Pub Date : 1989-05-23DOI: 10.1109/NSEMC.1989.37150
G. H. Baker, C. Gordon
A brief summary is presented of US Department of Defense (DOD) efforts for standardizing a high electromagnetic pulse (HEMP) radiation hardening approach for critical fixed ground-based command, control, and communication and intelligence (FGBC/sup 3/I) facilities. The approach adopted by DOD for hardening FGBC/sup 3/I facilities is called the low-risk hardening approach. This approach relies principally upon an electromagnetic barrier to prevent unacceptable electrical transients from reaching potentially vulnerable system components. The barrier consists of (1) an electromagnetic shield (steel or copper) which fully encloses all mission-critical components, and (2) treatment of each electrical penetration of the shield and each aperture in the shield to attenuate the transmission of conducted transients adequately. The number of shield penetrations and apertures is strictly controlled to facilitate validation testing. The low-risk hardening approach is illustrated. The hardening approach will be promulgated in MIL-STD-188-125 scheduled to appear in early 1990.<>
{"title":"Progress in the development of HEMP protection standards for C/sup 3/I facilities","authors":"G. H. Baker, C. Gordon","doi":"10.1109/NSEMC.1989.37150","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37150","url":null,"abstract":"A brief summary is presented of US Department of Defense (DOD) efforts for standardizing a high electromagnetic pulse (HEMP) radiation hardening approach for critical fixed ground-based command, control, and communication and intelligence (FGBC/sup 3/I) facilities. The approach adopted by DOD for hardening FGBC/sup 3/I facilities is called the low-risk hardening approach. This approach relies principally upon an electromagnetic barrier to prevent unacceptable electrical transients from reaching potentially vulnerable system components. The barrier consists of (1) an electromagnetic shield (steel or copper) which fully encloses all mission-critical components, and (2) treatment of each electrical penetration of the shield and each aperture in the shield to attenuate the transmission of conducted transients adequately. The number of shield penetrations and apertures is strictly controlled to facilitate validation testing. The low-risk hardening approach is illustrated. The hardening approach will be promulgated in MIL-STD-188-125 scheduled to appear in early 1990.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"18 8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126032016","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 : 1989-05-23DOI: 10.1109/NSEMC.1989.37195
K.R. Kowzlczyk
Electromagnetic (EM) coupling between cables containing shielded twisted pairs can cause system degradation, i.e., powerline noise induced onto cables used for communication. Software that uses mathematical models of differential- and common-mode coupling between shielded twisted pairs is described. The differential-mode coupling model is derived from Ampere's law and the Biot-Savart law. The common-mode coupling model is based on the percent imbalance in cable-shield current and inductance due to cable-shield distance from a ground plane. EM data tables and a set of routines using these models were generated using structured query language embedded in Fortran. A novel approach was taken to ensure correct results and reduce user error: the program accesses a large existing knowledge base of cable electrical and physical properties, requiring only cable designators and positions from a user to obtain an interference evaluation.<>
{"title":"Automated cable coupling analysis software for EMC prediction","authors":"K.R. Kowzlczyk","doi":"10.1109/NSEMC.1989.37195","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37195","url":null,"abstract":"Electromagnetic (EM) coupling between cables containing shielded twisted pairs can cause system degradation, i.e., powerline noise induced onto cables used for communication. Software that uses mathematical models of differential- and common-mode coupling between shielded twisted pairs is described. The differential-mode coupling model is derived from Ampere's law and the Biot-Savart law. The common-mode coupling model is based on the percent imbalance in cable-shield current and inductance due to cable-shield distance from a ground plane. EM data tables and a set of routines using these models were generated using structured query language embedded in Fortran. A novel approach was taken to ensure correct results and reduce user error: the program accesses a large existing knowledge base of cable electrical and physical properties, requiring only cable designators and positions from a user to obtain an interference evaluation.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133663080","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 : 1989-05-23DOI: 10.1109/NSEMC.1989.37157
L. Hoeft, J. Hofstra, W. Prather
A technique is reported for testing the electromagnetic radiation hardening of aircraft. The electromagnetic excitation of the aircraft is accomplished by driving the aircraft's high-frequency (HF) antenna at the fundamental resonant frequency of the aircraft. Surface magnetic fields in the range of 1 to 10 mA/m were easily produced with 15 W of RF power. In addition to exciting the fundamental resonances, useful surfaces fields from 10 to 100 MHz were also obtained. The technique is called antenna SPEHS (single-point excitation for hardness surveillance). Measurements of the magnetic field at a prescribed distance from the outside and inside surfaces of hardened apertures, such as window screens and gasketed doors, were made using a multiturn loop sensor and a battery-operated field strength meter allowing the shielding effectiveness to be determined.<>
{"title":"Excitation of aircraft for hardness surveillance using the aircraft's own HF antenna","authors":"L. Hoeft, J. Hofstra, W. Prather","doi":"10.1109/NSEMC.1989.37157","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37157","url":null,"abstract":"A technique is reported for testing the electromagnetic radiation hardening of aircraft. The electromagnetic excitation of the aircraft is accomplished by driving the aircraft's high-frequency (HF) antenna at the fundamental resonant frequency of the aircraft. Surface magnetic fields in the range of 1 to 10 mA/m were easily produced with 15 W of RF power. In addition to exciting the fundamental resonances, useful surfaces fields from 10 to 100 MHz were also obtained. The technique is called antenna SPEHS (single-point excitation for hardness surveillance). Measurements of the magnetic field at a prescribed distance from the outside and inside surfaces of hardened apertures, such as window screens and gasketed doors, were made using a multiturn loop sensor and a battery-operated field strength meter allowing the shielding effectiveness to be determined.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114825218","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 : 1989-05-23DOI: 10.1109/NSEMC.1989.37165
B. Bowles, C. Paul
The potential for a switched-mode power supply (SMPS) DC distribution bus to create electromagnetic interference (EMI) is examined using the SPICE circuit analysis program. Attaching a SMPS to a long length of transmission line essentially places a time changing load across that line. This generates reflections on the line that result in short periods over which the line voltage can change by a significant percentage of the nominal voltage (as much as 100% of the nominal DC bus voltage). Although these spikes do not substantially change the DC voltage of the bus, their rapid rise/fall times can generate high-frequency signals on the bus (as on long antenna) that can radiate and cause interference with other electronic subsystems. The frequency content of these voltage spikes can extend to frequencies well above the basic switch rate of the individual SMPS units that are connected to the bus. The potential EMI of these spikes is strongly related to the nominal DC operating voltage of the DC bus. The higher the bus voltage, the larger the amplitudes of these spikes.<>
{"title":"Modelling interference properties of SMPS DC power distribution buses","authors":"B. Bowles, C. Paul","doi":"10.1109/NSEMC.1989.37165","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37165","url":null,"abstract":"The potential for a switched-mode power supply (SMPS) DC distribution bus to create electromagnetic interference (EMI) is examined using the SPICE circuit analysis program. Attaching a SMPS to a long length of transmission line essentially places a time changing load across that line. This generates reflections on the line that result in short periods over which the line voltage can change by a significant percentage of the nominal voltage (as much as 100% of the nominal DC bus voltage). Although these spikes do not substantially change the DC voltage of the bus, their rapid rise/fall times can generate high-frequency signals on the bus (as on long antenna) that can radiate and cause interference with other electronic subsystems. The frequency content of these voltage spikes can extend to frequencies well above the basic switch rate of the individual SMPS units that are connected to the bus. The potential EMI of these spikes is strongly related to the nominal DC operating voltage of the DC bus. The higher the bus voltage, the larger the amplitudes of these spikes.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130405873","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 : 1989-05-23DOI: 10.1109/NSEMC.1989.37222
H. Ghadamabadi, J. Whalen
A description is given of an investigation to determine statistical variations for radio frequency interference (RFI) demodulation responses in operational amplifier (op amp) circuits. 50% amplitude-modulated (AM) RF signals were injected into the op amp signal input terminal to produce undesired demodulated responses at a 1 kHz AM frequency. The RF frequency was varied over the range 0.1 to 400 MHz. The demodulation RFI was characterized by a nonlinear transfer function H/sub 2/. The two op amp types tested were the 741 and the OP27. The results show that the OP27 has better RFI immunity than the 741 with and without RFI suppression capacitors.<>
{"title":"Semi-automatic measured statistics for demodulation RFI in inverting operational amplifier circuits with and without suppression capacitors","authors":"H. Ghadamabadi, J. Whalen","doi":"10.1109/NSEMC.1989.37222","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37222","url":null,"abstract":"A description is given of an investigation to determine statistical variations for radio frequency interference (RFI) demodulation responses in operational amplifier (op amp) circuits. 50% amplitude-modulated (AM) RF signals were injected into the op amp signal input terminal to produce undesired demodulated responses at a 1 kHz AM frequency. The RF frequency was varied over the range 0.1 to 400 MHz. The demodulation RFI was characterized by a nonlinear transfer function H/sub 2/. The two op amp types tested were the 741 and the OP27. The results show that the OP27 has better RFI immunity than the 741 with and without RFI suppression capacitors.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130822087","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 : 1989-05-23DOI: 10.1109/NSEMC.1989.37178
D. Kenneally, D. S. Koellen, S. Épshtein
A description is given of measurements of RF upset levels on two D-type flip-flops, the CD4013B and 54ALS74A, which are functionally identical but fabricated from different technologies: CMOS and low-power Schottky. Continuous-wave electromagnetic interference (CW EMI) from 1 MHz to 200 MHz was coupled into the clock, data, and collector bias, V/sub cc/, ports of each device type while test vectors were used to verify normal operation and subsequent upsets. Both the CMOS and the Schottky devices show decreasing RF susceptibility with increasing frequencies from 1 to 200 MHz. The differences in the susceptibility levels measured for the two technologies are apparent in the data and clock ports' upset levels.<>
{"title":"RF upset susceptibilities of CMOS and low power Schottky D-type flip-flops","authors":"D. Kenneally, D. S. Koellen, S. Épshtein","doi":"10.1109/NSEMC.1989.37178","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37178","url":null,"abstract":"A description is given of measurements of RF upset levels on two D-type flip-flops, the CD4013B and 54ALS74A, which are functionally identical but fabricated from different technologies: CMOS and low-power Schottky. Continuous-wave electromagnetic interference (CW EMI) from 1 MHz to 200 MHz was coupled into the clock, data, and collector bias, V/sub cc/, ports of each device type while test vectors were used to verify normal operation and subsequent upsets. Both the CMOS and the Schottky devices show decreasing RF susceptibility with increasing frequencies from 1 to 200 MHz. The differences in the susceptibility levels measured for the two technologies are apparent in the data and clock ports' upset levels.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125457588","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 : 1989-05-23DOI: 10.1109/NSEMC.1989.37196
M. Nave
A graphical technique for predicting the attenuation of a filter is described. The method centers around impedance paper and the use of several simple identities and is capable of solving for the attenuation of any multisection filter. The advantage of the method is that it gives the engineer intuitive insight into the operation of the filter, and possibilities for improvement. The weakness of the method is that it does not predict the effects of high-Q resonances in the filter. The method is also useful for powerline filter design.<>
{"title":"The graphical attenuation calculation methodology","authors":"M. Nave","doi":"10.1109/NSEMC.1989.37196","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37196","url":null,"abstract":"A graphical technique for predicting the attenuation of a filter is described. The method centers around impedance paper and the use of several simple identities and is capable of solving for the attenuation of any multisection filter. The advantage of the method is that it gives the engineer intuitive insight into the operation of the filter, and possibilities for improvement. The weakness of the method is that it does not predict the effects of high-Q resonances in the filter. The method is also useful for powerline filter design.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126269659","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 : 1989-05-23DOI: 10.1109/NSEMC.1989.37173
J. Maas, D. Hoolihan
A description is given of a 10-m open-area test site (OATS) for measuring radiated electromagnetic emissions from computing devices. The test site, located in southeastern Minnesota, is described. Its performance is analyzed by comparing horizontal and vertical site attenuation measured at the site to a theoretical model. The impact of the ground screen is examined by analyzing site attenuation data from two OATSs. The model developed by A.A. Smith et al. (1982) is used. The effects of the ground screen's size and the termination of its edges are discussed. Three methods of edge termination are examined. The vertical polarization is more sensitive to imperfections in the ground screen; hence, the bulk of the data presented is from vertically polarized site attenuation measurements.<>
介绍了一种用于测量计算设备辐射电磁发射的10米露天试验场(OATS)。该试验场位于明尼苏达州东南部。通过将现场测得的水平和垂直场地衰减与理论模型进行比较，分析了其性能。通过分析两个oats的现场衰减数据，考察了地面屏蔽的影响。采用a.a.s mith et al.(1982)开发的模型。讨论了地屏尺寸及其边缘终止的影响。研究了三种边缘终止的方法。垂直极化对地屏缺陷更敏感;因此，所提供的大部分数据来自垂直极化站点衰减测量。
{"title":"The effects of ground screen termination on OATS site attenuation","authors":"J. Maas, D. Hoolihan","doi":"10.1109/NSEMC.1989.37173","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37173","url":null,"abstract":"A description is given of a 10-m open-area test site (OATS) for measuring radiated electromagnetic emissions from computing devices. The test site, located in southeastern Minnesota, is described. Its performance is analyzed by comparing horizontal and vertical site attenuation measured at the site to a theoretical model. The impact of the ground screen is examined by analyzing site attenuation data from two OATSs. The model developed by A.A. Smith et al. (1982) is used. The effects of the ground screen's size and the termination of its edges are discussed. Three methods of edge termination are examined. The vertical polarization is more sensitive to imperfections in the ground screen; hence, the bulk of the data presented is from vertically polarized site attenuation measurements.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126682809","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 : 1989-05-23DOI: 10.1109/NSEMC.1989.37176
E. T. Chesworth
Calculations are presented that indicate with reasonable accuracy that hand-held transmitter-receiver units used by amateur radio operators, although excluded from ANSI Standard C95.1-1982 protection guidelines, may be a radiation hazard. The transmitters generate between 1 and 5 W of radiofrequency power and operate at the 2-m, 75-cm, and other UHF bands. These units use short spiral (rubber ducky) antennas that are held near the face during transmissions. Although no calculations or measurements give unequivocal values for the electromagnetic energy in the near-field, energy densities in the induction fields (within the head of the user) may be an order of magnitude greater than ANSI protection guidelines. This analysis indicates that it is not prudent to hold the transceiver four or five inches from the face, as is normally done. Certainly it should not be held against the cheek. It is recommended instead that a hand-held transceiver be held at arm's length when transmitting.<>
{"title":"Near field energy densities of hand-held transceivers","authors":"E. T. Chesworth","doi":"10.1109/NSEMC.1989.37176","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37176","url":null,"abstract":"Calculations are presented that indicate with reasonable accuracy that hand-held transmitter-receiver units used by amateur radio operators, although excluded from ANSI Standard C95.1-1982 protection guidelines, may be a radiation hazard. The transmitters generate between 1 and 5 W of radiofrequency power and operate at the 2-m, 75-cm, and other UHF bands. These units use short spiral (rubber ducky) antennas that are held near the face during transmissions. Although no calculations or measurements give unequivocal values for the electromagnetic energy in the near-field, energy densities in the induction fields (within the head of the user) may be an order of magnitude greater than ANSI protection guidelines. This analysis indicates that it is not prudent to hold the transceiver four or five inches from the face, as is normally done. Certainly it should not be held against the cheek. It is recommended instead that a hand-held transceiver be held at arm's length when transmitting.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115299018","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 : 1989-05-23DOI: 10.1109/NSEMC.1989.37162
J. Beilfuss, R. Gray, L. Ambrose, D. McDonald, Z. Landicho
Experimental results obtained on a set of simple multiconductor cables with external electromagnetic shields are presented. The purpose of the experiment was to investigate the relationship between the internal cable geometry and the electromagnetic pulse coupling the cables. A set of five cables was selected for this investigation. The cables had an increasing number of internal conductors, from three to a maximum of eight, and similar construction and external shielding. A physical and electrical description of the tested cables is provided, followed by details of the experiment conducted. The experiment was performed on relatively long (30 to 150 m) lengths of cable using a radiating electromagnetic source and the Harry Diamond Laboratories continuous wave instrumentation system. A summary of multiconductor transmission line theory for shielded cables is provided.<>
{"title":"Multiconductor cable coupling parameters","authors":"J. Beilfuss, R. Gray, L. Ambrose, D. McDonald, Z. Landicho","doi":"10.1109/NSEMC.1989.37162","DOIUrl":"https://doi.org/10.1109/NSEMC.1989.37162","url":null,"abstract":"Experimental results obtained on a set of simple multiconductor cables with external electromagnetic shields are presented. The purpose of the experiment was to investigate the relationship between the internal cable geometry and the electromagnetic pulse coupling the cables. A set of five cables was selected for this investigation. The cables had an increasing number of internal conductors, from three to a maximum of eight, and similar construction and external shielding. A physical and electrical description of the tested cables is provided, followed by details of the experiment conducted. The experiment was performed on relatively long (30 to 150 m) lengths of cable using a radiating electromagnetic source and the Harry Diamond Laboratories continuous wave instrumentation system. A summary of multiconductor transmission line theory for shielded cables is provided.<<ETX>>","PeriodicalId":408694,"journal":{"name":"National Symposium on Electromagnetic Compatibility","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115010296","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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