A micro-axicon was designed and fixed at the end of single core fiber to extend its light transmission distance. The effectiveness of the micro-axicon was verified through simulation and experiment. Simulation and experimental results indicated that compared to a flat end, the divergence angle of effluent light could be reduced from 4.1° to 0.47°, and an increase of 80μm could be achieved using the micro-axicon fixed at fiber end in the light transmission distance of single core fiber. The stability of light beam was improved by 97% using the micro-axicon. It was therefore concluded the micro-axicon fixed at the fiber end was effective in extending the light transmission distance of single core fiber.
{"title":"Extension of light transmission distance of single core fiber with a micro axicon fixed at fiber end","authors":"Yuanzheng Chen, Tong Zhou, Jiwen Cui, Jiubin Tan","doi":"10.1117/12.2084986","DOIUrl":"https://doi.org/10.1117/12.2084986","url":null,"abstract":"A micro-axicon was designed and fixed at the end of single core fiber to extend its light transmission distance. The effectiveness of the micro-axicon was verified through simulation and experiment. Simulation and experimental results indicated that compared to a flat end, the divergence angle of effluent light could be reduced from 4.1° to 0.47°, and an increase of 80μm could be achieved using the micro-axicon fixed at fiber end in the light transmission distance of single core fiber. The stability of light beam was improved by 97% using the micro-axicon. It was therefore concluded the micro-axicon fixed at the fiber end was effective in extending the light transmission distance of single core fiber.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128205638","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 new linear dynamic model of a six-spherical-prismatic-spherical (SPS) Stewart platform with the base excitation was formulated via Kane’s method. In order to satisfy the practical situation, the uncertainties of mass center location, stiffness and damping were concerned. Then a robust μ-synthesis controller was developed by applying D-K iteration to attenuate the base excitation. Comparisons were conducted by analyzing the responses of the open and closed loops in the frequency and time domain. Simulation results indicated that the proposed robust controller is of fine properties and good robustness, which laid a sound foundation of active micro-vibration control of a satellite.
{"title":"Modeling and active vibration control of six-DOF manipulator through μ-synthesis with parameter uncertainties","authors":"Kaiping Yu, Ying Wu","doi":"10.1117/12.2180664","DOIUrl":"https://doi.org/10.1117/12.2180664","url":null,"abstract":"A new linear dynamic model of a six-spherical-prismatic-spherical (SPS) Stewart platform with the base excitation was formulated via Kane’s method. In order to satisfy the practical situation, the uncertainties of mass center location, stiffness and damping were concerned. Then a robust μ-synthesis controller was developed by applying D-K iteration to attenuate the base excitation. Comparisons were conducted by analyzing the responses of the open and closed loops in the frequency and time domain. Simulation results indicated that the proposed robust controller is of fine properties and good robustness, which laid a sound foundation of active micro-vibration control of a satellite.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122327034","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 double-grating diffraction interferometric stylus probing transducer consisting of a cylindrical grating and a planar grating has been presented to transform the surface profile information to electrical signals. The transducer has the merit of compact construction and high resolution. The relationship between the electrical signals and the displacement of the cylindrical grating is briefly reviewed. The existence of the cylindrical grating brings angle and position deviation, and the deviation will affect the interference of the diffracted beams. To ensure the interference of the diffracted beams, the relationships between the angle deviation, the position deviation, and the radius of curvature of the cylindrical grating are analyzed. The analysis shows that the diffracted beams will interfere normally when suitable radius of curvature of the cylindrical grating and suitable distance between the two gratings are adopted, thus the profile information can be obtained.
{"title":"Double-grating diffraction interferometric stylus probing system for surface profiling and roughness measurement","authors":"Peipei Wei, Zhengang Lu, Lihua Liu","doi":"10.1117/12.2180826","DOIUrl":"https://doi.org/10.1117/12.2180826","url":null,"abstract":"A double-grating diffraction interferometric stylus probing transducer consisting of a cylindrical grating and a planar grating has been presented to transform the surface profile information to electrical signals. The transducer has the merit of compact construction and high resolution. The relationship between the electrical signals and the displacement of the cylindrical grating is briefly reviewed. The existence of the cylindrical grating brings angle and position deviation, and the deviation will affect the interference of the diffracted beams. To ensure the interference of the diffracted beams, the relationships between the angle deviation, the position deviation, and the radius of curvature of the cylindrical grating are analyzed. The analysis shows that the diffracted beams will interfere normally when suitable radius of curvature of the cylindrical grating and suitable distance between the two gratings are adopted, thus the profile information can be obtained.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114630424","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}
Bin Xu, Wei Chen, Yubo Huang, Kang‐Xiang Song, Shiping Zhao
A sample-titling strategy is proposed for the correction of the relative slope of microstructures and the scanning stylus during the surface profile measurement of microstructures with steep slopes. The correct surface profile of a measurement sample was reconstructed by data fusion of the probe trace, rotation angles of a sample and the motion of the scanner. Slope prediction and scanner control methods were also proposed to determine the rotation angle of a sample. Simulation was performed using a stylus with a tip of 2 μm and included angle of 90 degrees, and a trapezoid microstructure with a slope of 60 degrees to verify the feasibility of the proposed method. The measurement error of the proposed method is 0.31 μm while that of an existing scanning method is 4.50 μm in the simulation. Simulation results indicated that the proposed method could be used to increase the maximum detectable slope of a stylus profiling system and to reduce slope measurement errors as well.
{"title":"Surface profile measurement of microstructures with steep slopes by sample-titling strategy","authors":"Bin Xu, Wei Chen, Yubo Huang, Kang‐Xiang Song, Shiping Zhao","doi":"10.1117/12.2180891","DOIUrl":"https://doi.org/10.1117/12.2180891","url":null,"abstract":"A sample-titling strategy is proposed for the correction of the relative slope of microstructures and the scanning stylus during the surface profile measurement of microstructures with steep slopes. The correct surface profile of a measurement sample was reconstructed by data fusion of the probe trace, rotation angles of a sample and the motion of the scanner. Slope prediction and scanner control methods were also proposed to determine the rotation angle of a sample. Simulation was performed using a stylus with a tip of 2 μm and included angle of 90 degrees, and a trapezoid microstructure with a slope of 60 degrees to verify the feasibility of the proposed method. The measurement error of the proposed method is 0.31 μm while that of an existing scanning method is 4.50 μm in the simulation. Simulation results indicated that the proposed method could be used to increase the maximum detectable slope of a stylus profiling system and to reduce slope measurement errors as well.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130319600","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}
Ruijun Li, Meng Xiang, K. Fan, Hao Zhou, Jian Feng
A tungsten stylus with a ruby ball tip was screwed into a floating plate, which was supported by four leaf springs. The displacement of the tip caused by the contact force in 3D could be transferred into the tilt or vertical displacement of a plane mirror mounted on the floating plate. A quadrant photo detector (QPD) based two dimensional angle sensor was used to detect the tilt or the vertical displacement of the plane mirror. The structural parameters of the probe are optimized for equal sensitivity and equal stiffness in a displacement range of ±5 μm, and a restricted horizontal size of less than 40 mm. Simulation results indicated that the stiffness was less than 0.6 mN/μm and equal in 3D. Experimental results indicated that the probe could be used to achieve a resolution of 1 nm.
{"title":"Optimal design of a touch trigger probe","authors":"Ruijun Li, Meng Xiang, K. Fan, Hao Zhou, Jian Feng","doi":"10.1117/12.2180866","DOIUrl":"https://doi.org/10.1117/12.2180866","url":null,"abstract":"A tungsten stylus with a ruby ball tip was screwed into a floating plate, which was supported by four leaf springs. The displacement of the tip caused by the contact force in 3D could be transferred into the tilt or vertical displacement of a plane mirror mounted on the floating plate. A quadrant photo detector (QPD) based two dimensional angle sensor was used to detect the tilt or the vertical displacement of the plane mirror. The structural parameters of the probe are optimized for equal sensitivity and equal stiffness in a displacement range of ±5 μm, and a restricted horizontal size of less than 40 mm. Simulation results indicated that the stiffness was less than 0.6 mN/μm and equal in 3D. Experimental results indicated that the probe could be used to achieve a resolution of 1 nm.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134474903","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 reticle stage of lithography is a high precision servo motion platform, which requires using macro movement of linear motor and micro movement of voice coil motor to realize an nm-level positioning precision and tracking. In order to increase the control effect and response speed of macro movement linear motor of reticle stage of lithography, the paper presents an efficient control for linear motor. The method use input shaping technique with Proportional Integral Derivative (PID) controller to realize the high position precision in small stetting time. In the paper we firstly build the linear motor mathematical modeling which is end to velocity loop or position loop. so that we mainly focus on the tracking of speed signal. Then a PID controller is introduced in the system, which is high frequency used in industrial control. Finally, as the need of high positioning precision and small stetting time, we apply input shaping algorithm to solve the problem. The simulation of the system is performed by using MATLAB/Simulation. The evaluation of the method is the performance of input tracking capability.
{"title":"Research on PID controller with input shaping algorithm for linear motor","authors":"Yang Liu, Yue Dong, W. Fan, Zhenxian Fu","doi":"10.1117/12.2182387","DOIUrl":"https://doi.org/10.1117/12.2182387","url":null,"abstract":"The reticle stage of lithography is a high precision servo motion platform, which requires using macro movement of linear motor and micro movement of voice coil motor to realize an nm-level positioning precision and tracking. In order to increase the control effect and response speed of macro movement linear motor of reticle stage of lithography, the paper presents an efficient control for linear motor. The method use input shaping technique with Proportional Integral Derivative (PID) controller to realize the high position precision in small stetting time. In the paper we firstly build the linear motor mathematical modeling which is end to velocity loop or position loop. so that we mainly focus on the tracking of speed signal. Then a PID controller is introduced in the system, which is high frequency used in industrial control. Finally, as the need of high positioning precision and small stetting time, we apply input shaping algorithm to solve the problem. The simulation of the system is performed by using MATLAB/Simulation. The evaluation of the method is the performance of input tracking capability.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132698279","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}
This article describes the design and simulation of a novel multi-functional hinge equipped with a rotary magnetorheological damper for solar array deployment system, which is comprised of a hinge, an angular sensor, a positioning and locking mechanism and a rotary damper. In order to achieve the compact design in structure, some components were reused in different function modules. It’s the first to use magnet-rheological fluid (MRF) to dissipate the energy in solar array deployment system. The main advantage in using MR rotary damper instead of a viscous fluid rotary damper is that the damping force of MR damper can be adjusted according to the external magnetic field environment excited. A mechanic model was built and the structure design was focused on the MR rotary damper, a damping force model of this damper is deduced based on hydromechanics with Bingham plastic constitutive model. A simulation of deployment motion was taken to validate the motion sequence of various components during the unfolding and locking process. It can be obtained that a constant damping coefficient can hardly balance the different performance of solar deployment system, then a simulation of the proposed deployment system equipped with rotary MR damper was carried out. According to the simulation, it can be obtained that the terminal velocity decreased by 75.81% and the deployment time decreased by 72.37% compared with a given constant damping coefficients. Therefore, the proposed new type of rotary damper can reach a compromise with different performance utilizing an on-off control strategy.
{"title":"Multi-functional hinge equipped with a magneto-rheological rotary damper for solar array deployment system","authors":"Mingfu Wen, M. Yu, J. Fu, Zheng-Hong Wu","doi":"10.1117/12.2181839","DOIUrl":"https://doi.org/10.1117/12.2181839","url":null,"abstract":"This article describes the design and simulation of a novel multi-functional hinge equipped with a rotary magnetorheological damper for solar array deployment system, which is comprised of a hinge, an angular sensor, a positioning and locking mechanism and a rotary damper. In order to achieve the compact design in structure, some components were reused in different function modules. It’s the first to use magnet-rheological fluid (MRF) to dissipate the energy in solar array deployment system. The main advantage in using MR rotary damper instead of a viscous fluid rotary damper is that the damping force of MR damper can be adjusted according to the external magnetic field environment excited. A mechanic model was built and the structure design was focused on the MR rotary damper, a damping force model of this damper is deduced based on hydromechanics with Bingham plastic constitutive model. A simulation of deployment motion was taken to validate the motion sequence of various components during the unfolding and locking process. It can be obtained that a constant damping coefficient can hardly balance the different performance of solar deployment system, then a simulation of the proposed deployment system equipped with rotary MR damper was carried out. According to the simulation, it can be obtained that the terminal velocity decreased by 75.81% and the deployment time decreased by 72.37% compared with a given constant damping coefficients. Therefore, the proposed new type of rotary damper can reach a compromise with different performance utilizing an on-off control strategy.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131918932","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}
Abnormal events detection in crowded scenes has been a challenge due to volatility of the definitions for both normality and abnormality, the small number of pixels on the target, appearance ambiguity resulting from the dense packing, and severe inter-object occlusions. A novel framework was proposed for the detection of unusual events in crowded scenes using trajectories produced by moving pedestrians based on an intuition that the motion patterns of usual behaviors are similar to these of group activity, whereas unusual behaviors are not. First, spectral clustering is used to group trajectories with similar spatial patterns. Different trajectory clusters represent different activities. Then, unusual trajectories can be detected using these patterns. Furthermore, behavior of a mobile pedestrian can be defined by comparing its direction with these patterns, such as moving in the opposite direction of the group or traversing the group. Experimental results indicated that the proposed algorithm could be used to reliably locate the abnormal events in crowded scenes.
{"title":"Abnormal events detection in crowded scenes by trajectory cluster","authors":"Shifu Zhou, Zhijiang Zhang, Dan Zeng, Wei Shen","doi":"10.1117/12.2180725","DOIUrl":"https://doi.org/10.1117/12.2180725","url":null,"abstract":"Abnormal events detection in crowded scenes has been a challenge due to volatility of the definitions for both normality and abnormality, the small number of pixels on the target, appearance ambiguity resulting from the dense packing, and severe inter-object occlusions. A novel framework was proposed for the detection of unusual events in crowded scenes using trajectories produced by moving pedestrians based on an intuition that the motion patterns of usual behaviors are similar to these of group activity, whereas unusual behaviors are not. First, spectral clustering is used to group trajectories with similar spatial patterns. Different trajectory clusters represent different activities. Then, unusual trajectories can be detected using these patterns. Furthermore, behavior of a mobile pedestrian can be defined by comparing its direction with these patterns, such as moving in the opposite direction of the group or traversing the group. Experimental results indicated that the proposed algorithm could be used to reliably locate the abnormal events in crowded scenes.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128670406","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}
Uncertainty is the degree of suspicious for correctness or accuracy of measurement results. Parts of the manufacturing error directly affect the structural dynamic characteristics. The propagation of uncertainty in the static measurement from characteristics to the measurement results has been investigated for decades. However, the propagation of manufacture uncertainty to the results of dynamic measurement has been rarely investigated, which is an important issue for the design and tests of structures and equipment. In this paper, the propagation of manufacturing uncertainty to the dynamic measurement is investigated on the basis of modal analysis method. The manufacturing uncertainty here is represented by the tolerance of form and position, which is the difference between actual shape or position and the digital 3D model of geometry shape and position. Tolerance of form and position is an< important indicator to evaluate object geometry size and the relative position in the mechanical design. The uncertainty of the tolerance of form and position is assumed to satisfy Gaussian distribution. The relationship between modal parameters and tolerance is predicted by analyzing transition rules of modal parameters. A series of beams with tolerance of form and position analyzed experiment to verify transitive relation between varied modal parameters in modal analysis and tolerance. The investigation found that the distribution of the uncertainty of the parameters of dynamic measurement, such as the natural frequencies and modal shapes, are not inherently satisfied with Gaussian distribution, although the uncertainty of characteristics are Gaussian distributed, which confirms the difference of uncertainty propagation in the static measurement and dynamic measurement.
{"title":"The propagation of manufacture uncertainty to dynamic measurement","authors":"Jun Wang, Huaxia Deng, Jin Zhang, Liandong Yu","doi":"10.1117/12.2181409","DOIUrl":"https://doi.org/10.1117/12.2181409","url":null,"abstract":"Uncertainty is the degree of suspicious for correctness or accuracy of measurement results. Parts of the manufacturing error directly affect the structural dynamic characteristics. The propagation of uncertainty in the static measurement from characteristics to the measurement results has been investigated for decades. However, the propagation of manufacture uncertainty to the results of dynamic measurement has been rarely investigated, which is an important issue for the design and tests of structures and equipment. In this paper, the propagation of manufacturing uncertainty to the dynamic measurement is investigated on the basis of modal analysis method. The manufacturing uncertainty here is represented by the tolerance of form and position, which is the difference between actual shape or position and the digital 3D model of geometry shape and position. Tolerance of form and position is an< important indicator to evaluate object geometry size and the relative position in the mechanical design. The uncertainty of the tolerance of form and position is assumed to satisfy Gaussian distribution. The relationship between modal parameters and tolerance is predicted by analyzing transition rules of modal parameters. A series of beams with tolerance of form and position analyzed experiment to verify transitive relation between varied modal parameters in modal analysis and tolerance. The investigation found that the distribution of the uncertainty of the parameters of dynamic measurement, such as the natural frequencies and modal shapes, are not inherently satisfied with Gaussian distribution, although the uncertainty of characteristics are Gaussian distributed, which confirms the difference of uncertainty propagation in the static measurement and dynamic measurement.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"21 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125736573","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 spectral confocal sensor was used to measure the centering error for probe of swing arm profilometer (SAP). The feasibility of this technology was proved through simulation and experiment. The final measurement results was also analyzed to evaluate the advantages and disadvantages of this technology.
{"title":"Measurement of centering error for probe of swing arm profilometer using a spectral confocal sensor","authors":"Lin Chen, Hongwei Jing, Zhong-wei Wei, X. Cao","doi":"10.1117/12.2180887","DOIUrl":"https://doi.org/10.1117/12.2180887","url":null,"abstract":"A spectral confocal sensor was used to measure the centering error for probe of swing arm profilometer (SAP). The feasibility of this technology was proved through simulation and experiment. The final measurement results was also analyzed to evaluate the advantages and disadvantages of this technology.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126093386","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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