Pub Date : 2020-12-10DOI: 10.1109/ICCS51219.2020.9336525
MinhTri Tran, A. Kuwana, Haruo Kobayashi
This paper presents a ringing test for 2nd-order Sallen-Key low-pass filters. A comparison measurement is constructed, which takes into account the measurement of a self-loop function in a transfer function. Based on the phase margin at unity of the self-loop function, a general stability criterion for second-order linear systems is proposed in terms of operating regions. In case of under-damping region, the ringing occurs and makes the system unstable. The advantage of the proposed criterion lies in its simplicity than some of the existing results. The new stability criterion is applied to the network based negative feedback issues. Experimental results show that the proposed method is quite effective.
{"title":"Ringing Test for Second-Order Sallen-Key Low-Pass Filters","authors":"MinhTri Tran, A. Kuwana, Haruo Kobayashi","doi":"10.1109/ICCS51219.2020.9336525","DOIUrl":"https://doi.org/10.1109/ICCS51219.2020.9336525","url":null,"abstract":"This paper presents a ringing test for 2nd-order Sallen-Key low-pass filters. A comparison measurement is constructed, which takes into account the measurement of a self-loop function in a transfer function. Based on the phase margin at unity of the self-loop function, a general stability criterion for second-order linear systems is proposed in terms of operating regions. In case of under-damping region, the ringing occurs and makes the system unstable. The advantage of the proposed criterion lies in its simplicity than some of the existing results. The new stability criterion is applied to the network based negative feedback issues. Experimental results show that the proposed method is quite effective.","PeriodicalId":193552,"journal":{"name":"2020 IEEE 2nd International Conference on Circuits and Systems (ICCS)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114904315","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 : 2020-12-10DOI: 10.1109/ICCS51219.2020.9336594
Yiming Lyu, Zhiqin Zhao
A broadband Doherty power amplifier codesigned with filters and a series of continuous modes is presented. Three bandpass filters are used to design post matching network, output matching network for carrier and peaking stages. These filters can not only suppress the harmonics but also interferences outside the operating band of the power amplifier. Theory named a series of continuous modes is used to transform impedance looking from carrier stage into power combing point to the objective high efficiency design space while even-odd-mode analysis is used to analysis the response of the three BPFs. Finally, a broadband 6-dB output back-off DPA operating in 1.3-2.2 GHz is designed. Simulation results exhibit output backoff drain efficiency of 56.0%-78.6% and saturated drain efficiency of 42.1%-60.2%. Moreover, the saturated output power level is 43.3-44.9 dBm with a gain of 10.3-11.8 dB.
{"title":"Codesign of a Broadband Doherty Power Amplifier with Microstrip Bandpass Filters","authors":"Yiming Lyu, Zhiqin Zhao","doi":"10.1109/ICCS51219.2020.9336594","DOIUrl":"https://doi.org/10.1109/ICCS51219.2020.9336594","url":null,"abstract":"A broadband Doherty power amplifier codesigned with filters and a series of continuous modes is presented. Three bandpass filters are used to design post matching network, output matching network for carrier and peaking stages. These filters can not only suppress the harmonics but also interferences outside the operating band of the power amplifier. Theory named a series of continuous modes is used to transform impedance looking from carrier stage into power combing point to the objective high efficiency design space while even-odd-mode analysis is used to analysis the response of the three BPFs. Finally, a broadband 6-dB output back-off DPA operating in 1.3-2.2 GHz is designed. Simulation results exhibit output backoff drain efficiency of 56.0%-78.6% and saturated drain efficiency of 42.1%-60.2%. Moreover, the saturated output power level is 43.3-44.9 dBm with a gain of 10.3-11.8 dB.","PeriodicalId":193552,"journal":{"name":"2020 IEEE 2nd International Conference on Circuits and Systems (ICCS)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116606340","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 : 2020-12-10DOI: 10.1109/ICCS51219.2020.9336526
Yunzhao Sun, Chen-Chen Yang, Tong Li, N. Yan, Hongtao Xu
This paper presents an integrated attenuator (IATT) with 40nm bulk COMS process. The IATT that works from 15GHz to 20GHz can be used in phased array system and it only employs MOSFET rather than poly silicon resistors in the main signal path and can cover attenuation range up to 14 dB by step of 2 dB. Furthermore, the root-mean-square (RMS) attenuation error can be less than 0.15dB. Due to the integrated structure the IATT only occupies 0.167 mm2 including inductors (inds) and 0.0158 mm2 excluding inductors. Besides, the IATT also shows a relative low insertion loss less than 3dB. By adopting the shunt capacitor (cap) compensation technique the RMS phase error of the IATT can be less than 0.5°.
{"title":"Design of a Wideband Compact CMOS Integrated Attenuator with Low Insertion Loss and High Accuracy","authors":"Yunzhao Sun, Chen-Chen Yang, Tong Li, N. Yan, Hongtao Xu","doi":"10.1109/ICCS51219.2020.9336526","DOIUrl":"https://doi.org/10.1109/ICCS51219.2020.9336526","url":null,"abstract":"This paper presents an integrated attenuator (IATT) with 40nm bulk COMS process. The IATT that works from 15GHz to 20GHz can be used in phased array system and it only employs MOSFET rather than poly silicon resistors in the main signal path and can cover attenuation range up to 14 dB by step of 2 dB. Furthermore, the root-mean-square (RMS) attenuation error can be less than 0.15dB. Due to the integrated structure the IATT only occupies 0.167 mm2 including inductors (inds) and 0.0158 mm2 excluding inductors. Besides, the IATT also shows a relative low insertion loss less than 3dB. By adopting the shunt capacitor (cap) compensation technique the RMS phase error of the IATT can be less than 0.5°.","PeriodicalId":193552,"journal":{"name":"2020 IEEE 2nd International Conference on Circuits and Systems (ICCS)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129821614","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}
As large-capacity units shift down to low-level power grids, the problems of transient stability and short-circuit current of power systems become increasingly prominent. The traditional control methods such as generator-tripping and load-shedding can only solve one of the problems, but cannot fundamentally solve the contradiction between transient stability and short-circuit current at the same time, resulting in poor power grid stability. A practical control strategy of connecting transient stability and short-circuit current problems of the system through system impedance are studied for the first time in this paper and a mathematical model is established with system impedance as the core. An external penalty function method is proposed to solve the contradiction between transient stability and short-circuit current by seeking the optimal impedance of the system. Taking GGE (A power grid in Hubei) regional power grid as an example for simulation verification through Power System Analysis Software Package (PSASP), the results show that the problems of transient stability and short-circuit current in the GGE regional power grid have been effectively solved and the power grid can operate stably. It is verified that the proposed coordinated control strategy of transient stability and short-circuit current can effectively improve the stability of power system.
{"title":"Research on Coordination Solution Strategy of Power System Transient Stability and Short Circuit Current Based on External Penalty Function Method","authors":"Shuai Yang, Zhongwei He, Wentao Huang, Jun He, Zhijun Yuan, Jinman Yu","doi":"10.1109/ICCS51219.2020.9336605","DOIUrl":"https://doi.org/10.1109/ICCS51219.2020.9336605","url":null,"abstract":"As large-capacity units shift down to low-level power grids, the problems of transient stability and short-circuit current of power systems become increasingly prominent. The traditional control methods such as generator-tripping and load-shedding can only solve one of the problems, but cannot fundamentally solve the contradiction between transient stability and short-circuit current at the same time, resulting in poor power grid stability. A practical control strategy of connecting transient stability and short-circuit current problems of the system through system impedance are studied for the first time in this paper and a mathematical model is established with system impedance as the core. An external penalty function method is proposed to solve the contradiction between transient stability and short-circuit current by seeking the optimal impedance of the system. Taking GGE (A power grid in Hubei) regional power grid as an example for simulation verification through Power System Analysis Software Package (PSASP), the results show that the problems of transient stability and short-circuit current in the GGE regional power grid have been effectively solved and the power grid can operate stably. It is verified that the proposed coordinated control strategy of transient stability and short-circuit current can effectively improve the stability of power system.","PeriodicalId":193552,"journal":{"name":"2020 IEEE 2nd International Conference on Circuits and Systems (ICCS)","volume":"5 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113963164","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 : 2020-12-10DOI: 10.1109/ICCS51219.2020.9336609
Jinghe Wei, Zongguang Yu, De Liu
In the fields of artificial intelligence and signal processing where computing tasks are dense or algorithms are complex, researchers usually design heterogeneous SoC of CPU + accelerator to improve the efficiency of system. In heterogeneous SoC, accelerators often act as coprocessors or channel accelerators. In this paper, in order to study the coupling relationship between accelerators and CPU, we respectively design CORDIC algorithm accelerators of coprocessor, CORIDC channel accelerator, vector dot product accelerators of coprocessor and channel accelerator based on RISC-V open source project - RocketChip. The acceleration effect of each accelerator is simulated by Modelsim. It is verified that the acceleration ratio of CORDIC algorithm coprocessor to CPU is about 151 times, and the accelerator ratio of CORDIC channel accelerator is about 103 times. The longer the vector length is, the more significant the acceleration effect of the vector dot product accelerator is, and the acceleration effect of the vector dot product channel accelerator is significantly better than that of the vector dot product coprocessor. We find that the performance of the coprocessor is limited by the speed of data access. Moreover, when the coprocessor is not tightly coupled to the CPU, additional time overhead is introduced.
{"title":"Evaluation of On-Chip Accelerator Performance Based on RocketChip","authors":"Jinghe Wei, Zongguang Yu, De Liu","doi":"10.1109/ICCS51219.2020.9336609","DOIUrl":"https://doi.org/10.1109/ICCS51219.2020.9336609","url":null,"abstract":"In the fields of artificial intelligence and signal processing where computing tasks are dense or algorithms are complex, researchers usually design heterogeneous SoC of CPU + accelerator to improve the efficiency of system. In heterogeneous SoC, accelerators often act as coprocessors or channel accelerators. In this paper, in order to study the coupling relationship between accelerators and CPU, we respectively design CORDIC algorithm accelerators of coprocessor, CORIDC channel accelerator, vector dot product accelerators of coprocessor and channel accelerator based on RISC-V open source project - RocketChip. The acceleration effect of each accelerator is simulated by Modelsim. It is verified that the acceleration ratio of CORDIC algorithm coprocessor to CPU is about 151 times, and the accelerator ratio of CORDIC channel accelerator is about 103 times. The longer the vector length is, the more significant the acceleration effect of the vector dot product accelerator is, and the acceleration effect of the vector dot product channel accelerator is significantly better than that of the vector dot product coprocessor. We find that the performance of the coprocessor is limited by the speed of data access. Moreover, when the coprocessor is not tightly coupled to the CPU, additional time overhead is introduced.","PeriodicalId":193552,"journal":{"name":"2020 IEEE 2nd International Conference on Circuits and Systems (ICCS)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125129613","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 : 2020-12-10DOI: 10.1109/ICCS51219.2020.9336593
Han Cui, Leijun Xu
This paper introduces a frequency tripler with improved output power in 40nm CMOS process. Low insertion loss and high balanced Baluns are designed for the input and output impedance matching. Meanwhile, LC series resonance is used to suppress the fundamental wave and improve the power of third harmonic wave. When the input power is 10dBm, the peak output power is 3.7dBm, the frequency conversion loss is 6.3dBm and the fundamental suppression ratio is 41dBc. The total DC power consumption is 9.6mW. The 3-dB bandwidth is 12GHz (115.5GHz~127.5GHz).
{"title":"A 120GHz Frequency Tripler with Improved Output Power in 40nm CMOS","authors":"Han Cui, Leijun Xu","doi":"10.1109/ICCS51219.2020.9336593","DOIUrl":"https://doi.org/10.1109/ICCS51219.2020.9336593","url":null,"abstract":"This paper introduces a frequency tripler with improved output power in 40nm CMOS process. Low insertion loss and high balanced Baluns are designed for the input and output impedance matching. Meanwhile, LC series resonance is used to suppress the fundamental wave and improve the power of third harmonic wave. When the input power is 10dBm, the peak output power is 3.7dBm, the frequency conversion loss is 6.3dBm and the fundamental suppression ratio is 41dBc. The total DC power consumption is 9.6mW. The 3-dB bandwidth is 12GHz (115.5GHz~127.5GHz).","PeriodicalId":193552,"journal":{"name":"2020 IEEE 2nd International Conference on Circuits and Systems (ICCS)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121775620","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 : 2020-12-10DOI: 10.1109/ICCS51219.2020.9336612
Xingyu Zhu, T. Jin
Power system stabilizer (PSS) is used to generate excitation system auxiliary control signals which can suppress low frequency oscillation in power system. It has the ability of self-learning and parameter online tuning, which is a development trend of smart grid PSS controller in the future. This paper presents a design method of power system stabilizer based on reinforcement learning. Q-learning algorithm is one of reinforcement learning, and is used to PSS as the additional control. The simulation results show that the PSS based on Q-learning can effectively improve the ability of suppressing low frequency oscillation in power system, and the robustness of the system is significantly enhanced.
{"title":"Research of Control Strategy of Power System Stabilizer Based on Reinforcement Learning","authors":"Xingyu Zhu, T. Jin","doi":"10.1109/ICCS51219.2020.9336612","DOIUrl":"https://doi.org/10.1109/ICCS51219.2020.9336612","url":null,"abstract":"Power system stabilizer (PSS) is used to generate excitation system auxiliary control signals which can suppress low frequency oscillation in power system. It has the ability of self-learning and parameter online tuning, which is a development trend of smart grid PSS controller in the future. This paper presents a design method of power system stabilizer based on reinforcement learning. Q-learning algorithm is one of reinforcement learning, and is used to PSS as the additional control. The simulation results show that the PSS based on Q-learning can effectively improve the ability of suppressing low frequency oscillation in power system, and the robustness of the system is significantly enhanced.","PeriodicalId":193552,"journal":{"name":"2020 IEEE 2nd International Conference on Circuits and Systems (ICCS)","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129630156","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 : 2020-12-10DOI: 10.1109/ICCS51219.2020.9336611
Wei Liu, Wenzhuo Yin, Jian Xie, Rong Luo, Shunren Hu
Existing solar energy harvesting structures with maximum power point tracking capability are typically a bit complicated and expensive for low cost sensor nodes, which makes them unsuitable for large-scale deployments of wireless sensor networks. In this paper, a voltage matching method for suboptimal solar energy harvesting is proposed. By matching the working voltage ranges of rechargeable batteries with the maximum power point voltages of solar panels, the output voltages of solar panels could be clamped around the maximum power point only using a simple and cheap diode. In this way, suboptimal but efficient enough solar energy harvesting could be achieved. Experimental results show that compared with existing structures, energy harvesting efficiency of the proposed method only reduces by 2.3%~18.8%.
{"title":"Do We Really Need Complicated Solar Energy Harvesting Circuits for Low Cost Sensor Nodes?","authors":"Wei Liu, Wenzhuo Yin, Jian Xie, Rong Luo, Shunren Hu","doi":"10.1109/ICCS51219.2020.9336611","DOIUrl":"https://doi.org/10.1109/ICCS51219.2020.9336611","url":null,"abstract":"Existing solar energy harvesting structures with maximum power point tracking capability are typically a bit complicated and expensive for low cost sensor nodes, which makes them unsuitable for large-scale deployments of wireless sensor networks. In this paper, a voltage matching method for suboptimal solar energy harvesting is proposed. By matching the working voltage ranges of rechargeable batteries with the maximum power point voltages of solar panels, the output voltages of solar panels could be clamped around the maximum power point only using a simple and cheap diode. In this way, suboptimal but efficient enough solar energy harvesting could be achieved. Experimental results show that compared with existing structures, energy harvesting efficiency of the proposed method only reduces by 2.3%~18.8%.","PeriodicalId":193552,"journal":{"name":"2020 IEEE 2nd International Conference on Circuits and Systems (ICCS)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133414658","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 : 2020-12-10DOI: 10.1109/ICCS51219.2020.9336524
Xuguang Liu, K. Wu, Rui Wang, Zhengwei Pan, Erxian Yao
For the design of wireless charging magnetic coupling coil, the principle is explained and the loss calculation analysis is carried out, and the loss calculation method of the magnetic coupling coil, magnetic core and shielding plate is analyzed. This paper uses the finite element method to model and design the target parameters of the magnetic coupling mechanism, compare and calculate the mass proportion of each component of the magnetic coupling mechanism, and optimize the magnetic core mass proportion. The magnetic permeability and loss curve of nanocrystalline materials and ferrite materials are compared and analyzed in detail. This paper proposes to use high permeability and low loss nanocrystalline materials to optimize the thickness of the magnetic core. Through the optimization scheme, it can be seen that the quality of the magnetic core is reduced by about 51%, and the transmission efficiency of the magnetic coupling coil remains basically unchanged. Co-simulation has been used to verify the influence of the optimization scheme on the transmission efficiency. The results show that the optimization of the magnetic core does not have a significant impact on the system efficiency, to achieve the intended purpose of the design.
{"title":"Magnetic Field Shielding Optimization Based on Wireless Charging","authors":"Xuguang Liu, K. Wu, Rui Wang, Zhengwei Pan, Erxian Yao","doi":"10.1109/ICCS51219.2020.9336524","DOIUrl":"https://doi.org/10.1109/ICCS51219.2020.9336524","url":null,"abstract":"For the design of wireless charging magnetic coupling coil, the principle is explained and the loss calculation analysis is carried out, and the loss calculation method of the magnetic coupling coil, magnetic core and shielding plate is analyzed. This paper uses the finite element method to model and design the target parameters of the magnetic coupling mechanism, compare and calculate the mass proportion of each component of the magnetic coupling mechanism, and optimize the magnetic core mass proportion. The magnetic permeability and loss curve of nanocrystalline materials and ferrite materials are compared and analyzed in detail. This paper proposes to use high permeability and low loss nanocrystalline materials to optimize the thickness of the magnetic core. Through the optimization scheme, it can be seen that the quality of the magnetic core is reduced by about 51%, and the transmission efficiency of the magnetic coupling coil remains basically unchanged. Co-simulation has been used to verify the influence of the optimization scheme on the transmission efficiency. The results show that the optimization of the magnetic core does not have a significant impact on the system efficiency, to achieve the intended purpose of the design.","PeriodicalId":193552,"journal":{"name":"2020 IEEE 2nd International Conference on Circuits and Systems (ICCS)","volume":"197 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114358584","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 : 2020-12-10DOI: 10.1109/iccs51219.2020.9336592
{"title":"[Copyright notice]","authors":"","doi":"10.1109/iccs51219.2020.9336592","DOIUrl":"https://doi.org/10.1109/iccs51219.2020.9336592","url":null,"abstract":"","PeriodicalId":193552,"journal":{"name":"2020 IEEE 2nd International Conference on Circuits and Systems (ICCS)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124935512","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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