz. This paper proposes a simple solution to implement synchronous rectification for resonant dc-dc power converters operating at above 10 MHz, by using a symmetric bandpass matching network between the inverter and rectifier. The bandpass matching network enables the synchronous switch to be driven by the same clock signal as the inverter switch. Furthermore, this family of high frequency converter is able to maintain zero-voltage-switching operation over a wide load range. A 200 W 13.56 MHz 210 V-to-30 V bidirectional converter with a peak efficiency of 90% is demonstrated.","PeriodicalId":6610,"journal":{"name":"2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia)","volume":"628 1","pages":"632-638"},"PeriodicalIF":0.0,"publicationDate":"2018-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85232551","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 : 2018-05-20DOI: 10.23919/IPEC.2018.8507647
Hoang Linh Bach, Tobias Maximilian Endres, Daniel Dirksen, Sigrid Zischler, C. F. Bayer, A. Schletz, M. März
This paper proposes a novel packaging concept for power electronic applications on basis of embedding power devices in ceramic circuit carriers, such as direct bonded copper (DBC) substrates. The semiconductor devices are assembled into laser structured DBC substrates and then sealed with a copper cover afterwards. This proposed method is an alternative solution to printed circuit board (PCB) embedding and low-temperature co-fired ceramic (LTCC) based multilayer technologies, which are insufficient for high power applications due to the limited temperature resistance and current carrying capacity. The feasibility study confirmed that the DBC embedding approach was successfully implemented by using laser technology combined with conductive gluing, solder, and silver sintering processes.
{"title":"Ceramic Embedding as Packaging Solution for Future Power Electronic Applications","authors":"Hoang Linh Bach, Tobias Maximilian Endres, Daniel Dirksen, Sigrid Zischler, C. F. Bayer, A. Schletz, M. März","doi":"10.23919/IPEC.2018.8507647","DOIUrl":"https://doi.org/10.23919/IPEC.2018.8507647","url":null,"abstract":"This paper proposes a novel packaging concept for power electronic applications on basis of embedding power devices in ceramic circuit carriers, such as direct bonded copper (DBC) substrates. The semiconductor devices are assembled into laser structured DBC substrates and then sealed with a copper cover afterwards. This proposed method is an alternative solution to printed circuit board (PCB) embedding and low-temperature co-fired ceramic (LTCC) based multilayer technologies, which are insufficient for high power applications due to the limited temperature resistance and current carrying capacity. The feasibility study confirmed that the DBC embedding approach was successfully implemented by using laser technology combined with conductive gluing, solder, and silver sintering processes.","PeriodicalId":6610,"journal":{"name":"2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia)","volume":"1 1","pages":"2410-2415"},"PeriodicalIF":0.0,"publicationDate":"2018-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86376974","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 : 2018-05-20DOI: 10.23919/IPEC.2018.8507384
Young-Dal Lee, Chong-Eun Kim, J. Baek, Dong-Kwan Kim, G. Moon
A new bridgeless totem-pole boost PFC rectifier is proposed to achieve a soft-switching for power factor correction (PFC) circuit. Based on the conventional totem-pole bridgeless rectifier, an auxiliary circuit is applied to retain zero-voltage-switching (ZVS) of main switches under the middle-to-heavy load conditions and minimized conduction loss under the light load conditions utilizing auxiliary switches. Moreover, the proposed converter can reduce additional conduction loss under the light load conditions without complicated control method. Therefore, the proposed converter can have high efficiency at the entire load conditions. The feasibility of the proposed converter is verified by experimental results of prototype configurations with universal AC input and 750W output.
{"title":"A Zero-Voltage-Switching Totem-pole Bridgeless Boost Power Factor Correction Rectifier having Minimized Conduction Losses","authors":"Young-Dal Lee, Chong-Eun Kim, J. Baek, Dong-Kwan Kim, G. Moon","doi":"10.23919/IPEC.2018.8507384","DOIUrl":"https://doi.org/10.23919/IPEC.2018.8507384","url":null,"abstract":"A new bridgeless totem-pole boost PFC rectifier is proposed to achieve a soft-switching for power factor correction (PFC) circuit. Based on the conventional totem-pole bridgeless rectifier, an auxiliary circuit is applied to retain zero-voltage-switching (ZVS) of main switches under the middle-to-heavy load conditions and minimized conduction loss under the light load conditions utilizing auxiliary switches. Moreover, the proposed converter can reduce additional conduction loss under the light load conditions without complicated control method. Therefore, the proposed converter can have high efficiency at the entire load conditions. The feasibility of the proposed converter is verified by experimental results of prototype configurations with universal AC input and 750W output.","PeriodicalId":6610,"journal":{"name":"2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia)","volume":"6 1","pages":"3538-3543"},"PeriodicalIF":0.0,"publicationDate":"2018-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84193895","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 : 2018-05-20DOI: 10.23919/IPEC.2018.8507885
K. Hasegawa, I. Omura, S. Nishizawa
This paper presents a condition monitoring method of dc-link capacitors used in a high-power three-phase PWM inverter intended for load life testing with an evaluation circuit consisting a low-voltage inverter. The evaluation circuit provides the equivalent ripple current waveform and dc-bias voltage to those of the high-power inverter. Hence, the monitoring method allows the load life testing with the equivalent condition to the high-power inverter at low cost. Experimental results verify that the monitoring method extracts both the ESR and capacitance changes of a capacitor under test.
{"title":"An Evaluation Circuit for DC-Link Capacitors Used in a High-Power Three-Phase Inverter with Condition Monitoring","authors":"K. Hasegawa, I. Omura, S. Nishizawa","doi":"10.23919/IPEC.2018.8507885","DOIUrl":"https://doi.org/10.23919/IPEC.2018.8507885","url":null,"abstract":"This paper presents a condition monitoring method of dc-link capacitors used in a high-power three-phase PWM inverter intended for load life testing with an evaluation circuit consisting a low-voltage inverter. The evaluation circuit provides the equivalent ripple current waveform and dc-bias voltage to those of the high-power inverter. Hence, the monitoring method allows the load life testing with the equivalent condition to the high-power inverter at low cost. Experimental results verify that the monitoring method extracts both the ESR and capacitance changes of a capacitor under test.","PeriodicalId":6610,"journal":{"name":"2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia)","volume":"1 1","pages":"1938-1942"},"PeriodicalIF":0.0,"publicationDate":"2018-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89261492","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 : 2018-05-20DOI: 10.23919/IPEC.2018.8507416
K. Kusaka, J. Itoh
A three-phase inductive power transfer system with six transmission coils and six receiving coils is proposed in this paper. The proposed system achieves a reduction in radiation noise by canceling the noise using multiple coils, which are placed opposite to each other. However, in IPT systems with multiple coils, a magnetic interference among the multiple coils decreases a transmission efficiency due to the occurrence of circulating current. The proposed three-phase IPT system achieves cancellation of the interference using six coils on each side. First, the IPT system with the 12 coils is proposed. Then, a canceling condition of the magnetic interference among the coils is mathematically introduced from the voltage equation on the coils. Finally, the proposed IPT system is experimentally demonstrated with the 3-kW prototype. The experimental result shows that the radiation noise at the fundamental frequency is suppressed to 1/6 (from 12.2dBμA to 2.1dBμA).
{"title":"Three-phase Inductive Power Transfer System with 12 coils for Radiation Noise Reduction","authors":"K. Kusaka, J. Itoh","doi":"10.23919/IPEC.2018.8507416","DOIUrl":"https://doi.org/10.23919/IPEC.2018.8507416","url":null,"abstract":"A three-phase inductive power transfer system with six transmission coils and six receiving coils is proposed in this paper. The proposed system achieves a reduction in radiation noise by canceling the noise using multiple coils, which are placed opposite to each other. However, in IPT systems with multiple coils, a magnetic interference among the multiple coils decreases a transmission efficiency due to the occurrence of circulating current. The proposed three-phase IPT system achieves cancellation of the interference using six coils on each side. First, the IPT system with the 12 coils is proposed. Then, a canceling condition of the magnetic interference among the coils is mathematically introduced from the voltage equation on the coils. Finally, the proposed IPT system is experimentally demonstrated with the 3-kW prototype. The experimental result shows that the radiation noise at the fundamental frequency is suppressed to 1/6 (from 12.2dBμA to 2.1dBμA).","PeriodicalId":6610,"journal":{"name":"2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia)","volume":"63 1","pages":"69-76"},"PeriodicalIF":0.0,"publicationDate":"2018-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79285708","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 : 2018-05-20DOI: 10.23919/ipec.2018.8507554
A. Choudhury
Wide band gap (WBG) based semiconductor devices are considered to be the next generation of power electronic devices due to their higher switching frequency of operation with reduced device losses compared to their strong competitor Si based switches. Among the WBG devices (SiC, GaN), SiCs (Silicon Carbide) are considered to be the most preferable choice for the medium and higher power levels due to their reliability in physical construction. The major part of the loss reduction in SiC devices come from the lower on state resistance and the reduction in the reverse recovery losses associated with the antiparallel diodes. The total estimated loss reduction can be around 70% in SiC based converters compared to the Si based ones. However, there are issues related to driving these switches at safer operating area (SOA) with reduced switching losses at higher switching frequencies (20 kHz – 100 kHz), which also leads to a significant EMI/EMC issues in comparison to Si device (Operates at 20 kHz maximum). Higher switching frequency of operation further increases the effect of stray capacitances and associated oscillation which might not be acceptable for stable system operation. This paper will present different applications of SiC based inverters, challenges associated with high switching frequency SiC driver design and the problem with commercially available drivers.
{"title":"Present Status of SiC based Power Converters and Gate Drivers – A Review","authors":"A. Choudhury","doi":"10.23919/ipec.2018.8507554","DOIUrl":"https://doi.org/10.23919/ipec.2018.8507554","url":null,"abstract":"Wide band gap (WBG) based semiconductor devices are considered to be the next generation of power electronic devices due to their higher switching frequency of operation with reduced device losses compared to their strong competitor Si based switches. Among the WBG devices (SiC, GaN), SiCs (Silicon Carbide) are considered to be the most preferable choice for the medium and higher power levels due to their reliability in physical construction. The major part of the loss reduction in SiC devices come from the lower on state resistance and the reduction in the reverse recovery losses associated with the antiparallel diodes. The total estimated loss reduction can be around 70% in SiC based converters compared to the Si based ones. However, there are issues related to driving these switches at safer operating area (SOA) with reduced switching losses at higher switching frequencies (20 kHz – 100 kHz), which also leads to a significant EMI/EMC issues in comparison to Si device (Operates at 20 kHz maximum). Higher switching frequency of operation further increases the effect of stray capacitances and associated oscillation which might not be acceptable for stable system operation. This paper will present different applications of SiC based inverters, challenges associated with high switching frequency SiC driver design and the problem with commercially available drivers.","PeriodicalId":6610,"journal":{"name":"2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia)","volume":"4 1","pages":"3401-3405"},"PeriodicalIF":0.0,"publicationDate":"2018-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78669320","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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