Pub Date : 2012-05-08DOI: 10.1109/MMM.2012.2189035
Han Wang, A. Hsu, Ki Kang Kim, J. Kong, T. Palacios
Graphene, a one-atom-thick layer of carbon atoms arranged in a honeycomb lattice, has recently attracted great interest among physicists and engineers. The combination of the unique properties of this material, with new device concepts and nanotechnology may overcome some of the main limitations of traditional radio-frequency (RF) electronics in terms of maximum frequency, linearity and power dissipation. In this paper, we review the recent progress on graphene-based electronic devices for RF applications. In particular, the growth and technology of graphene transistors with an ƒT.LG product of 24 GHz.µm will be discussed. These devices have shown excellent potential for high speed RF applications and frequency multiplier circuits with cut-off frequencies of more than 1.4 GHz have been demonstrated. The future challenges facing this rising technology and its feasibility for a new generation of applications in RF communications and circuits are also discussed.
{"title":"Graphene electronics for RF applications","authors":"Han Wang, A. Hsu, Ki Kang Kim, J. Kong, T. Palacios","doi":"10.1109/MMM.2012.2189035","DOIUrl":"https://doi.org/10.1109/MMM.2012.2189035","url":null,"abstract":"Graphene, a one-atom-thick layer of carbon atoms arranged in a honeycomb lattice, has recently attracted great interest among physicists and engineers. The combination of the unique properties of this material, with new device concepts and nanotechnology may overcome some of the main limitations of traditional radio-frequency (RF) electronics in terms of maximum frequency, linearity and power dissipation. In this paper, we review the recent progress on graphene-based electronic devices for RF applications. In particular, the growth and technology of graphene transistors with an ƒT.LG product of 24 GHz.µm will be discussed. These devices have shown excellent potential for high speed RF applications and frequency multiplier circuits with cut-off frequencies of more than 1.4 GHz have been demonstrated. The future challenges facing this rising technology and its feasibility for a new generation of applications in RF communications and circuits are also discussed.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120993532","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972582
L. Slater
The paper outlines the early days of satellite navigation, focusing on the work of the Naval Research Laboratory (NRL) on systems that contributed to the later Global Positioning System (GPS). NRL's innovations included the Minitrack system for space surveillance, the development of high-precision timing systems for use in space, the Timation navigation satellite program, and the first two Navigation Technology Satellites (NTS-1 and NTS-2). NAVSTAR-GPS emerged as a joint Department of Defense (DoD) program in 1973, by which time much of the GPS concept had been developed and a number of GPS technologies had been tested.
{"title":"From Minitrack to NAVSTAR: The early development of the global positioning system, 1955–1975","authors":"L. Slater","doi":"10.1109/MWSYM.2011.5972582","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972582","url":null,"abstract":"The paper outlines the early days of satellite navigation, focusing on the work of the Naval Research Laboratory (NRL) on systems that contributed to the later Global Positioning System (GPS). NRL's innovations included the Minitrack system for space surveillance, the development of high-precision timing systems for use in space, the Timation navigation satellite program, and the first two Navigation Technology Satellites (NTS-1 and NTS-2). NAVSTAR-GPS emerged as a joint Department of Defense (DoD) program in 1973, by which time much of the GPS concept had been developed and a number of GPS technologies had been tested.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"211 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114995078","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972573
B. Perlman
Dr. Nathan Marcuvitz stands out clearly as the leading figure in the field of electromagnetic waves for the period of at least two decades following World War II. He was widely viewed by his colleagues as the premier electromagnetics scholar of his generation. This presentation about state of the art of simulation of battlefields is a tribute to his contribution and a symbol of how he early modeling efforts to very sophisticated system modeling schemes.
{"title":"Modeling communications effects and simulation of the electronic battlefield environment (EBE) a tribute to Prof. Nathan Marcuvitz","authors":"B. Perlman","doi":"10.1109/MWSYM.2011.5972573","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972573","url":null,"abstract":"Dr. Nathan Marcuvitz stands out clearly as the leading figure in the field of electromagnetic waves for the period of at least two decades following World War II. He was widely viewed by his colleagues as the premier electromagnetics scholar of his generation. This presentation about state of the art of simulation of battlefields is a tribute to his contribution and a symbol of how he early modeling efforts to very sophisticated system modeling schemes.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127199687","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972738
M. Liang, W. Ng, Kihun Chang, M. Gehm, H. Xin
In this paper, a 3-D Luneburg Lens has been designed, fabricated and characterized. Refractive index control of the lens is based on the mixing ratio of air voids and a polymer. The 12 cm (4λ0 at 10 GHz) diameter lens is designed to work at X-band. The effective permittivity of the unit cell is estimated by effective medium theory and calculated by the finite-element simulation software Ansoft HFSS. Fabrication is implemented by a polymer jetting rapid prototyping method. In the measurement, the lens antenna is fed by an X-band waveguide. The half-power beam width of the antenna is 14 degrees and no obvious side lobe is found in the measurement above the noise floor.
本文设计、制作了一种三维鲁讷堡透镜，并对其进行了表征。透镜的折射率控制是基于空气空隙和聚合物的混合比例。直径12厘米(4λ0 at 10 GHz)的透镜设计用于x波段。利用有效介质理论估算了单元电池的有效介电常数，并利用有限元模拟软件Ansoft HFSS进行了计算。通过聚合物喷射快速成型方法实现制造。在测量中，透镜天线由x波段波导馈电。天线的半功率波束宽度为14度，在噪声底以上的测量中未发现明显的旁瓣。
{"title":"An X-band Luneburg Lens antenna fabricated by rapid prototyping technology","authors":"M. Liang, W. Ng, Kihun Chang, M. Gehm, H. Xin","doi":"10.1109/MWSYM.2011.5972738","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972738","url":null,"abstract":"In this paper, a 3-D Luneburg Lens has been designed, fabricated and characterized. Refractive index control of the lens is based on the mixing ratio of air voids and a polymer. The 12 cm (4λ0 at 10 GHz) diameter lens is designed to work at X-band. The effective permittivity of the unit cell is estimated by effective medium theory and calculated by the finite-element simulation software Ansoft HFSS. Fabrication is implemented by a polymer jetting rapid prototyping method. In the measurement, the lens antenna is fed by an X-band waveguide. The half-power beam width of the antenna is 14 degrees and no obvious side lobe is found in the measurement above the noise floor.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127230287","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972993
A. Tonyushkin, A. Kiruluta
Fundamental properties of holography such as storage, recall and matched filtering, arising out of momentum matching considerations of the propagating excitation fields, have been experimentally demonstrated for the first time in MR. As the wavelength of the MR scanner becomes commensurate or smaller than the geometrical thickness of the sample, new phenomena common in quantum optics but hitherto unknown in MR. Far-field concept such as interference and diffraction, will become prevalent with the use of propagating excitation fields in MRI. This realization of holographic principles in MR can be fruitful in designing MR imaging and spectroscopic techniques such as phase conjugate imaging for correcting image distortions caused by field inhomogeneities, as well as new spatial encoding schemes based on a holographic grating encoding. In addition, it has potential to lead to new concepts for information storage and processing at MR frequencies. For example, the use of convolution operations opens the possibility of applying spectral filters directly to the hologram as part of the readout while holographic recording has the potential to increase resolution in MR limited only by the fringe spacing and T2 of the sample. Our analysis shows that for a Larmor frequency of 300 MHz in a 7.0 T whole-body scanner, traveling wave modes in dielectric samples within the range of biological tissues can be sufficient to support imaging of the body parts. The modes diversity depends on the tissue efficient diameter, relative permittivity, conductivity, and the Larmor frequency. The imaging contrast will depend on the particular modes that have been excited in the tissue. A more complicated case of heterogeneous axial symmetric dielectric can be also analyzed using effective permittivity with our approach of mode transformation.
{"title":"MR in the far field: From mode transformation and holography to quasi-optics","authors":"A. Tonyushkin, A. Kiruluta","doi":"10.1109/MWSYM.2011.5972993","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972993","url":null,"abstract":"Fundamental properties of holography such as storage, recall and matched filtering, arising out of momentum matching considerations of the propagating excitation fields, have been experimentally demonstrated for the first time in MR. As the wavelength of the MR scanner becomes commensurate or smaller than the geometrical thickness of the sample, new phenomena common in quantum optics but hitherto unknown in MR. Far-field concept such as interference and diffraction, will become prevalent with the use of propagating excitation fields in MRI. This realization of holographic principles in MR can be fruitful in designing MR imaging and spectroscopic techniques such as phase conjugate imaging for correcting image distortions caused by field inhomogeneities, as well as new spatial encoding schemes based on a holographic grating encoding. In addition, it has potential to lead to new concepts for information storage and processing at MR frequencies. For example, the use of convolution operations opens the possibility of applying spectral filters directly to the hologram as part of the readout while holographic recording has the potential to increase resolution in MR limited only by the fringe spacing and T2 of the sample. Our analysis shows that for a Larmor frequency of 300 MHz in a 7.0 T whole-body scanner, traveling wave modes in dielectric samples within the range of biological tissues can be sufficient to support imaging of the body parts. The modes diversity depends on the tissue efficient diameter, relative permittivity, conductivity, and the Larmor frequency. The imaging contrast will depend on the particular modes that have been excited in the tissue. A more complicated case of heterogeneous axial symmetric dielectric can be also analyzed using effective permittivity with our approach of mode transformation.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124802243","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972751
Moon-Gyu Choi, Hye-Min Lee, Young‐Ho Cho, Xu-Guang Wang, S. Yun
This paper presents a modified microstrip Wilkinson power divider with improved stopband characteristics. By using embedded stepped-impedance low-pass filters and a cross-stub, not only wide stopband performance but also a controllable transmission zero for specified nth harmonic suppression can be effectively obtained. In addition, the explicit design equations of the proposed power divider are derived. Several power divider examples centered at 1.5 GHz are designed, fabricated and measured for demonstration. Experimental results show a good agreement with the simulated ones, which validates the proposed design.
{"title":"Design of Wilkinson power divider with embedded low-pass filter and cross-stub for improved stop-band characteristics","authors":"Moon-Gyu Choi, Hye-Min Lee, Young‐Ho Cho, Xu-Guang Wang, S. Yun","doi":"10.1109/MWSYM.2011.5972751","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972751","url":null,"abstract":"This paper presents a modified microstrip Wilkinson power divider with improved stopband characteristics. By using embedded stepped-impedance low-pass filters and a cross-stub, not only wide stopband performance but also a controllable transmission zero for specified nth harmonic suppression can be effectively obtained. In addition, the explicit design equations of the proposed power divider are derived. Several power divider examples centered at 1.5 GHz are designed, fabricated and measured for demonstration. Experimental results show a good agreement with the simulated ones, which validates the proposed design.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"94 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126061364","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972672
A. Haderer, P. Scherz, A. Stelzer
In this contribution, we address the position estimation of thin, conducting plates by means of a frequency-stepped continuous wave (FSCW) radar system. In particular, we focus on polarimetric scattering properties, introduced by an edge at the border of a conducting plate. To account for the edge's contribution to the overall FSCW radar signal, the method of equivalent currents is applied and finally the implemented scattering model is verified by measurements. Based on the scattering properties, a simplified signal model is deduced by the method of stationary phase. The proposed signal model can be used to precisely estimate the position of the edge if multiple measurements from spatially distributed positions are available.
{"title":"Position estimation of thin, conducting plates at mm-Wave frequencies utilizing polarimetric effects","authors":"A. Haderer, P. Scherz, A. Stelzer","doi":"10.1109/MWSYM.2011.5972672","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972672","url":null,"abstract":"In this contribution, we address the position estimation of thin, conducting plates by means of a frequency-stepped continuous wave (FSCW) radar system. In particular, we focus on polarimetric scattering properties, introduced by an edge at the border of a conducting plate. To account for the edge's contribution to the overall FSCW radar signal, the method of equivalent currents is applied and finally the implemented scattering model is verified by measurements. Based on the scattering properties, a simplified signal model is deduced by the method of stationary phase. The proposed signal model can be used to precisely estimate the position of the edge if multiple measurements from spatially distributed positions are available.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125310026","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972832
Liang Han, K. Wu
A multifunctional and time-agile system combining both radar sensing and radio communication capabilities is proposed and experimentally demonstrated for 24-GHz vehicular applications. By arranging the radar sensing mode and the radio communication mode in sequential time slots, the present system can operate with the flexibility and capability of functional reconfiguration and fusion using a single transceiver platform. To further reduce cost and also increase efficiency, a 24-GHz system demonstrator has been designed based on the substrate integrated waveguide (SIW) technology. Preliminary experiments have verified system performance. In addition to high-precision range detection, the proposed system has proved a great capability of communication at a data rate of 50 Mbps for both binary-phase-shift-keying (BPSK) and quadrature-phase-shift-keying (QPSK). Therefore, this system is a very promising cost-effective solution for the development of 24-GHz onboard multifunctional systems.
{"title":"24-GHz joint radar and radio system capable of time-agile wireless sensing and communication","authors":"Liang Han, K. Wu","doi":"10.1109/MWSYM.2011.5972832","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972832","url":null,"abstract":"A multifunctional and time-agile system combining both radar sensing and radio communication capabilities is proposed and experimentally demonstrated for 24-GHz vehicular applications. By arranging the radar sensing mode and the radio communication mode in sequential time slots, the present system can operate with the flexibility and capability of functional reconfiguration and fusion using a single transceiver platform. To further reduce cost and also increase efficiency, a 24-GHz system demonstrator has been designed based on the substrate integrated waveguide (SIW) technology. Preliminary experiments have verified system performance. In addition to high-precision range detection, the proposed system has proved a great capability of communication at a data rate of 50 Mbps for both binary-phase-shift-keying (BPSK) and quadrature-phase-shift-keying (QPSK). Therefore, this system is a very promising cost-effective solution for the development of 24-GHz onboard multifunctional systems.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114941792","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972927
Bilel Fehri, S. Boumaiza
This paper deals with systematic behavioral modeling of power amplifiers through the study of the parameters involved in the memory effects phenomenon and the appropriate method for their estimation. The gained knowledge is integrated in both memory polynomial and real-valued time-delay neural network models; and, their linearization capability is investigated and compared to their empirical non-system based counterparts. According to the measurement results, the memory polynomial was required to be over dimensioned to achieve the same linearization performance obtained using a system memory parameters based one. It is also shown that the integration of prior knowledge of system to be modeled reduces the complexity and improves model robustness.
{"title":"Systematic estimation of memory effects parameters in power amplifiers' behavioral models","authors":"Bilel Fehri, S. Boumaiza","doi":"10.1109/MWSYM.2011.5972927","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972927","url":null,"abstract":"This paper deals with systematic behavioral modeling of power amplifiers through the study of the parameters involved in the memory effects phenomenon and the appropriate method for their estimation. The gained knowledge is integrated in both memory polynomial and real-valued time-delay neural network models; and, their linearization capability is investigated and compared to their empirical non-system based counterparts. According to the measurement results, the memory polynomial was required to be over dimensioned to achieve the same linearization performance obtained using a system memory parameters based one. It is also shown that the integration of prior knowledge of system to be modeled reduces the complexity and improves model robustness.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115200968","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5973573
E. Serebryakova, K. Blau, M. Hein
This paper presents the design of a reconstruction filter for a class-S power amplifier. Previously, a few doubly terminated filters for a switched-mode amplifier system were presented, but measurement results showed significant ripples up to 3 dB in output power. This effect can be explained by the current mode final stage acting like a current source with infinite internal impedance, thus demanding a singly terminated filter. This paper presents a comprehensive comparison of the doubly and singly terminated filters in terms of a symbolic algorithm and, moreover, proves mathematically that only singly terminated filters owing to their constant input impedance can fulfil the requirements of current-mode switching amplifiers.
{"title":"Singly terminated reconstruction filters for current-mode class-S power amplifiers","authors":"E. Serebryakova, K. Blau, M. Hein","doi":"10.1109/MWSYM.2011.5973573","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5973573","url":null,"abstract":"This paper presents the design of a reconstruction filter for a class-S power amplifier. Previously, a few doubly terminated filters for a switched-mode amplifier system were presented, but measurement results showed significant ripples up to 3 dB in output power. This effect can be explained by the current mode final stage acting like a current source with infinite internal impedance, thus demanding a singly terminated filter. This paper presents a comprehensive comparison of the doubly and singly terminated filters in terms of a symbolic algorithm and, moreover, proves mathematically that only singly terminated filters owing to their constant input impedance can fulfil the requirements of current-mode switching amplifiers.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"200 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116157161","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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