Pub Date : 2012-12-31DOI: 10.1109/UPEC.2012.6398417
M. Grond, N. H. Luong, J. Morren, J. Slootweg
Efficient operation and planning of power systems is important for a reliable and sustainable electricity supply. Therefore, optimization techniques have been applied to several optimization problems in power systems in order to achieve technical and economic efficiency. This paper presents an overview of existing optimization techniques and applications in power systems, with a special focus on multi-objective optimization in power system planning. Power system planning is by its nature a very complex multi-objective optimization problem involving perspectives of different stakeholders. Besides, a single stakeholder can also have various objectives that need to be optimized at the same time. This paper provides a review of the state-of-the-art in multi-objective evolutionary algorithms applied to power systems planning problems.
{"title":"Multi-objective optimization techniques and applications in electric power systems","authors":"M. Grond, N. H. Luong, J. Morren, J. Slootweg","doi":"10.1109/UPEC.2012.6398417","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398417","url":null,"abstract":"Efficient operation and planning of power systems is important for a reliable and sustainable electricity supply. Therefore, optimization techniques have been applied to several optimization problems in power systems in order to achieve technical and economic efficiency. This paper presents an overview of existing optimization techniques and applications in power systems, with a special focus on multi-objective optimization in power system planning. Power system planning is by its nature a very complex multi-objective optimization problem involving perspectives of different stakeholders. Besides, a single stakeholder can also have various objectives that need to be optimized at the same time. This paper provides a review of the state-of-the-art in multi-objective evolutionary algorithms applied to power systems planning problems.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129487981","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}
This paper presents new module-style power system training device. Power system engineers are demanding for electric utilities, railway companies, facility engineering companies, and power apparatus management sections in factories. However, electrical engineer lacks of experimental-based education due to high-cost of experiment device. This paper provides idea for improvement of this situation by prepared module-style power experiment device.
{"title":"Proposal of new module-style power system training device","authors":"Y. Hitotsumatsu, G. Fujita","doi":"10.4307/JSEE.61.2_62","DOIUrl":"https://doi.org/10.4307/JSEE.61.2_62","url":null,"abstract":"This paper presents new module-style power system training device. Power system engineers are demanding for electric utilities, railway companies, facility engineering companies, and power apparatus management sections in factories. However, electrical engineer lacks of experimental-based education due to high-cost of experiment device. This paper provides idea for improvement of this situation by prepared module-style power experiment device.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126983147","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398589
A. Holdyk, Joachim Holboell, I. Arana, Asger Jensen
Transient voltages resulting from switching operations depend on an interaction between the breaker, the transformer, cables and a neighbourhood grid and imply a risk for the transformer and other components. In this paper the Frequency Domain Severity Factor (FDSF) is used to assess the severity of electrical stress imposed on wind turbine transformers by voltage waveforms produced during switching operations. The method is implemented in Matlab together with automatic and systematic variation of parameters. Simulations of a radial energization are performed on a 90MVA offshore wind farm model implemented in ATP-EMTP using standard component models and further validated against measurements. The results show the range of overvoltages on the transformer terminals as well as the corresponding FSDF for all turbines under a number of varying parameters. The maximum FDSF of 1.235 and frequency of 445 kHz has been found on the low voltage side of the transformer at the last wind turbine in the neighbouring radial to the one being energized.
{"title":"Switching operation simulations in a large offshore wind farm with use of parametric variation and Frequency Domain Severity Factor","authors":"A. Holdyk, Joachim Holboell, I. Arana, Asger Jensen","doi":"10.1109/UPEC.2012.6398589","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398589","url":null,"abstract":"Transient voltages resulting from switching operations depend on an interaction between the breaker, the transformer, cables and a neighbourhood grid and imply a risk for the transformer and other components. In this paper the Frequency Domain Severity Factor (FDSF) is used to assess the severity of electrical stress imposed on wind turbine transformers by voltage waveforms produced during switching operations. The method is implemented in Matlab together with automatic and systematic variation of parameters. Simulations of a radial energization are performed on a 90MVA offshore wind farm model implemented in ATP-EMTP using standard component models and further validated against measurements. The results show the range of overvoltages on the transformer terminals as well as the corresponding FSDF for all turbines under a number of varying parameters. The maximum FDSF of 1.235 and frequency of 445 kHz has been found on the low voltage side of the transformer at the last wind turbine in the neighbouring radial to the one being energized.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129122536","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398641
Mark E. Collins, R. Silversides, Tim C. Green
Multi-Agent Systems (MAS) have the potential to solve Active Network Management (ANM) problems arising from an increase in Distributed Energy Resources (DER). The aim of this research is to integrate a MAS into an electrical network emulation for the purpose of implementing ANM. Initially an overview of agents and MAS and how their characteristics can be used to control and coordinate an electrical network is presented. An electrical network comprising a real-time emulated transmission network connected to a live DER network controlled and coordinated by a MAS is then constructed. The MAS is then used to solve a simple ANM problem: the control and coordination of an electrical network in order to maintain frequency within operational limits. The research concludes that a MAS is successful in solving this ANM problem and also that in the future the developed MAS can be applied to other ANM problems.
{"title":"Multi-Agent System control and coordination of an electrical network","authors":"Mark E. Collins, R. Silversides, Tim C. Green","doi":"10.1109/UPEC.2012.6398641","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398641","url":null,"abstract":"Multi-Agent Systems (MAS) have the potential to solve Active Network Management (ANM) problems arising from an increase in Distributed Energy Resources (DER). The aim of this research is to integrate a MAS into an electrical network emulation for the purpose of implementing ANM. Initially an overview of agents and MAS and how their characteristics can be used to control and coordinate an electrical network is presented. An electrical network comprising a real-time emulated transmission network connected to a live DER network controlled and coordinated by a MAS is then constructed. The MAS is then used to solve a simple ANM problem: the control and coordination of an electrical network in order to maintain frequency within operational limits. The research concludes that a MAS is successful in solving this ANM problem and also that in the future the developed MAS can be applied to other ANM problems.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116348945","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398440
B. Alipuria, B. Asare-Bediako, R. J. de Groot, J. Sarker, J. Slootweg, W. Kling
Smart Grids have been one of the prime focuses of studies for the past few years on power systems. The goal is to make the power infrastructure more reliable and effective to cater for the needs of the future. Another goal for improving the power infrastructure is to incorporate renewable energy sources in an efficient and cost-effective manner. The popularity of solar PV has increased in recent times which has lead to exponential growth in the installed solar PV. This paper compares four possible scenarios for incorporating household solar PV systems into the power grid. It discusses the properties of each scenario along with their advantages and disadvantages. An effective system layout can be obtained by choosing the suitable case for incorporation of solar home systems according to the requirements.
{"title":"Incorporating solar home systems for smart grid applications","authors":"B. Alipuria, B. Asare-Bediako, R. J. de Groot, J. Sarker, J. Slootweg, W. Kling","doi":"10.1109/UPEC.2012.6398440","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398440","url":null,"abstract":"Smart Grids have been one of the prime focuses of studies for the past few years on power systems. The goal is to make the power infrastructure more reliable and effective to cater for the needs of the future. Another goal for improving the power infrastructure is to incorporate renewable energy sources in an efficient and cost-effective manner. The popularity of solar PV has increased in recent times which has lead to exponential growth in the installed solar PV. This paper compares four possible scenarios for incorporating household solar PV systems into the power grid. It discusses the properties of each scenario along with their advantages and disadvantages. An effective system layout can be obtained by choosing the suitable case for incorporation of solar home systems according to the requirements.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126279728","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398444
L. Czumbil, D. Şteţ, D. Micu, V. Topa, L. Ancas
The paper studies the electromagnetic interference between an existing high voltage power line and a new designed stream gas pipeline intended to be placed in the same distribution corridor. A companion paper has investigated soil resistivity along the common right-of-way. Based on the obtained horizontally and vertically layered equivalent soil models, in this paper, a detailed analysis of the induced AC interferences in the underground pipeline is done, for different normal and fault operating conditions. Two different software packages were used to evaluate the induced voltage and current levels: CDEGS and InterfStud (developed by the authors). Obtained result has been compared to each other and to European Standard Regulations.
{"title":"Stream gas pipeline in proximity of high voltage power lines. Part II — Induced voltage evaluation","authors":"L. Czumbil, D. Şteţ, D. Micu, V. Topa, L. Ancas","doi":"10.1109/UPEC.2012.6398444","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398444","url":null,"abstract":"The paper studies the electromagnetic interference between an existing high voltage power line and a new designed stream gas pipeline intended to be placed in the same distribution corridor. A companion paper has investigated soil resistivity along the common right-of-way. Based on the obtained horizontally and vertically layered equivalent soil models, in this paper, a detailed analysis of the induced AC interferences in the underground pipeline is done, for different normal and fault operating conditions. Two different software packages were used to evaluate the induced voltage and current levels: CDEGS and InterfStud (developed by the authors). Obtained result has been compared to each other and to European Standard Regulations.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127963952","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398681
Z. Xu, S. Kariuki, S. Chowdhury, S. Chowdhury
Worldwide initiative to transform its energy industry from being based on polluting fossil-fuels into cleaner renewable energy resources is growing. Interest is growing in generating power using Concentrating Solar Thermal Power (CSTP) plants where solar energy is concentrated to heat a working fluid and run the turbine to generate electricity. The paper focuses on the selection process of thermal fluids/salts for thermal storage of a parabolic trough CSTP plant by analyzing their Levelized Cost of Electricity (LCOE) and power output after each optimization process. Simulation is performed under the geographic context of Cape Town in an investigative attempt to achieve 24 hour generation. The software used for simulation is the System Advisor Model (SAM) which is an open source software made by the National Renewable Energy Laboratories, USA.
世界范围内将其能源工业从污染严重的化石燃料转变为更清洁的可再生能源的倡议正在增加。人们对聚光太阳能热发电(CSTP)的兴趣越来越大。聚光太阳能热发电是指将太阳能集中起来加热工作流体，然后运行涡轮机发电。研究了某抛物线槽式CSTP电站蓄热用热液/热盐的选择过程，分析了各优化过程后的平准化电力成本(LCOE)和输出功率。模拟是在开普敦的地理背景下进行的，以调查尝试实现24小时发电。模拟使用的软件是System Advisor Model (SAM)，这是美国国家可再生能源实验室开发的开源软件。
{"title":"Investigation of thermal storage options for Concentrating Solar Power plants","authors":"Z. Xu, S. Kariuki, S. Chowdhury, S. Chowdhury","doi":"10.1109/UPEC.2012.6398681","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398681","url":null,"abstract":"Worldwide initiative to transform its energy industry from being based on polluting fossil-fuels into cleaner renewable energy resources is growing. Interest is growing in generating power using Concentrating Solar Thermal Power (CSTP) plants where solar energy is concentrated to heat a working fluid and run the turbine to generate electricity. The paper focuses on the selection process of thermal fluids/salts for thermal storage of a parabolic trough CSTP plant by analyzing their Levelized Cost of Electricity (LCOE) and power output after each optimization process. Simulation is performed under the geographic context of Cape Town in an investigative attempt to achieve 24 hour generation. The software used for simulation is the System Advisor Model (SAM) which is an open source software made by the National Renewable Energy Laboratories, USA.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132543802","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398423
D. Smith, S. McMeekin, B. Stewart, P. Wallace
Within a high voltage substation, power transformer bushings are key components and an assessment of their condition is important to ensure operational reliability. Bushings represent a large proportion of transformer failures, where most issues are as a result of moisture ingress. Moisture ingress affects the distribution of the electric field and changes the capacitance and dissipation factor (tanδ) of the insulation. In this paper, a numerical model is built for an oil impregnated paper (OIP) condenser bushing. The simulated dielectric frequency response (DFR) dependence of transformer oil and OIP with varying moisture content is given. Simulations are made of the AC and very low frequency (approximated to DC) potential and electric field distributions. Furthermore, the capacitance and dissipation factor over a frequency range of between 1mHz to 1kHz is presented. The results are found to be consistent with typical bushing manufacturers' data.
{"title":"The modelling of electric field, capacitance and dissipation factor of a high voltage bushing over varying frequency","authors":"D. Smith, S. McMeekin, B. Stewart, P. Wallace","doi":"10.1109/UPEC.2012.6398423","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398423","url":null,"abstract":"Within a high voltage substation, power transformer bushings are key components and an assessment of their condition is important to ensure operational reliability. Bushings represent a large proportion of transformer failures, where most issues are as a result of moisture ingress. Moisture ingress affects the distribution of the electric field and changes the capacitance and dissipation factor (tanδ) of the insulation. In this paper, a numerical model is built for an oil impregnated paper (OIP) condenser bushing. The simulated dielectric frequency response (DFR) dependence of transformer oil and OIP with varying moisture content is given. Simulations are made of the AC and very low frequency (approximated to DC) potential and electric field distributions. Furthermore, the capacitance and dissipation factor over a frequency range of between 1mHz to 1kHz is presented. The results are found to be consistent with typical bushing manufacturers' data.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129996692","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398624
P. I. Domingues dos Santos, J. P. Pinto e Abreu, C. Ferreira, R. Pestana, F. Barbosa
In the last years, the electric power systems have been restructured, moving from a vertical integrated model to a market oriented environment. The new paradigms associated with the restructuring of the electricity sector made it critical to develop new efficient and reliable methodologies to study and analyze the security of the power networks. In this paper it is proposed a method to evaluate the impact of external elements on the responsibility area of a Transmission System Operator (TSO) using the influence factor method. This approach offers a concrete support in the determination of the observability area, which at the end remains in the responsibility of the single TSO. The influence factor is a numerical value used to quantify the greatest effect of the outage of an external network component on any internal network branch. The developed methodology was applied to study the IEEE 118 bus test power network. All simulations of the transmission systems of the IEEE 118 bus were performed using the PSS®E software package from Siemens PTI, making the division of the network in two countries (areas). From the simulation results, some conclusions that provide a valuable contribution to understanding the influence factor method are pointed out.
{"title":"Impact of external elements on the responsibility area of a Transmission System Operator using the influence factor method","authors":"P. I. Domingues dos Santos, J. P. Pinto e Abreu, C. Ferreira, R. Pestana, F. Barbosa","doi":"10.1109/UPEC.2012.6398624","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398624","url":null,"abstract":"In the last years, the electric power systems have been restructured, moving from a vertical integrated model to a market oriented environment. The new paradigms associated with the restructuring of the electricity sector made it critical to develop new efficient and reliable methodologies to study and analyze the security of the power networks. In this paper it is proposed a method to evaluate the impact of external elements on the responsibility area of a Transmission System Operator (TSO) using the influence factor method. This approach offers a concrete support in the determination of the observability area, which at the end remains in the responsibility of the single TSO. The influence factor is a numerical value used to quantify the greatest effect of the outage of an external network component on any internal network branch. The developed methodology was applied to study the IEEE 118 bus test power network. All simulations of the transmission systems of the IEEE 118 bus were performed using the PSS®E software package from Siemens PTI, making the division of the network in two countries (areas). From the simulation results, some conclusions that provide a valuable contribution to understanding the influence factor method are pointed out.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134148828","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398677
S. Ang, M. Salam
In this paper, a high frequency characteristic of a 6.6 kV transformer winding with a continuous disc type high voltage (HV) winding which consists of 13 turn and 22 discs is modeled. The formulation of the distributed parameters particularly the capacitances are determined according to the geometry and construction of the HV winding of the transformer. The determination of turn-to-turn and coil-to-coil capacitances of the winding is also taken into consideration. In addition, the model also includes the total value of series capacitance, Cs for the unshielded winding, the total ground capacitance, Cg, the series resistance, Rs and resistance to ground, Rg. The accuracy of the developed high frequency transformer model is simulated by using a computer simulation package, PSCAD and compared with the measurement results. A low voltage impulse with a double-exponential waveform which is similar to the characteristic of a lightning impulse is employed for the performance study of the developed model. The results obtained from both the simulation and the measurement are in good agreement.
{"title":"Modeling of high frequency characteristic of a 6.6 kV transformer","authors":"S. Ang, M. Salam","doi":"10.1109/UPEC.2012.6398677","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398677","url":null,"abstract":"In this paper, a high frequency characteristic of a 6.6 kV transformer winding with a continuous disc type high voltage (HV) winding which consists of 13 turn and 22 discs is modeled. The formulation of the distributed parameters particularly the capacitances are determined according to the geometry and construction of the HV winding of the transformer. The determination of turn-to-turn and coil-to-coil capacitances of the winding is also taken into consideration. In addition, the model also includes the total value of series capacitance, Cs for the unshielded winding, the total ground capacitance, Cg, the series resistance, Rs and resistance to ground, Rg. The accuracy of the developed high frequency transformer model is simulated by using a computer simulation package, PSCAD and compared with the measurement results. A low voltage impulse with a double-exponential waveform which is similar to the characteristic of a lightning impulse is employed for the performance study of the developed model. The results obtained from both the simulation and the measurement are in good agreement.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134087177","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：