Pub Date : 2009-11-01DOI: 10.1109/COMCAS.2009.5386079
R. Arusi, Y. Pinhasi, Boris Kapilevitch, D. Hardon, B. Litvak, M. Anisimov
Sub-millimeter and Terahertz waves maintain reasonable penetration depth in certain common materials, such as cloth, plastic, wood, sand and soil. Therefore, THz radiation can detect concealed weapons since many non-metallic, non-polar materials are transparent to this type of radiation (and are not transparent to visible radiation). Target compounds such as explosives and illicit drugs have characteristic THz spectra that can be used to identify these compounds. Investigation, design and development of a sub-millimeter wave remote sensing RADAR system for homeland security applications are presented. The RADAR, operating at 330GHz is based on transmission of a frequency modulated continuous wave (FMCW) and aimed at detection of concealed objects for ranges up to 20m. The system consists of 2 horn-lens antennas integrated with a homodyne transceiver. The synthesized linear FM signal with a frequency span of 200MHz at X-band is multiplied by a factor of 32 to generate the transmitted Tera-Hertz wave. Using a splitter, the signal is fed to an antenna and to a local oscillator port of a second harmonic balanced mixer. As a result, an intermediate frequency signal is obtained, containing the information on the target. Distance measurements were made by performing data acquisition and signal processing commercial programs, resulting in a range resolution better than 1cm. Preliminary Tera-Hertz imaging was also carried out to perform a three-dimensional image of the object.
{"title":"Linear FM radar operating in the Tera-Hertz regime for concealed objects detection","authors":"R. Arusi, Y. Pinhasi, Boris Kapilevitch, D. Hardon, B. Litvak, M. Anisimov","doi":"10.1109/COMCAS.2009.5386079","DOIUrl":"https://doi.org/10.1109/COMCAS.2009.5386079","url":null,"abstract":"Sub-millimeter and Terahertz waves maintain reasonable penetration depth in certain common materials, such as cloth, plastic, wood, sand and soil. Therefore, THz radiation can detect concealed weapons since many non-metallic, non-polar materials are transparent to this type of radiation (and are not transparent to visible radiation). Target compounds such as explosives and illicit drugs have characteristic THz spectra that can be used to identify these compounds. Investigation, design and development of a sub-millimeter wave remote sensing RADAR system for homeland security applications are presented. The RADAR, operating at 330GHz is based on transmission of a frequency modulated continuous wave (FMCW) and aimed at detection of concealed objects for ranges up to 20m. The system consists of 2 horn-lens antennas integrated with a homodyne transceiver. The synthesized linear FM signal with a frequency span of 200MHz at X-band is multiplied by a factor of 32 to generate the transmitted Tera-Hertz wave. Using a splitter, the signal is fed to an antenna and to a local oscillator port of a second harmonic balanced mixer. As a result, an intermediate frequency signal is obtained, containing the information on the target. Distance measurements were made by performing data acquisition and signal processing commercial programs, resulting in a range resolution better than 1cm. Preliminary Tera-Hertz imaging was also carried out to perform a three-dimensional image of the object.","PeriodicalId":372928,"journal":{"name":"2009 IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems","volume":"359 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123387260","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 : 2009-11-01DOI: 10.1109/COMCAS.2009.5386073
T. Zlotnikov, O. Degani, Y. Nemirovsky
We present design and characterization of an integrated passive analog phase shifter at 24GHz in a commercially available 45 nm RF-CMOS process. The design is based on a well known RC bridge topology which was optimized for maximum phase shift and minimal amplitude response variation versus phase and frequency. Phase is controlled by varying DC voltage on a varactor, resulting in 60º maximum phase shift with 0.1 dB amplitude variation at 24GHz. The size of the phase shifter circuit excluding pads and input/output buffers is 40×50 µm2.
{"title":"Constant loss miniature 45nm RF-CMOS 24 GHz phase shifter","authors":"T. Zlotnikov, O. Degani, Y. Nemirovsky","doi":"10.1109/COMCAS.2009.5386073","DOIUrl":"https://doi.org/10.1109/COMCAS.2009.5386073","url":null,"abstract":"We present design and characterization of an integrated passive analog phase shifter at 24GHz in a commercially available 45 nm RF-CMOS process. The design is based on a well known RC bridge topology which was optimized for maximum phase shift and minimal amplitude response variation versus phase and frequency. Phase is controlled by varying DC voltage on a varactor, resulting in 60º maximum phase shift with 0.1 dB amplitude variation at 24GHz. The size of the phase shifter circuit excluding pads and input/output buffers is 40×50 µm2.","PeriodicalId":372928,"journal":{"name":"2009 IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121293805","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 : 2009-11-01DOI: 10.1109/COMCAS.2009.5385977
P. N. Zakharov, A. Korolev, A. P. Sukhorukov
In wireless systems (networks) planning, the typical goal is to maximize two parameters: coverage and capacity. Metrics describing each of these parameters are systemlevel channel characteristics: BER or data rate spatial distributions, etc. However, in practice, metrics based on physical radio channel characteristics are commonly employed instead (spatial distributions of signal level, SINR, delay spread, etc.). Since determination of these parameters at a specific point of space is in general not possible with acceptable accuracy due to fast fading, their statistical estimates (local mean, outage probability, minimum, maximum values, variance, etc.), determined along small spatial areas typical of practical application, are used as metrics. Objective functions used in network planning further statistically generalize these local statistics. Since information transmission channel characteristics (BER, data rate, capacity, etc.) describing the obtained system performance are in general nonlinear functions of physical channel parameters, their statistical estimates cannot be correctly determined based on statistical estimates of physical parameters. Thus, network planning based on physical parameters will generally lead to errors. In the current contribution, this error is quantified analytically and experimentally. The obtained error values achieved 320% for local mean channel capacity and 3 orders for BER on significant part of analyzed spatial area. Thus, the high importance of considering and using system-level channel characteristics as a preferred metric in network planning is pointed out.
{"title":"On the necessity of information transmission channel characteristics consideration in wireless systems planning","authors":"P. N. Zakharov, A. Korolev, A. P. Sukhorukov","doi":"10.1109/COMCAS.2009.5385977","DOIUrl":"https://doi.org/10.1109/COMCAS.2009.5385977","url":null,"abstract":"In wireless systems (networks) planning, the typical goal is to maximize two parameters: coverage and capacity. Metrics describing each of these parameters are systemlevel channel characteristics: BER or data rate spatial distributions, etc. However, in practice, metrics based on physical radio channel characteristics are commonly employed instead (spatial distributions of signal level, SINR, delay spread, etc.). Since determination of these parameters at a specific point of space is in general not possible with acceptable accuracy due to fast fading, their statistical estimates (local mean, outage probability, minimum, maximum values, variance, etc.), determined along small spatial areas typical of practical application, are used as metrics. Objective functions used in network planning further statistically generalize these local statistics. Since information transmission channel characteristics (BER, data rate, capacity, etc.) describing the obtained system performance are in general nonlinear functions of physical channel parameters, their statistical estimates cannot be correctly determined based on statistical estimates of physical parameters. Thus, network planning based on physical parameters will generally lead to errors. In the current contribution, this error is quantified analytically and experimentally. The obtained error values achieved 320% for local mean channel capacity and 3 orders for BER on significant part of analyzed spatial area. Thus, the high importance of considering and using system-level channel characteristics as a preferred metric in network planning is pointed out.","PeriodicalId":372928,"journal":{"name":"2009 IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems","volume":"13 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114099990","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 : 2009-11-01DOI: 10.1109/COMCAS.2009.5386024
M. Horowitz, E. Levy, O. Okusaga, C. Menyuk, W. Zhou, G. Carter
Optoelectronic oscillators (OEOs) are used to generate RF signals in the X-band region with a very low phase noise. These hybrid opto-electronic devices are based on a long optical fiber that forms a very high-Q RF cavity. We have studied theoretically and experimentally single-loop and dual-loop optoelectronic oscillators. Excellent agreement between theory and experiments was obtained. The results indicate that flicker noise limits the performance of long cavity OEOs at low frequencies (<500 Hz). We have also studied physical effects in dual-injection locked OEO. The locking of two OEOs with different cavity lengths enables the generation of signals with a very low noise and with very low spurs. We demonstrate theoretically that it is possible to reduce the first spur level by more than 20 dB in compare with that obtained in current experiments.
{"title":"Theoretical and experimental study of single and dual-loop optoelectronic oscillators","authors":"M. Horowitz, E. Levy, O. Okusaga, C. Menyuk, W. Zhou, G. Carter","doi":"10.1109/COMCAS.2009.5386024","DOIUrl":"https://doi.org/10.1109/COMCAS.2009.5386024","url":null,"abstract":"Optoelectronic oscillators (OEOs) are used to generate RF signals in the X-band region with a very low phase noise. These hybrid opto-electronic devices are based on a long optical fiber that forms a very high-Q RF cavity. We have studied theoretically and experimentally single-loop and dual-loop optoelectronic oscillators. Excellent agreement between theory and experiments was obtained. The results indicate that flicker noise limits the performance of long cavity OEOs at low frequencies (<500 Hz). We have also studied physical effects in dual-injection locked OEO. The locking of two OEOs with different cavity lengths enables the generation of signals with a very low noise and with very low spurs. We demonstrate theoretically that it is possible to reduce the first spur level by more than 20 dB in compare with that obtained in current experiments.","PeriodicalId":372928,"journal":{"name":"2009 IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115796118","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 : 2009-11-01DOI: 10.1109/COMCAS.2009.5385981
O. Degani, S. Ravid
A push-push VCO with embedded BALUN and resistive CML divider for 60GHz heterodyne transceiver architecture, are presented. The measured VCO second harmonic output frequency is ~44.6–50[GHz], i.e. ~11.4% tuning range. The phase noise at 1[MHz] offset from the carrier, is ranging between −109 to −112[dBc/Hz] and −97 to −100 [dBc/Hz], for f0/2 and 2×f0 outputs, respectively. The circuit works from 1.3V supply and consumes ~20mA current (VCO ~7mA, Divider + Divider buffer~8mA, second harmonic buffer ~3mA). The output power is ~ −13dBm and −20dBm at the f0/2 and 2×f0 outputs, respectively.
{"title":"Differential output, transformer coupled push-push VCO and divider for 60GHz applications in 90nm CMOS","authors":"O. Degani, S. Ravid","doi":"10.1109/COMCAS.2009.5385981","DOIUrl":"https://doi.org/10.1109/COMCAS.2009.5385981","url":null,"abstract":"A push-push VCO with embedded BALUN and resistive CML divider for 60GHz heterodyne transceiver architecture, are presented. The measured VCO second harmonic output frequency is ~44.6–50[GHz], i.e. ~11.4% tuning range. The phase noise at 1[MHz] offset from the carrier, is ranging between −109 to −112[dBc/Hz] and −97 to −100 [dBc/Hz], for f0/2 and 2×f0 outputs, respectively. The circuit works from 1.3V supply and consumes ~20mA current (VCO ~7mA, Divider + Divider buffer~8mA, second harmonic buffer ~3mA). The output power is ~ −13dBm and −20dBm at the f0/2 and 2×f0 outputs, respectively.","PeriodicalId":372928,"journal":{"name":"2009 IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115533019","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 : 2009-11-01DOI: 10.1109/COMCAS.2009.5385978
P. N. Zakharov, E. V. Mikhailov, A. Korolev, A. P. Sukhorukov
The results of prediction using radio propagation models typically represent physical characteristics of a radio channel. The commonly exploited use of these characteristics as a metric in network planning, instead of rigorous system-level channel parameters, may lead to non-satisfactory results for modern communication and broadcast systems. In the current contribution, a general method for prediction of system-level channel characteristics (BER, data rate, etc.) is proposed, based on site-specific propagation models, deterministic system models and spatial statistical generalization. Validation of the method with direct measurements in a complex indoor environment (for BPSK, QAM, OFDM QAM) has shown its high accuracy (below 21 % RMS error of local mean channel capacity prediction). Another subject of the current work is the experimental investigation of the dependence of system-level characteristics prediction accuracy upon spatial detailing of prediction, which demonstrated the considerable enhancement of accuracy with a decrease in detailing. The proposed method may be directly applied to network planning: it provides means for metric calculation and coverage maps estimation.
{"title":"Deterministic method of information transmission channel prediction in multipath environments","authors":"P. N. Zakharov, E. V. Mikhailov, A. Korolev, A. P. Sukhorukov","doi":"10.1109/COMCAS.2009.5385978","DOIUrl":"https://doi.org/10.1109/COMCAS.2009.5385978","url":null,"abstract":"The results of prediction using radio propagation models typically represent physical characteristics of a radio channel. The commonly exploited use of these characteristics as a metric in network planning, instead of rigorous system-level channel parameters, may lead to non-satisfactory results for modern communication and broadcast systems. In the current contribution, a general method for prediction of system-level channel characteristics (BER, data rate, etc.) is proposed, based on site-specific propagation models, deterministic system models and spatial statistical generalization. Validation of the method with direct measurements in a complex indoor environment (for BPSK, QAM, OFDM QAM) has shown its high accuracy (below 21 % RMS error of local mean channel capacity prediction). Another subject of the current work is the experimental investigation of the dependence of system-level characteristics prediction accuracy upon spatial detailing of prediction, which demonstrated the considerable enhancement of accuracy with a decrease in detailing. The proposed method may be directly applied to network planning: it provides means for metric calculation and coverage maps estimation.","PeriodicalId":372928,"journal":{"name":"2009 IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems","volume":"153 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116729283","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 : 2009-11-01DOI: 10.1109/COMCAS.2009.5385936
J. Baal-Schem
In September 2008, the IEEE History Committee has launched the Global History Network (GHN) at the occasion of the IEEE Section Congress in Montreal, Canada. The IEEE Global History Network (GHN) intends to be the world's premier site for the documentation, analysis and explanation of the history of electrical, electronic, and computer technologies, the scientists, engineers and business people who made these technologies happen, and on the history of the organizations to which these men and women belonged.
{"title":"GHN — The IEEE Global History Network","authors":"J. Baal-Schem","doi":"10.1109/COMCAS.2009.5385936","DOIUrl":"https://doi.org/10.1109/COMCAS.2009.5385936","url":null,"abstract":"In September 2008, the IEEE History Committee has launched the Global History Network (GHN) at the occasion of the IEEE Section Congress in Montreal, Canada. The IEEE Global History Network (GHN) intends to be the world's premier site for the documentation, analysis and explanation of the history of electrical, electronic, and computer technologies, the scientists, engineers and business people who made these technologies happen, and on the history of the organizations to which these men and women belonged.","PeriodicalId":372928,"journal":{"name":"2009 IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117071074","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 : 2009-11-01DOI: 10.1109/COMCAS.2009.5385946
S. Ruschin, E. Shekel, S. Zach
We demonstrate several schemes of RF frequency analysis by optical means. They are based on the sampling of RF signals in time-domain and subsequently translating them into the spatial domain where Fourier transformation and other signal processing operations are readily executed. The most general option introduces true-time delays in the form of optical fibers. A drawback of this method is the need to stabilize and control optical phases. We report the achievement of such control by closed-loop active phase stabilization.
{"title":"RF frequency analysis and separation by optical sampling","authors":"S. Ruschin, E. Shekel, S. Zach","doi":"10.1109/COMCAS.2009.5385946","DOIUrl":"https://doi.org/10.1109/COMCAS.2009.5385946","url":null,"abstract":"We demonstrate several schemes of RF frequency analysis by optical means. They are based on the sampling of RF signals in time-domain and subsequently translating them into the spatial domain where Fourier transformation and other signal processing operations are readily executed. The most general option introduces true-time delays in the form of optical fibers. A drawback of this method is the need to stabilize and control optical phases. We report the achievement of such control by closed-loop active phase stabilization.","PeriodicalId":372928,"journal":{"name":"2009 IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117178457","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 : 2009-11-01DOI: 10.1109/COMCAS.2009.5385945
S. Zach, Z. Zalevsky, A. Shemer
Processing of wide band signals and antenna beam forming by photonic means and principals offers significant advantages compared to current electronic systems. The integration of optics in RF systems like EW and RADAR or manipulating optic based principals enables to decrease the size, to increase the bandwidth, and to reduce the power dissipation far beyond what can be obtained in current electronic systems. Thus, several novel photonic architectures were suggested based on converting analog RF signals into photonics.
{"title":"RF systems approach based on photonics architecture","authors":"S. Zach, Z. Zalevsky, A. Shemer","doi":"10.1109/COMCAS.2009.5385945","DOIUrl":"https://doi.org/10.1109/COMCAS.2009.5385945","url":null,"abstract":"Processing of wide band signals and antenna beam forming by photonic means and principals offers significant advantages compared to current electronic systems. The integration of optics in RF systems like EW and RADAR or manipulating optic based principals enables to decrease the size, to increase the bandwidth, and to reduce the power dissipation far beyond what can be obtained in current electronic systems. Thus, several novel photonic architectures were suggested based on converting analog RF signals into photonics.","PeriodicalId":372928,"journal":{"name":"2009 IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems","volume":"620 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123079620","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 : 2009-11-01DOI: 10.1109/COMCAS.2009.5385957
Z. Yun, Soo Yong Lim, M. Iskander
In this paper, we will first review the ray-tracing algorithms developed in our group; then examples of the exploitation of geospatial data for radio propagation and its benefits will be presented. We will discuss the techniques to extract three dimensional (3D) building structures in urban propagation environment using 2D images in cyberspace. Finally, a real-time ray tracer will be briefly described.
{"title":"Radio propagation modeling in complex environments for wireless communications","authors":"Z. Yun, Soo Yong Lim, M. Iskander","doi":"10.1109/COMCAS.2009.5385957","DOIUrl":"https://doi.org/10.1109/COMCAS.2009.5385957","url":null,"abstract":"In this paper, we will first review the ray-tracing algorithms developed in our group; then examples of the exploitation of geospatial data for radio propagation and its benefits will be presented. We will discuss the techniques to extract three dimensional (3D) building structures in urban propagation environment using 2D images in cyberspace. Finally, a real-time ray tracer will be briefly described.","PeriodicalId":372928,"journal":{"name":"2009 IEEE International Conference on Microwaves, Communications, Antennas and Electronics Systems","volume":"177 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123269494","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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