Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.最新文献

筛选
英文 中文
Rf-magnetron sputtered ferroelectric (Na,K)NbO/sub 3/ films 射频磁控溅射铁电(Na,K)NbO/ sub3 /薄膜
M. Blomqvist, J. Koh, S. Khartsev, A. Grishin
{"title":"Rf-magnetron sputtered ferroelectric (Na,K)NbO/sub 3/ films","authors":"M. Blomqvist, J. Koh, S. Khartsev, A. Grishin","doi":"10.1109/ISAF.2002.1195903","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195903","url":null,"abstract":"Sodium potassium niobate (Na,K)NbO/sub 3/ (NKN) thin films were grown by rf-magnetron sputtering from stoichiometric Na/sub 0.5/K/sub 0.5/NbO/sub 3/ target on LaAlO/sub 3/ (LAO) single crystals and polycrystalline Pt/sub 80/Ir/sub 20/ (PtIr) substrates. NKN films on polycrystalline PtIr substrates were found to be preferentially (00l) oriented while XRD measurements reveal epitaxial quality of NKN/LaAlO/sub 3/ film structures. The ferroelectric state in NKN/PtIr films at room temperature is indicated by polarization loops with polarization as high as 33.4 /spl mu/C/cm/sup 2/ at 700 kV/cm remnant polarization of 9.9 /spl mu/C/cm/sup 2/, and coercive field of 91 kV/cm. I-V characteristics of vertical Au/NKN/PtIr capacitive cells and planar Au/NKN/LAO interdigital capacitors (IDCs) showed very good insulating properties. For NKN IDC the leakage current density was in the order of 30 nA/cm/sup 2/ at 400 kV/cm. Rf dielectric spectroscopy demonstrates low loss, low frequency dispersion, and high voltage tunability both for vertical Au/NKN/PtIr and planar interdigital Au/NKN/LAO capacitors.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133655230","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}
引用次数: 2
Spectral analysis of the electromechanical response of an electroactive material by implementation of Fourier decomposition 利用傅里叶分解实现电活性材料机电响应的频谱分析
C. B. DiAntonio, F. Williams, S. Pilgrim, W. Schulze
{"title":"Spectral analysis of the electromechanical response of an electroactive material by implementation of Fourier decomposition","authors":"C. B. DiAntonio, F. Williams, S. Pilgrim, W. Schulze","doi":"10.1109/ISAF.2002.1195868","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195868","url":null,"abstract":"Implementation of a discrete Fourier transform in conjunction with Devonshire phenomenology allows the electromechanical response of an electroactive material to be fully characterized. The main thrust of this examination is the incorporation of signal decomposition through Fourier analysis to quantify the electro-mechanical and aging properties. Fourier analysis is a well-used technique in the electrical engineering community; however, it has not been applied to materials. The application presented here allows a fresh look at some old phenomena. The spectral representation provides to the underlying physics of the response, i.e., odd harmonics only exist for acentric materials. The ability to create the harmonic spectrum also provides a new way to characterize the effects of aging by revealing subtle changes in the fundamental components that comprise the response. This study shows how Fourier analysis can be applied to a PMN-PT-BT composition to characterize and quantify its electromechanical properties.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133541493","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}
引用次数: 0
A novel MEMS gas sensor with effective combination of high sensitivity and high selectivity 一种新型的MEMS气体传感器,有效地结合了高灵敏度和高选择性
Jia Zhou, Po Li, Song Zhang, Feng Zhou, Yipin Huang, Pengyuan Yang, M. Bao
{"title":"A novel MEMS gas sensor with effective combination of high sensitivity and high selectivity","authors":"Jia Zhou, Po Li, Song Zhang, Feng Zhou, Yipin Huang, Pengyuan Yang, M. Bao","doi":"10.1109/ISAF.2002.1195970","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195970","url":null,"abstract":"A, novel MEMS gas sensor including a PZT thin film layer and a zeolite layer is developed in this paper, which shows effective combination of high sensitivity and high selectivity. Working in resonating mode, the sensor depicts the mass loading due to molecular adsorption of the zeolite by the frequency shift. The relationship between the frequency shift in percent and the concentration of Freon is linear. The minimum mass loading of 3.5 /spl times/ 10/sup -9/ and the sensitivity of -0.0024%/ppm can be determined from the experimental results.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"52 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114132513","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}
引用次数: 12
The effect of annealing temperature on the structure and dielectric properties of (Ba/sub 0.6/Sr/sub 0.4/)TiO/sub 3/ thin films 退火温度对(Ba/sub 0.6/Sr/sub 0.4/)TiO/sub 3/薄膜结构和介电性能的影响
Wenbiao Wu, Dong-wen Peng, Xiaofeng Liang, Z. Meng
{"title":"The effect of annealing temperature on the structure and dielectric properties of (Ba/sub 0.6/Sr/sub 0.4/)TiO/sub 3/ thin films","authors":"Wenbiao Wu, Dong-wen Peng, Xiaofeng Liang, Z. Meng","doi":"10.1109/ISAF.2002.1195907","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195907","url":null,"abstract":"Ba/sub 0.6/Sr/sub 0.4/TiO/sub 3/ thin films were prepared on LaAlO/sub 3/ substrates by sol-gel method. The effects of annealing temperature on the structure and dielectric properties were studied. The microstructure was examined by XRD, SEM and AFM. It was observed that as the annealing temperature increased, films were crystallized in preferential (001) orientation. When annealed at 1100/spl deg/C, the films reveal agglomeration structure, and surface roughness increase. By the measurement, we found that the dielectric properties strongly depend upon annealing temperature. The higher the annealing temperature, the lower dissipation factor and the larger tunability will be. At the same thickness, the tunability of the films annealed at 1100/spl deg/C enhanced to 46.9% (DC bias electric field of 80KV/cm) and the dissipation factor is 0.008 at 1 MHz.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114787369","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}
引用次数: 0
Light modulation properties of novel piezoelectric polymers 新型压电聚合物的光调制特性
Y. Tajitsu
{"title":"Light modulation properties of novel piezoelectric polymers","authors":"Y. Tajitsu","doi":"10.1109/ISAF.2002.1195926","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195926","url":null,"abstract":"Using new techniques, we fabricated two kinds of piezoelectric films, polyurea-5 and poly-L-lactic acid (PLLA) films, in order to investigate their optical properties, of which the higher order structures are simple. Our main findings are as follows. In the case of the PLLA film fabricated by the new technique, giant optical rotatory power and high-speed light modulation exists. On the other hand, in the case of the polyurea-5 film prepared by vapor deposition polymerization, the Pockels coefficient of 0.09 pm/V is obtained. This value is fairly large for polymers.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"205 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114213987","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}
引用次数: 0
Growth and characterisation of piezoelectric PZN-PT 91/9 and PMN-PT 66/34 single crystals for ultrasonic transducers 超声换能器用压电PZN-PT 91/9和PMN-PT 66/34单晶的生长和表征
J. Santailler, B. Ferrand, Dragan Damjanovic, M. Couchaud, P. Dusserre, M. Budimir, S. Mibord, T. Abad
{"title":"Growth and characterisation of piezoelectric PZN-PT 91/9 and PMN-PT 66/34 single crystals for ultrasonic transducers","authors":"J. Santailler, B. Ferrand, Dragan Damjanovic, M. Couchaud, P. Dusserre, M. Budimir, S. Mibord, T. Abad","doi":"10.1109/ISAF.2002.1195963","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195963","url":null,"abstract":"Today, high crystal quality in sufficient size with high crystal growth yield appears to be a key point for a wide dissemination and use in ferroelectrics applications. So, this paper is related to the growth of PZN-PT solid solution compound like (1-x)(PbZn/sub 1/3/Nb/sub 2/3/O/sub 3/)-xPbTiO/sub 3/ and PMN-PT compound like (1-y)(PbMg/sub 1/3/Nb/sub 2/3/O/sub 3/)-yPbTiO/sub 3/. For these two relaxor ferroelectric single crystals promising properties are obtained near the Morphotropic Phase Boundary (MPB) transition which occurred at values closed to x=0.09 for PZN-PT and y=0.34 for PMN-PT. The complex unit cell phase transition combined with an adequate applied electric field, oriented in the pseudo <001>/sub c/ direction; confer to these single crystals some interesting piezoelectric properties. We present some crystal growth results obtained by the Vertical Gradient Freeze-Solution Growth method (VGF-SG) for PZN-PT and by a pseudo Kyropoulos method developed for PMN-PT. The obtained single crystals, up to 120 g for PZN-PT and 160 g for PMN-PT are then analysed in term of composition and structure. Both PMN-PT and PZN-PT perovskite crystals are rhombohedral (@RT), they show a good global homogeneity. Samples demonstrate ferroelectric behaviour, and after polarisation process, dielectric constants up to 48000 near the Curie temperature (Tc /spl sim/174/spl deg/C @ 1kHz) are obtained for PZN-PT and respectively 74000 for PMN-PT (Tc /spl sim/ 142/spl deg/C @ 100 Hz). The piezoelectric coefficient d/sub 33/ gives values up to /spl sim/2200 pC/N (@RT 9 kV/cm) for PZN-PT and 1700 pC/N(@RT) for PMN-PT. A value up to 94% is measured for the electromechanical coupling coefficient k/sub 33/.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114415452","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}
引用次数: 0
La-doped PbZrTiO/sub 3/(PLZT) thin film optical detectors (TOD) for retinal implantation-a "bionic" eye 用于视网膜植入的la掺杂PbZrTiO/sub 3/(PLZT)薄膜光学探测器(TOD) -仿生眼
A. Zomorrodian, N. Wu, S. Wilczak, C. Colbert, A. Ignatiev, C. Garcia
{"title":"La-doped PbZrTiO/sub 3/(PLZT) thin film optical detectors (TOD) for retinal implantation-a \"bionic\" eye","authors":"A. Zomorrodian, N. Wu, S. Wilczak, C. Colbert, A. Ignatiev, C. Garcia","doi":"10.1109/ISAF.2002.1195887","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195887","url":null,"abstract":"A new ceramic optical microdetector has been developed for retinal implant as a direct replacement for damaged retinal photo-detectors in patients with dystrophies such as Retinitis Pigmentosa (RP) and Age-related Macular degeneration (AMD). The thin film optical detector (TOD) is a heterostructure device composed of an atomically ordered La-doped PbZrTiO/sub 3/(PLZT) layer epitaxially grown on an atomically ordered Pt thin film layer. The TOD has an optical response, which in the visible region has a peak at around 550 nm with a sensitivity that overlaps the eye response from 400 nm to 650 nm. The device responsivity in the visible range is at a value of /spl sim/ 1000 V/W. Individual detectors are fabricated by photolithography and etch processing as is common in the microelectronics industry. Detectors 40 /spl mu/m in diameter have been processed and have been integrated with a newly developed polymer carrier layer technique for ease of handling and implantation of microdetector arrays into the eye.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123287424","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}
引用次数: 5
Single-crystal Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.93/Ti/sub 0.07/]O/sub 3/ (PZNT 93/7) for highly reliable ultrasonic transducers 用于高可靠性超声波换能器的单晶Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.93/Ti/sub 0.07/]O/sub 3/ (PZNT 93/7)
K. Harada, Y. Hosono, Y. Yamashita
{"title":"Single-crystal Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.93/Ti/sub 0.07/]O/sub 3/ (PZNT 93/7) for highly reliable ultrasonic transducers","authors":"K. Harada, Y. Hosono, Y. Yamashita","doi":"10.1109/ISAF.2002.1195956","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195956","url":null,"abstract":"Piezoelectric single crystals of Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.93/Ti/sub 0.07/]O/sub 3/ (PZNT 93/7) 40 mm in diameter were grown with PbO flux by the solution Bridgman method. The prerequisites for the growth of PZNT 93/7 single crystals are higher melting temperature, a longer melting time than Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.91/Ti/sub 0.09/]O/sub 3/ (PZNT 91/9), and the addition of ZnO. The pyrochlore pellets of PZNT 93/7 are more stable than those of PZNT 91/9. The Curie temperature is 155-175/spl deg/C and the temperature corresponds to the rhombohedral-tetragonal phase change, T/sub rt/, is higher than 100/spl deg/C for PZNT 93/7 single crystals. T/sub rt/ corresponds to the degradation boundary temperature of the electromechanical coupling coefficient, k/sub 33/, and also of the dielectric constant. The sensitivity degradation of ultrasonic transducers using PZNT 93/7 single crystals can be avoided up to a high temperature of about 100/spl deg/C. Although the piezoelectric properties of single crystals of PZNT 91/9 are excellent, it has become clear that the electromechanical coupling coefficient, k/sub 33/, and other properties degrade drastically above about 80/spl deg/C. Therefore, our results indicate that PZNT 93/7 has good potential for application in the mass production of ultrasonic transducers.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123634773","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}
引用次数: 0
Domains and piezo-image of PZT family thin films PZT族薄膜的畴与压电像
Y. Masuda, K. Kakimoto, H. Kakemoto, K. Watanabe
{"title":"Domains and piezo-image of PZT family thin films","authors":"Y. Masuda, K. Kakimoto, H. Kakemoto, K. Watanabe","doi":"10.1109/ISAF.2002.1195879","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195879","url":null,"abstract":"PZT thin films are promising materials for ferroelectric random access memory (FeRAM) and micro electro-mechanical system (MEMS). For these applications, it is important to clarify the relationship between the motion of ferroelectric domains and their piezoelectric properties. Nanometer-size structure of polarized domains and grains for PLD-derived PZT thin film was investigated by AFM and KFM, when dc voltage was applied to the film through a conductive tip. Topographic and piezoelectric domain images in the film surface clearly showed switchable domains with 100 nm in size.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126860777","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}
引用次数: 0
Preparation and electrical property of /spl beta/-PVDF/PbTiO/sub 3/ thin films /spl β /-PVDF/PbTiO/sub - 3/薄膜的制备及其电学性能
C. Wang, M. Kao, Y. Chen
{"title":"Preparation and electrical property of /spl beta/-PVDF/PbTiO/sub 3/ thin films","authors":"C. Wang, M. Kao, Y. Chen","doi":"10.1109/ISAF.2002.1195898","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195898","url":null,"abstract":"Ferroelectric polymer/ceramic structure thin films were fabricated on Pt/SiO/sub 2//Si substrates using a sol-gel method. The bilayer thin film was composed of polar /spl beta/-phase poly(vinylidene fluoride) (PVDF) and 1 /spl mu/m thickness of polycrystalline lead titanate (PbTiO/sub 3/) thin film. By changing the concentrations of PVDF solutions (0.6/spl sim/1.0 M), various thickness of PVDF thin films (50-580 nm) were obtained, and the effects of various processing parameters on the characteristics of PVDF/PbTiO/sub 3/ thin films were studied. The characteristic of the /spl beta/ phase at infrared spectrum of 511 and 840 cm/sup -1/ can be observed in PVDF film crystallized at 65/spl deg/C for 2 h. With the increase of the PVDF thickness of the PVDF/PbTiO/sub 3/ films, the relative dielectric constant (/spl epsi//sub r/) decreased from 63 to 20 and the leakage current density (J) also decreased from 1.54 /spl times/ 10/sup -6/ to 3.86 /spl times/ 10/sup -7/ A/cm/sup 2/.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126373403","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}
引用次数: 3
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信