Pub Date : 2013-10-08DOI: 10.1109/ICSD.2013.6619808
S. Parameshwara, N. Renukappa
Organic thin film transistors (OTFTs) were fabricated using polyaniline (PANI) of 3wt.% concentration, as the active layer with two different gate dielectrics, namely silicon dioxide (SiO2) and poly(methyl methacrylate) (PMMA), in top contact geometry for comparative studies. To deal with poor stability and large leakage currents between source/drain and gate electrodes, isolated OTFTs with reduced source/drain contact area were fabricated by selective deposition of PANI on SiO2 through shadow mask. The effects of the PMMA thickness on the performance of OTFTs has been investigated. The results analysis of the PMMA-based OTFTs exhibited encouraging performance because of their good dielectric characteristics as compared to SiO2.
{"title":"Performance evaluation of top contact PANI organic thin film transistors with SiO2 and poly(methyl methacrylate) as gate dielectrics","authors":"S. Parameshwara, N. Renukappa","doi":"10.1109/ICSD.2013.6619808","DOIUrl":"https://doi.org/10.1109/ICSD.2013.6619808","url":null,"abstract":"Organic thin film transistors (OTFTs) were fabricated using polyaniline (PANI) of 3wt.% concentration, as the active layer with two different gate dielectrics, namely silicon dioxide (SiO2) and poly(methyl methacrylate) (PMMA), in top contact geometry for comparative studies. To deal with poor stability and large leakage currents between source/drain and gate electrodes, isolated OTFTs with reduced source/drain contact area were fabricated by selective deposition of PANI on SiO2 through shadow mask. The effects of the PMMA thickness on the performance of OTFTs has been investigated. The results analysis of the PMMA-based OTFTs exhibited encouraging performance because of their good dielectric characteristics as compared to SiO2.","PeriodicalId":437475,"journal":{"name":"2013 IEEE International Conference on Solid Dielectrics (ICSD)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124314786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-08DOI: 10.1109/ICSD.2013.6619664
G. Stevens, A. Pye, J. Samuel, M. Fu, F. Perrot, A. Vaughan, P. Baker, J. Cooper, G. Tzemis, D. Walker, A. Robertson
This paper reviews the objectives of a new project that is engaging the challenge to develop and scale the processing of nanocomposite thermosetting electrical insulation materials for HVDC power transmission applications. We discuss some of the work being carried out by the project and potential deployment in HVDC schemes.
{"title":"Nanocomposite thermosetting materials for HVDC applications","authors":"G. Stevens, A. Pye, J. Samuel, M. Fu, F. Perrot, A. Vaughan, P. Baker, J. Cooper, G. Tzemis, D. Walker, A. Robertson","doi":"10.1109/ICSD.2013.6619664","DOIUrl":"https://doi.org/10.1109/ICSD.2013.6619664","url":null,"abstract":"This paper reviews the objectives of a new project that is engaging the challenge to develop and scale the processing of nanocomposite thermosetting electrical insulation materials for HVDC power transmission applications. We discuss some of the work being carried out by the project and potential deployment in HVDC schemes.","PeriodicalId":437475,"journal":{"name":"2013 IEEE International Conference on Solid Dielectrics (ICSD)","volume":"138 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124557495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-08DOI: 10.1109/ICSD.2013.6619652
C. Chang, T. Bai, P. Lewin, P. Morshuis, J. Pilgrim, A. Cavallini, A. Vaughan, G. Montanari, S. Serra
Despite the large amount of activities undertaken in both the area of partial discharge (PD) in cavities and polymeric insulation degradation, degradation of polymeric insulation induced by cavity PD remains a subject where there are more questions than answers. In this paper, an experimental approach is discussed which has the aim of allowing observation of degradation induced by cavity PD. A model based on electron scattering mechanisms in both the cavity gas gap and polymeric insulation is proposed. From observing electron avalanche behavior and its damage mechanisms to the insulation, it may be possible to develop approaches that improve our ability to estimate remaining life of polymeric insulation systems in high voltage plant.
{"title":"Developing an experimental method for a cavity PD based life model","authors":"C. Chang, T. Bai, P. Lewin, P. Morshuis, J. Pilgrim, A. Cavallini, A. Vaughan, G. Montanari, S. Serra","doi":"10.1109/ICSD.2013.6619652","DOIUrl":"https://doi.org/10.1109/ICSD.2013.6619652","url":null,"abstract":"Despite the large amount of activities undertaken in both the area of partial discharge (PD) in cavities and polymeric insulation degradation, degradation of polymeric insulation induced by cavity PD remains a subject where there are more questions than answers. In this paper, an experimental approach is discussed which has the aim of allowing observation of degradation induced by cavity PD. A model based on electron scattering mechanisms in both the cavity gas gap and polymeric insulation is proposed. From observing electron avalanche behavior and its damage mechanisms to the insulation, it may be possible to develop approaches that improve our ability to estimate remaining life of polymeric insulation systems in high voltage plant.","PeriodicalId":437475,"journal":{"name":"2013 IEEE International Conference on Solid Dielectrics (ICSD)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114743186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-08DOI: 10.1109/ICSD.2013.6619822
K. Wang, Tianzheng Wang, Yu Deng, Z. Jia, Z. Guan
Ice accumulation always happen to insulators in south China in early spring. In the year 2008, southern cities were suffered from serious icing disaster, leading to great economic loss, thus icing problems are paid more attentions. This paper is concerned with salt migration in ice layer, the relationship between pollution level and cooling time were presented, as well as interpretations on when the ice flashover is most likely to appear. Cooling water was freezing from the solid-liquid interface to the top of water film. Salt migration phenomenon appeared because of the decline of solubility under low temperature. Finally according to 110 kV full-size insulator test, melting water conductivity is nearly six times of the applied water conductivity and conclusions can be drawn that salt migration in ice layer was a critical reason to initiate ice flashover.
{"title":"The mechanism of salt migration phenomena in cooling water and its impact on ice flashover","authors":"K. Wang, Tianzheng Wang, Yu Deng, Z. Jia, Z. Guan","doi":"10.1109/ICSD.2013.6619822","DOIUrl":"https://doi.org/10.1109/ICSD.2013.6619822","url":null,"abstract":"Ice accumulation always happen to insulators in south China in early spring. In the year 2008, southern cities were suffered from serious icing disaster, leading to great economic loss, thus icing problems are paid more attentions. This paper is concerned with salt migration in ice layer, the relationship between pollution level and cooling time were presented, as well as interpretations on when the ice flashover is most likely to appear. Cooling water was freezing from the solid-liquid interface to the top of water film. Salt migration phenomenon appeared because of the decline of solubility under low temperature. Finally according to 110 kV full-size insulator test, melting water conductivity is nearly six times of the applied water conductivity and conclusions can be drawn that salt migration in ice layer was a critical reason to initiate ice flashover.","PeriodicalId":437475,"journal":{"name":"2013 IEEE International Conference on Solid Dielectrics (ICSD)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115110821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-08DOI: 10.1109/ICSD.2013.6619839
J. Niedernhuber, J. Kindersberger
The study addresses the treeing-performance of unsaturated polyester resins with and without silica nanofillers and epoxy resin. Specimens with embedded needles mounted on a grounded plate are used. Time to electrical tree initiation, time to breakdown and growth behavior are determined. The influence of filler loading on the treeing performance as well as the effect of voltage amplitude are investigated. The results show that the resistance to treeing strongly depends on the type of matrix material used. While 1 wt. % nanofiller leads to improved resistance to electrical treeing, 5 wt. % worsens the treeing performance.
{"title":"Electrical treeing in insulating resins with silica nanofillers","authors":"J. Niedernhuber, J. Kindersberger","doi":"10.1109/ICSD.2013.6619839","DOIUrl":"https://doi.org/10.1109/ICSD.2013.6619839","url":null,"abstract":"The study addresses the treeing-performance of unsaturated polyester resins with and without silica nanofillers and epoxy resin. Specimens with embedded needles mounted on a grounded plate are used. Time to electrical tree initiation, time to breakdown and growth behavior are determined. The influence of filler loading on the treeing performance as well as the effect of voltage amplitude are investigated. The results show that the resistance to treeing strongly depends on the type of matrix material used. While 1 wt. % nanofiller leads to improved resistance to electrical treeing, 5 wt. % worsens the treeing performance.","PeriodicalId":437475,"journal":{"name":"2013 IEEE International Conference on Solid Dielectrics (ICSD)","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122128012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-08DOI: 10.1109/ICSD.2013.6619711
I. Preda, J. Castellon, S. Agnel, P. Notingher, M. Frechette, T. Heid, H. Couderc, N. Freebody, A. Vaughan
This paper concerns several epoxy resin nanocomposites. A DER 332 epoxy resin was chosen as matrix and nanosilica and/or Boron Nitride were chosen as fillers. Conduction currents results obtained using Polarization and Depolarization Current (PDC) tests at room temperature are presented and discussed. Different conduction phenomena were observed following the analysis of the variation of the current density versus the applied electric field. Using the depolarization currents obtained at room temperature under several applied electric fields, time to frequency domain transformation was performed. For this purpose, the currents were fitted using a general time response function based on Curie-von Schweidler law and on the transform proposed by Hamon. The empiric law proposed by Helegeson was also investigated. The time to frequency domain transformed spectra were compared with those obtained by Dielectric Spectroscopy.
{"title":"Conduction currents and time to frequency domain transformation for epoxy resin nanocomposites","authors":"I. Preda, J. Castellon, S. Agnel, P. Notingher, M. Frechette, T. Heid, H. Couderc, N. Freebody, A. Vaughan","doi":"10.1109/ICSD.2013.6619711","DOIUrl":"https://doi.org/10.1109/ICSD.2013.6619711","url":null,"abstract":"This paper concerns several epoxy resin nanocomposites. A DER 332 epoxy resin was chosen as matrix and nanosilica and/or Boron Nitride were chosen as fillers. Conduction currents results obtained using Polarization and Depolarization Current (PDC) tests at room temperature are presented and discussed. Different conduction phenomena were observed following the analysis of the variation of the current density versus the applied electric field. Using the depolarization currents obtained at room temperature under several applied electric fields, time to frequency domain transformation was performed. For this purpose, the currents were fitted using a general time response function based on Curie-von Schweidler law and on the transform proposed by Hamon. The empiric law proposed by Helegeson was also investigated. The time to frequency domain transformed spectra were compared with those obtained by Dielectric Spectroscopy.","PeriodicalId":437475,"journal":{"name":"2013 IEEE International Conference on Solid Dielectrics (ICSD)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116827914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-08DOI: 10.1109/ICSD.2013.6619699
P. Mráz, V. Mentlík, M. Rok
This paper deals with a possibility of application of new repairing procedure concerning stator end winding bracings in the large rotating machines - specifically changing of inter coil end winding bracings. For this purpose 3D glass fabric in several layers configuration was tested. It is a sandwich composite material consisted of two thin glass fabric layers, which are mutually interweaved with core in the shape of number 8. Complex tests were performed to verify application suitability of this new arrangement. Partial discharge measurements, dielectric dissipation factor and mechanical tests were done. Experimental results showed significant lack of uniformity of suggested material and limits of application of this arrangement.
{"title":"Evaluation of a stator end winding bracing system to be used in large rotating machines","authors":"P. Mráz, V. Mentlík, M. Rok","doi":"10.1109/ICSD.2013.6619699","DOIUrl":"https://doi.org/10.1109/ICSD.2013.6619699","url":null,"abstract":"This paper deals with a possibility of application of new repairing procedure concerning stator end winding bracings in the large rotating machines - specifically changing of inter coil end winding bracings. For this purpose 3D glass fabric in several layers configuration was tested. It is a sandwich composite material consisted of two thin glass fabric layers, which are mutually interweaved with core in the shape of number 8. Complex tests were performed to verify application suitability of this new arrangement. Partial discharge measurements, dielectric dissipation factor and mechanical tests were done. Experimental results showed significant lack of uniformity of suggested material and limits of application of this arrangement.","PeriodicalId":437475,"journal":{"name":"2013 IEEE International Conference on Solid Dielectrics (ICSD)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124461322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-08DOI: 10.1109/ICSD.2013.6619683
Fei Liu, R. Huo, Xingyi Huang, P. Jiang
Graphene oxide nanosheets (GOn)/PVDF nanocomposites with various GOn contents were fabricated using solution mixing followed by hot press molding and solution casting respectively. The dielectric behavior of those nanocomposites was determined over a wide frequency range from 102 to 107 Hz. The percolation phenomenon was observed in GOn/PVDF nanocomposites prepared by hot press molding method instead of solution casting method. It indicates that the GOn in nanocomposites were partially reduced in-situ under the molding conditions (180 °C, 8 min). And a percolation threshold of nearly 0.5 wt% was achieved by the homogeneous dispersion and distribution of GOn within the matrix due to the strong and specific interaction between carbonyl group in GOn surface and fluorine group in PVDF, which is lower than that of graphene sheets (GSs)/PVDF nanocomposites reported. The dielectric permittivity of in-situ reduced GOn/PVDF nanocomposites was found to increase with increasing GOn contents, while the dielectric permittivity of samples by solution casting with GOn contents lower than 1 wt% was found to be lower than that of pure PVDF. The gradual crystal transformation of PVDF from α-phase structure into β-phase with increasing GOn contents was observed in the in-situ reduced GOn/PVDF nanocomposites, which also confirms the destruction of oxygen-containning groups in GOn surface due to the thermal stress in sample preparation.
{"title":"Effect of processing method on the dielectric behavior of graphene oxide/PVDF nanocomposites","authors":"Fei Liu, R. Huo, Xingyi Huang, P. Jiang","doi":"10.1109/ICSD.2013.6619683","DOIUrl":"https://doi.org/10.1109/ICSD.2013.6619683","url":null,"abstract":"Graphene oxide nanosheets (GOn)/PVDF nanocomposites with various GOn contents were fabricated using solution mixing followed by hot press molding and solution casting respectively. The dielectric behavior of those nanocomposites was determined over a wide frequency range from 102 to 107 Hz. The percolation phenomenon was observed in GOn/PVDF nanocomposites prepared by hot press molding method instead of solution casting method. It indicates that the GOn in nanocomposites were partially reduced in-situ under the molding conditions (180 °C, 8 min). And a percolation threshold of nearly 0.5 wt% was achieved by the homogeneous dispersion and distribution of GOn within the matrix due to the strong and specific interaction between carbonyl group in GOn surface and fluorine group in PVDF, which is lower than that of graphene sheets (GSs)/PVDF nanocomposites reported. The dielectric permittivity of in-situ reduced GOn/PVDF nanocomposites was found to increase with increasing GOn contents, while the dielectric permittivity of samples by solution casting with GOn contents lower than 1 wt% was found to be lower than that of pure PVDF. The gradual crystal transformation of PVDF from α-phase structure into β-phase with increasing GOn contents was observed in the in-situ reduced GOn/PVDF nanocomposites, which also confirms the destruction of oxygen-containning groups in GOn surface due to the thermal stress in sample preparation.","PeriodicalId":437475,"journal":{"name":"2013 IEEE International Conference on Solid Dielectrics (ICSD)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128682502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-08DOI: 10.1109/ICSD.2013.6619786
C. Neusel, G. Schneider
The dielectric breakdown strengths of Al2O3 and BaTiO3 ceramics have been investigated in terms of thickness and permittivity dependence. From the obtained results, it is possible to define a thickness dependent breakdown strength regime. For bulk samples it will be shown, that the breakdown strength is inversely proportional to the permittivity. Furthermore space charge limited conduction (SCLC) can be identified as dominating conduction mechanism in Al2O3 and BaTiO3 ceramics. Based on the experimental findings a recently developed Griffith type energy release rate model for tubular channels can be applied [1].
{"title":"Dependence of the breakdown strength on thickness and permittivity","authors":"C. Neusel, G. Schneider","doi":"10.1109/ICSD.2013.6619786","DOIUrl":"https://doi.org/10.1109/ICSD.2013.6619786","url":null,"abstract":"The dielectric breakdown strengths of Al2O3 and BaTiO3 ceramics have been investigated in terms of thickness and permittivity dependence. From the obtained results, it is possible to define a thickness dependent breakdown strength regime. For bulk samples it will be shown, that the breakdown strength is inversely proportional to the permittivity. Furthermore space charge limited conduction (SCLC) can be identified as dominating conduction mechanism in Al2O3 and BaTiO3 ceramics. Based on the experimental findings a recently developed Griffith type energy release rate model for tubular channels can be applied [1].","PeriodicalId":437475,"journal":{"name":"2013 IEEE International Conference on Solid Dielectrics (ICSD)","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129041346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-08DOI: 10.1109/ICSD.2013.6619723
G. Mazzanti, M. Marzinotto
In this paper, a new method is proposed for the estimation of time to failure percentiles and life fraction lost in the so-called “Extension of pre-Qualification (EQ) test” according to CIGRE TBs 303. The method accounts for the time-varying temperature during the EQ load cycles via an approach that relies on: 1) Miner's law of cumulated aging; 2) an improved voltage-time characteristic that includes the electro-thermal stress; 3) a probabilistic framework based on the Weibull hypothesis. On these grounds, an alternative to the EQ test is proposed, referred to as “Improved Extension of Qualification (IEQ) test”, based on a more strict correlation between cable insulation reliability in design stress conditions and that during the test itself, thereby taking into account the electro-thermal endurance features of a given extruded cable design.
{"title":"Effects of load cycles on AC extruded cable reliability: Is a reduced pre-qualification test always the right choice?","authors":"G. Mazzanti, M. Marzinotto","doi":"10.1109/ICSD.2013.6619723","DOIUrl":"https://doi.org/10.1109/ICSD.2013.6619723","url":null,"abstract":"In this paper, a new method is proposed for the estimation of time to failure percentiles and life fraction lost in the so-called “Extension of pre-Qualification (EQ) test” according to CIGRE TBs 303. The method accounts for the time-varying temperature during the EQ load cycles via an approach that relies on: 1) Miner's law of cumulated aging; 2) an improved voltage-time characteristic that includes the electro-thermal stress; 3) a probabilistic framework based on the Weibull hypothesis. On these grounds, an alternative to the EQ test is proposed, referred to as “Improved Extension of Qualification (IEQ) test”, based on a more strict correlation between cable insulation reliability in design stress conditions and that during the test itself, thereby taking into account the electro-thermal endurance features of a given extruded cable design.","PeriodicalId":437475,"journal":{"name":"2013 IEEE International Conference on Solid Dielectrics (ICSD)","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132414522","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：