Pub Date : 2011-12-01DOI: 10.1109/ICPES.2011.6156637
M. Suzuki, A. Itoh, N. Yoshimura
It is widely recognized that degradation by water tree of electrical power cables would cause serious problems. Therefore, many methods have been studied in order to detect water tree at the early stages. The loss current analysis is one of the method which can detect water tree, since the degradation of CV cable by water tree gives rise to harmonics in the loss current. Many researches by simulation and experiment have been carried out for the purpose of the elucidation of the mechanism of the harmonics in the loss current generation. In the present study, a polyethylene sample where water tree was generated was replaced by the equivalent circuit composed of a lot of resistance, capacitor and voltage dependent resistance. These elements were united like the network. It will be possible to consider not only length of water tree but also shape of water tree by this method. From the simulation results, it has been understood that the characteristics of loss current vary greatly depending on not only the length of water tree but also the shape of water tree.
{"title":"Three-dimensional equivalent circuit analysis of water tree","authors":"M. Suzuki, A. Itoh, N. Yoshimura","doi":"10.1109/ICPES.2011.6156637","DOIUrl":"https://doi.org/10.1109/ICPES.2011.6156637","url":null,"abstract":"It is widely recognized that degradation by water tree of electrical power cables would cause serious problems. Therefore, many methods have been studied in order to detect water tree at the early stages. The loss current analysis is one of the method which can detect water tree, since the degradation of CV cable by water tree gives rise to harmonics in the loss current. Many researches by simulation and experiment have been carried out for the purpose of the elucidation of the mechanism of the harmonics in the loss current generation. In the present study, a polyethylene sample where water tree was generated was replaced by the equivalent circuit composed of a lot of resistance, capacitor and voltage dependent resistance. These elements were united like the network. It will be possible to consider not only length of water tree but also shape of water tree by this method. From the simulation results, it has been understood that the characteristics of loss current vary greatly depending on not only the length of water tree but also the shape of water tree.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131657590","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 : 2008-12-31DOI: 10.1109/ISEIM.2008.4664609
T. Imai, T. Ozaki, F. Sawa, T. Shimizu, M. Harada, M. Ochi, N. Tagami, Y. Ohki, T. Tanaka
This project develops a nanocomposite insulating material with high insulation performance obtained by homogeneous dispersion of nano-fillers to epoxy resin. This project aims to apply solid insulating technology with nanocomposite material to electric power apparatuses for power distribution such as switchgears.
{"title":"Nanocomposite insulating materials for environmental-conscious heavy electric apparatuses","authors":"T. Imai, T. Ozaki, F. Sawa, T. Shimizu, M. Harada, M. Ochi, N. Tagami, Y. Ohki, T. Tanaka","doi":"10.1109/ISEIM.2008.4664609","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664609","url":null,"abstract":"This project develops a nanocomposite insulating material with high insulation performance obtained by homogeneous dispersion of nano-fillers to epoxy resin. This project aims to apply solid insulating technology with nanocomposite material to electric power apparatuses for power distribution such as switchgears.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"341 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113958491","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664473
S. Ashihara, T. Goto, T. Yamazaki, K. Tomimatsu, H. Ito
We introduce the technology to make silane cross-linked polyethylene (Si-XLPE) thermoplastic using supercritical alcohol for material recycling of Si-XLPE. The new continuous process was developed using extruder for the treatment of supercritical fluid for industrialization. We successfully obtained recycled PE at the rate of 20 kg/h. The gel fraction of recycled PE was 0%, and its mechanical properties were similar to virgin PE. It means that siloxane bond was selectively decomposed. Then, 100% recycled PE was applied for the insulation of 600 V XLPE cable. The properties of the recycled cable satisfied JIS C 3605, the Japanese Industrial Standards of 600 V XLPE insulated cable. These results indicated that this technology can be applicable to the cable to cable recycling. Moreover, it was calculated that CO2 emission can be reduced by this technology in comparison with virgin PE.
介绍了利用超临界醇制备硅烷交联聚乙烯(Si-XLPE)热塑性塑料的工艺，并对硅烷交联聚乙烯(Si-XLPE)材料进行了循环利用。提出了用挤出机连续处理超临界流体的工业化新工艺。我们成功地以20公斤/小时的速度获得了再生PE。再生PE的凝胶分数为0%，其力学性能与原始PE相似。说明硅氧烷键被选择性分解。然后，采用100%再生PE对600v交联聚乙烯电缆进行绝缘。回收电缆的性能满足日本工业标准JIS C 3605, 600 V交联聚乙烯绝缘电缆。结果表明，该技术可应用于电缆对电缆的回收。并计算出与纯PE相比，该工艺可降低CO2排放量。
{"title":"Recycling of insulation of 600V XLPE cable using supercritical alcohol","authors":"S. Ashihara, T. Goto, T. Yamazaki, K. Tomimatsu, H. Ito","doi":"10.1109/ISEIM.2008.4664473","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664473","url":null,"abstract":"We introduce the technology to make silane cross-linked polyethylene (Si-XLPE) thermoplastic using supercritical alcohol for material recycling of Si-XLPE. The new continuous process was developed using extruder for the treatment of supercritical fluid for industrialization. We successfully obtained recycled PE at the rate of 20 kg/h. The gel fraction of recycled PE was 0%, and its mechanical properties were similar to virgin PE. It means that siloxane bond was selectively decomposed. Then, 100% recycled PE was applied for the insulation of 600 V XLPE cable. The properties of the recycled cable satisfied JIS C 3605, the Japanese Industrial Standards of 600 V XLPE insulated cable. These results indicated that this technology can be applicable to the cable to cable recycling. Moreover, it was calculated that CO2 emission can be reduced by this technology in comparison with virgin PE.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116667536","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664494
C. Reddy, M. Gosyowaki, Y. Murata, Y. Sekiguchi
In spite of the bourgeoning evidence of improvements in material properties, the mechanism of conduction and breakdown in nanocomposite dielectrics is not yet clear. Understanding the macroscopic properties of nanocomposites is essential for the use and application of the nanodielectrics as also to pave the way for providing an understanding at nano-scale. Any hypothesis explaining the nano-scale effects must explain the changes in macroscopic material properties. With this objective in view, the authors investigated the dc conduction and breakdown in nanocomposites. Experimental results and a rigorous analysis of the volume resistivity data presented in the paper provides a more clear evidence of the effect of variation in the material properties on insulation breakdown.
{"title":"Superior thermal breakdown performance of MgO-LDPE nanocomposite materials for HVDC insulation","authors":"C. Reddy, M. Gosyowaki, Y. Murata, Y. Sekiguchi","doi":"10.1109/ISEIM.2008.4664494","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664494","url":null,"abstract":"In spite of the bourgeoning evidence of improvements in material properties, the mechanism of conduction and breakdown in nanocomposite dielectrics is not yet clear. Understanding the macroscopic properties of nanocomposites is essential for the use and application of the nanodielectrics as also to pave the way for providing an understanding at nano-scale. Any hypothesis explaining the nano-scale effects must explain the changes in macroscopic material properties. With this objective in view, the authors investigated the dc conduction and breakdown in nanocomposites. Experimental results and a rigorous analysis of the volume resistivity data presented in the paper provides a more clear evidence of the effect of variation in the material properties on insulation breakdown.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124799835","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664556
T. Imai, G. Komiya, K. Murayama, T. Ozaki, F. Sawa, T. Shimizu, M. Harada, M. Ochi, Y. Ohki, T. Tanaka
Recent interests concerning nanocomposites are shifting emphasis from fundamental research to application-oriented research. In this study, nano- and micro-filler mixed composites were made and evaluated toward practical use of nanocomposite insulating materials. Some kinds of the nano-filler/micro-filler combinations such as nano-layered silicate/micro-silica, nano-silica/micro-silica and nano-titania/micro-silica were compared from viewpoints of volume resistivitiy, relative permittivity, thermal expansion and insulation breakdown properties. Comprehensive consideration based on experimental results determined a candidate nano- and micro-filler mixed composites to make trial models. An aluminum conductor and a vacuum interrupter were molded from the nano- and micro-filler mixed composites for the first time in nanocomposite research.
{"title":"Nano- and micro-filler combination enabling practical use of nanocomposite insulating materials","authors":"T. Imai, G. Komiya, K. Murayama, T. Ozaki, F. Sawa, T. Shimizu, M. Harada, M. Ochi, Y. Ohki, T. Tanaka","doi":"10.1109/ISEIM.2008.4664556","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664556","url":null,"abstract":"Recent interests concerning nanocomposites are shifting emphasis from fundamental research to application-oriented research. In this study, nano- and micro-filler mixed composites were made and evaluated toward practical use of nanocomposite insulating materials. Some kinds of the nano-filler/micro-filler combinations such as nano-layered silicate/micro-silica, nano-silica/micro-silica and nano-titania/micro-silica were compared from viewpoints of volume resistivitiy, relative permittivity, thermal expansion and insulation breakdown properties. Comprehensive consideration based on experimental results determined a candidate nano- and micro-filler mixed composites to make trial models. An aluminum conductor and a vacuum interrupter were molded from the nano- and micro-filler mixed composites for the first time in nanocomposite research.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124884511","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664467
R. Saldivar-Guerrero, L. Rejón
The present study focuses on the preparation of EPDM nanocomposites by using silica nanoparticles, as well as mechanical and electrical characterization of the nanocomposites. To incorporate nanoparticles on the polymer we use two different methods. The nanoparticles were chemical modified using vinyltriethoxysilane in order to make them compatible with the polymer, this process is commonly known as silanization. Tensile and dielectric properties were measured for EPDM nanocomposites at two filler concentration, making difference between modified and unmodified silica nanoparticles. The dispersion of nanoparticles in the nanocomposites was observed by transmission electronic microscopy (TEM).
{"title":"Preparation and electrical characterization of EPDM nanocomposites by using silica nanoparticles","authors":"R. Saldivar-Guerrero, L. Rejón","doi":"10.1109/ISEIM.2008.4664467","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664467","url":null,"abstract":"The present study focuses on the preparation of EPDM nanocomposites by using silica nanoparticles, as well as mechanical and electrical characterization of the nanocomposites. To incorporate nanoparticles on the polymer we use two different methods. The nanoparticles were chemical modified using vinyltriethoxysilane in order to make them compatible with the polymer, this process is commonly known as silanization. Tensile and dielectric properties were measured for EPDM nanocomposites at two filler concentration, making difference between modified and unmodified silica nanoparticles. The dispersion of nanoparticles in the nanocomposites was observed by transmission electronic microscopy (TEM).","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123548477","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664537
M. T. Do, J. Augé, T. Vu, S. Catellani
In this paper, we have investigated the behavior of dielectric properties (partial discharges) of liquids of different natures (silicon oil, aromatic liquid). Partial discharges measurements have been done over the voltage range (0-25 kVpp). Two types of devices have been analyzed. The first one consists of a ceramic covered by liquid, the second one of a needle-plane system embedded in liquid. The origin of partial discharges for the both devices is discussed. A mixture of corona effect and discharge in micro voids appear for the ceramic based system whereas only the corona effect was identified for the second one. Results are then discussed in correlation with potential applications in power electronic components where rubber and gel are used for IGBT module.
{"title":"Partial discharges in dielectric liquids","authors":"M. T. Do, J. Augé, T. Vu, S. Catellani","doi":"10.1109/ISEIM.2008.4664537","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664537","url":null,"abstract":"In this paper, we have investigated the behavior of dielectric properties (partial discharges) of liquids of different natures (silicon oil, aromatic liquid). Partial discharges measurements have been done over the voltage range (0-25 kVpp). Two types of devices have been analyzed. The first one consists of a ceramic covered by liquid, the second one of a needle-plane system embedded in liquid. The origin of partial discharges for the both devices is discussed. A mixture of corona effect and discharge in micro voids appear for the ceramic based system whereas only the corona effect was identified for the second one. Results are then discussed in correlation with potential applications in power electronic components where rubber and gel are used for IGBT module.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"174 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122953746","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664547
S. Nordas, S. Hellesø, S. Hvidsten
The main objective of this paper is to characterise and numerically model the sorption of water vapour in three commercially available water blocking tapes for medium and high voltage extruded cables. The main purpose of these tapes is to avoid longitudinal water penetration. However, the swelling tapes can also delay radial water ingress in the cable, thus delaying the formation of water trees and extending the life time of the cable. Sorption measurements have been perfomed in temperature and humidity controlled climate chambers using ultra-microbalances at 22-80%RH and 30degC. The results show that the tapes have high sorption capability and that the equlibrium water vapour content do not follow Henry's law. This is particularly clear at high water vapour pressures. The average diffusion coefficients increase by decades with increasing water vapour pressure indicating a strong dependence on water concentration.
{"title":"Measurements and modeling of water diffusion in water blocking tapes for high voltage extruded cables","authors":"S. Nordas, S. Hellesø, S. Hvidsten","doi":"10.1109/ISEIM.2008.4664547","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664547","url":null,"abstract":"The main objective of this paper is to characterise and numerically model the sorption of water vapour in three commercially available water blocking tapes for medium and high voltage extruded cables. The main purpose of these tapes is to avoid longitudinal water penetration. However, the swelling tapes can also delay radial water ingress in the cable, thus delaying the formation of water trees and extending the life time of the cable. Sorption measurements have been perfomed in temperature and humidity controlled climate chambers using ultra-microbalances at 22-80%RH and 30degC. The results show that the tapes have high sorption capability and that the equlibrium water vapour content do not follow Henry's law. This is particularly clear at high water vapour pressures. The average diffusion coefficients increase by decades with increasing water vapour pressure indicating a strong dependence on water concentration.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123013819","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664549
B. Du, Yong Liu, R. L. Wang
With the broad application of silicone rubber (SIR) insulator in high-altitude regions, corona degradation is one of the inevitable electrical degradation caused by electric stress due to the organic properties of SIR. Although this phenomenon is investigated at atmospheric pressure, there is little investigation at low pressures. It is urgent to systematically investigate effects of low pressure on the corona degradation for the reliable application. Experiments were carried out in a decompression chamber and the ambient pressure was reduced by a rotary pump from the atmospheric pressure to 40 kPa. The specimens were exposed to corona discharges at low pressures for different lapse time. The surface static contact angles on the insulator were measured to reveal the hydrophobicity changes. The currents during corona discharges at different low pressures were measured to confirm the corona degradation with variation of the pressures. The results obtained showed that the intensity of corona discharge increased with reducing the ambient pressure, which accelerated the process of corona degradation.
{"title":"Effects of corona discharge on surface deterioration of silicone rubber insulator under reduced pressures","authors":"B. Du, Yong Liu, R. L. Wang","doi":"10.1109/ISEIM.2008.4664549","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664549","url":null,"abstract":"With the broad application of silicone rubber (SIR) insulator in high-altitude regions, corona degradation is one of the inevitable electrical degradation caused by electric stress due to the organic properties of SIR. Although this phenomenon is investigated at atmospheric pressure, there is little investigation at low pressures. It is urgent to systematically investigate effects of low pressure on the corona degradation for the reliable application. Experiments were carried out in a decompression chamber and the ambient pressure was reduced by a rotary pump from the atmospheric pressure to 40 kPa. The specimens were exposed to corona discharges at low pressures for different lapse time. The surface static contact angles on the insulator were measured to reveal the hydrophobicity changes. The currents during corona discharges at different low pressures were measured to confirm the corona degradation with variation of the pressures. The results obtained showed that the intensity of corona discharge increased with reducing the ambient pressure, which accelerated the process of corona degradation.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"278 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114438459","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 : 2008-10-31DOI: 10.1109/ISEIM.2008.4664508
Y. Sakai, T. Ninose, H. Murase, M. Yoda, G. Sawa
We investigate surface leakage current on porcelain insulators under dry weather conditions. Clean and polluted insulators are compared. And the relationship between their surface leakage current and weather conditions is studied. As a result, the polluted insulator gives a larger leakage current than the clean insulator. Also, it is shown that the leakage current of the clean insulator is strongly dependent on the absolute humidity.
{"title":"Comparison of surface leakage current between clean and polluted insulators under dry weather conditions","authors":"Y. Sakai, T. Ninose, H. Murase, M. Yoda, G. Sawa","doi":"10.1109/ISEIM.2008.4664508","DOIUrl":"https://doi.org/10.1109/ISEIM.2008.4664508","url":null,"abstract":"We investigate surface leakage current on porcelain insulators under dry weather conditions. Clean and polluted insulators are compared. And the relationship between their surface leakage current and weather conditions is studied. As a result, the polluted insulator gives a larger leakage current than the clean insulator. Also, it is shown that the leakage current of the clean insulator is strongly dependent on the absolute humidity.","PeriodicalId":158811,"journal":{"name":"2008 International Symposium on Electrical Insulating Materials (ISEIM 2008)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114497137","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：