Pub Date : 2014-12-01DOI: 10.1109/APPEEC.2014.7066061
B. Tian, Xutao Li, Hongqiang Li, Duo-Yan Xu, Wei Hu
With the integration of large-scale wind power, cascading tripping out of numerous wind turbines has been a serious threat to the security of power grid. This paper discusses the failure mechanism of cascading trips, and focuses on the strategies to prevent this kind of failure. Firstly, the typical development process of the failures has been analyzed. Furthermore, based on the topology structure and parameters of an actual power grid in China, the cascading trip-off failure has been simulated. According to the failure mechanism and characters, two optional voltage control strategies, have been presented. The computer simulation has been carried to verify the validity of the proposed strategies.
{"title":"Research on numerous wind turbines cascading trip-off failure in China","authors":"B. Tian, Xutao Li, Hongqiang Li, Duo-Yan Xu, Wei Hu","doi":"10.1109/APPEEC.2014.7066061","DOIUrl":"https://doi.org/10.1109/APPEEC.2014.7066061","url":null,"abstract":"With the integration of large-scale wind power, cascading tripping out of numerous wind turbines has been a serious threat to the security of power grid. This paper discusses the failure mechanism of cascading trips, and focuses on the strategies to prevent this kind of failure. Firstly, the typical development process of the failures has been analyzed. Furthermore, based on the topology structure and parameters of an actual power grid in China, the cascading trip-off failure has been simulated. According to the failure mechanism and characters, two optional voltage control strategies, have been presented. The computer simulation has been carried to verify the validity of the proposed strategies.","PeriodicalId":206418,"journal":{"name":"2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115860973","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 : 2014-12-01DOI: 10.1109/APPEEC.2014.7066063
Lizheng Chen, Hengxu Zhang
The increasing penetration rate of intermittent power, such as wind or photovoltaic power and electric vehicle load, leads to voltage being more vulnerable to intermittent power fluctuation and impact charging load. The background of quantitative voltage security assessment is analyzed. A new voltage deviation security margin index is presented, which takes into account both the duration of voltage deviation and the degree of voltage deviation. The new security index has clear physical concept, better linearity and smoothness. Characteristics of the index have been analyzed based on the voltage data obtained from simulation of IEEE 39-bus system and actual power grid. Based on WAMS, the quantitative voltage security assessment method has been deployed online.
{"title":"Improved voltage deviation security margin index","authors":"Lizheng Chen, Hengxu Zhang","doi":"10.1109/APPEEC.2014.7066063","DOIUrl":"https://doi.org/10.1109/APPEEC.2014.7066063","url":null,"abstract":"The increasing penetration rate of intermittent power, such as wind or photovoltaic power and electric vehicle load, leads to voltage being more vulnerable to intermittent power fluctuation and impact charging load. The background of quantitative voltage security assessment is analyzed. A new voltage deviation security margin index is presented, which takes into account both the duration of voltage deviation and the degree of voltage deviation. The new security index has clear physical concept, better linearity and smoothness. Characteristics of the index have been analyzed based on the voltage data obtained from simulation of IEEE 39-bus system and actual power grid. Based on WAMS, the quantitative voltage security assessment method has been deployed online.","PeriodicalId":206418,"journal":{"name":"2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130160485","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 : 2014-12-01DOI: 10.1109/APPEEC.2014.7066183
T. Leveringhaus, L. Hofmann
The precise prediction of changes in load flows, currents and voltage magnitudes due to changes in power is important for forecasting and managing grid congestions, voltage deviations and minimizing grid losses for example. This paper describes three different methods and further variants of those for state prediction and compares their approximations, neglects and quality of prediction. Since PTDFs and PFD modify the characteristics of the non-linear load flow equations by approximations and neglects, their qualities of prediction are less than those of the AC-PTDFs. To consider the way changings in grid losses are counteracted by the grid a new variant to consider secondary control reserve in the prediction is established. The AC-PTDFs deliver the highest quality of current and loss prediction, the most comprehensive mathematical approximation of the non-linear load flow equations, and the most potential for further development like optimized management of multiple congestions and Optimal Power Flow.
{"title":"Comparison of methods for state prediction: Power Flow Decomposition (PFD), AC Power Transfer Distribution factors (AC-PTDFs), and Power Transfer Distribution factors (PTDFs)","authors":"T. Leveringhaus, L. Hofmann","doi":"10.1109/APPEEC.2014.7066183","DOIUrl":"https://doi.org/10.1109/APPEEC.2014.7066183","url":null,"abstract":"The precise prediction of changes in load flows, currents and voltage magnitudes due to changes in power is important for forecasting and managing grid congestions, voltage deviations and minimizing grid losses for example. This paper describes three different methods and further variants of those for state prediction and compares their approximations, neglects and quality of prediction. Since PTDFs and PFD modify the characteristics of the non-linear load flow equations by approximations and neglects, their qualities of prediction are less than those of the AC-PTDFs. To consider the way changings in grid losses are counteracted by the grid a new variant to consider secondary control reserve in the prediction is established. The AC-PTDFs deliver the highest quality of current and loss prediction, the most comprehensive mathematical approximation of the non-linear load flow equations, and the most potential for further development like optimized management of multiple congestions and Optimal Power Flow.","PeriodicalId":206418,"journal":{"name":"2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134289629","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 : 2014-12-01DOI: 10.1109/APPEEC.2014.7066157
Z. Du, Donghao Luo, Yaoxuan Ruan, F. Zhan, Yao Zhang, Chengjun Xia
The large demand of dynamic reactive power for MIDC recovery is a big challenge to voltage stability of the receiving system. Thus, the research on active power (P) and reactive power (Q) characteristics of inverter station in the recovery process of multi-infeed HVDC (MIDC) attracts more and more attention. With the CIGRE HVDC benchmark, this paper studies the P and Q responses under various faults through the electromagnetic transient simulation platform PSCAD/EMTDC. The major factors dominating P-Q behaviors are analyzed. Then, in order to obtain a relative simple and analytical relation between P (or Q) and HVDC control means in recovery for future theoretical stability analysis method, numerical analysis technique is used to establish reasonable fitting equations of V=f(V) and Q=f(P). When considering voltage dependant current order limiter (VDCOL) of HVDC, the VDCOL control equation and P-Q coupling equation is combined into a simplified model of DC recovery. It helps transient stability mechanism analysis of MIDC system in whole, only utilizing the external characteristic of HVDC and avoiding HVDC complex structure and control schemes. The obtained model of power recovery of HVDC is tested with good engineering accuracy shown.
{"title":"Study on fitting equations of HVDC recovery P-Q characteristics after faults","authors":"Z. Du, Donghao Luo, Yaoxuan Ruan, F. Zhan, Yao Zhang, Chengjun Xia","doi":"10.1109/APPEEC.2014.7066157","DOIUrl":"https://doi.org/10.1109/APPEEC.2014.7066157","url":null,"abstract":"The large demand of dynamic reactive power for MIDC recovery is a big challenge to voltage stability of the receiving system. Thus, the research on active power (P) and reactive power (Q) characteristics of inverter station in the recovery process of multi-infeed HVDC (MIDC) attracts more and more attention. With the CIGRE HVDC benchmark, this paper studies the P and Q responses under various faults through the electromagnetic transient simulation platform PSCAD/EMTDC. The major factors dominating P-Q behaviors are analyzed. Then, in order to obtain a relative simple and analytical relation between P (or Q) and HVDC control means in recovery for future theoretical stability analysis method, numerical analysis technique is used to establish reasonable fitting equations of V=f(V) and Q=f(P). When considering voltage dependant current order limiter (VDCOL) of HVDC, the VDCOL control equation and P-Q coupling equation is combined into a simplified model of DC recovery. It helps transient stability mechanism analysis of MIDC system in whole, only utilizing the external characteristic of HVDC and avoiding HVDC complex structure and control schemes. The obtained model of power recovery of HVDC is tested with good engineering accuracy shown.","PeriodicalId":206418,"journal":{"name":"2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130926012","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 : 2014-12-01DOI: 10.1109/APPEEC.2014.7066062
Yuli Wang, Dan Yang, Rong Xia, Li Zhou
The attenuation and propagation characteristics of partial discharges in high voltage XLPE cable is the critical theoretical basis to achieve precise detection and positioning of partial discharges. In this paper, the propagation characteristics of partial discharges have been analyzed, simulating partial discharge test system of composed by 35kV, 110kV and 220kV XLPE power cables was constructed to study the propagation characteristics in high voltage XLPE cables. Moreover, propagation and attenuation coefficient of partial discharge in different frequency were compared through calculating and analyzing. The results showed that cables have significant high frequency filtering effect to partial discharge and steep rising edge impulses would severely attenuate with the growth of cable length. Meanwhile, semi-conducting layer has significant effects on partial discharge attenuation, Therefore, in precise detection and positioning of partial discharges in HV XLPE cable lines, attenuation compensation should be adopted, even in the distributed measurement system.
{"title":"Characteristic analysis and experimental research of PD propagation in HV XLPE cables","authors":"Yuli Wang, Dan Yang, Rong Xia, Li Zhou","doi":"10.1109/APPEEC.2014.7066062","DOIUrl":"https://doi.org/10.1109/APPEEC.2014.7066062","url":null,"abstract":"The attenuation and propagation characteristics of partial discharges in high voltage XLPE cable is the critical theoretical basis to achieve precise detection and positioning of partial discharges. In this paper, the propagation characteristics of partial discharges have been analyzed, simulating partial discharge test system of composed by 35kV, 110kV and 220kV XLPE power cables was constructed to study the propagation characteristics in high voltage XLPE cables. Moreover, propagation and attenuation coefficient of partial discharge in different frequency were compared through calculating and analyzing. The results showed that cables have significant high frequency filtering effect to partial discharge and steep rising edge impulses would severely attenuate with the growth of cable length. Meanwhile, semi-conducting layer has significant effects on partial discharge attenuation, Therefore, in precise detection and positioning of partial discharges in HV XLPE cable lines, attenuation compensation should be adopted, even in the distributed measurement system.","PeriodicalId":206418,"journal":{"name":"2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133004135","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 : 2014-12-01DOI: 10.1109/APPEEC.2014.7066033
Yue Cui, Lin Zeng, H. Chiang
Large-scale power system dynamic analysis usually bears large storage and massive calculation burdens. Equivalence of complex excitation systems is an effective approach to decrease computational complexity with due accuracy. In this paper, we propose a two-stage Trust-Tech based method for deriving excitation system equivalence which aims to provide an optimal equivalent model which satisfies users' requirements. At the first stage, Trust-Tech methodology is used to find high-quality optimal solutions, if not the global optimal solution. This stage offers multiple local optimal alternatives, which ensures the availability of suitable equivalent models to meet different engineering requirements from users. At the second stage, critical clearing time and H infinity performance indexes are applied to provide useful information to evaluate the alternative sets. Thus, users can select a satisfying solution according to the index value or the practical requirements. Finally, a case is included to verify the effectiveness of the method.
{"title":"A two-stage trust-tech based methodology for excitation system equivalence","authors":"Yue Cui, Lin Zeng, H. Chiang","doi":"10.1109/APPEEC.2014.7066033","DOIUrl":"https://doi.org/10.1109/APPEEC.2014.7066033","url":null,"abstract":"Large-scale power system dynamic analysis usually bears large storage and massive calculation burdens. Equivalence of complex excitation systems is an effective approach to decrease computational complexity with due accuracy. In this paper, we propose a two-stage Trust-Tech based method for deriving excitation system equivalence which aims to provide an optimal equivalent model which satisfies users' requirements. At the first stage, Trust-Tech methodology is used to find high-quality optimal solutions, if not the global optimal solution. This stage offers multiple local optimal alternatives, which ensures the availability of suitable equivalent models to meet different engineering requirements from users. At the second stage, critical clearing time and H infinity performance indexes are applied to provide useful information to evaluate the alternative sets. Thus, users can select a satisfying solution according to the index value or the practical requirements. Finally, a case is included to verify the effectiveness of the method.","PeriodicalId":206418,"journal":{"name":"2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133540259","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 : 2014-12-01DOI: 10.1109/APPEEC.2014.7066113
GaoZhan Jun, W. Shan, Gao Nuo
The main fault diagnosis algorithms of traditional substation are based on the protections and breakers. And they have not concerned the influence of abnormal communication network to the stable operation of the intelligent substation. Based on the questions mentioned above, this paper introduces the fault information of the intelligent substation first of all, which contains the static configuration information and the online monitoring information, and then builds the basic model of the whole intelligent substation, and analyses the inference mechanism of the fault diagnosis of the secondary system, and at last tests the correctness of this model through a case.
{"title":"Fault diagnosis method of the intelligent substation","authors":"GaoZhan Jun, W. Shan, Gao Nuo","doi":"10.1109/APPEEC.2014.7066113","DOIUrl":"https://doi.org/10.1109/APPEEC.2014.7066113","url":null,"abstract":"The main fault diagnosis algorithms of traditional substation are based on the protections and breakers. And they have not concerned the influence of abnormal communication network to the stable operation of the intelligent substation. Based on the questions mentioned above, this paper introduces the fault information of the intelligent substation first of all, which contains the static configuration information and the online monitoring information, and then builds the basic model of the whole intelligent substation, and analyses the inference mechanism of the fault diagnosis of the secondary system, and at last tests the correctness of this model through a case.","PeriodicalId":206418,"journal":{"name":"2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128886643","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 : 2014-12-01DOI: 10.1109/APPEEC.2014.7066052
Hou Jun-xian, Tao Xiang-yu, Zhang Shi, S. Hong, T. Haiyan, Liu Tao, Zi Peng
The double-fed inductor generator (DFIG) is one important type of wind generator. Because of high percentage of wind energy, it is necessary to build accurate wind generator model and parameters for power system electro-mechanic simulation. The paper mainly presents the simulation model and parameter identification method of DFIG type wind generators. For power system transient simulation, the characteristic related to low voltage ride-through (LVRT) is most important, and the model related to LVRT is mainly presented. The parameters of the model are divided into three types and use different identification method. The identification method of important parameters is mainly presented. One actual wind generator is used as an example to explain the identification process and testify the validity of the model.
{"title":"The dynamic simulation model and parameter identification method of DFIG type wind generator for power system electro-mechanic simulation","authors":"Hou Jun-xian, Tao Xiang-yu, Zhang Shi, S. Hong, T. Haiyan, Liu Tao, Zi Peng","doi":"10.1109/APPEEC.2014.7066052","DOIUrl":"https://doi.org/10.1109/APPEEC.2014.7066052","url":null,"abstract":"The double-fed inductor generator (DFIG) is one important type of wind generator. Because of high percentage of wind energy, it is necessary to build accurate wind generator model and parameters for power system electro-mechanic simulation. The paper mainly presents the simulation model and parameter identification method of DFIG type wind generators. For power system transient simulation, the characteristic related to low voltage ride-through (LVRT) is most important, and the model related to LVRT is mainly presented. The parameters of the model are divided into three types and use different identification method. The identification method of important parameters is mainly presented. One actual wind generator is used as an example to explain the identification process and testify the validity of the model.","PeriodicalId":206418,"journal":{"name":"2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134645875","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 : 2014-12-01DOI: 10.1109/APPEEC.2014.7066032
Zhongfu Wang, Hao Wang, Haoyong Chen, K. Tan, Peizheng Xuan
Island power investment is very important and intractable to the construction of island power system and development of the electricity market, for various market models, and in which power producers will have different investment strategies and different investment considerations of other power producers. This paper firstly gives an overview on the trading patterns as well as market structure in electricity market, and also an analysis of investment decisions in different market modes. On the basis of characteristics of market modes, three kinds of investment decision modes are established. Besides, net present value method is applied to the analysis of investment decision under oligopoly market mode; real option method is applied to the analysis of investment decisions including fuel prices, price subsidy rate, depreciation rate, and the impact of competition under the market environment. Results indicate that investment threshold is mostly sensitive to price subsidy rate and power producers are tend to make advanced investment where competition exists.
{"title":"Analysis of island power investment decision models under different market stages","authors":"Zhongfu Wang, Hao Wang, Haoyong Chen, K. Tan, Peizheng Xuan","doi":"10.1109/APPEEC.2014.7066032","DOIUrl":"https://doi.org/10.1109/APPEEC.2014.7066032","url":null,"abstract":"Island power investment is very important and intractable to the construction of island power system and development of the electricity market, for various market models, and in which power producers will have different investment strategies and different investment considerations of other power producers. This paper firstly gives an overview on the trading patterns as well as market structure in electricity market, and also an analysis of investment decisions in different market modes. On the basis of characteristics of market modes, three kinds of investment decision modes are established. Besides, net present value method is applied to the analysis of investment decision under oligopoly market mode; real option method is applied to the analysis of investment decisions including fuel prices, price subsidy rate, depreciation rate, and the impact of competition under the market environment. Results indicate that investment threshold is mostly sensitive to price subsidy rate and power producers are tend to make advanced investment where competition exists.","PeriodicalId":206418,"journal":{"name":"2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124147936","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 : 2014-12-01DOI: 10.1109/APPEEC.2014.7066187
Zhenshan Zhu, Dichen Liu, Qingfen Liao, Xiangyu Han
A new method based on sample entropy algorithm that can perform real-time detection of sub-synchronous oscillation is proposed. The rotor torque signal is chose to be analyzed. The sample entropy of rotor torque during continuous period is calculated. Sub-synchronous oscillation detection is achieved by analyzing the variation of sample entropy. The method needs less data and has good anti-interference ability. The effectiveness of the proposed method is proven by the result of the IEEE first benchmark system model simulation.
{"title":"Subsynchronous oscillation detection based on sample entropy","authors":"Zhenshan Zhu, Dichen Liu, Qingfen Liao, Xiangyu Han","doi":"10.1109/APPEEC.2014.7066187","DOIUrl":"https://doi.org/10.1109/APPEEC.2014.7066187","url":null,"abstract":"A new method based on sample entropy algorithm that can perform real-time detection of sub-synchronous oscillation is proposed. The rotor torque signal is chose to be analyzed. The sample entropy of rotor torque during continuous period is calculated. Sub-synchronous oscillation detection is achieved by analyzing the variation of sample entropy. The method needs less data and has good anti-interference ability. The effectiveness of the proposed method is proven by the result of the IEEE first benchmark system model simulation.","PeriodicalId":206418,"journal":{"name":"2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124586463","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：