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Issue 3 ， 2017
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3D reconstruction and optimization of dense bubbly flow based on laser scanning
Abstract：In order to reconstruct the flow regime of dense bubbly flow and to measure flow parameters, a 3D visual measurement system based on laser scanning was constructed. Laser sheet combined with a rotating polygonal prism was employed for optical scanning of the flow field. The slice images of field were recorded by a high-speed camera and the 3D structure was reconstructed by a series of image preprocessing methods. Considering the multiple exposure in slices during the scanning process, an optimization algori Keywords：optical three-dimensional measurement;laser scanning;dense bubbly flow;three-dimensional reconstruction;template convolution;void fraction- 114
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Published：2020-07-07 -
Color analytical reader for procalcitonin colloidal gold test strips
Abstract：The semi-quantitative method of Colloidal gold strip detection by colorimetric principle is widely used in biomedical diagnosis. To achieve quantitative measurement of calcitonin concentration, a CMOS color analytical reader based on raspberry Pi was designed for the acquisition of color characteristics of chromogenic reaction by taking a picture of colloidal gold strip. According to the color characteristics of procalcitonin colloidal gold test strips, the CMOS sensor was corrected by proper white balance Keywords：chrominance analysis;colloidal gold;color space;polynomial regression;procalcitonin;concentrate measurement- 101
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Published：2020-07-07 -
Acquisition and enhancement of remote voice based on laser coherent method
Abstract：An all-fiber Laser Doppler Vibrometer (LDV) based on laser coherent method was investigated to acquire remote and high quality speech signals, combining with the Wiener speech enhancement technology. First, the heterodyne detection theory and the characteristic of fiber devices were introduced and the all-fiber LDV was established experimentally to detect the throat vibration, thus the remote voice was acquired. Whereas the direct acquisition of speech signals was prone to be disturbed by serious noise, the Wiener Filtering based on Minima Controlled Recursive Averaging (MCRA) was used to suppress the noise and improve the voice quality. The results indicate that the comprehensible speech signals within the range of 70 m can be obtained by the LDV. The speech enhancement technology can suppress the noise effectively and the Signal to Noise Ratio (SNR) was increased by 5 dB, thus the speech intelligibility was improved. This system has ability to acquire remote voice with high quality.Keywords：laser Doppler vibrometer;voice acquisition;speech enhancement;Wiener filtering- 99
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Published：2020-07-07 -
Measurement of surface defects of optical elements using digital holography
Abstract：In order to measure the three-dimensional microstructure of surface defects on optical components, a novel measuring system based on digital image-plane holographic microscopy (DIPHM) was proposed and experimentally designed. The optical path of the system was built to record digital holograms, which comprised phase information of object light. The object light wavefront was reconstructed by the angular spectrum algorithm, and the wavefront distortion attributed to the system errors was eliminated via phase Keywords：digital holographic microscopy;three-dimensional microstructure measurement;optical component;surface defects;phase correction- 90
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Published：2020-07-07 -
Development of portable up-conversion photoluminescence strip detector
Abstract：A portable up-conversion fluorescent strip detector was developed to achieve the quantitative analysis of the up-conversion fluorescent strip. The performance of the detector was verified by practical measurements. The up-conversion fluorescent technology and the principle of up-conversion fluorescent strip were introduced firstly. The up-conversion fluorescent strip detector contained two critical components that were optical scanning system and electrical system, enabling the conversion of fluorescence si Keywords：up-conversion fluorescence technique;optical scanning;standard curve fitting;quantitative detection;low power consumption- 89
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Published：2020-07-07 -
Multi-functional fluorescent sensing properties of rhodamine B
Abstract：The influence of physical or chemical factors such as temperature, stress and pH value on the fluorescence spectrum of organic dye rhodamine B (RhB) was researched experimentally. An RhB/H610-resin composite and aqueous solutions of RhB were excited under a diode laser with a wavelength of 405 nm. Then, the fluorescence spectra were obtained. The peak shift and the newly proposed barycenter shift of the emission band were employed to characterize the effect of the environmental factors on the band location. Keywords：fluorescent sensing;rhodamine B;band shift;temperature;stress;pH value- 75
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Published：2020-07-07 -
Enhancement of photovoltaic performance of MoS2/SiO2/Si heterojunction solar cells by film annealing
Abstract：MoS2 thin films were prepared using magnetron sputtering technology and annealed in sulfur surrounding. Then, MoS2/SiO2/Si heterojunction solar cells were fabricated with annealed and unannealed MoS2 thin films respectively. The effects of annealing on the microstructure of MoS2 thin films and the photovoltaic performance of MoS2/SiO2/Si heterojunction solar cells were investigated. Compared with the unannealed MoS2 thin film, the full width at half maximum (FWHM) of Raman peaks of the annealed MoS2 thin fi Keywords：solar cells;MoS2 thin film;annealing;photovoltaic performances- 85
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Published：2020-07-07 -
Design and implementation of Placido disk and projection lighting system for corneal topography
Abstract：In order to detect the cornel surface topography, a projection lighting system of corneal topography was designed based on Placido disk. Firstly, LED backlight was designed according to the visual spectral luminous efficiency of human eyes, the spectral response curve of CCD element and requirements for illumination and uniformity of the light source opposite to the instrument. Secondly, based on detection principles of corneal topography, the advantages and disadvantages of spherical Placido disk were comp Keywords：corneal topography;projection lighting system;Placido disk;LED backlight- 131
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Published：2020-07-07 -
Terahertz digital holographic imaging of biological tissues
Abstract：Terahertz (THz) radiation has low photon energy and high transmissivity and is sensitive to polar materials such as hydrone. Thus, THz digital holographic imaging method has the capacity to acquire biological tissue information rapidly and correctly. Herein, tissue slices of pork and mutton were measured with THz digital holographic imaging system. The experimental images were optimized with method of Fresnel diffraction and the amplitude image of 0.9 THz component was selected for analysis. 0.9 THz absorba Keywords：digital holographic imaging;terahertz imaging;biological tissues;absorbance- 74
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Published：2020-07-07 -
Detection of wheel-set size of rail vehicle using double 2D laser displacement sensors based on point cloud data registration in frequency domain
Abstract：Detection method for train wheel set was proposed based on binocular and double-line structured light for solving the problem that rim and tread of the whole wheel can not be detected due to the limited measurement scope and shield of single-line structured light and other relevant reasons. Two groups of line structured sensor were employed in the measurement and data aquisition. Each group contained two laser displacement sensors. Point cloud matrix was restored with point cloud data on section in the proc Keywords：non-contact measurement;line structured light;wheel-set detection;point cloud data registration in the frequency domain;couple 2D laser- 71
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Published：2020-07-07 -
Extinction characteristics and resonant wavelength of spherical gold nanoparticles in different ambient mediums
Abstract：In order to study extinction characteristic of spherical Au nanoparticles and the relation between resonance wavelength and ambient refractive index, the extinction spectra of spherical Au nanoparticles in diameters of 20, 40, 60 and 80 nm in mediums with different refractive indexes were calculated with Mie theory. The absorbance of Au nanoparticles in the four particle sizes was measured in sweet water with different concentrations experimentally to obtain relation between refractive index of medium in sw Keywords：nanoparticles;scattering;extinction method;absorbance;dispersion- 127
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Published：2020-07-07 -
Ascertainment of operating posture of KDP crystal supporting system
Abstract：With the aim to investigate optimum operating postures of the supporting system of a KDP crystal, the influence of operating posture on the gravity-induced distortion of the supporting system, as well as the deflection of the KDP crystal and the incident angle change of the laser beam due to the distortion were studied. A concept of key stiffness component was proposed to theoretically analyze the gravity-induced distortion of the supporting system on the occasion of various operating postures. Using the fi Keywords：Inertial Confinement Fusion (ICF);KDP crystal;supporting system;operating posture;key stiffness component;deformation- 94
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Published：2020-07-07 -
Design of mirror subassembly in CO2 sounder
Abstract：To lower the impact of thermal deformation due to gravity, mechanical test, launching environment and linear expansion coefficient difference of the material on mirror surface of the CO2 sounder, an analysis was conducted in material selection, structural design and cooperation mode of the mirror subassembly. In the analysis, SiC material was adopted for mirror making, and light weight design was carried out in the mirror body through finite element analysis based on ring-shaped support mode of the mirror; Keywords：light weighted mirror;light weight;flexible support structure;mechanical test- 64
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Published：2020-07-07 -
Research on precision temperature control of laser diode based on the novel fuzzy-PID control unit
Abstract：To improve the impact of temperature fluctuation on performance of diode laser used for optical communication, a high-precision temperature control system by tracking error based on 3D linguistic variable was designed. To lower the system cost, at the same time, a temperature acquisition system was also designed under the help of operational amplifier AD620 and OP07, and least square method was used to fit the temperature data, thus establishing a temperature-resistance relationship model to predict the tem Keywords：optical communication;laser diode;fuzzy PID;temperature control- 95
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Published：2020-07-07 -
Structure optimization based sensitivity improving method forhigh order mode multi-stepped cantilever mass sensor
Abstract：High sensitivity serves as the key indicator for micro-mass sensor to accurately detect substances such as bacteria, virus and gases etc. In spite of the fact that the detection sensitivity can be improved by vibration of miniaturized high order mode micro-cantilever, the micro-size effect, at the same time, lowers anti-jamming capability of the sensor. Hence, how to improve the sensitivity of high-order mode sensor under special size constraint has been leading edge problem for sensor design. In this paper Keywords：micro mass sensor;higher-order mode;sensitivity;resonance;structural optimization- 102
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Published：2020-07-07 -
Electrostatic field assisted micro imprint lithography technology
Abstract：In this paper, a new type of micro imprint lithography assisted by electrostatic field was introduced, and an in-depth theoretical research was conducted on its technological process. First, numerical simulation software (COMSOLTM Multiphysics) was adopted to establish a transient simulation model for electrostatic filed assisted imprint lithography and discussed the evolution process of micro structure in different time domains. Then a detailed analysis was conducted on the qualitative relationship between Keywords：electrostatic field;imprint;micro-nanostructures;two-phase flow- 73
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Published：2020-07-07 -
Influence of pump-chamber height on bubble retention in piezoelectric micro-pump
Abstract：Since bubble retention may cause serious damage to output performance of piezoelectric micro-pump, properly reducing bubble retention can effectively improve stability and reliability of the piezoelectric pump system. Pump chamber is the main area for bubble retention and an important element determining the output performance, so change in the chamber height will have significant influence on bubble retention. In this paper, a mathematic model was established based on bubble pressure drop and output pressu Keywords：piezoelectric micro-pump;chamber height;bubble retention;pressure drop- 74
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Published：2020-07-07 -
Multi-physics analysis and rotor loss optimization of high-speed magnetic suspension PM machine
Abstract：To improve the overall performance of high-speed magnetic suspension PM machine and obtain the optimal design parameters, an electromagnetic filed, rotor dynamics and rotor strength analysis was conducted on a magnetic suspension machine (30 kW, 48 000 rpm), and a size optimization method based on such multi-physics analysis was put forward. Used ANSYS and ANSOFT to carry out modeling and finite element analysis on the motor, and then completed the integrated optimization designed by adopting the ISIGHT sof Keywords：electromagnetic analysis;multi-physics analysis;high-speed machine;PM machine;FEM- 92
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Published：2020-07-07 -
Fabrication of paper-based RFID tag antennas using jet printing and chemical deposition
Abstract：Considering the problems of RFID (Radio Frequency Identification) tag antennas, including high manufacturing cost and complicated process, a method for fabrication of half wave dipole antennas combining 3D micro-droplet jet printing with chemical reaction deposition was put forward. Method: a constructed double nozzle pneumatic micro-droplet ejection device was used to carry out an experimental research on micro-droplet consistency of silver nitrate and ascorbic acid produced under the required ejection con Keywords：micro-droplet ejection;chemical deposition;resistivity;RFID tag antennas- 112
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Published：2020-07-07 -
Design and optimization of carbon fiber framework for space camera
Abstract：In this paper, a CFC framework applied to light-small space camera was designed. Selected, through comparison, the M40J carbon fiber composite with excellent structural performance and processing property to complete structural design of the camera framework based on spatial distribution characteristics of each optical element in the optical system, and then used TC4 embedded parts to solve the problem of low interface accuracy of CFC framework; carried out regional division in the CFC framework, and then c Keywords：framework of space camera;carbon fiber composite;integrated optimization;combined optimization strategy- 115
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Published：2020-07-07 -
The research of floating-point codingimproved genetic algorithmin flatnesserror evaluation
Abstract：With rapid development of intelligent manufacturing system, using Meta heuristic method to quickly and accurately calculate the flatness error is of great practical significance. To further improve the accuracy of flatness error calculation, an improved genetic algorithm based on floating-point coding was studied. In this method, the simulated annealing idea was introduced and a mathematic model for minimum zone method was established based on crossover and variation of the original genetic algorithm; and t Keywords：genetic algorithm;annealing algorithm;minimum zone;flatness error evaluation- 82
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Published：2020-07-07 -
Measurement method of initial position and attitude alignment error for three-axis simulator
Abstract：Three-axis intersecting point of horizontal three-axis flight simulator used for radar simulation experiment shall be homocentric with spherical center of the RF array simulation system, and initial attitude of the simulator shall meet the requirements to reduce the radar simulation error. To achieve accurate position and attitude alignment of the simulator, an alignment method which can compensate for plumb error in vertical axis of the theodolite and the initial angular error in the pitch axis was put for Keywords：three-axis flight simulator;the position and attitude alignment;theodolite;least square method;iterative algorithm- 84
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Published：2020-07-07 -
Super-harmonic resonance experiment about bolt connected cantilever beam
Abstract：A single bolt connection cantilever model is used to analyze the difference of vibrational property due to bolt-joint which is widely used in optoelectronic devices. The phenomenon of super-harmonic resonance due to bolt joint connection is verified using the shaker experiment combined with the signal acquisition equipment. In the case that the torque incerease, the resonance frequency of the model increase first and then decrease. The first resonance frequency decrease when the excitation amplitude decreas Keywords：nonlinear vibration;harmonic response;bolt joint- 92
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Published：2020-07-07 -
Lighting model construction and haze removal for nighttime image
Abstract：Nighttime haze images degrade seriously and artificial light sources cause uneven atmospheric light. Aimed at those problems, this paper introduced a kind of lighting model applicable to nighttime haze image and realizes nighttime image dehazing. The model mainly consisted of two parameters of atmospheric light and transmission, of which space changed with change of local image content. Firstly, the above parameters were initially estimated based on information loss constraint theory and then refinement was Keywords：nighttime image;image dehazing;lighting model;information loss constraint;fast guide filter- 98
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Published：2020-07-07 -
Improvements of image haze removal algorithm and its subjective and objective performance evaluation
Abstract：In this paper, a study was conducted in the image haze removal to improve the subjective quality of images distorted due to haze. First, the haze removal algorithm based on dark channel prior and atmospheric scattering model was improved, and a new method for calculation of the sky area and determination of the transmittance threshold was designed; then the distortion of such algorithm was further lowered by enhancing the image contrast and adjusting the brightness; finally, mathematical statistic method was used to compare the performance of each relevant algorithm by adding haze to the image, with subjective quality assessment and structural similarity as the objective criterion. The experiment in the existing haze images and the actually shot images indicates that the proposed algorithm can effectively reduce the distortion of images (with the highest assessment scores), thus keeping the haze removed images with relatively high subjective quality (tying first in the overall assessment).Keywords：image haze removal;image distortion;structural similarity index measurement;subjective quality assessment- 87
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Published：2020-07-07 -
Pooling strategy for full-reference IQA via general means
Abstract：In order to design a full-reference objective Image Quality Assessment (IQA) algorithm that consistent with subjective evaluation. Based on local feature extracted according to different algorithms and nonlinear properties of generalized means strategy, two pooling strategies were proposed to promote the ability to evaluate Structural Similarity Image Measurement (SSIM), Gradient Structural Similarity Image Measurement (GSSIM) and Feature Similarity Index (FSIM). Numerical test was conducted in TID2008 and Keywords：image quality assessment;full reference;pooling strategy;general mean- 97
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Published：2020-07-07 -
An image encryption scheme based on quantum chaos and folding algorithm
Abstract：An image encryption system combining quantum chaos with folding algorithm was proposed. The main idea of the proposed algorithm is to make Arnold transform through quantum chaos map and 2D Logistic map respectively, to generate the matrix Qand the matrix E, and the two matrices were made of pseudo random numbers and identical to grayscale image. Then, such matrices were used for two operations on the image and to achieve image encryption, as follows: one was to achieve "folding operation" on image at four d Keywords：quantum chaotic map;logistic map;Arnold transform;folding operation;differential attack- 126
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Published：2020-07-07
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Retinal blood segmentation with adaptive PCNN and matched filter
Abstract：According to the several problems on retinal vessel segmentation caused by many factors such as low contrast of vessels and background in fundus image and the complicated structure of blood vessel, a retinal vessel segmentation method combining the Pulsed Coupled Neural Network (PCNN) which has self-adaptive linking value, with the Gaussian matched filter was proposed in the paper. Firstly, the contrast of the retinal vessel area was effectively enhanced by application of Contrast Limited Adaptive Histogram Keywords：retinal image processing;blood vessels segmentation;Pulse Coupled Neural Network (PCNN);Gaussian matched filter;fast linking- 139
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Published：2020-07-07 -
Method for initial point positioning of micro butt welding seam
Abstract：A vision based method for initial point positioning of micro butt welding seam was studied in order to automatically position and weld the welding seam for the welding-robot. The method could be divided into two steps as follows. Firstly, the images of the workpiece at different scale and rotation angle were obtained and a typical template matching library was established, and then the initial point location area of the weld was extracted by using the template matching method. Secondly, the Shi-Tomasi algor Keywords：Initial point of welding seam;normalized correlation coefficient;template library;sub pixel;Shi-Tomasi corner detection- 97
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Published：2020-07-07 -
Salient detection via local and global feature
Abstract：Due to the most of existing salient detection methods have some disadvantages on using background seeds and local area contrast salient detection model, a visual saliency detection algorithm named salient detection, which combines local feature and global feature, was proposed. After image segmentation, the algorithm firstly applied a background image created by multi-feature methods and a foreground saliency image created by foreground area contrast method, then, the fusion results was optimized by using G Keywords：multiple feature;salient detection;gaussian filter;local feature;global feature- 67
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Published：2020-07-07 -
A distributed face recognition method and performance optimization
Abstract：Since the scale of video to be monitored and processed by face recognition system has been increasing, the traditional centralized face recognition methods are insufficient in time efficiency and scalability and no longer able to meet the needs of large scale and real-time face recognition. Aimed at such technical bottleneck, a distributed face recognition method was proposed. The model consisted of several agents and one server, in which the agent was able to detect, trace and extract features of pedestria Keywords：face recognition;distributed;agent;load balance;performance optimization- 86
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Published：2020-07-07 -
An easy and high-precision camera calibration method based on planar five points
Abstract：A simpler 5-point calibration algorithm was proposed to further improve the accuracy of camera parameter and simplify the calibration process, on the basis of Zhang Zhengyou's plane calibration algorithm. In this method, a rectangle was used to serve as a calibration template and the four angular points and central point were selected as the points to be matched. All internal and external parameters could be solved with only 10 (10-20 all were ok) images shot in different angles. First, to decrease the infl Keywords：camera calibration;rectangle;homography;normalization;global optimization- 106
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Published：2020-07-07 -
Image retrieval method based on image principal part detection
Abstract：Aimed at the problem-poor result of image retrieval arising from the complexity of image background, a kind of image retrieval method combined with subject detection was put forward. This method has initially trained the deep Convolutional Neural Network (CNN) model used in object detection and used the model detection well trained to inquiry the object class, class probability and the coordinate and feature of region where it was placed in the image. After the image subject estimated in accordance with the Keywords：deep learning;feature extract;image retrieval;cosine distance- 106
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Published：2020-07-07 -
Action recognition model construction based on multi-scale deep convolution neural network
Abstract：In order to simplify the feature extracting process of Human Activity Recognition (HAR) and improve the generalization of extracted feature, an algorithm based on multi-scale deep convolution neural network was proposed. In this algorithm, the depth video was selected as research object and a parallel CNN (Convolution Neural Network) based deep network was constructed to process coarse global information of the action and fine-grained local information of hand part simultaneously. Experiments were executed on MSRDailyActivity3D dataset. The average recognition accuracy on actions ranging from No.11 to No.16 was 98%, while that on all actions was 60.625%. The experimental results showed that proposed algorithm could take effective recognition for human activity. Almost all of the actions with obvious movements and most of actions with local movements just in hands could be recognized effectively.Keywords：convolution neural network;deep learning;human activity recognition;computer vision;multi-scale- 158
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Published：2020-07-07 -
An improved ViBe algorithm and its application in traffic video processing
Abstract：Moving object detection based on the ViBe algorithm has high processing efficiency, but also some defects under complicated background, for example, it is unable to effectively suppress the ghost shadows and residual shadows of moving objects, vulnerable to noise, which is more apparent in processing of traffic videos. Subject to such deficiencies, the original ViBe algorithm was improved in the paper, as in to make judgment on pixel of ghost shadows and residual shadows by using life length matrix of pixel Keywords：moving object detection;improved ViBe algorithm;video processing;dynamic noise suppression;dynamic threshold- 102
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Published：2020-07-07
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