A. Bourdine, M. Dashkov, A. Evtushenko, G. Pchelkin, Konstantin P. Sachuk, Mukhammadzoir S. Khadjaev, A. A. Vasilets, E. Zaitseva, A. Barashkin, V. Demidov, E. Ter-Nersesyants, E. Dmitriev, Nadezhda A. Shishova, Andrey A. Semenov, Manish Tiwari, M. Bylina, S. Glagolev, Elena V. Polyakova, K. Dukelskii
This work presents results of test series, performed for earlier on designed and successfully fabricated silica few-mode microstructured optical fibers (MOF) with six GeO2-doped cores, induced twisting 100 revolutions per meter, typical “telecommunication” outer diameter 125 μm, core diameter 8.7 μm, air hole diameter 4.6 μm, pitch 7.2 μm, and core quasi-step / graded refractive index profiles with height 0.0360/0.0275, respectively. Part I introduces attempts for splicing of typical telecommunication optical fibers and fabricated samples of MOFs by commercially available field arc fusion splicer kits and results of differential mode delay map measurements, performed for laser excited large core (multimode) optical fibers with core diameters 50 and 100 μm, jointed via free space to described above 2 m long pilot samples of 6-GeO2-core MOFs at both receiving and transmitting ends under laser-excited gaussian optical pulse launching with precision offset conditions, while Part II is concerned with researches of spectral responses, measured for fiber Bragg gratings, recorded in these MOFs.
{"title":"Experimental researches and testing of silica twisted six-GeO2-doped core microstructured optical fiber. Part I: fusion splicing with telecommunication optical fibers and differential mode delay map measurements","authors":"A. Bourdine, M. Dashkov, A. Evtushenko, G. Pchelkin, Konstantin P. Sachuk, Mukhammadzoir S. Khadjaev, A. A. Vasilets, E. Zaitseva, A. Barashkin, V. Demidov, E. Ter-Nersesyants, E. Dmitriev, Nadezhda A. Shishova, Andrey A. Semenov, Manish Tiwari, M. Bylina, S. Glagolev, Elena V. Polyakova, K. Dukelskii","doi":"10.1117/12.3012145","DOIUrl":"https://doi.org/10.1117/12.3012145","url":null,"abstract":"This work presents results of test series, performed for earlier on designed and successfully fabricated silica few-mode microstructured optical fibers (MOF) with six GeO2-doped cores, induced twisting 100 revolutions per meter, typical “telecommunication” outer diameter 125 μm, core diameter 8.7 μm, air hole diameter 4.6 μm, pitch 7.2 μm, and core quasi-step / graded refractive index profiles with height 0.0360/0.0275, respectively. Part I introduces attempts for splicing of typical telecommunication optical fibers and fabricated samples of MOFs by commercially available field arc fusion splicer kits and results of differential mode delay map measurements, performed for laser excited large core (multimode) optical fibers with core diameters 50 and 100 μm, jointed via free space to described above 2 m long pilot samples of 6-GeO2-core MOFs at both receiving and transmitting ends under laser-excited gaussian optical pulse launching with precision offset conditions, while Part II is concerned with researches of spectral responses, measured for fiber Bragg gratings, recorded in these MOFs.","PeriodicalId":424251,"journal":{"name":"Optical Technologies for Telecommunications","volume":"17 1","pages":"127430Q - 127430Q-16"},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139323563","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}
A. Bourdine, M. Dashkov, A. Evtushenko, G. Pchelkin, Konstantin P. Sachuk, Mukhammadzoir S. Khadjaev, A. A. Vasilets, Ekaterina D. Bessonova, E. Zaitseva, B. Reznikov, S. Pashin, Tatiana V. Nikulina, Roman Z. Ibragimov, Nadezhda A. Shishova, Andrey A. Semenov, Daniil M. Titkov, Alexey N. Sergeev, M. Bylina, S. Glagolev, Elena V. Polyakova, K. Dukelskii
This work introduces first time fabricated spun silica microstructured optical fiber (MOF) with inclusion seven GeO2-doped capillaries, placed in the central part of MOF cross-section, and induced twisting. While Part I discussed technological issues for manufacturing of described complicated twisted fiber optic structure, presented some pilot samples of described MOFs with various twisting order and measured their transmission spectra, Part II describes some results of results of experimental researches, performed for successfully manufactured twisted MOF pilot samples with typical hexagonal geometry under hole radius 4.40 μm and pitch 9.80 μm, outer “telecommunication” diameter 125 μm, and center part, formed by seven hollow GeO2-doped ring cores with inner radius 2.50 μm, pitch 8.80 μm and refractive index difference Δn=0.030 with induced twisting 130, 300 and 730 revolutions per meter. Following test series were performed: measurements of far-field laser beam profiles, some attempts of fusion splicing of typical telecommunication optical fibers and fabricated MOF with insertion loss estimation, and spectral response measurements of both single and group WDM (Wavelength Division Multiplexing)-channels of commercially available telecom WDM-system under inclusion of 2 m length MOF into various spans of short-range lab fiber optic link.
{"title":"Silica microstructured optical fiber with centralized inclusion of seven GeO2-doped capillaries and induced twisting. Part II: test and research","authors":"A. Bourdine, M. Dashkov, A. Evtushenko, G. Pchelkin, Konstantin P. Sachuk, Mukhammadzoir S. Khadjaev, A. A. Vasilets, Ekaterina D. Bessonova, E. Zaitseva, B. Reznikov, S. Pashin, Tatiana V. Nikulina, Roman Z. Ibragimov, Nadezhda A. Shishova, Andrey A. Semenov, Daniil M. Titkov, Alexey N. Sergeev, M. Bylina, S. Glagolev, Elena V. Polyakova, K. Dukelskii","doi":"10.1117/12.3012150","DOIUrl":"https://doi.org/10.1117/12.3012150","url":null,"abstract":"This work introduces first time fabricated spun silica microstructured optical fiber (MOF) with inclusion seven GeO2-doped capillaries, placed in the central part of MOF cross-section, and induced twisting. While Part I discussed technological issues for manufacturing of described complicated twisted fiber optic structure, presented some pilot samples of described MOFs with various twisting order and measured their transmission spectra, Part II describes some results of results of experimental researches, performed for successfully manufactured twisted MOF pilot samples with typical hexagonal geometry under hole radius 4.40 μm and pitch 9.80 μm, outer “telecommunication” diameter 125 μm, and center part, formed by seven hollow GeO2-doped ring cores with inner radius 2.50 μm, pitch 8.80 μm and refractive index difference Δn=0.030 with induced twisting 130, 300 and 730 revolutions per meter. Following test series were performed: measurements of far-field laser beam profiles, some attempts of fusion splicing of typical telecommunication optical fibers and fabricated MOF with insertion loss estimation, and spectral response measurements of both single and group WDM (Wavelength Division Multiplexing)-channels of commercially available telecom WDM-system under inclusion of 2 m length MOF into various spans of short-range lab fiber optic link.","PeriodicalId":424251,"journal":{"name":"Optical Technologies for Telecommunications","volume":"11 1 1","pages":"127430S - 127430S-12"},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139323618","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}
O. Morozov, A. Ivanov, A. Sakhabutdinov, P. E. Denisenko, G. A. Morozov, Evgeny P. Denisenko, A. A. Lustina, V. D. Andreev
This article describes a new method for the Doppler frequency shift (DFS) measurement of a radar microwave signal reflected from a moving object, based on radio photonics technologies. The DFS measurement device has the same structure as the sequential radiophotonic link with filtration and consists of a laser, a block of electro-optical modulators, a fiber Bragg grating (FBG), and a photodetector. The block of electro-optical modulators, in contrast to the known solutions based on a two-port Mach-Zehnder amplitude modulator, is based on two subunits, consisting of connected tandem single-port amplitude and phase modulators (TAPM). The general structure of the TAPM subunits is parallelserial. The microwave signal reflected from the object arrives at the first TAPM, which forms the measurement channel. The second and third TAPMs, connected in series, form a reference channel connected in parallel to the measurement one. The second TAPM receives a reference signal from the locator transmitter at the probing microwave frequency, after which the two-frequency radiation, spaced by twice of the probing frequency, is fed to the third TAPM, which generates from each component of the two-frequency radiation two more with a difference frequency equal to twice the maximum possible DFS. The beats of signals from the measurement and reference channels at the output of the photodetector are three high-frequency (GHz) or low-frequency (MHz) electrical signals, the frequencies and powers of which used for the DFS determination.
{"title":"Radiophotonic module for Doppler frequency shift measurement of a reflected signal for radar type problems solving","authors":"O. Morozov, A. Ivanov, A. Sakhabutdinov, P. E. Denisenko, G. A. Morozov, Evgeny P. Denisenko, A. A. Lustina, V. D. Andreev","doi":"10.1117/12.2629393","DOIUrl":"https://doi.org/10.1117/12.2629393","url":null,"abstract":"This article describes a new method for the Doppler frequency shift (DFS) measurement of a radar microwave signal reflected from a moving object, based on radio photonics technologies. The DFS measurement device has the same structure as the sequential radiophotonic link with filtration and consists of a laser, a block of electro-optical modulators, a fiber Bragg grating (FBG), and a photodetector. The block of electro-optical modulators, in contrast to the known solutions based on a two-port Mach-Zehnder amplitude modulator, is based on two subunits, consisting of connected tandem single-port amplitude and phase modulators (TAPM). The general structure of the TAPM subunits is parallelserial. The microwave signal reflected from the object arrives at the first TAPM, which forms the measurement channel. The second and third TAPMs, connected in series, form a reference channel connected in parallel to the measurement one. The second TAPM receives a reference signal from the locator transmitter at the probing microwave frequency, after which the two-frequency radiation, spaced by twice of the probing frequency, is fed to the third TAPM, which generates from each component of the two-frequency radiation two more with a difference frequency equal to twice the maximum possible DFS. The beats of signals from the measurement and reference channels at the output of the photodetector are three high-frequency (GHz) or low-frequency (MHz) electrical signals, the frequencies and powers of which used for the DFS determination.","PeriodicalId":424251,"journal":{"name":"Optical Technologies for Telecommunications","volume":"240 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123109226","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}
V. Kiselev, Dmitry D. Mishin, V. Pashintsev, Alexandr A. Chipiga
The article presents a spectral analysis of the transmission coefficient of an optical fiber in the event of short attenuation jumps. In this case, it is assumed that the time function of the additional loss factor is a symmetrical triangular function with the same rise and fall times. It is shown that the spectral loss density is sensitive to the number of attenuation jumps, has a low-frequency character and has a filtering effect on the useful signal. Approaches to the analysis of performance characteristics of fiber-optic transmission systems under specific operating conditions are considered.
{"title":"Spectral analysis of attenuation in optical fibers in the process operations","authors":"V. Kiselev, Dmitry D. Mishin, V. Pashintsev, Alexandr A. Chipiga","doi":"10.1117/12.2631988","DOIUrl":"https://doi.org/10.1117/12.2631988","url":null,"abstract":"The article presents a spectral analysis of the transmission coefficient of an optical fiber in the event of short attenuation jumps. In this case, it is assumed that the time function of the additional loss factor is a symmetrical triangular function with the same rise and fall times. It is shown that the spectral loss density is sensitive to the number of attenuation jumps, has a low-frequency character and has a filtering effect on the useful signal. Approaches to the analysis of performance characteristics of fiber-optic transmission systems under specific operating conditions are considered.","PeriodicalId":424251,"journal":{"name":"Optical Technologies for Telecommunications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122365348","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}
The diffraction of Laguerre-super-Gaussian (1,0) modes with circular polarization by sub-wavelength silicon optical micro-axicons with relief height change has been studied in this paper. The height of the all relief of the microelements was varied and only the central part. Modeling by the finite difference time domain method showed that, depending on the height of the element, it is possible to form the required size of the focal segment. It was also shown that by adjusting the height of the central part of the axicon relief, the size of the focal spot can be reduced from 0.51λ to 0.24λ.
{"title":"The laser beams formation with an extended light focal segment by subwavelength silicon microaxicons","authors":"D. Savelyev","doi":"10.1117/12.2631676","DOIUrl":"https://doi.org/10.1117/12.2631676","url":null,"abstract":"The diffraction of Laguerre-super-Gaussian (1,0) modes with circular polarization by sub-wavelength silicon optical micro-axicons with relief height change has been studied in this paper. The height of the all relief of the microelements was varied and only the central part. Modeling by the finite difference time domain method showed that, depending on the height of the element, it is possible to form the required size of the focal segment. It was also shown that by adjusting the height of the central part of the axicon relief, the size of the focal spot can be reduced from 0.51λ to 0.24λ.","PeriodicalId":424251,"journal":{"name":"Optical Technologies for Telecommunications","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126399347","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}
Synthetic Aperture Radar (SAR) interferometry is an active remote sensing technology that uses microwaves to characterize the earth's surface. SAR interferometry allows to measure the 3D profile of the earth's surface, recover surface topography, and determine topographic displacements over time. The microwave SAR signal is usually highly distorted. Distortions can be caused by, for example, atmospheric disturbances and various characteristics of earth's surface scatterers reflectance. Compensation for these distortions is performed by filtering the phase and evaluating the degree of coherence of the original images. This is an important step to improve the accuracy of the subsequent pphase-unwrapping operation. In this paper, we investigate the use of U-net neural networks for preprocessing the SAR interferogram at various parameters of the distortion of the SAR signal. Two neural networks filter the SAR interferogram and determine the degree of coherence, respectively.
{"title":"Using U-Net for signal preprocessing in interferometric synthetic aperture radar","authors":"P. Serafimovich, A. Dzyuba, S. Khonina, S. Popov","doi":"10.1117/12.2631723","DOIUrl":"https://doi.org/10.1117/12.2631723","url":null,"abstract":"Synthetic Aperture Radar (SAR) interferometry is an active remote sensing technology that uses microwaves to characterize the earth's surface. SAR interferometry allows to measure the 3D profile of the earth's surface, recover surface topography, and determine topographic displacements over time. The microwave SAR signal is usually highly distorted. Distortions can be caused by, for example, atmospheric disturbances and various characteristics of earth's surface scatterers reflectance. Compensation for these distortions is performed by filtering the phase and evaluating the degree of coherence of the original images. This is an important step to improve the accuracy of the subsequent pphase-unwrapping operation. In this paper, we investigate the use of U-net neural networks for preprocessing the SAR interferogram at various parameters of the distortion of the SAR signal. Two neural networks filter the SAR interferogram and determine the degree of coherence, respectively.","PeriodicalId":424251,"journal":{"name":"Optical Technologies for Telecommunications","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127935519","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}
In optical data transmission, among the information carriers of special interest are laser beams, whose shape does not change on propagation in free space and in a homogeneous medium. In this work, we study a continuous superposition of paraxial propagation-invariant off-axis Gaussian beams. We obtain conditions when this superposition yields an offaxis elliptic beam with a given geometric parameters (center displacement, waist radii, tilt angle), which conserves its shape on propagation and rotates around the optical axis. Properties are derived of the normalized-to-power orbital angular momentum of such beams.
{"title":"Paraxial shifted elliptic beams, conserving their shape on free space propagation","authors":"A. Kovalev, V. Kotlyar","doi":"10.1117/12.2631638","DOIUrl":"https://doi.org/10.1117/12.2631638","url":null,"abstract":"In optical data transmission, among the information carriers of special interest are laser beams, whose shape does not change on propagation in free space and in a homogeneous medium. In this work, we study a continuous superposition of paraxial propagation-invariant off-axis Gaussian beams. We obtain conditions when this superposition yields an offaxis elliptic beam with a given geometric parameters (center displacement, waist radii, tilt angle), which conserves its shape on propagation and rotates around the optical axis. Properties are derived of the normalized-to-power orbital angular momentum of such beams.","PeriodicalId":424251,"journal":{"name":"Optical Technologies for Telecommunications","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133883811","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}
S. A. Gavryushin, M. Dashkov, I. I. Alekhin, V. Burdin, B. V. Popov, V. Popov, A. Barashkin, A. Evtushenko
The testing ground based on the different technologies of optical cable installation is described in paper. The testing ground consist from communication lines based on microduct system and using direct underground installation. The comparison of different methods for cable trace location was performed. The experimental approbation of electromagnetic induction method, ground penetrating radar method and acoustic method was carried out on the testing ground.
{"title":"Testing ground for approbation of the methods for fiber-optic communication line trace location","authors":"S. A. Gavryushin, M. Dashkov, I. I. Alekhin, V. Burdin, B. V. Popov, V. Popov, A. Barashkin, A. Evtushenko","doi":"10.1117/12.2631782","DOIUrl":"https://doi.org/10.1117/12.2631782","url":null,"abstract":"The testing ground based on the different technologies of optical cable installation is described in paper. The testing ground consist from communication lines based on microduct system and using direct underground installation. The comparison of different methods for cable trace location was performed. The experimental approbation of electromagnetic induction method, ground penetrating radar method and acoustic method was carried out on the testing ground.","PeriodicalId":424251,"journal":{"name":"Optical Technologies for Telecommunications","volume":"2018 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114534228","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}
In this paper, the effect of different noises on Laguerre-Gaussian (LG) modes recognition by convolution neural network (CNN). A dataset of halftone images with LG modes and noises was prepared during the study. It is shown that not only intensity but also type of noise has high influence on classification process. However, presence of noisy images in the training sample allows to increase the recognition accuracy from 50% to 100% in most cases.
{"title":"Neural network for recognition noisy images of Laguerre-Gaussian modes","authors":"Dmitry P. Bukin, E. Kozlova","doi":"10.1117/12.2631735","DOIUrl":"https://doi.org/10.1117/12.2631735","url":null,"abstract":"In this paper, the effect of different noises on Laguerre-Gaussian (LG) modes recognition by convolution neural network (CNN). A dataset of halftone images with LG modes and noises was prepared during the study. It is shown that not only intensity but also type of noise has high influence on classification process. However, presence of noisy images in the training sample allows to increase the recognition accuracy from 50% to 100% in most cases.","PeriodicalId":424251,"journal":{"name":"Optical Technologies for Telecommunications","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124608558","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}
In this research, a plasmonic lens with a concentric relief in thin metal film was numerically studied by the (FD)2TD method. Parameters of the plasmonic lens were optimized. It is shown that the silver plasmonic lens operates better than gold one and focuses laser light with wavelength of 633 nm into a spot with full width at half maximum of 0.38λ and maximum intensity of 4.04 a.u. It is shown that silver plasmonic lens could focus cylindrical vector beams, forming several peaks on the circle.
{"title":"Numerical simulation of the diffraction of optical vortices by a plasmonic lens with a ring structure","authors":"A. Savelyeva, E. Kozlova, V. Kotlyar","doi":"10.1117/12.2631734","DOIUrl":"https://doi.org/10.1117/12.2631734","url":null,"abstract":"In this research, a plasmonic lens with a concentric relief in thin metal film was numerically studied by the (FD)2TD method. Parameters of the plasmonic lens were optimized. It is shown that the silver plasmonic lens operates better than gold one and focuses laser light with wavelength of 633 nm into a spot with full width at half maximum of 0.38λ and maximum intensity of 4.04 a.u. It is shown that silver plasmonic lens could focus cylindrical vector beams, forming several peaks on the circle.","PeriodicalId":424251,"journal":{"name":"Optical Technologies for Telecommunications","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126268246","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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