Pub Date : 2013-11-01DOI: 10.1109/IECON.2013.6699288
P. Garsed, R. McMahon
A SPICE simulation model of a novel cascode switch that combines a high voltage normally-on silicon carbide (SiC) junction field effect transistor (JFET) with a low voltage enhancement-mode gallium nitride field effect transistor (eGaN FET) has been developed, with the aim of optimising cascode switching performance. The effect of gate resistance on stability and switching losses is investigated and optimum values chosen. The effects of stray inductance on cascode switching performance are considered and the benefits of low inductance packaging discussed. The use of a positive JFET gate bias in a cascode switch is shown to reduce switching losses as well as reducing on-state losses. The findings of the simulation are used to produce a list of priorities for the design and layout of wide-bandgap cascode switches, relevant to both SiC and GaN high voltage devices.
{"title":"Optimising the dynamic performance of an all-wide-bandgap cascode switch","authors":"P. Garsed, R. McMahon","doi":"10.1109/IECON.2013.6699288","DOIUrl":"https://doi.org/10.1109/IECON.2013.6699288","url":null,"abstract":"A SPICE simulation model of a novel cascode switch that combines a high voltage normally-on silicon carbide (SiC) junction field effect transistor (JFET) with a low voltage enhancement-mode gallium nitride field effect transistor (eGaN FET) has been developed, with the aim of optimising cascode switching performance. The effect of gate resistance on stability and switching losses is investigated and optimum values chosen. The effects of stray inductance on cascode switching performance are considered and the benefits of low inductance packaging discussed. The use of a positive JFET gate bias in a cascode switch is shown to reduce switching losses as well as reducing on-state losses. The findings of the simulation are used to produce a list of priorities for the design and layout of wide-bandgap cascode switches, relevant to both SiC and GaN high voltage devices.","PeriodicalId":237327,"journal":{"name":"IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115718145","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 : 2013-11-01DOI: 10.1109/IECON.2013.6699304
Chi Jin, Yi Tang, Peng Wang, Xiong Liu, Dexuan Zhu, F. Blaabjerg
Three-phase three-wire shunt active power filters (APFs) usually employ very large electrolytic capacitors in the dc-link to mitigate utility side harmonics. These capacitors are however known to be bulky and of short operating lifetime, particularly for systems where high ripple currents exist. This paper presents the concept of dc-link compensator (DLC) that aims to decouple the harmonic power from the dc-link of APF. With proper system sizing and design, most of the harmonic power can be eliminated by this DLC circuit and very small electrolytic capacitors or even film type capacitors can be used instead. Moreover, DLC itself is constructed with small passive components and features very simple circuit configuration. Experimental results are provided to show its effectiveness.
{"title":"Reduction of dc-link capacitance for three-phase three-wire shunt active power filters","authors":"Chi Jin, Yi Tang, Peng Wang, Xiong Liu, Dexuan Zhu, F. Blaabjerg","doi":"10.1109/IECON.2013.6699304","DOIUrl":"https://doi.org/10.1109/IECON.2013.6699304","url":null,"abstract":"Three-phase three-wire shunt active power filters (APFs) usually employ very large electrolytic capacitors in the dc-link to mitigate utility side harmonics. These capacitors are however known to be bulky and of short operating lifetime, particularly for systems where high ripple currents exist. This paper presents the concept of dc-link compensator (DLC) that aims to decouple the harmonic power from the dc-link of APF. With proper system sizing and design, most of the harmonic power can be eliminated by this DLC circuit and very small electrolytic capacitors or even film type capacitors can be used instead. Moreover, DLC itself is constructed with small passive components and features very simple circuit configuration. Experimental results are provided to show its effectiveness.","PeriodicalId":237327,"journal":{"name":"IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123128404","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 : 2013-11-01DOI: 10.1109/IECON.2013.6699552
Yao Zhao, Huizhen Wang, Xiao-Zhong Zhao, Lan Xiao, Chunying Gong
Five-phase fault-tolerant doubly salient electromagnetic generator (FTDSEG) is proposed for high reliability applications in this paper. On the basis of comparative analysis on structure characteristics between five-phase non-fault-tolerant doubly salient electro-magnetic generator (NFTDSEG) and five-phase FTDSEG, the variation of stator and rotor pole number from NFTDSEG to FTDSEG is revealed and the phase width of back electromotive force (EMF) of five-phase FTDSEG approaching 144°is deduced. Then the flux linkage and EMF of five-phase NFTDSEG and five-phase FTDSEG are investigated using finite-element method with two dimensions and four fault modes of five-phase FTDSEG are analyzed in detail. The laws of fault operating influence on external and power characteristic of motor and output voltages of rectifier are researched in four fault modes with different exciting currents. Meanwhile, the reason why the output voltage of rectifier of single phase short circuit fault is bigger than open circuit fault is given. Finally, the fault-tolerant characteristic of five-phase FTDSEG is verified by the experimental results.
{"title":"Characteristics analysis of five-phase fault-tolerant doubly salient electro-magnetic generators","authors":"Yao Zhao, Huizhen Wang, Xiao-Zhong Zhao, Lan Xiao, Chunying Gong","doi":"10.1109/IECON.2013.6699552","DOIUrl":"https://doi.org/10.1109/IECON.2013.6699552","url":null,"abstract":"Five-phase fault-tolerant doubly salient electromagnetic generator (FTDSEG) is proposed for high reliability applications in this paper. On the basis of comparative analysis on structure characteristics between five-phase non-fault-tolerant doubly salient electro-magnetic generator (NFTDSEG) and five-phase FTDSEG, the variation of stator and rotor pole number from NFTDSEG to FTDSEG is revealed and the phase width of back electromotive force (EMF) of five-phase FTDSEG approaching 144°is deduced. Then the flux linkage and EMF of five-phase NFTDSEG and five-phase FTDSEG are investigated using finite-element method with two dimensions and four fault modes of five-phase FTDSEG are analyzed in detail. The laws of fault operating influence on external and power characteristic of motor and output voltages of rectifier are researched in four fault modes with different exciting currents. Meanwhile, the reason why the output voltage of rectifier of single phase short circuit fault is bigger than open circuit fault is given. Finally, the fault-tolerant characteristic of five-phase FTDSEG is verified by the experimental results.","PeriodicalId":237327,"journal":{"name":"IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124399827","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 : 2013-11-01DOI: 10.1109/IECON.2013.6699451
C. Miguel, T. D. Rybel, J. Driesen
Fault Passage Indicators (FPIs) are a cost effective solution to increase grid reliability. The connection of Distributed Generation units can lead them to misoperate and undermine the reliability improvements. Directional FPIs is a solution to overcome this problem. In this paper, the fault detection methods and direction-polarization principles for an isolated grid are described. As well, the implementation is done in Matlab-Simulink, from the signal processing techniques till the logic scheme for fault confirmation and automated reset. Some simulations are conducted to evaluate the performance of such FPI.
{"title":"Implementation of a digital directional Fault Passage Indicator","authors":"C. Miguel, T. D. Rybel, J. Driesen","doi":"10.1109/IECON.2013.6699451","DOIUrl":"https://doi.org/10.1109/IECON.2013.6699451","url":null,"abstract":"Fault Passage Indicators (FPIs) are a cost effective solution to increase grid reliability. The connection of Distributed Generation units can lead them to misoperate and undermine the reliability improvements. Directional FPIs is a solution to overcome this problem. In this paper, the fault detection methods and direction-polarization principles for an isolated grid are described. As well, the implementation is done in Matlab-Simulink, from the signal processing techniques till the logic scheme for fault confirmation and automated reset. Some simulations are conducted to evaluate the performance of such FPI.","PeriodicalId":237327,"journal":{"name":"IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124419514","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 : 2013-11-01DOI: 10.1109/IECON.2013.6699359
F. Lima, C. Branco, J. Guerrero, Luis Juarez C. B. C. Neto, S. Carvalho, R. Torrico-Bascopé
This paper explores a control strategy for parallel uninterruptible power systems (UPS). The control technique used in that work was based on the droop control method. This method is usually applied to achieve good active and reactive power sharing when communication between the inverters is difficult due to its physical location. This paper has considered that the UPS systems there were no communication between their controls. A detailed mathematical model about the explored system is shown in that work and simulation results are presented in order to prove the theory presented.
{"title":"Analysis, modelling, and simulation of droop control with virtual impedance loop applied to parallel UPS systems","authors":"F. Lima, C. Branco, J. Guerrero, Luis Juarez C. B. C. Neto, S. Carvalho, R. Torrico-Bascopé","doi":"10.1109/IECON.2013.6699359","DOIUrl":"https://doi.org/10.1109/IECON.2013.6699359","url":null,"abstract":"This paper explores a control strategy for parallel uninterruptible power systems (UPS). The control technique used in that work was based on the droop control method. This method is usually applied to achieve good active and reactive power sharing when communication between the inverters is difficult due to its physical location. This paper has considered that the UPS systems there were no communication between their controls. A detailed mathematical model about the explored system is shown in that work and simulation results are presented in order to prove the theory presented.","PeriodicalId":237327,"journal":{"name":"IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123167389","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 : 2013-11-01DOI: 10.1109/IECON.2013.6699322
N. Yousefpoor, Sungmin Kim, S. Bhattacharya, B. Parkhideh
The Convertible static transmission controller is a versatile device which can be installed across a transmission transformer to extend the life time of existing transformers by partially bypassing and conditioning the substation throughput power. The proposed technology can provide several integration options with multiple operational modes. From the supervisory control point of view, a control algorithm is required to set the reference values of active and reactive power flow of CSTC converters based on the desired operating points for transformer active and reactive power. In this paper, the algebraic model of CSTC in shunt-shunt mode of operation is derived. Algebraic model of CSTC is used for steady state and transient stability analysis. Algebraic model will present the behavior of transformer power flow with respect to various operating points of CSTC converters. The P-Q transformer operating range can be obtained based on the proposed algebraic model. Dynamic performance of the CSTC system is also investigated in PSCAD/EMTDC environment. Simulation results will be presented to verify the proposed algebraic model of CSTC in shunt-shunt mode of operation based on steady state results.
{"title":"Supervisory control of convertible static transmission controller in shunt-shunt mode of operation","authors":"N. Yousefpoor, Sungmin Kim, S. Bhattacharya, B. Parkhideh","doi":"10.1109/IECON.2013.6699322","DOIUrl":"https://doi.org/10.1109/IECON.2013.6699322","url":null,"abstract":"The Convertible static transmission controller is a versatile device which can be installed across a transmission transformer to extend the life time of existing transformers by partially bypassing and conditioning the substation throughput power. The proposed technology can provide several integration options with multiple operational modes. From the supervisory control point of view, a control algorithm is required to set the reference values of active and reactive power flow of CSTC converters based on the desired operating points for transformer active and reactive power. In this paper, the algebraic model of CSTC in shunt-shunt mode of operation is derived. Algebraic model of CSTC is used for steady state and transient stability analysis. Algebraic model will present the behavior of transformer power flow with respect to various operating points of CSTC converters. The P-Q transformer operating range can be obtained based on the proposed algebraic model. Dynamic performance of the CSTC system is also investigated in PSCAD/EMTDC environment. Simulation results will be presented to verify the proposed algebraic model of CSTC in shunt-shunt mode of operation based on steady state results.","PeriodicalId":237327,"journal":{"name":"IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125223547","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 : 2013-11-01DOI: 10.1109/IECON.2013.6699500
M. Nakamoto, N. Shimizu, Toru Yamamoto
In general, the problem of infinite impulse response (IIR) filters design has a non-linearity due to the presence of denominator polynomial; hence, an iterative optimization is usually needed to obtain the solution. In this paper, we independently generate several time series signals in stop-band, transition zone, and pass-band based on an algorithm which generates a Gaussian stochastic process with a prescribed frequency characteristic. After that, we synthesis the input signal and its ideal output signal, and can obtain the IIR filter by using system identification method from these signals. The advantage of the proposed method is that we can compute the IIR stable digital filters as a closed-form solution. We can approximate the given frequency response and the constant group delay without using iterative optimization. Finally, a design example is presented to illustrate the effectiveness of the proposed method by designing a high-pass IIR digital filter. As a result, we confirm the filter designed has a good magnitude response and an almost flat group delay.
{"title":"A system identification approach for design of IIR digital filters","authors":"M. Nakamoto, N. Shimizu, Toru Yamamoto","doi":"10.1109/IECON.2013.6699500","DOIUrl":"https://doi.org/10.1109/IECON.2013.6699500","url":null,"abstract":"In general, the problem of infinite impulse response (IIR) filters design has a non-linearity due to the presence of denominator polynomial; hence, an iterative optimization is usually needed to obtain the solution. In this paper, we independently generate several time series signals in stop-band, transition zone, and pass-band based on an algorithm which generates a Gaussian stochastic process with a prescribed frequency characteristic. After that, we synthesis the input signal and its ideal output signal, and can obtain the IIR filter by using system identification method from these signals. The advantage of the proposed method is that we can compute the IIR stable digital filters as a closed-form solution. We can approximate the given frequency response and the constant group delay without using iterative optimization. Finally, a design example is presented to illustrate the effectiveness of the proposed method by designing a high-pass IIR digital filter. As a result, we confirm the filter designed has a good magnitude response and an almost flat group delay.","PeriodicalId":237327,"journal":{"name":"IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society","volume":"31 15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116683889","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 : 2013-11-01DOI: 10.1109/IECON.2013.6699264
V. Blahnik, Z. Peroutka, J. Talla, I. Matuljak
This paper describes a control algorithm of a single-phase voltage-source converter with an LCL output filter behaving like a high-quality controlled current source. Designed control algorithm combines model based (feed-forward) control with a feedback direct current control based on resonant controllers. This control method provides precise (low THDi) sinusoidal waveform of required output current. The theoretical conclusions presented in this paper are verified by experiments made on developed laboratory prototype of current source.
{"title":"Low ripple current source based on resonant controllers","authors":"V. Blahnik, Z. Peroutka, J. Talla, I. Matuljak","doi":"10.1109/IECON.2013.6699264","DOIUrl":"https://doi.org/10.1109/IECON.2013.6699264","url":null,"abstract":"This paper describes a control algorithm of a single-phase voltage-source converter with an LCL output filter behaving like a high-quality controlled current source. Designed control algorithm combines model based (feed-forward) control with a feedback direct current control based on resonant controllers. This control method provides precise (low THDi) sinusoidal waveform of required output current. The theoretical conclusions presented in this paper are verified by experiments made on developed laboratory prototype of current source.","PeriodicalId":237327,"journal":{"name":"IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116709581","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 : 2013-11-01DOI: 10.1109/IECON.2013.6700486
M. Schwark, K. Berger, R. Ebner, G. Ujvari, C. Hirschl, L. Neumaier, W. Mühleisen
In recent years the potential induced degradation (PID) of photovoltaic modules (crystalline and thin film) has attracted a strong interest, as it turned out that PID occurs frequently in PV systems and solar parks. PID is the loss of system power initiated by leakage currents at high voltages. The phenomenon occurs most commonly in photovoltaic (PV) modules that are closest to the negative pol when modules with p-type cells of c-Si are used. Especially in wet weather undesired leakage current decreases the performance of the cells. In this work different standard modules from different manufacturers and customized mini modules with different components were PID tested and analyzed. Additionally, indoor and outdoor degraded modules were investigated. The influence of the encapsulant was seen and it was shown that a simple PID test is not sufficient for life time prediction.
{"title":"Investigation of potential induced degradation (PID) of solar modules from different manufacturers","authors":"M. Schwark, K. Berger, R. Ebner, G. Ujvari, C. Hirschl, L. Neumaier, W. Mühleisen","doi":"10.1109/IECON.2013.6700486","DOIUrl":"https://doi.org/10.1109/IECON.2013.6700486","url":null,"abstract":"In recent years the potential induced degradation (PID) of photovoltaic modules (crystalline and thin film) has attracted a strong interest, as it turned out that PID occurs frequently in PV systems and solar parks. PID is the loss of system power initiated by leakage currents at high voltages. The phenomenon occurs most commonly in photovoltaic (PV) modules that are closest to the negative pol when modules with p-type cells of c-Si are used. Especially in wet weather undesired leakage current decreases the performance of the cells. In this work different standard modules from different manufacturers and customized mini modules with different components were PID tested and analyzed. Additionally, indoor and outdoor degraded modules were investigated. The influence of the encapsulant was seen and it was shown that a simple PID test is not sufficient for life time prediction.","PeriodicalId":237327,"journal":{"name":"IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society","volume":"2011 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116950215","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 : 2013-11-01DOI: 10.1109/IECON.2013.6700436
Hiroki Sasabuchi, K. Morioka
Intelligent spaces based on many networked sensors have been studied in recent years. In this study, a mobile intelligent space using a human-following robot is considered. The proposed system provides various informational supports to the users via the human-following robot. For example, Augmented Reality (AR) is as an application of the proposed system. Generally, positions and orientations of a user camera are needed for AR system. In the proposed system, the human-following robot built local maps around the users while following them. Then, camera position estimation using maps is achieved for AR without using markers. This paper calls the proposed system with map building and informational supports to users “Mobile Intelligent Space”. At first, map building while human following is introduced. Especially, some methods to assure reasonable map building speed and stability simultaneously in wide area are described. Experiment results are also shown in this paper.
{"title":"A map building system for Mobile Intelligent Space using human-following robot","authors":"Hiroki Sasabuchi, K. Morioka","doi":"10.1109/IECON.2013.6700436","DOIUrl":"https://doi.org/10.1109/IECON.2013.6700436","url":null,"abstract":"Intelligent spaces based on many networked sensors have been studied in recent years. In this study, a mobile intelligent space using a human-following robot is considered. The proposed system provides various informational supports to the users via the human-following robot. For example, Augmented Reality (AR) is as an application of the proposed system. Generally, positions and orientations of a user camera are needed for AR system. In the proposed system, the human-following robot built local maps around the users while following them. Then, camera position estimation using maps is achieved for AR without using markers. This paper calls the proposed system with map building and informational supports to users “Mobile Intelligent Space”. At first, map building while human following is introduced. Especially, some methods to assure reasonable map building speed and stability simultaneously in wide area are described. Experiment results are also shown in this paper.","PeriodicalId":237327,"journal":{"name":"IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116986354","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：