Pub Date : 2014-11-20DOI: 10.1109/ICELMACH.2014.6960573
Anthony Aigbomian, P. Arumugam, T. Hamiti, C. Gerada
This paper proposes a fast computing tool for performance evaluation of electrical machines where a combination of Finite-Element (FE) method and mathematical approximations are used to predict iron losses and eddy current losses in the magnets in addition to torque-speed characteristics. The adopted tool is based on FE and computes the complete machines' characteristic analytically without any further FE computation. For the initial analysis and model verification a 16-pole 24-slot Interior Permanent Magnet (IPM) is adopted. The results obtained, compared to completely FE-based solution show that the proposed tool predicts the electromagnetic losses effectively within less computation time.
{"title":"Fast computing tool for performance evaluation in Interior Permanent Magnet machines","authors":"Anthony Aigbomian, P. Arumugam, T. Hamiti, C. Gerada","doi":"10.1109/ICELMACH.2014.6960573","DOIUrl":"https://doi.org/10.1109/ICELMACH.2014.6960573","url":null,"abstract":"This paper proposes a fast computing tool for performance evaluation of electrical machines where a combination of Finite-Element (FE) method and mathematical approximations are used to predict iron losses and eddy current losses in the magnets in addition to torque-speed characteristics. The adopted tool is based on FE and computes the complete machines' characteristic analytically without any further FE computation. For the initial analysis and model verification a 16-pole 24-slot Interior Permanent Magnet (IPM) is adopted. The results obtained, compared to completely FE-based solution show that the proposed tool predicts the electromagnetic losses effectively within less computation time.","PeriodicalId":288960,"journal":{"name":"2014 International Conference on Electrical Machines (ICEM)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123217948","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 : 2014-11-20DOI: 10.1109/ICELMACH.2014.6960357
Y. L. Karnavas, C. Korkas
Conventional high torque low speed drive systems commonly have a mechanical transmission between the induction motor and the load consisting of gears, gear heads, belt/pulleys or camshafts. The main drawbacks of such setups, are the deficiency of the drive system, its high cost and the maintenance needs. An alternative to this, is the replacement of the induction motor and its mechanical transmission elements with a permanent magnet (PM) synchronous motor (PMSM) directly coupled to the load running at low speed. In this context, the paper deals with the design evaluation of a 5kW 50rpm motor and concentrates on two radial flux promising topologies i.e. with surface-mounted permanent magnets with inner and outer rotor. Since the goal is mainly the minimization of the machine's active weight (with respect to constraints related to outer dimensions, efficiency and cost), the designs of the PM machines are conducted by solving an optimization problem. Three optimization methods are adopted and three weighted cost functions are presented. The effectiveness of the methods in finding competitive alternative PMSM designs is then evaluated. The presented results are compared with other found in literature and reveal satisfactorily enhanced design solutions and performance of the proposed methods.
{"title":"Optimization methods evaluation for the design of radial flux surface PMSM","authors":"Y. L. Karnavas, C. Korkas","doi":"10.1109/ICELMACH.2014.6960357","DOIUrl":"https://doi.org/10.1109/ICELMACH.2014.6960357","url":null,"abstract":"Conventional high torque low speed drive systems commonly have a mechanical transmission between the induction motor and the load consisting of gears, gear heads, belt/pulleys or camshafts. The main drawbacks of such setups, are the deficiency of the drive system, its high cost and the maintenance needs. An alternative to this, is the replacement of the induction motor and its mechanical transmission elements with a permanent magnet (PM) synchronous motor (PMSM) directly coupled to the load running at low speed. In this context, the paper deals with the design evaluation of a 5kW 50rpm motor and concentrates on two radial flux promising topologies i.e. with surface-mounted permanent magnets with inner and outer rotor. Since the goal is mainly the minimization of the machine's active weight (with respect to constraints related to outer dimensions, efficiency and cost), the designs of the PM machines are conducted by solving an optimization problem. Three optimization methods are adopted and three weighted cost functions are presented. The effectiveness of the methods in finding competitive alternative PMSM designs is then evaluated. The presented results are compared with other found in literature and reveal satisfactorily enhanced design solutions and performance of the proposed methods.","PeriodicalId":288960,"journal":{"name":"2014 International Conference on Electrical Machines (ICEM)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123720630","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 : 2014-11-20DOI: 10.1109/ICELMACH.2014.6960522
Bonkil Koo, Ilsu Jeong, K. Nam
Since a belt driven integrated starter and generator (ISG) can make a vehicle hybridized with a minor modification, it receives a great attention recently. It provides vehicles “stop and go” function, as well as power generation like an alternator. A 12 slot - 10 pole excited synchronous machine (ESM) is designed and analyzed via JMAG in this work. The ISG is required to have a high starting torque (43 Nm) and a high speed range (~18000 rpm). Apart from Nd-free advantage, a ESM has a freedom of controlling the field current: Thereby it is not necessary to apply a high negative d-axis current at a high speed, reducing thermal load. In this design, an optimum split ratio is investigated over copper and iron losses. It is also found a proper field current capable of producing a rated power satisfying the voltage limit at a maximum speed.
{"title":"12 Slot — 10 Pole excited synchronous motor design for ISG applications","authors":"Bonkil Koo, Ilsu Jeong, K. Nam","doi":"10.1109/ICELMACH.2014.6960522","DOIUrl":"https://doi.org/10.1109/ICELMACH.2014.6960522","url":null,"abstract":"Since a belt driven integrated starter and generator (ISG) can make a vehicle hybridized with a minor modification, it receives a great attention recently. It provides vehicles “stop and go” function, as well as power generation like an alternator. A 12 slot - 10 pole excited synchronous machine (ESM) is designed and analyzed via JMAG in this work. The ISG is required to have a high starting torque (43 Nm) and a high speed range (~18000 rpm). Apart from Nd-free advantage, a ESM has a freedom of controlling the field current: Thereby it is not necessary to apply a high negative d-axis current at a high speed, reducing thermal load. In this design, an optimum split ratio is investigated over copper and iron losses. It is also found a proper field current capable of producing a rated power satisfying the voltage limit at a maximum speed.","PeriodicalId":288960,"journal":{"name":"2014 International Conference on Electrical Machines (ICEM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127683998","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 : 2014-11-20DOI: 10.1109/ICELMACH.2014.6960405
Bram Corne, C. Debruyne, P. de Baets, J. Desmet
Condition monitoring of electrical machines has proven to be economically beneficial within industrial production sites. This paper illustrates the technical implications of implementing Motor Current Signature Analysis (MCSA) as a tool for condition monitoring. The majority of machine failures are illustrated and are related to the state-of-the-art of MCSA. Because MCSA has become a valuable tool within the broader scope of condition monitoring during the last decade, a vast amount of new research opportunities can be presented. One of these opportunities is to determine Frequency Response Functions (FRFs) between the rotor vibrations and the stator current as a function of the operating point of the machine. This allows to estimate the mechanical machine fault vibrations out of the stator current frequency components, independently of its speed and load. This paper ends by presenting a research strategy to obtain this goal.
{"title":"Stator current measurements as a condition monitoring technology — The-state-of-the-art","authors":"Bram Corne, C. Debruyne, P. de Baets, J. Desmet","doi":"10.1109/ICELMACH.2014.6960405","DOIUrl":"https://doi.org/10.1109/ICELMACH.2014.6960405","url":null,"abstract":"Condition monitoring of electrical machines has proven to be economically beneficial within industrial production sites. This paper illustrates the technical implications of implementing Motor Current Signature Analysis (MCSA) as a tool for condition monitoring. The majority of machine failures are illustrated and are related to the state-of-the-art of MCSA. Because MCSA has become a valuable tool within the broader scope of condition monitoring during the last decade, a vast amount of new research opportunities can be presented. One of these opportunities is to determine Frequency Response Functions (FRFs) between the rotor vibrations and the stator current as a function of the operating point of the machine. This allows to estimate the mechanical machine fault vibrations out of the stator current frequency components, independently of its speed and load. This paper ends by presenting a research strategy to obtain this goal.","PeriodicalId":288960,"journal":{"name":"2014 International Conference on Electrical Machines (ICEM)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126398719","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 : 2014-11-20DOI: 10.1109/ICELMACH.2014.6960281
Shota Kondo, Y. Sato, Taiga Goto, M. Tomita, M. Hasegawa, S. Doki, S. Kato
Recently, synchronous reluctance motors (SynRMs) have attracted study because of their favorable properties, including limited thermal expansion of the shaft due to low heat generation by the rotor, the ability to drive at high velocity, a low degree of torque ripple and an absence of demagnetization problems. Sensorless control of SynRMs is now desired, and several methods have been proposed. These methods, however, have difficulties at low speed when the voltage signal necessary to estimate rotor position is very small. This paper proposes a new rotor position estimation method using both a high-frequency extended e.m.f.(EEMF) disturbance observer and a heterodyne detection. In this paper, it is shown, experimentally, that it is possible to control the SynRMs at low speeds and under loaded conditions without the position and velocity sensor using the new proposed method.
{"title":"Position and velocity sensorless control for synchronous reluctance motor at low speeds and under loaded conditions using high-frequency extended EMF observer and heterodyne detection","authors":"Shota Kondo, Y. Sato, Taiga Goto, M. Tomita, M. Hasegawa, S. Doki, S. Kato","doi":"10.1109/ICELMACH.2014.6960281","DOIUrl":"https://doi.org/10.1109/ICELMACH.2014.6960281","url":null,"abstract":"Recently, synchronous reluctance motors (SynRMs) have attracted study because of their favorable properties, including limited thermal expansion of the shaft due to low heat generation by the rotor, the ability to drive at high velocity, a low degree of torque ripple and an absence of demagnetization problems. Sensorless control of SynRMs is now desired, and several methods have been proposed. These methods, however, have difficulties at low speed when the voltage signal necessary to estimate rotor position is very small. This paper proposes a new rotor position estimation method using both a high-frequency extended e.m.f.(EEMF) disturbance observer and a heterodyne detection. In this paper, it is shown, experimentally, that it is possible to control the SynRMs at low speeds and under loaded conditions without the position and velocity sensor using the new proposed method.","PeriodicalId":288960,"journal":{"name":"2014 International Conference on Electrical Machines (ICEM)","volume":"276 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125846008","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 : 2014-11-20DOI: 10.1109/ICELMACH.2014.6960225
H. Karmaker, Mantak Ho, E. Chen, D. Kulkarni
This paper describes the results of investigative studies performed for various design topologies of a direct drive HTS wind turbine generator. The investigation covers electrical, mechanical and thermal design with special considerations for design optimization for cost reduction and practical manufacturability for commercial applications. Detailed modeling and analyses are performed by taking into account the characteristic properties of the HTS and non-HTS materials. The investigations also use improved YBCO second generation (2G) HTS wire under development in a research program sponsored by the U.S. Department of Energy.
{"title":"Direct drive HTS wind generator design for commercial applications","authors":"H. Karmaker, Mantak Ho, E. Chen, D. Kulkarni","doi":"10.1109/ICELMACH.2014.6960225","DOIUrl":"https://doi.org/10.1109/ICELMACH.2014.6960225","url":null,"abstract":"This paper describes the results of investigative studies performed for various design topologies of a direct drive HTS wind turbine generator. The investigation covers electrical, mechanical and thermal design with special considerations for design optimization for cost reduction and practical manufacturability for commercial applications. Detailed modeling and analyses are performed by taking into account the characteristic properties of the HTS and non-HTS materials. The investigations also use improved YBCO second generation (2G) HTS wire under development in a research program sponsored by the U.S. Department of Energy.","PeriodicalId":288960,"journal":{"name":"2014 International Conference on Electrical Machines (ICEM)","volume":"75 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121949348","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 : 2014-11-20DOI: 10.1109/ICELMACH.2014.6960296
B. Funieru, A. Binder
A calculation method, which allows a time efficient coupling of the machine stator and moving rotor parts and force calculation in electrical machines, dedicated to 3D Finite Element (FE) models, is presented in this paper. The method requires only a single mesh generation at the beginning of the simulation. The applied force calculation method is stabilized, using a whole air gap averaging method, which does not require a special air gap mesh. Standard tetrahedral mesh elements can be used in the air gap, without affecting the torque or force calculation results even for the numerically demanding cogging torque calculation.
{"title":"3D numerical calculation method of electrical machines with time efficient air gap coupling and stabilized torque and force calculation","authors":"B. Funieru, A. Binder","doi":"10.1109/ICELMACH.2014.6960296","DOIUrl":"https://doi.org/10.1109/ICELMACH.2014.6960296","url":null,"abstract":"A calculation method, which allows a time efficient coupling of the machine stator and moving rotor parts and force calculation in electrical machines, dedicated to 3D Finite Element (FE) models, is presented in this paper. The method requires only a single mesh generation at the beginning of the simulation. The applied force calculation method is stabilized, using a whole air gap averaging method, which does not require a special air gap mesh. Standard tetrahedral mesh elements can be used in the air gap, without affecting the torque or force calculation results even for the numerically demanding cogging torque calculation.","PeriodicalId":288960,"journal":{"name":"2014 International Conference on Electrical Machines (ICEM)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121761170","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 : 2014-11-20DOI: 10.1109/ICELMACH.2014.6960260
A. Accetta, M. Pucci, A. Lidozzi, L. Solero, F. Crescimbini
Both the static and the dynamic end effects of the linear induction motor (LIM) cause an increase of the difficulty in controlling with good performance the main electro-mechanical characteristics of the machine, in particular the thrust and the linear speed. These effects are related to asymmetries in the inductor structure with respect to the rotating counterpart, in both the longitudinal and in the transversal direction. This paper propose a technique for the compensation of the LIM static end effects by a synchronous controller in conjunction with a neural adaptive filter, exploited to extract the inverse sequence current component from the inductor current signature. This permits to compensate the static-end effects and thus to cover the static asymmetries of the LIM with respect to the rotating induction motor (RIM).
{"title":"Compensation of static end effects in linear induction motor drives by frequency-adaptive synchronous controllers","authors":"A. Accetta, M. Pucci, A. Lidozzi, L. Solero, F. Crescimbini","doi":"10.1109/ICELMACH.2014.6960260","DOIUrl":"https://doi.org/10.1109/ICELMACH.2014.6960260","url":null,"abstract":"Both the static and the dynamic end effects of the linear induction motor (LIM) cause an increase of the difficulty in controlling with good performance the main electro-mechanical characteristics of the machine, in particular the thrust and the linear speed. These effects are related to asymmetries in the inductor structure with respect to the rotating counterpart, in both the longitudinal and in the transversal direction. This paper propose a technique for the compensation of the LIM static end effects by a synchronous controller in conjunction with a neural adaptive filter, exploited to extract the inverse sequence current component from the inductor current signature. This permits to compensate the static-end effects and thus to cover the static asymmetries of the LIM with respect to the rotating induction motor (RIM).","PeriodicalId":288960,"journal":{"name":"2014 International Conference on Electrical Machines (ICEM)","volume":"332 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115878210","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 : 2014-11-20DOI: 10.1109/ICELMACH.2014.6960257
V. Boscaino, R. Liga, R. Miceli, C. Cavallaro, A. Raciti
In this paper, a complete simulation setup for AC motor drives which is suitable for automotive purposes is proposed. The simulation model of the whole motor drive including the motor, inverter drive and primary supply is implemented in MATLAB/Simulink environment. The proposed simulation setup is a well-suited tool for system sizing and control algorithm design. System performances can be evaluated under effective working conditions since the simulation step. According to actual regulation in force, the urban cycle test is carried out. The speed profile of a vehicle through an urban way is forced as speed input of the motor drive. Thanks to the proposed approach, sizing, suitability of the fuel cell stack and need of load leveling algorithms as well are evaluated since the simulation stage. Simulation results are discussed to highlights benefits brought by the proposed simulation approach.
{"title":"Automotive brushless motor powered by fuel cell","authors":"V. Boscaino, R. Liga, R. Miceli, C. Cavallaro, A. Raciti","doi":"10.1109/ICELMACH.2014.6960257","DOIUrl":"https://doi.org/10.1109/ICELMACH.2014.6960257","url":null,"abstract":"In this paper, a complete simulation setup for AC motor drives which is suitable for automotive purposes is proposed. The simulation model of the whole motor drive including the motor, inverter drive and primary supply is implemented in MATLAB/Simulink environment. The proposed simulation setup is a well-suited tool for system sizing and control algorithm design. System performances can be evaluated under effective working conditions since the simulation step. According to actual regulation in force, the urban cycle test is carried out. The speed profile of a vehicle through an urban way is forced as speed input of the motor drive. Thanks to the proposed approach, sizing, suitability of the fuel cell stack and need of load leveling algorithms as well are evaluated since the simulation stage. Simulation results are discussed to highlights benefits brought by the proposed simulation approach.","PeriodicalId":288960,"journal":{"name":"2014 International Conference on Electrical Machines (ICEM)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132371673","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 : 2014-11-20DOI: 10.1109/ICELMACH.2014.6960525
S. Tsotoulidis, G. Athanasiou, E. Mitronikas
Nowadays, in order to provide high efficiency products, automotive industry is looking towards Hybrid Electric Vehicles. Fuel Cells technology is considered to be a promising solution for on board power generation. However, FCs require auxiliary sources, such as Batteries and/or Ultracapacitors, in order to deal with the issue of fast load dynamics. Within that context, Energy Management Strategy is defined as a critical component of Hybrid Electric Vehicle, since it is responsible for energy sharing among the different sources. In this paper, a novel Energy Management Strategy is proposed that aims on current sharing between primary and auxiliary sources. This strategy is deployed in two stages through a set of rate limiter and a Fuzzy Logic Controller. The first stage defines the low harmonic component of current load demand and assigns it to FC, while the second determines which harmonic component of current load demand Ultracapacitor should cover. That procedure takes considerably into consideration energy stored in ancillary sources as well as load demands. Simulation results validate the efficiency of the proposed Energy Management Strategy.
{"title":"Development of a novel Energy Management Strategy for Hybrid Electric Vehicles","authors":"S. Tsotoulidis, G. Athanasiou, E. Mitronikas","doi":"10.1109/ICELMACH.2014.6960525","DOIUrl":"https://doi.org/10.1109/ICELMACH.2014.6960525","url":null,"abstract":"Nowadays, in order to provide high efficiency products, automotive industry is looking towards Hybrid Electric Vehicles. Fuel Cells technology is considered to be a promising solution for on board power generation. However, FCs require auxiliary sources, such as Batteries and/or Ultracapacitors, in order to deal with the issue of fast load dynamics. Within that context, Energy Management Strategy is defined as a critical component of Hybrid Electric Vehicle, since it is responsible for energy sharing among the different sources. In this paper, a novel Energy Management Strategy is proposed that aims on current sharing between primary and auxiliary sources. This strategy is deployed in two stages through a set of rate limiter and a Fuzzy Logic Controller. The first stage defines the low harmonic component of current load demand and assigns it to FC, while the second determines which harmonic component of current load demand Ultracapacitor should cover. That procedure takes considerably into consideration energy stored in ancillary sources as well as load demands. Simulation results validate the efficiency of the proposed Energy Management Strategy.","PeriodicalId":288960,"journal":{"name":"2014 International Conference on Electrical Machines (ICEM)","volume":"354 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132403050","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：