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Influence of morphology on tree growth in polyethylene 聚乙烯中形态对树木生长的影响
装备机械 Pub Date : 2001-11-19 DOI: 10.1109/ISEIM.2001.973610
Yuanxiang Zhou, Xiaoguang Luo, P. Yan, Xidong Liang, Z. Guan, N. Yoshimura
{"title":"Influence of morphology on tree growth in polyethylene","authors":"Yuanxiang Zhou, Xiaoguang Luo, P. Yan, Xidong Liang, Z. Guan, N. Yoshimura","doi":"10.1109/ISEIM.2001.973610","DOIUrl":"https://doi.org/10.1109/ISEIM.2001.973610","url":null,"abstract":"It is well known that electrical trees are greatly influenced by the morphological structure in semi-crystalline materials. In this paper, samples of polyethylene films, including low-density polyethylene (LDPE) and high-density polyethylene (HDPE) have been re-crystallized by two kinds of different ways: natural cooling and quenching. The growth rate and the length of electrical trees were measured under the various conditions. It was found that electrical trees in HDPE grow easier than that in LDPE, even though HDPE is of high crystallinity and large spherulites size and show high resistance in tree initiation. It was presumed that the morphology is of different effects on the tree initiation and growth.","PeriodicalId":71964,"journal":{"name":"装备机械","volume":"34 1","pages":"194-197"},"PeriodicalIF":0.0,"publicationDate":"2001-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80056930","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}
引用次数: 6
State signal and fuzzy membership function of fault diagnosis in electrical equipment 电气设备故障诊断的状态信号和模糊隶属函数
装备机械 Pub Date : 2001-11-19 DOI: 10.1109/ISEIM.2001.973618
Wen Yuan-fang, Liu Chun, Yan Xianglian, Z. Chunyan, Tang-Yao Chi, Liang Yuelong
{"title":"State signal and fuzzy membership function of fault diagnosis in electrical equipment","authors":"Wen Yuan-fang, Liu Chun, Yan Xianglian, Z. Chunyan, Tang-Yao Chi, Liang Yuelong","doi":"10.1109/ISEIM.2001.973618","DOIUrl":"https://doi.org/10.1109/ISEIM.2001.973618","url":null,"abstract":"It is an effective approach to combine state signal processing with fuzzy mathematics for recognizing fuzziness and randomness clearly. This paper shows how the fuzzy membership functions are obtained from results of signal processing of fault diagnosis in electrical equipment. Hence the properties of electrical equipment are revealed more thoroughly. Finally, this method is proved to be effective by an example.","PeriodicalId":71964,"journal":{"name":"装备机械","volume":"83 1","pages":"213-216"},"PeriodicalIF":0.0,"publicationDate":"2001-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83481289","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}
引用次数: 0
AC partial discharges propagating on an unpenetrated crack wall 在未穿透裂缝壁上传播的交流局部放电
装备机械 Pub Date : 2001-11-19 DOI: 10.1109/ISEIM.2001.973601
N. Watanabe, Y. Yamano
{"title":"AC partial discharges propagating on an unpenetrated crack wall","authors":"N. Watanabe, Y. Yamano","doi":"10.1109/ISEIM.2001.973601","DOIUrl":"https://doi.org/10.1109/ISEIM.2001.973601","url":null,"abstract":"The purpose of this study is to make clear the influences of partial discharges (PD) propagating in the walls of an unpenetrated crack. The high densities of charges due to PD are expected to accumulate in the unpenetrated crack. ne unpenetrated crack in this study was formed with walls of opposed two insulator blocks (PMMA) on an insulating board (PMMA). Two blocks on the board were set in the needle-plate electrode system. AC high voltage (30 kV, 50 Hz) was applied to a needle electrode. The crack width studied ranged from 10 /spl mu/m to 1000 /spl mu/m. The length of the crack mainly studied was 40 mm. The results indicate that the PD propagation into the crack is strictly changed at a critical width of the crack. When the crack width is from 10 /spl mu/m to 200 /spl mu/m, strong positive pulses with Q>2/spl times/10/sup -8/ C appears. When the crack width s>500 /spl mu/m, the strong positive pulses disappears. The critical width exists between 200 /spl mu/m and 500 /spl mu/m. Negative pulses of relatively high magnitude are observed just before the phase where strong positive pulses appear. The strong positive PD will be generated when the negative pulses neutralize the accumulated positive charge on the wall of the crack.","PeriodicalId":71964,"journal":{"name":"装备机械","volume":"6 1","pages":"179-182"},"PeriodicalIF":0.0,"publicationDate":"2001-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88845966","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}
引用次数: 0
A study of partial discharge acoustic signal propagation in a model transformer 局部放电声信号在模型变压器中的传播研究
装备机械 Pub Date : 2001-11-19 DOI: 10.1109/ISEIM.2001.973736
A. Akumu, N. Kawaguchi, R. Ozaki, H. Ihori, M. Fujii, K. Arii
{"title":"A study of partial discharge acoustic signal propagation in a model transformer","authors":"A. Akumu, N. Kawaguchi, R. Ozaki, H. Ihori, M. Fujii, K. Arii","doi":"10.1109/ISEIM.2001.973736","DOIUrl":"https://doi.org/10.1109/ISEIM.2001.973736","url":null,"abstract":"Many researchers have studied the partial discharge (PD) source location in transformers using acoustical methods. However, most of these studies have treated the transformer as a homogeneous medium, thus rendering the location of discharges inside the transformer winding difficult. In this paper, the authors present a 3-D computer simulation of the PD acoustic signal propagation path in an attempt to locate the PD source. The computer simulation is in agreement with experimental data obtained from the laboratory. Further, the effect of the real transformer tank on the acoustic signal is studied with an aim of distinguishing the various frequency dependent signal components that are detected by an acoustic emission (AE) sensor. This is particularly important in explaining the acoustic coupling between oil and transformer tank material and for determining the propagation velocities when determining the PD source location.","PeriodicalId":71964,"journal":{"name":"装备机械","volume":"33 1","pages":"583-586"},"PeriodicalIF":0.0,"publicationDate":"2001-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77459473","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}
引用次数: 7
Studies on compatibility of silicone oil with pressboard insulation 硅油与压制板绝缘材料相容性的研究
装备机械 Pub Date : 2001-11-19 DOI: 10.1109/ISEIM.2001.973816
C. Viswanatha, K. Dwarakanath, V. Kumar
{"title":"Studies on compatibility of silicone oil with pressboard insulation","authors":"C. Viswanatha, K. Dwarakanath, V. Kumar","doi":"10.1109/ISEIM.2001.973816","DOIUrl":"https://doi.org/10.1109/ISEIM.2001.973816","url":null,"abstract":"The paper oil insulation system is an integral and essential part of large power transformers. The failure of power transformers under combined stresses and fast transients has made it necessary to look for an alternate liquid insulant. In this study, silicone oil was investigated for use as a liquid insulant. The samples of pressboard are subjected to dielectric tests like electric strength, surface electric strength under AC, DC and combined AC/DC voltages, dielectric dissipation factor and others. The variation of dielectric constant, dissipation factor of silicone oil has been studied over a range of frequency. The surface electric strengths of cellulosic insulation with silicone oil and with mineral oils have been compared. Some very interesting results on the performance of silicone oils have been observed and discussed.","PeriodicalId":71964,"journal":{"name":"装备机械","volume":"42 1","pages":"868-871"},"PeriodicalIF":0.0,"publicationDate":"2001-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87005990","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}
引用次数: 0
Photoirradiation effects on light-emitting devices using conjugated polymers as emission material 以共轭聚合物为发射材料的发光器件的光辐射效应
装备机械 Pub Date : 2001-11-19 DOI: 10.1109/ISEIM.2001.973724
K. Tada, M. Onoda
{"title":"Photoirradiation effects on light-emitting devices using conjugated polymers as emission material","authors":"K. Tada, M. Onoda","doi":"10.1109/ISEIM.2001.973724","DOIUrl":"https://doi.org/10.1109/ISEIM.2001.973724","url":null,"abstract":"The photoirradiation effects on the emission characteristics of polymer light-emitting devices (PLEDs) based on conjugated polymer have been studied. In this study, we have used PLEDs with semitransparent Al cathode to accelerate the photooxidation of the emission layer. It was already confirmed that the semitransparent-Al film having optical transmittance /spl sim/30% does not reduce the photooxidation rate of underlying polymer film. When poly(2-methoxy-5-dodecyloxy-1,4-phenylene vinylene) (MDOPPV) is used in the emission layer, the emission intensity at a constant voltage drops significantly. It has been also observed that the photoluminescence quantum efficiency of MDOPPV film significantly reduces by similar photooxidation. On the other hand, the electroluminescence quantum efficiency remains constant. These apparently curious results have been explained by taking the difference in the exciton formation sites between electroluminescence and photoluminescence processes into account.","PeriodicalId":71964,"journal":{"name":"装备机械","volume":"29 1","pages":"545-548"},"PeriodicalIF":0.0,"publicationDate":"2001-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87189288","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}
引用次数: 0
Three dimensional space charge observation of printed circuit boards 印刷电路板三维空间电荷观察
装备机械 Pub Date : 2001-11-19 DOI: 10.1109/ISEIM.2001.973713
K. Fukunaga, T. Maeno, K. Okamoto
{"title":"Three dimensional space charge observation of printed circuit boards","authors":"K. Fukunaga, T. Maeno, K. Okamoto","doi":"10.1109/ISEIM.2001.973713","DOIUrl":"https://doi.org/10.1109/ISEIM.2001.973713","url":null,"abstract":"We have investigated the ion migration phenomena of printed circuit boards, and found that the pulsed electroacoustic space charge measurement system can monitor the copper ion migration into the epoxy resin from the electrode surface. The migration, however, can proceed in any direction in the specimen simultaneously; therefore, it should be measured in three dimensions. We have measured metal-base epoxy resin insulated printed circuit boards by a newly developed three-dimensional pulsed electroacoustic method. The experimental results show that the space charge density varies in the lateral direction when ion migration occurs in the specimen.","PeriodicalId":71964,"journal":{"name":"装备机械","volume":"221 1","pages":"501-504"},"PeriodicalIF":0.0,"publicationDate":"2001-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77528814","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}
引用次数: 1
On-line monitoring of capacitive electric apparatus using the sum current method 用和电流法在线监测电容性电器
装备机械 Pub Date : 2001-11-19 DOI: 10.1109/ISEIM.2001.973790
Jin Zhijian, Huang Jiecheng, Zhu Zhishu
{"title":"On-line monitoring of capacitive electric apparatus using the sum current method","authors":"Jin Zhijian, Huang Jiecheng, Zhu Zhishu","doi":"10.1109/ISEIM.2001.973790","DOIUrl":"https://doi.org/10.1109/ISEIM.2001.973790","url":null,"abstract":"The article describes the application of the sum current method to the on-line monitoring of capacitive equipment, analyses the influence factors to the measurement result, and gives the flowchart for on-line monitoring system.","PeriodicalId":71964,"journal":{"name":"装备机械","volume":"269 1","pages":"765-768"},"PeriodicalIF":0.0,"publicationDate":"2001-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77811154","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}
引用次数: 0
Research on transition condition between streamer and leader in 1 m plane-rod gap under switching impulse voltage 开关冲击电压下1 m平面杆间隙拖缆与导缆过渡条件的研究
装备机械 Pub Date : 2001-11-19 DOI: 10.1109/ISEIM.2001.973642
B. Yang, L.M. Wang, Z. Guan, X.D. Liang
{"title":"Research on transition condition between streamer and leader in 1 m plane-rod gap under switching impulse voltage","authors":"B. Yang, L.M. Wang, Z. Guan, X.D. Liang","doi":"10.1109/ISEIM.2001.973642","DOIUrl":"https://doi.org/10.1109/ISEIM.2001.973642","url":null,"abstract":"In this paper, the experimental results of the quantitative transition condition between streamer and leader are presented for a plane-rod gap. The charge injected into the rod, energy input caused by charge moving in streamer channel before the first leader, and charge injection during leader discharge are measured and calculated. The test gives new results: (1) the charge injected to the rod prior to inception leader point is increased correspondingly from 3.9 /spl mu/C to 11.1 /spl mu/C with the change of the time to peak of switching impulse from 100 /spl mu/s to 250 /spl mu/s; (2) the more charge needed at transition point from streamer to leader discharge, the higher the sparkover voltage, but the smaller the charge injected to the rod during the leader discharge; (3) the relationship of energy input to streamer channel and sparkover voltage is obtained. The more the energy input, the lower the sparkover voltage; and (4) in the U50% breakdown case, with increase time to peak of impulse voltage, the injected charge in the leader up to the point where voltage collapsed tends to decrease, but the instantaneous voltage at this transition point tends to increase.","PeriodicalId":71964,"journal":{"name":"装备机械","volume":"15 1","pages":"266-269"},"PeriodicalIF":0.0,"publicationDate":"2001-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77976671","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}
引用次数: 0
Statistical investigation of dielectric breakdown of LDPE LDPE介质击穿的统计研究
装备机械 Pub Date : 2001-11-19 DOI: 10.1109/ISEIM.2001.973730
Y. Sekii, K. Asakawa, K. Mouri
{"title":"Statistical investigation of dielectric breakdown of LDPE","authors":"Y. Sekii, K. Asakawa, K. Mouri","doi":"10.1109/ISEIM.2001.973730","DOIUrl":"https://doi.org/10.1109/ISEIM.2001.973730","url":null,"abstract":"The statistical characteristics of the dielectric breakdown of low-density polyethylene (LDPE) were investigated through experiments using two grades of LDPE film. The experiments were performed using a parallel plate electrode system with three electrode diameters and three film thicknesses. The breakdown strength data obtained was analyzed by Weibull statistics, and a noticeable difference was observed in the Weibull parameters of breakdown strength for the two film types examined. Based on the statistical results and correlation with microscopic observations of the films, the electric strength of LDPE film is found to be closely related to the abundance of impurities in the material.","PeriodicalId":71964,"journal":{"name":"装备机械","volume":"49 1","pages":"562-565"},"PeriodicalIF":0.0,"publicationDate":"2001-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78258743","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}
引用次数: 5
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