Pub Date : 2020-01-24DOI: 10.1080/07315171.2020.1799630
Chao Zhong, L. Qin, Likun Wang
Abstract A piezoelectric composite transducer was developed in this study to improve the bandwidth and beamwidth of the high-frequency transducer. The piezocomposite was designed as arc-shaped to expand the beamwidth, and the matching layer technique was adopted to increase the bandwidth. The directivity function was obtained by the acoustic field theory. The parameters of the matching layer were also calculated using the quarter-wavelength model. Then, a novel preparation process of arc 1–3 piezoelectric composite was given in detail. Finally, the arc 1–3 piezocomposite and transducer were prepared and tested. The bandwidth and beamwidth of the transducer reach 100 kHz and 123°, respectively. Experimental results show that the designed transducer realizes the aims of broadband and wide-beam.
{"title":"Design and preparation of high-frequency transducer with broadband and wide-beam properties","authors":"Chao Zhong, L. Qin, Likun Wang","doi":"10.1080/07315171.2020.1799630","DOIUrl":"https://doi.org/10.1080/07315171.2020.1799630","url":null,"abstract":"Abstract A piezoelectric composite transducer was developed in this study to improve the bandwidth and beamwidth of the high-frequency transducer. The piezocomposite was designed as arc-shaped to expand the beamwidth, and the matching layer technique was adopted to increase the bandwidth. The directivity function was obtained by the acoustic field theory. The parameters of the matching layer were also calculated using the quarter-wavelength model. Then, a novel preparation process of arc 1–3 piezoelectric composite was given in detail. Finally, the arc 1–3 piezocomposite and transducer were prepared and tested. The bandwidth and beamwidth of the transducer reach 100 kHz and 123°, respectively. Experimental results show that the designed transducer realizes the aims of broadband and wide-beam.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"38 1","pages":"20 - 26"},"PeriodicalIF":0.4,"publicationDate":"2020-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87021800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-24DOI: 10.1080/07315171.2020.1799632
Weidong Diao, Xinxin Liao, Zhihua Feng
Abstract The resonant frequency difference of piezoelectric transformers (PTs) with a classical parallel connection could worsen system performance, then the mechanical coupling of PTs was proposed to avoid the disadvantage. Experimental results showed that when the difference was relatively small, the performance of the classical parallel system and proposed mechanical coupling system was similar. However, when the difference increased, the maximum output power of a classical parallel system at a temperature rise of 20 °C reduced by 32.6% and that of mechanical coupling system reduced by 7.7%. This indicated mechanical coupling was better than classical parallel connection in improving the output power of PTs.
{"title":"Reducing the resonant frequency difference of piezoelectric transformers parallel system with mechanical coupling","authors":"Weidong Diao, Xinxin Liao, Zhihua Feng","doi":"10.1080/07315171.2020.1799632","DOIUrl":"https://doi.org/10.1080/07315171.2020.1799632","url":null,"abstract":"Abstract The resonant frequency difference of piezoelectric transformers (PTs) with a classical parallel connection could worsen system performance, then the mechanical coupling of PTs was proposed to avoid the disadvantage. Experimental results showed that when the difference was relatively small, the performance of the classical parallel system and proposed mechanical coupling system was similar. However, when the difference increased, the maximum output power of a classical parallel system at a temperature rise of 20 °C reduced by 32.6% and that of mechanical coupling system reduced by 7.7%. This indicated mechanical coupling was better than classical parallel connection in improving the output power of PTs.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"36 1","pages":"27 - 39"},"PeriodicalIF":0.4,"publicationDate":"2020-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77179566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-24DOI: 10.1080/07315171.2020.1799627
S. Kostritskii, Y. Korkishko, V. Fedorov, O. Sevostyanov, I. М. Chirkova, E. Kokanyan, M. Aillerie
Abstract Micro-Raman spectroscopy and method of Raman data calibration are proposed for the quantitative study of the proton-exchanged LiNbO3 channel waveguides, which contain the different HxLi1–xNbO3 phases, depending on the fabrication conditions. The spectroscopic parameters, phase composition and electro-optic properties of these waveguides have been found to be depending on the small variation of stoichiometry in the near-congruent lithium niobate substrates used for waveguides fabrication.
{"title":"Phase composition of channel proton-exchanged waveguides in different near-congruent LiNbO3","authors":"S. Kostritskii, Y. Korkishko, V. Fedorov, O. Sevostyanov, I. М. Chirkova, E. Kokanyan, M. Aillerie","doi":"10.1080/07315171.2020.1799627","DOIUrl":"https://doi.org/10.1080/07315171.2020.1799627","url":null,"abstract":"Abstract Micro-Raman spectroscopy and method of Raman data calibration are proposed for the quantitative study of the proton-exchanged LiNbO3 channel waveguides, which contain the different HxLi1–xNbO3 phases, depending on the fabrication conditions. The spectroscopic parameters, phase composition and electro-optic properties of these waveguides have been found to be depending on the small variation of stoichiometry in the near-congruent lithium niobate substrates used for waveguides fabrication.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"2 1","pages":"15 - 9"},"PeriodicalIF":0.4,"publicationDate":"2020-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75163586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The microwave dielectric properties of (Mg0.93Ni0.07)2SnO4 ceramics were examined with a view to their exploitation for wireless high-temperature dielectric resonator antenna temperature sensor. A dielectric constant of 8.1, a quality factor of 124,200 GHz, and a temperature coefficient of the resonant frequency of −67 ppm/°C were obtained for (Mg0.93Ni0.07)2SnO4 ceramics that were sintered at 1550 °C for 4 h. The developing procedures and test results for dielectric resonator antenna temperature sensor were recorded. The resonating frequency and 3 dB bandwidth measured at 25 °C were 12.62 GHz and 53 MHz, respectively. A sensitivity of −0.99 MHz/°C was successfully achieved.
{"title":"A high-quality factor dielectric resonator antenna for use in a wireless high-temperature sensor","authors":"Chih-hung Li, Yih-Chien Chen, Tse-Lung Lin, Cheng-Chien Kuoa","doi":"10.1080/07315171.2020.1799633","DOIUrl":"https://doi.org/10.1080/07315171.2020.1799633","url":null,"abstract":"Abstract The microwave dielectric properties of (Mg0.93Ni0.07)2SnO4 ceramics were examined with a view to their exploitation for wireless high-temperature dielectric resonator antenna temperature sensor. A dielectric constant of 8.1, a quality factor of 124,200 GHz, and a temperature coefficient of the resonant frequency of −67 ppm/°C were obtained for (Mg0.93Ni0.07)2SnO4 ceramics that were sintered at 1550 °C for 4 h. The developing procedures and test results for dielectric resonator antenna temperature sensor were recorded. The resonating frequency and 3 dB bandwidth measured at 25 °C were 12.62 GHz and 53 MHz, respectively. A sensitivity of −0.99 MHz/°C was successfully achieved.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"2 1","pages":"40 - 49"},"PeriodicalIF":0.4,"publicationDate":"2020-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84496066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-24DOI: 10.1080/07315171.2020.1799626
L. Korotkov, O. Bulgakov, A. I. Bocharov, F. D. Al Jaafari
Abstract Dielectric properties of nanostructured strontium titanate samples sintered from nanoparticles obtained by grinding of previously synthesized SrTiO3 and nanoparticles obtained by chemical deposition were studied in the temperature range 10–300 K. The first sample shows the characteristic features of a relaxor ferroelectric. The dispersion of the dielectric response observed in the vicinity of 40 K is characterized by two relaxation processes, with broad spectra of relaxation times. It is assumed that the “high-temperature” relaxation process is associated with the dynamics of the elastic domain. Possible mechanisms for the interaction of elastic deformation and polarization are discussed.
{"title":"Relaxor-like behavior of mechanically activated ultrafine SrTiO3","authors":"L. Korotkov, O. Bulgakov, A. I. Bocharov, F. D. Al Jaafari","doi":"10.1080/07315171.2020.1799626","DOIUrl":"https://doi.org/10.1080/07315171.2020.1799626","url":null,"abstract":"Abstract Dielectric properties of nanostructured strontium titanate samples sintered from nanoparticles obtained by grinding of previously synthesized SrTiO3 and nanoparticles obtained by chemical deposition were studied in the temperature range 10–300 K. The first sample shows the characteristic features of a relaxor ferroelectric. The dispersion of the dielectric response observed in the vicinity of 40 K is characterized by two relaxation processes, with broad spectra of relaxation times. It is assumed that the “high-temperature” relaxation process is associated with the dynamics of the elastic domain. Possible mechanisms for the interaction of elastic deformation and polarization are discussed.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"34 1","pages":"1 - 8"},"PeriodicalIF":0.4,"publicationDate":"2020-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77056771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-03DOI: 10.1080/07315171.2019.1668681
Lakhbir Singh, Baljinder Kaur, T. Garg, A. Nautiyal, N. Dabra, J. Hundal
Abstract We investigated switching behavior in PVA based NaNO2-CsNO3 mixed system composite films fabricated at moderate elevated temperature. The switching transients in ‘ceramic-polymer mixed system’ exhibiting best ferroelectric response optimized with CsNO3 mole% 0.09 have been analyzed by two different approaches. Following Landauer approach, an activation field is calculated by measuring the rate at which ‘polarization switching’ takes place; it is calculated by measuring average polarization current under the switching transient over the switching time. In second approach, another kind of activation field is calculated by measuring maximum value of polarization current attained in the transient. The calculation of the activation field in the former approach gives the value of minimum field required to take the sample into its saturated state of polarization during the life time of the experiment whereas the one calculated from later approach helps to find the activation field which is just sufficient to initiate the state of polarization reversal.
{"title":"Switching related activation field for polarization-reversal and for polarization-saturation in PVA based NaNO2–CsNO3 mixed system composite films fabricated at moderate elevated temperature","authors":"Lakhbir Singh, Baljinder Kaur, T. Garg, A. Nautiyal, N. Dabra, J. Hundal","doi":"10.1080/07315171.2019.1668681","DOIUrl":"https://doi.org/10.1080/07315171.2019.1668681","url":null,"abstract":"Abstract We investigated switching behavior in PVA based NaNO2-CsNO3 mixed system composite films fabricated at moderate elevated temperature. The switching transients in ‘ceramic-polymer mixed system’ exhibiting best ferroelectric response optimized with CsNO3 mole% 0.09 have been analyzed by two different approaches. Following Landauer approach, an activation field is calculated by measuring the rate at which ‘polarization switching’ takes place; it is calculated by measuring average polarization current under the switching transient over the switching time. In second approach, another kind of activation field is calculated by measuring maximum value of polarization current attained in the transient. The calculation of the activation field in the former approach gives the value of minimum field required to take the sample into its saturated state of polarization during the life time of the experiment whereas the one calculated from later approach helps to find the activation field which is just sufficient to initiate the state of polarization reversal.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"39 1","pages":"73 - 81"},"PeriodicalIF":0.4,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78517986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-03DOI: 10.1080/07315171.2019.1668683
S. Qu, Qi Zhao, Keyu Zheng, R. K. Pan, Lei Zhang, Zhi Zhong, W. Cao
Abstract Energy storage is one of the major applications of antiferroelectrics due to their large energy releasing density and stronger releasing power. Theoretic researches demonstrate following results. An antiferroelectric state exists above Curie temperature. When temperature is higher than this interim antiferroelectric state, an energy storage peak appears with extremly low discharging current and without irrecoverable energy; when temperature is slightly low than the Curie temperature, a sharp discharging current appears at EFE-AFE; when temperature is much lower than the Curie temperature, a broad discharging current peak (about 40% of the sharp one in height) will appear at certain temperature.
{"title":"Theoretic research on recoverable energy release in antiferroelectrics","authors":"S. Qu, Qi Zhao, Keyu Zheng, R. K. Pan, Lei Zhang, Zhi Zhong, W. Cao","doi":"10.1080/07315171.2019.1668683","DOIUrl":"https://doi.org/10.1080/07315171.2019.1668683","url":null,"abstract":"Abstract Energy storage is one of the major applications of antiferroelectrics due to their large energy releasing density and stronger releasing power. Theoretic researches demonstrate following results. An antiferroelectric state exists above Curie temperature. When temperature is higher than this interim antiferroelectric state, an energy storage peak appears with extremly low discharging current and without irrecoverable energy; when temperature is slightly low than the Curie temperature, a sharp discharging current appears at EFE-AFE; when temperature is much lower than the Curie temperature, a broad discharging current peak (about 40% of the sharp one in height) will appear at certain temperature.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"101 1","pages":"90 - 98"},"PeriodicalIF":0.4,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74757621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-03DOI: 10.1080/07315171.2019.1570767
M. V. Takarkhede, S. Band
Abstract 0.6PMN-0.4PZN solid solution ceramic was synthesized employing two stage columbite route using sintering temperature range 1000–1170 °C for calcination temperature 800 °C and 850 °C, respectively. XRD and SEM characterization revealed single perovskite phase formation in ceramic between 1050 °C to 1100 °C. The highest density upto 94% was achieved for the composition under study. The excellent dielectric properties were obtained at lower sintering temperature 1000–1100 °C. Ceramics sintered between 1000 °C–1100 °C exhibit εmax≈14000 and 24000 at 1 kHz with Tc = 51–48 °C which is near room temperature. A good correlation was obtained between dielectric properties with structure, microstructure and density. The TCC values within the limit of Z5U capacitor specification reflect ceramics of composition 0.6PMN-0.4PZN is a potential candidate for MLC.
{"title":"Large dielectric response of 0.6PMN-0.4PZN relaxor ferroelectric ceramic for multilayer capacitors","authors":"M. V. Takarkhede, S. Band","doi":"10.1080/07315171.2019.1570767","DOIUrl":"https://doi.org/10.1080/07315171.2019.1570767","url":null,"abstract":"Abstract 0.6PMN-0.4PZN solid solution ceramic was synthesized employing two stage columbite route using sintering temperature range 1000–1170 °C for calcination temperature 800 °C and 850 °C, respectively. XRD and SEM characterization revealed single perovskite phase formation in ceramic between 1050 °C to 1100 °C. The highest density upto 94% was achieved for the composition under study. The excellent dielectric properties were obtained at lower sintering temperature 1000–1100 °C. Ceramics sintered between 1000 °C–1100 °C exhibit εmax≈14000 and 24000 at 1 kHz with Tc = 51–48 °C which is near room temperature. A good correlation was obtained between dielectric properties with structure, microstructure and density. The TCC values within the limit of Z5U capacitor specification reflect ceramics of composition 0.6PMN-0.4PZN is a potential candidate for MLC.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"18 1","pages":"111 - 123"},"PeriodicalIF":0.4,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75740422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-03DOI: 10.1080/07315171.2019.1668680
W. Cao, Y. Yue, S. Qu, Keyu Zheng, R. K. Pan, Y. Qi, Lei Zhang
Abstract Antiferroelectric double loops and double dielectric peaks occurred at an electric field circle synchronously are confirmed theretically by solving the kittel’s function with the idea of different responses of dipoles to applied electric field (E) in E-direction and anti-E-direction in antiferroelectrics. By solving problem of inversion of dipoles to ferroelectric phase controlled by thermodynamic parameters and the antiferroelectric coupling coefficient in antiferroelectric phase, the numerically simulated results exhibit that antiferroelectric phase can transform to ferroelectric phase with two approaches: decrease in temperature to a critical temperature, and increase in parameter α0. The results are well coincident with experimental results.
{"title":"Mechanism of double-loop and double-dielectric-peak in antiferroelectrics","authors":"W. Cao, Y. Yue, S. Qu, Keyu Zheng, R. K. Pan, Y. Qi, Lei Zhang","doi":"10.1080/07315171.2019.1668680","DOIUrl":"https://doi.org/10.1080/07315171.2019.1668680","url":null,"abstract":"Abstract Antiferroelectric double loops and double dielectric peaks occurred at an electric field circle synchronously are confirmed theretically by solving the kittel’s function with the idea of different responses of dipoles to applied electric field (E) in E-direction and anti-E-direction in antiferroelectrics. By solving problem of inversion of dipoles to ferroelectric phase controlled by thermodynamic parameters and the antiferroelectric coupling coefficient in antiferroelectric phase, the numerically simulated results exhibit that antiferroelectric phase can transform to ferroelectric phase with two approaches: decrease in temperature to a critical temperature, and increase in parameter α0. The results are well coincident with experimental results.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"69 1","pages":"65 - 72"},"PeriodicalIF":0.4,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85620354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-03DOI: 10.1080/07315171.2019.1668682
R. K. Jha, P. Singh, M. Goswami, B. R. Singh
Abstract Sr0.8Bi2.2Ta2O9 (SBT) ferroelectric and HfO2 dielectric layers were successively deposited onto the p-type (100) Si substrate via RF sputtering. Metal-Ferroelectric-Insulator-Silicon (MFIS) capacitors were fabricated with 200 nm SBT and 10 nm HfO2 film shows the improved memory window of 1.811 V as compared to the 1.27 V in Metal-Ferroelectric-Silicon (MFS) structures. Improvement in leakage current and breakdown voltage was also observed in the MFIS structures as compared to the MFS structures. Degradation of ferroelectric polarization was not pronounced even after applying 8 × 1012 bipolar cycles in MF(200nm)I(10nm)S structures and the device shows significant data retention time of more than 2.5 hours.
{"title":"Integration of Sr0.8Bi2.2Ta2O9/HfO2 ferroelectric/dielectric composite film on Si substrate for nonvolatile memory applications","authors":"R. K. Jha, P. Singh, M. Goswami, B. R. Singh","doi":"10.1080/07315171.2019.1668682","DOIUrl":"https://doi.org/10.1080/07315171.2019.1668682","url":null,"abstract":"Abstract Sr0.8Bi2.2Ta2O9 (SBT) ferroelectric and HfO2 dielectric layers were successively deposited onto the p-type (100) Si substrate via RF sputtering. Metal-Ferroelectric-Insulator-Silicon (MFIS) capacitors were fabricated with 200 nm SBT and 10 nm HfO2 film shows the improved memory window of 1.811 V as compared to the 1.27 V in Metal-Ferroelectric-Silicon (MFS) structures. Improvement in leakage current and breakdown voltage was also observed in the MFIS structures as compared to the MFS structures. Degradation of ferroelectric polarization was not pronounced even after applying 8 × 1012 bipolar cycles in MF(200nm)I(10nm)S structures and the device shows significant data retention time of more than 2.5 hours.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":"1 1","pages":"82 - 89"},"PeriodicalIF":0.4,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80520363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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