A cross-shaped piezoelectric motor with length of 43mm and diameter of 11 mm was proposed in this paper. Two third bending modes were used to generate ellipse trajectory at the driving foot located at the vibrator's center. Sixteen pieces of piezoelectric ceramic plates with sizes of 5mm×3mm×1mm were used to excite two third bending modes. Sine and cosine voltages with effective value of 100V at the frequency of 54.696 kHz were applied to the piezoelectric ceramic plates in right and left sides of the vibrator. Symmetrical structure of the motor solved the problem of mode frequency degeneracy. Two excitation methods were put forward to excite two third bending vibrations. And effectiveness of the two excitation methods was compared by the transient analysis with finite element method. Transient analysis results showed that motion trajectories of nodes on the driving feet were three-dimensional and that ellipse motion in the XOY plane was fit to drive the motor, and the new excitation method improves the vibration amplitude in the OX and OY by 2 times and 4 times, respectively compared with the vibration amplitude excited by the traditional excitation method.
{"title":"Design of a cross-shaped piezoelectric motor with single driving foot","authors":"Jun-kao Liu, Dongmei Xu, Yingxiang Liu, Xiu-hua Ni, Weishan Chen","doi":"10.1109/SPAWDA.2015.7364436","DOIUrl":"https://doi.org/10.1109/SPAWDA.2015.7364436","url":null,"abstract":"A cross-shaped piezoelectric motor with length of 43mm and diameter of 11 mm was proposed in this paper. Two third bending modes were used to generate ellipse trajectory at the driving foot located at the vibrator's center. Sixteen pieces of piezoelectric ceramic plates with sizes of 5mm×3mm×1mm were used to excite two third bending modes. Sine and cosine voltages with effective value of 100V at the frequency of 54.696 kHz were applied to the piezoelectric ceramic plates in right and left sides of the vibrator. Symmetrical structure of the motor solved the problem of mode frequency degeneracy. Two excitation methods were put forward to excite two third bending vibrations. And effectiveness of the two excitation methods was compared by the transient analysis with finite element method. Transient analysis results showed that motion trajectories of nodes on the driving feet were three-dimensional and that ellipse motion in the XOY plane was fit to drive the motor, and the new excitation method improves the vibration amplitude in the OX and OY by 2 times and 4 times, respectively compared with the vibration amplitude excited by the traditional excitation method.","PeriodicalId":205914,"journal":{"name":"2015 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications (SPAWDA)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121953432","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 : 2015-12-28DOI: 10.1109/SPAWDA.2015.7364442
Xu Wang, Jun-hui Hu
In this report, we demonstrate an ultrasonic nanowire cutting method, which uses the linear vibration of the tip of a micro tool and the fixing capability of the water molecules between the NW and substrate. The nanowires with a diameter from 50 nm to 400 nm are cut by the needle with the vibration velocity amplitude from 18-220 mm/s at 96.9 kHz. The dependency of the minimum cutting velocity and lower limit of the optimum cutting velocity range on the NW diameter is experimentally clarified. The incision quality is compared with that caused by an elliptical vibration of the micro cutting tool.
{"title":"Ultrasonic cutting of individual silver nanowires by a linearly vibrating micro tool","authors":"Xu Wang, Jun-hui Hu","doi":"10.1109/SPAWDA.2015.7364442","DOIUrl":"https://doi.org/10.1109/SPAWDA.2015.7364442","url":null,"abstract":"In this report, we demonstrate an ultrasonic nanowire cutting method, which uses the linear vibration of the tip of a micro tool and the fixing capability of the water molecules between the NW and substrate. The nanowires with a diameter from 50 nm to 400 nm are cut by the needle with the vibration velocity amplitude from 18-220 mm/s at 96.9 kHz. The dependency of the minimum cutting velocity and lower limit of the optimum cutting velocity range on the NW diameter is experimentally clarified. The incision quality is compared with that caused by an elliptical vibration of the micro cutting tool.","PeriodicalId":205914,"journal":{"name":"2015 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications (SPAWDA)","volume":"56 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131540183","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 : 2015-12-28DOI: 10.1109/SPAWDA.2015.7364439
Xiao-fei Wang, Jun-hui Hu
We show a method of concentrating nanoscale samples in a film of aqueous suspension on a stationary substrate (not in vibration), which employs the acoustic streaming generated by an ultrasonically vibrating needle parallel to and above the stationary substrate. The acoustic streaming eddy on the substrate surface brings nano particles (NPs) to the center of the eddy. Concentrated SiO2 nano particles with a diameter of 250 nm may form one circular spot on the stationary substrate, with a diameter up to 400 μm. The principles of the above phenomena are analyzed and verified by the finite element method.
{"title":"Controlled ultrasonic concentration of nano particles on a nonvibrating substrate","authors":"Xiao-fei Wang, Jun-hui Hu","doi":"10.1109/SPAWDA.2015.7364439","DOIUrl":"https://doi.org/10.1109/SPAWDA.2015.7364439","url":null,"abstract":"We show a method of concentrating nanoscale samples in a film of aqueous suspension on a stationary substrate (not in vibration), which employs the acoustic streaming generated by an ultrasonically vibrating needle parallel to and above the stationary substrate. The acoustic streaming eddy on the substrate surface brings nano particles (NPs) to the center of the eddy. Concentrated SiO2 nano particles with a diameter of 250 nm may form one circular spot on the stationary substrate, with a diameter up to 400 μm. The principles of the above phenomena are analyzed and verified by the finite element method.","PeriodicalId":205914,"journal":{"name":"2015 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications (SPAWDA)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130324953","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 : 2015-12-28DOI: 10.1109/SPAWDA.2015.7364434
Mei-ling Guo, Xue Bai, Jia Li, G. Zhou
The three-dimensional slowness surface method is used to investigate the pure mode axes of single crystal BaTeMo2O9 on the basis of the experimental data. The relationship of the slowness surface and pure mode axes is studied. Under the condition of taking account of the piezoelectric effect, the piezoelectrically stiffened elastic constants are calculated. Pure mode axes of the BaTeMo2O9 crystal are determined and plotted out on the slowness surfaces by software program. The result indicates that Y axis and Z axis are the pure mode axes of single crystal BaTeMo2O9. The validity of the result has been proved by theoretical calculation.
{"title":"Pure mode axes of single crystal BaTeMo2O9","authors":"Mei-ling Guo, Xue Bai, Jia Li, G. Zhou","doi":"10.1109/SPAWDA.2015.7364434","DOIUrl":"https://doi.org/10.1109/SPAWDA.2015.7364434","url":null,"abstract":"The three-dimensional slowness surface method is used to investigate the pure mode axes of single crystal BaTeMo2O9 on the basis of the experimental data. The relationship of the slowness surface and pure mode axes is studied. Under the condition of taking account of the piezoelectric effect, the piezoelectrically stiffened elastic constants are calculated. Pure mode axes of the BaTeMo2O9 crystal are determined and plotted out on the slowness surfaces by software program. The result indicates that Y axis and Z axis are the pure mode axes of single crystal BaTeMo2O9. The validity of the result has been proved by theoretical calculation.","PeriodicalId":205914,"journal":{"name":"2015 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications (SPAWDA)","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133563091","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 : 2015-12-28DOI: 10.1109/SPAWDA.2015.7364470
Jinhui Zhang, Sheng-lin Ma, L. Qin
In this paper, the parameters effect on resonant frequency of MEMS piezoelectric cantilever beam is studied by FEA simulation, which is aimed to provide estimation of the frequency error using simple beam formula for piezoelectric cantilever beam based vibration energy harvester. In the simulation, piezoelectric vibration energy harvester is simplified to a thin silicon cantilever beam with a proof mass attached at the free end; the frequency error (Er) was achieved from the difference of simulation value and the value determined by beam formula, and its three main parameters width to length ratio of cantilever beam, covering area of proof mass, and mass ratio of proof mass to cantilever mass are systematically analyzed with a range of 0.1 to 1, 0.05 to 0.6, 0.5 to 150 respectively; multiple linear regression analysis was used to evaluate these parameters effects. The results show that Er increases with each of these three parameters; the covering area of proof mass has the greatest effect on Er; the range of parameters should be carefully considered to avoid big frequency error using beam equation; the simulation results can be used to guide the design of piezoelectric cantilever beam based vibration energy harvester.
{"title":"Analysis of frequency characteristics of MEMS piezoelectric cantilever beam based energy harvester","authors":"Jinhui Zhang, Sheng-lin Ma, L. Qin","doi":"10.1109/SPAWDA.2015.7364470","DOIUrl":"https://doi.org/10.1109/SPAWDA.2015.7364470","url":null,"abstract":"In this paper, the parameters effect on resonant frequency of MEMS piezoelectric cantilever beam is studied by FEA simulation, which is aimed to provide estimation of the frequency error using simple beam formula for piezoelectric cantilever beam based vibration energy harvester. In the simulation, piezoelectric vibration energy harvester is simplified to a thin silicon cantilever beam with a proof mass attached at the free end; the frequency error (Er) was achieved from the difference of simulation value and the value determined by beam formula, and its three main parameters width to length ratio of cantilever beam, covering area of proof mass, and mass ratio of proof mass to cantilever mass are systematically analyzed with a range of 0.1 to 1, 0.05 to 0.6, 0.5 to 150 respectively; multiple linear regression analysis was used to evaluate these parameters effects. The results show that Er increases with each of these three parameters; the covering area of proof mass has the greatest effect on Er; the range of parameters should be carefully considered to avoid big frequency error using beam equation; the simulation results can be used to guide the design of piezoelectric cantilever beam based vibration energy harvester.","PeriodicalId":205914,"journal":{"name":"2015 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications (SPAWDA)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115965789","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 : 2015-12-28DOI: 10.1109/SPAWDA.2015.7364451
S. Zhgoon, O. Legrani, O. Elmazria, T. Aubert, M. Elhosni, Hamza Mersni, L. Lefevre, S. Hage-Ali
This paper describes the investigation of the potential of packageless structures for acoustic wave sensor applications based on Al2O3/IDT/GaN/Sapphire structure. The finite elements modeling predicts the possibility of acoustically isolated waveguiding layer acoustic wave (WLAW) to propagate inside this structure with very low displacement at the top surface of the topmost Al2O3 layer. This layer serves as a protecting layer against oxidation of internal layers as well as an acoustically isolating layer, providing a mean for packageless packaging of this structure. The modeling results get confirmation in experiments with the precursor IDT/GaN/Sapphire structure thus supporting hopes on the predicted correct operation of the final Al2O3/IDT/GaN/Sapphire structure.
{"title":"Potential of Al2O3/GaN/Sapphire layered structure for high temperature SAW sensors","authors":"S. Zhgoon, O. Legrani, O. Elmazria, T. Aubert, M. Elhosni, Hamza Mersni, L. Lefevre, S. Hage-Ali","doi":"10.1109/SPAWDA.2015.7364451","DOIUrl":"https://doi.org/10.1109/SPAWDA.2015.7364451","url":null,"abstract":"This paper describes the investigation of the potential of packageless structures for acoustic wave sensor applications based on Al2O3/IDT/GaN/Sapphire structure. The finite elements modeling predicts the possibility of acoustically isolated waveguiding layer acoustic wave (WLAW) to propagate inside this structure with very low displacement at the top surface of the topmost Al2O3 layer. This layer serves as a protecting layer against oxidation of internal layers as well as an acoustically isolating layer, providing a mean for packageless packaging of this structure. The modeling results get confirmation in experiments with the precursor IDT/GaN/Sapphire structure thus supporting hopes on the predicted correct operation of the final Al2O3/IDT/GaN/Sapphire structure.","PeriodicalId":205914,"journal":{"name":"2015 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications (SPAWDA)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114692350","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 : 2015-12-28DOI: 10.1109/SPAWDA.2015.7364435
Ji-peng Yan, Yingxiang Liu, S. Shi, Xiu-hua Ni, Huaiyin Xiong
This paper presents a new idea for constructing ring-type linear ultrasonic motor. The stator of proposed motor contains two driving feet, sixteen pieces of piezoelectric ceramic plates and three rings-inner ring, middle ring and outer ring. The proposed ultrasonic motor forms elliptical movements on the driving feet by the superposition of stretching and bending vibration of the metal rings. This paper presents the working principle of proposed motor. By using FEM method, the proposed motor is designed and analyzed. By adjusting the structure parameters, the resonance frequencies of two working modes were tuned to be close. And by transient analysis, the elliptical motion trajectories of nodes on the driving feet are obtained and verify the theoretical feasibility.
{"title":"Working principle and design of a linear ultrasonic motor with ring-type stator","authors":"Ji-peng Yan, Yingxiang Liu, S. Shi, Xiu-hua Ni, Huaiyin Xiong","doi":"10.1109/SPAWDA.2015.7364435","DOIUrl":"https://doi.org/10.1109/SPAWDA.2015.7364435","url":null,"abstract":"This paper presents a new idea for constructing ring-type linear ultrasonic motor. The stator of proposed motor contains two driving feet, sixteen pieces of piezoelectric ceramic plates and three rings-inner ring, middle ring and outer ring. The proposed ultrasonic motor forms elliptical movements on the driving feet by the superposition of stretching and bending vibration of the metal rings. This paper presents the working principle of proposed motor. By using FEM method, the proposed motor is designed and analyzed. By adjusting the structure parameters, the resonance frequencies of two working modes were tuned to be close. And by transient analysis, the elliptical motion trajectories of nodes on the driving feet are obtained and verify the theoretical feasibility.","PeriodicalId":205914,"journal":{"name":"2015 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications (SPAWDA)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116893631","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 electronic structure and optical properties of pure and Mn doped NaNbO3 are investigated employing the first principle method based on the density functional theory. The results indicate that the hybridization of Nb 4d and O 2p states play an important role on the piezoelectricity of NaNbO3. The calculated formation energies show that Mn prefers to built into Na sites. Moreover, Mn doping leads to the redistribution of charge density and a red shift of absorption to visible light region in the absorption edge.
{"title":"First-principles study on the electronic structure and optical properties of Mn-doped NaNbO3","authors":"Shulan Zhou, Xiao-dong Han, Xian Zhao, Xiang-ping Jiang","doi":"10.1109/SPAWDA.2015.7364445","DOIUrl":"https://doi.org/10.1109/SPAWDA.2015.7364445","url":null,"abstract":"The electronic structure and optical properties of pure and Mn doped NaNbO3 are investigated employing the first principle method based on the density functional theory. The results indicate that the hybridization of Nb 4d and O 2p states play an important role on the piezoelectricity of NaNbO3. The calculated formation energies show that Mn prefers to built into Na sites. Moreover, Mn doping leads to the redistribution of charge density and a red shift of absorption to visible light region in the absorption edge.","PeriodicalId":205914,"journal":{"name":"2015 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications (SPAWDA)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115736672","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 : 2015-12-28DOI: 10.1109/SPAWDA.2015.7364459
Haoliang Hu, Wen Wang, S. He, Yong Pan, Caihong Zhang, C. Dong
Accurately measurement and monitor on methane gas (CH4) concentration is an urgent problem to be solved in the purpose of safety and process control in homes, industries and mines. This paper proposed a new surface acoustic wave (SAW) based methane gas sensor, which was coated by a supra-molecular cryptophane A (CrypA). A differential SAW oscillator with excellent frequency stability was performed, and the two-port SAW resonator with low insertion and high Q-value was designed as the feedback element of the oscillator. CrypA was deposited along the SAW propagation path of the sensing device by drop-coating. Fast response and excellent repeatability were observed in methane gas sensing experiment at room temperature (20°C), and the estimated detection limit and measured sensitivity in CH4 dynamic range of 0.2%~5% was evaluated as ~0.05% and ~204Hz/%, respectively.
{"title":"Development of cryptophane A-coated SAW methane gas sensor","authors":"Haoliang Hu, Wen Wang, S. He, Yong Pan, Caihong Zhang, C. Dong","doi":"10.1109/SPAWDA.2015.7364459","DOIUrl":"https://doi.org/10.1109/SPAWDA.2015.7364459","url":null,"abstract":"Accurately measurement and monitor on methane gas (CH4) concentration is an urgent problem to be solved in the purpose of safety and process control in homes, industries and mines. This paper proposed a new surface acoustic wave (SAW) based methane gas sensor, which was coated by a supra-molecular cryptophane A (CrypA). A differential SAW oscillator with excellent frequency stability was performed, and the two-port SAW resonator with low insertion and high Q-value was designed as the feedback element of the oscillator. CrypA was deposited along the SAW propagation path of the sensing device by drop-coating. Fast response and excellent repeatability were observed in methane gas sensing experiment at room temperature (20°C), and the estimated detection limit and measured sensitivity in CH4 dynamic range of 0.2%~5% was evaluated as ~0.05% and ~204Hz/%, respectively.","PeriodicalId":205914,"journal":{"name":"2015 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications (SPAWDA)","volume":"172 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115918108","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 : 2015-12-28DOI: 10.1109/SPAWDA.2015.7364532
Ying Zhang, Ze-ming Wen, Bin Li, Hao Wu
In order to study the effect of different meso-structural on the acoustic emission (AE) characteristics of the material damage process, Different heat treatment methods were used to get the coarse grain and fine grain of Q345 specimens. And the acoustic emission monitoring of the single axis stretching process was carried out. The results show that: the acoustic emission hits, amplitude and energy can reflect and describe the damage process of specimens. Normal specimens of AE signals were small and low strength, fine specimens compared with normal specimens were more active. Because of the coarse grains, the performance of the specimen was degraded and more prone to damage, so the acoustic emission activity was the most active.
{"title":"Experimental research on acoustic emission characteristics in damage process of different meso-structural specimens","authors":"Ying Zhang, Ze-ming Wen, Bin Li, Hao Wu","doi":"10.1109/SPAWDA.2015.7364532","DOIUrl":"https://doi.org/10.1109/SPAWDA.2015.7364532","url":null,"abstract":"In order to study the effect of different meso-structural on the acoustic emission (AE) characteristics of the material damage process, Different heat treatment methods were used to get the coarse grain and fine grain of Q345 specimens. And the acoustic emission monitoring of the single axis stretching process was carried out. The results show that: the acoustic emission hits, amplitude and energy can reflect and describe the damage process of specimens. Normal specimens of AE signals were small and low strength, fine specimens compared with normal specimens were more active. Because of the coarse grains, the performance of the specimen was degraded and more prone to damage, so the acoustic emission activity was the most active.","PeriodicalId":205914,"journal":{"name":"2015 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications (SPAWDA)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130640851","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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