Pub Date : 1989-10-29DOI: 10.1109/CEIDP.1989.69557
H. Gnerlich
It is noted that the introduction of cables with solid dielectric insulation and of modern splicing technology has imposed new standards and restrictions on cable testing and cable fault locating. The arbitrary use of high voltages and energies during DC, AC, and impulse testing of in-service power cables with solid dielectric insulation frequently programs the cables with defects which become faults after the cables are returned to service. The inadequacy of DC testing in determining the cables' AC breakdown strength, the danger of programming the cables with faults when DC and impulse testing at unnecessarily high voltages, and the advantages of very low frequency (VLF) testing and arc reflection methods (ARM) in locating cable defects and faults are presented. It is concluded that by establishing cable fault locating and cable testing guidelines for cable with solid dielectric insulation, which incorporate current research and available technology, utilities can realize substantial savings in cable replacement, cable rehabilitation, and work force budgets.<>
{"title":"Cable testing and cable fault locating with minimum risk to good cable","authors":"H. Gnerlich","doi":"10.1109/CEIDP.1989.69557","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69557","url":null,"abstract":"It is noted that the introduction of cables with solid dielectric insulation and of modern splicing technology has imposed new standards and restrictions on cable testing and cable fault locating. The arbitrary use of high voltages and energies during DC, AC, and impulse testing of in-service power cables with solid dielectric insulation frequently programs the cables with defects which become faults after the cables are returned to service. The inadequacy of DC testing in determining the cables' AC breakdown strength, the danger of programming the cables with faults when DC and impulse testing at unnecessarily high voltages, and the advantages of very low frequency (VLF) testing and arc reflection methods (ARM) in locating cable defects and faults are presented. It is concluded that by establishing cable fault locating and cable testing guidelines for cable with solid dielectric insulation, which incorporate current research and available technology, utilities can realize substantial savings in cable replacement, cable rehabilitation, and work force budgets.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"51 1","pages":"265-271"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90485834","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69565
T. Mizutani, M. Hikita, A. Umemura, M. Ieda
The electrical breakdown of PPS (polyphenylene sulfide) films of three different thicknesses was investigated. Impulse breakdown strength was almost constant in the temperature range from -60 to 150 degrees C, but showed a negative thickness dependence, suggesting electron avalanche breakdown. Assuming single electron avalanche breakdown, the mean free path was estimated to be about 9 AA. The DC breakdown strength was lower than the impulse breakdown strength, which suggested space charge effects on the DC breakdown or the thermal breakdown. The impulse breakdown strength was also measured with DC prestress superposed. The results can be explained by the formation of homospace charge in PPS during the DC prestress. For the thinner film, the homospace charge was found to act like heterospace charge for the counterelectrode, which causes an enhancement of the electric field there, resulting in the lower breakdown strength.<>
{"title":"Electrical breakdown and space charge of polyphenylene sulfide films","authors":"T. Mizutani, M. Hikita, A. Umemura, M. Ieda","doi":"10.1109/CEIDP.1989.69565","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69565","url":null,"abstract":"The electrical breakdown of PPS (polyphenylene sulfide) films of three different thicknesses was investigated. Impulse breakdown strength was almost constant in the temperature range from -60 to 150 degrees C, but showed a negative thickness dependence, suggesting electron avalanche breakdown. Assuming single electron avalanche breakdown, the mean free path was estimated to be about 9 AA. The DC breakdown strength was lower than the impulse breakdown strength, which suggested space charge effects on the DC breakdown or the thermal breakdown. The impulse breakdown strength was also measured with DC prestress superposed. The results can be explained by the formation of homospace charge in PPS during the DC prestress. For the thinner film, the homospace charge was found to act like heterospace charge for the counterelectrode, which causes an enhancement of the electric field there, resulting in the lower breakdown strength.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"22 1","pages":"315-320"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78486236","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69542
G. Stone, R. V. van Heeswijk
An experiment conducted to study the light emission from an electrically stressed transparent epoxy prior to the initiation of electrical trees is described. The effects of surge voltages from 0 to 15 kV, positive and negative polarities and repetition rate from 1 to 10000 p.p.s. on the light output were determined. It is shown that light pulses are emitted from transparent epoxy insulation, prior to the occurrence of a visible tree, during the application of 1- mu s-duration surges. The location of the light pulses with respect to the surge pulse shape depends on the surge polarity. That is, charge carriers cause light emission (and presumably move) when the needle is negative with respect to the space charge region in the surrounding epoxy. An observation that the rate of light emission decreases with decreasing time between surges may imply that it takes a finite time for the space charge in the epoxy surrounding the needle tip to decay. Such repetition rate measurements may provide a measure of the detrapping times.<>
{"title":"The effect of polarity and surge repetition rate on electroluminescence in epoxy","authors":"G. Stone, R. V. van Heeswijk","doi":"10.1109/CEIDP.1989.69542","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69542","url":null,"abstract":"An experiment conducted to study the light emission from an electrically stressed transparent epoxy prior to the initiation of electrical trees is described. The effects of surge voltages from 0 to 15 kV, positive and negative polarities and repetition rate from 1 to 10000 p.p.s. on the light output were determined. It is shown that light pulses are emitted from transparent epoxy insulation, prior to the occurrence of a visible tree, during the application of 1- mu s-duration surges. The location of the light pulses with respect to the surge pulse shape depends on the surge polarity. That is, charge carriers cause light emission (and presumably move) when the needle is negative with respect to the space charge region in the surrounding epoxy. An observation that the rate of light emission decreases with decreasing time between surges may imply that it takes a finite time for the space charge in the epoxy surrounding the needle tip to decay. Such repetition rate measurements may provide a measure of the detrapping times.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"33 1","pages":"173-179"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84765240","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69552
R. Gilbert, J. Crine, B. Noirhomme, S. Pélissou
It was demonstrated that HPIC (high-performance ion chromatography) can detect inorganic and organic ions in PE (polyethylene) and XLPE (cross-linked PE) insulation and shields in concentrations as low as approximately 10 mu g/L in the extraction solutions. This analytical technique requires liquid extraction of the ions prior to their content evaluation. The limitations of the extraction technique used are discussed. The detected inorganic ions correspond to the elements determined by other analytical techniques, but the ionic fraction is small. The actual ionic fraction could be higher, since the extraction technique used is far from being optimized. Manufacturing and aging lead to increased SO/sup 2-//sub 4/ and Cl/sup -/ contamination in XLPE cables. Migration from the contaminated shields appears to be one of the causes for this increase. Use of the much cleaner acetylene black should improve the situation. Organic ions were also detected and appear to be essentially by-products of PE oxidation. It is possible that service aging induces the formation of more oxalate ions. Shields made with ethylene vinyl acetate may also generate some acetate ions.<>
{"title":"Measurement of organic and inorganic ions in cable insulation and shields","authors":"R. Gilbert, J. Crine, B. Noirhomme, S. Pélissou","doi":"10.1109/CEIDP.1989.69552","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69552","url":null,"abstract":"It was demonstrated that HPIC (high-performance ion chromatography) can detect inorganic and organic ions in PE (polyethylene) and XLPE (cross-linked PE) insulation and shields in concentrations as low as approximately 10 mu g/L in the extraction solutions. This analytical technique requires liquid extraction of the ions prior to their content evaluation. The limitations of the extraction technique used are discussed. The detected inorganic ions correspond to the elements determined by other analytical techniques, but the ionic fraction is small. The actual ionic fraction could be higher, since the extraction technique used is far from being optimized. Manufacturing and aging lead to increased SO/sup 2-//sub 4/ and Cl/sup -/ contamination in XLPE cables. Migration from the contaminated shields appears to be one of the causes for this increase. Use of the much cleaner acetylene black should improve the situation. Organic ions were also detected and appear to be essentially by-products of PE oxidation. It is possible that service aging induces the formation of more oxalate ions. Shields made with ethylene vinyl acetate may also generate some acetate ions.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"59 1","pages":"235-240"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81528070","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69532
T. Ito, K. Jogan, T. Saito, Y. Ehara
A breakdown phenomenon of electrical equipment due to the deterioration of insulation was investigated. The degree of deterioration or breakdown of the insulating system was predicted from the distribution of induced electric charges inside small voids in an insulator-the discharge magnitude distribution. This distribution was measured by a special internal-discharge pulse measurement system, which analyzes it according to the phase area of the applied AC 50-Hz voltage. This technique was used to investigate tree progression in the microvoid of PMMA (polymethyl methacrylate). The density and the growing speed of the trees are analyzed in terms of the discharge magnitude distributions.<>
{"title":"Phase analysis of discharge magnitude distributions inside a small void and its applications to diagnosis of deteriorating insulations","authors":"T. Ito, K. Jogan, T. Saito, Y. Ehara","doi":"10.1109/CEIDP.1989.69532","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69532","url":null,"abstract":"A breakdown phenomenon of electrical equipment due to the deterioration of insulation was investigated. The degree of deterioration or breakdown of the insulating system was predicted from the distribution of induced electric charges inside small voids in an insulator-the discharge magnitude distribution. This distribution was measured by a special internal-discharge pulse measurement system, which analyzes it according to the phase area of the applied AC 50-Hz voltage. This technique was used to investigate tree progression in the microvoid of PMMA (polymethyl methacrylate). The density and the growing speed of the trees are analyzed in terms of the discharge magnitude distributions.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"30 1","pages":"111-116"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76670971","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69534
J. Skubis
The author presents the measurement results of the parameter A/sub RMS/ for three types of partial discharges (PDs) generated in a typical high-voltage system: on pressboard, on resin, and on glass. A typical run of A/sub RMS/ on an X-Y register is shown. It manifests a relatively stable instantaneous root mean square value of the electric signal converted from the acoustic signal as a function of time. Results obtained for the three surfaces demonstrate that the parameter A/sub RMS/ is perfectly suitable for characterizing PDs measured by the acoustic method. It is univocally connected with the energy of the generated PD.<>
{"title":"Instantaneous root mean squire value of the acoustic emission as a means of measuring partial discharges","authors":"J. Skubis","doi":"10.1109/CEIDP.1989.69534","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69534","url":null,"abstract":"The author presents the measurement results of the parameter A/sub RMS/ for three types of partial discharges (PDs) generated in a typical high-voltage system: on pressboard, on resin, and on glass. A typical run of A/sub RMS/ on an X-Y register is shown. It manifests a relatively stable instantaneous root mean square value of the electric signal converted from the acoustic signal as a function of time. Results obtained for the three surfaces demonstrate that the parameter A/sub RMS/ is perfectly suitable for characterizing PDs measured by the acoustic method. It is univocally connected with the energy of the generated PD.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"18 1","pages":"125-130"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77991468","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69568
W. Wong, M. Shaw
The role of water in ER (electrorheological) fluid systems is investigated by correlating its physical state with the rheological properties of the fluid. In particular, the suitability of the water bridging model of the ER effect is evaluated. The electrorheology of three model fluids was studied as a function of electric field strength, moisture content, and placement under dynamic oscillatory shearing. It has been demonstrated that an ER fluid with a porous hydrophilic dispersed phase may behave very similarly to one with a nonporous hydrophobic dispersed phase. A novel ER fluid was prepared using a microencapsulated dispersed phase containing an abundance of water. It was found that although water was present in large amounts, as long as it was segregated from the continuous interparticle environment, the ER effect was greatly diminished from what one would expect based on this criterion alone. The results are in agreement with the idea that interparticle bridging by water may be an important aspect of the ER effect.<>
{"title":"The role of water in electrorheological fluids","authors":"W. Wong, M. Shaw","doi":"10.1109/CEIDP.1989.69568","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69568","url":null,"abstract":"The role of water in ER (electrorheological) fluid systems is investigated by correlating its physical state with the rheological properties of the fluid. In particular, the suitability of the water bridging model of the ER effect is evaluated. The electrorheology of three model fluids was studied as a function of electric field strength, moisture content, and placement under dynamic oscillatory shearing. It has been demonstrated that an ER fluid with a porous hydrophilic dispersed phase may behave very similarly to one with a nonporous hydrophobic dispersed phase. A novel ER fluid was prepared using a microencapsulated dispersed phase containing an abundance of water. It was found that although water was present in large amounts, as long as it was segregated from the continuous interparticle environment, the ER effect was greatly diminished from what one would expect based on this criterion alone. The results are in agreement with the idea that interparticle bridging by water may be an important aspect of the ER effect.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"6 1","pages":"332-337"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73864534","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69563
Zhang Yewen, Baitun Yang, T. Demin, Yaonan Liu
The space charge at the interface of FEP-PMMA (fluorinated ethylene propylene-polymethyl methacrylate) is measured by the step pressure wave method, and the relationship between the space charge and its discharge time at room temperature is studied. Considering the dynamic process of the carrier jumping out of the trap at the interface, it is possible to determine the carrier trap energy state density distribution at the interface. It is concluded that information about carrier traps in dielectric materials can be obtained by this technique.<>
{"title":"Measuring distribution of carrier trap energy state density at interface of dielectric with step pressure wave method","authors":"Zhang Yewen, Baitun Yang, T. Demin, Yaonan Liu","doi":"10.1109/CEIDP.1989.69563","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69563","url":null,"abstract":"The space charge at the interface of FEP-PMMA (fluorinated ethylene propylene-polymethyl methacrylate) is measured by the step pressure wave method, and the relationship between the space charge and its discharge time at room temperature is studied. Considering the dynamic process of the carrier jumping out of the trap at the interface, it is possible to determine the carrier trap energy state density distribution at the interface. It is concluded that information about carrier traps in dielectric materials can be obtained by this technique.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"40 1","pages":"303-308"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85346264","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69536
N. Sugawara, K. Hokari
In order to gain a better understanding of the DC discharge performance of a string of ice-covered insulators with icicles, discharges were performed with three shapes of artificial icicles under DC voltages in a cold chamber. The DC flashover voltage is shown to increase with a decrease in temperature because of the simultaneous increase of the resistance of the icicle. This increase in resistance occurs as the thickness of the water film on the icicle surface decreases exponentially with the decrease in temperature. The melted weight W/sub m/ of the icicles was greater for negative polarity than for positive polarity when melting occurred by corona discharge. These differences in W/sub m/ may confirm reports that negative flashover voltage for ice-accreted insulators is lower than positive flashover voltage. There was a hot region on the icicle surface of the rod type near the boundary between the electrode in the ice and the ice.<>
{"title":"DC discharge performance at the tip of an icicle","authors":"N. Sugawara, K. Hokari","doi":"10.1109/CEIDP.1989.69536","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69536","url":null,"abstract":"In order to gain a better understanding of the DC discharge performance of a string of ice-covered insulators with icicles, discharges were performed with three shapes of artificial icicles under DC voltages in a cold chamber. The DC flashover voltage is shown to increase with a decrease in temperature because of the simultaneous increase of the resistance of the icicle. This increase in resistance occurs as the thickness of the water film on the icicle surface decreases exponentially with the decrease in temperature. The melted weight W/sub m/ of the icicles was greater for negative polarity than for positive polarity when melting occurred by corona discharge. These differences in W/sub m/ may confirm reports that negative flashover voltage for ice-accreted insulators is lower than positive flashover voltage. There was a hot region on the icicle surface of the rod type near the boundary between the electrode in the ice and the ice.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"232 1","pages":"137-142"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89034249","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 : 1989-10-29DOI: 10.1109/CEIDP.1989.69581
R. Hegerberg, O. Lillevik, G. Balog
Three-layer PP (polypropylene) film shows some unexpected dielectric behavior, possibly related to the existence of film-film interfaces in such systems. An experimental technique for studying the space charge distribution in multilayer structures has been developed. Depolarization currents and space charge distribution were measured in the model samples of 25- mu m-thick biaxially stretched PP film. A record of the charge distribution after poling with 2 kV (corresponding to 27 MV/m) for 20 hours at 295 K is shown. The scan shows heterocharge at both electrodes, and the middle layer is also charged positively. There is a large variation parallel to the electrodes.<>
{"title":"Space charge distribution in multilayer dielectrics","authors":"R. Hegerberg, O. Lillevik, G. Balog","doi":"10.1109/CEIDP.1989.69581","DOIUrl":"https://doi.org/10.1109/CEIDP.1989.69581","url":null,"abstract":"Three-layer PP (polypropylene) film shows some unexpected dielectric behavior, possibly related to the existence of film-film interfaces in such systems. An experimental technique for studying the space charge distribution in multilayer structures has been developed. Depolarization currents and space charge distribution were measured in the model samples of 25- mu m-thick biaxially stretched PP film. A record of the charge distribution after poling with 2 kV (corresponding to 27 MV/m) for 20 hours at 295 K is shown. The scan shows heterocharge at both electrodes, and the middle layer is also charged positively. There is a large variation parallel to the electrodes.<<ETX>>","PeriodicalId":10719,"journal":{"name":"Conference on Electrical Insulation and Dielectric Phenomena,","volume":"46 1","pages":"409-413"},"PeriodicalIF":0.0,"publicationDate":"1989-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73815680","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}
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