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2023 Vol. 44, No. 9 Published: 2023-09-28

	1317	Research on Programmable AC Voltage Ratio Standard
		ZHANG Shu-zhe,LI Rui-lin,LU Qing,CHI Zong-tao,YANG Yan
		DOI: 10.3969/j.issn.1000-1158.2023.09.01
		A broadband programmable AC voltage ratio standard based on the combined voltage divider of a two-stage inductive voltage divider and a multiplying digital-to-analog converter (mDAC) is proposed to achieve high-precision arbitrary AC voltage ratio output within the operating frequency range. The ratio standard adopts the self-locking relay switch to realize the programmable control of the two-stage inductive voltage divider, and uses the injection voltage method to realize the combined voltage division of the mDAC and the two-stage inductive divider. A broadband mDAC ratio error correction method is proposed, which improves the accuracy of the ratio standard by an order of magnitude. A precision comparison measurement system for AC voltage is proposed, and the performance of the ratio standard is tested. The programmable AC voltage ratio standard output ratio resolution is better than 1μV/V, the in-phase error is better than 0.2μV/V in the operating frequency range of 50Hz~10kHz, and the quadrature error is better than 1μrad at 1kHz.
		2023 Vol. 44 (9): 1317-1324 [Abstract] ( 136 ) HTML (1 KB) PDF (641 KB) ( 58 )

	1325	Parameter Identification of Permanent Magnet Synchronous Motor Based on Hybrid Variation RAO Algorithm
		LI Hong-ji,JIAN Xian-zhong,WANG Zu-jian
		DOI: 10.3969/j.issn.1000-1158.2023.09.02
		Aiming at the problem that PMSM parameter identification is prone to fall into local optimum, which leads to low accuracy and slow identification speed, a hybrid Variation RAO algorithm (GCRAO) was proposed to be applied to PMSM parameter identification. According to the distribution characteristics of Gauss and Cauchy functions, the raO-1 algorithm was improved by introducing the strategy of self-selecting the optimal individual variation in three running stages in real time. A permanent magnet synchronous motor model based on vector control (SVPMSM) was built by matlab/Simulink under the dq axis coordinates, and the standard test function test and simulation experiment were carried out. The test results show that the local mining ability and global exploration ability of GCRAO algorithm are improved, which verifies the effectiveness of the improved RAO-1 algorithm. Simulation results show that compared with RAO-1 and PSO algorithms, GCRAO algorithm can identify electromagnetic parameters faster and has better convergence accuracy.
		2023 Vol. 44 (9): 1325-1332 [Abstract] ( 99 ) HTML (1 KB) PDF (610 KB) ( 150 )

	1333	Fabrication of Nb/Al-AlOx/Nb Josephson Junction Films by a Sputtering Process with a Long Target-substrate Distance
		WANG Zhen-yu,ZENG Jiu-sun,GAO He,WANG Shi-jian,XU Da,ZHONG Qing,LI Jin-jin,WANG Xue-shen
		DOI: 10.3969/j.issn.1000-1158.2023.09.03
		The fabrication of high-quality Nb/Al-AlOx/Nb trilayer films is crucial for quantum voltage standard chips and superconducting quantum interference devices based on superconductor-insulator-superconductor (SIS) type Josephson junctions. The effects of sputtering atmosphere and sputtering power on the structure, morphology and electrical properties of Nb and Nb/Al films are investigated for remote target-based distance DC magnetron sputtering process. The Nb film prepared with a Ar flow rate of 20mL/min, 0.53Pa, and 600W shows a stress close to zero pressure, a roughness of only 1.05nm, a superconducting transition temperature of 9.2K, and a residual resistance ratio of 5.33. The roughness of the 10nm Al film on 150nm Nb prepared at 0.53Pa, 450W is only 1.51nm and completely covers the underlying Nb film. The energy gap voltage of the Nb/Al-AlOx/Nb SIS junction prepared by these conditions reaches 2.6mV, indicating that remote sputtering process can achieve high-quality trilayer films required for the SIS junction process.
		2023 Vol. 44 (9): 1333-1338 [Abstract] ( 148 ) HTML (1 KB) PDF (605 KB) ( 331 )

	1339	Fault Diagnosis of Shunt Capacitor Based on Markov Transfer Field Transformation of Vibration Signal
		GAO Zhi,YANG Hai-yun,GONG Yan-chao,MU Yong-bao
		DOI: 10.3969/j.issn.1000-1158.2023.09.04
		Aiming at the four typical defects of shunt capacitor,such as internal defect,contact defect,overlapping defect and oil defect,a fault diagnosis method of shunt capacitor based on Markov transfer field transformation of vibration signal is proposed. Firstly,four typical defect samples are made according to the field conditions,the mechanical vibration signals of the samples under different defects are tested,and the vibration data set is built. Then,the one-dimensional vibration signal is transformed into two-dimensional image based on Markov transfer field transform to improve the visibility of the signal. Finally,the feature Self Extraction and classification of Markov density map are carried out by convolution neural network. The visualization ability of signals under different quantiles is discussed and compared with common diagnosis methods. The results show that the Markov transfer field transformation of the vibration signal improves the visualization ability of the signal,and the deep learning algorithm can extract the signal features more comprehensively. The average recognition accuracy of the proposed method is about 98%,which can better realize the fault diagnosis of shunt capacitor,and is better than other common methods.
		2023 Vol. 44 (9): 1339-1346 [Abstract] ( 88 ) HTML (1 KB) PDF (886 KB) ( 106 )

	1347	Design and Measurement of Weak Current Heating Structure Based on Magnetron Sputtering
		YAN Xiao-yan,LIANG Shi-shuo,LIU Yu-qi,GUO Qi
		DOI: 10.3969/j.issn.1000-1158.2023.09.05
		In high-precision atomic magnetometer, because the temperature of the atomic gas chamber directly affects the polarization of the electron spin of alkali metal, and then affects the sensitivity of the magnetometer, precisely controlling the temperature of the atomic gas chamber is the key to realize the application of high-precision atomic magnetometer. Based on the principle of electric heating and the principle of back-folding magnetic cancellation,the micro weak magnetic electric heating chips with single-layer and double-layer structures are designed and completed through the derivation of Biot-Savart law and simplified model simulation. By measuring the magnetic flux density modes at different distances and different current conditions on the surface of single and double-layer chips,the suppression effect of the single and double-layer coil structure on the magnetic field generated by the current is verified. The double-layer heating chip is about 6.9 times higher than the electric heating remanence suppression characteristics of the folding chip.The magnetic field change rate at 5mm from the chip is only 72.2nT/A.By comparing the heating effect of the same working current at the same time,it can be found that the double-layer has a faster temperature response.
		2023 Vol. 44 (9): 1347-1351 [Abstract] ( 124 ) HTML (1 KB) PDF (536 KB) ( 292 )

	1352	Research on cryocooled programmable Josephson voltage standard and its cryostat
		WANG Zeng-min,LI Hong-hui,LIAO Fu-jian,JIA Zheng-sen,XU Qing,TIAN Zheng-qi,DUAN Mei-mei,WANG Lei
		DOI: 10.3969/j.issn.1000-1158.2023.09.06
		To propose a domestic liquid helium free DC programmable Josephson voltage standard (PJVS) operating on a cryocooler around 10K. The design and structure of the cryogenic system of liquid helium free quantum voltage standard are presented. The structure of NMIJ array at around 10K temperature are analyzed in detail. The experimental results show that the liquid helium free quantum voltage standard cryogenic system can provide stable temperature for NMIJ Josephson junction array, and the measured critical current and the quantum voltage step width meet the requirements of superconducting characteristics of the junction array. The research lays an important foundation for the accurate liquid helium free DC quantum voltage output in the next step.
		2023 Vol. 44 (9): 1352-1359 [Abstract] ( 108 ) HTML (1 KB) PDF (662 KB) ( 325 )

	1360	A Flatness Error Evaluation Method Based on Improved Sparrow Search Algorithm
		JIANG Chun-ying,ZHANG Xi-ran,WANG Yin-chao,TAO Guang-hong,YE Chang-long
		DOI: 10.3969/j.issn.1000-1158.2023.09.07
		Aiming at the shortcomings in the minimum zone evaluation of flatness errors, such as easy to fall into local optimums and low convergence speed and low accuracy, a flatness error evaluation method based on the improved sparrow search algorithm (ISSA) was proposed. Firstly, Kent chaotic sequence was applied to generate initial population instead of traditional Logistic chaotic sequence, which is with better ergodicity and can enhance the global searching ability of the ISSA algorithm. Then, a new opposition-learning strategy based on the optical lens imaging principle was applied to avoid the algorithm failing to jump out of the local optimums. The effectiveness of ISSA was proved by the classic test functions, and the result was better than SSA. Finally, the proposed approach ISSA was used to evaluate flatness errors and compared with the other algorithms cited. The experimental results show that the optimal plane can be calculated in 0.4884s and 0.3705s can be saved by ISSA compared with SSA algorithm, and the calculation accuracy compared with the flatness error evaluation methods using the least square method, genetic algorithm and particle swarm optimization algorithm is reduced by 18.0325μm、2.3325μm、6.1325μm respectively。 Flatness error evaluation method based on ISSA has advantages in optimization efficiency, solution quality and stability, and calculating precision. It is suitable for the evaluation of position measuring instruments such as coordinate measuring machines.
		2023 Vol. 44 (9): 1360-1368 [Abstract] ( 110 ) HTML (1 KB) PDF (599 KB) ( 58 )

	1369	Study on Measurement Uncertainty of Total Station Additive Constant and Multiplication Constant
		ZHANG Zi-da,YANG Wei-fang,JI Xiao-xiao,LI Wen-hui
		DOI: 10.3969/j.issn.1000-1158.2023.09.08
		ISO/IEC 17025 requires that “the laboratory carrying out testing shall evaluate the measurement uncertainty”, but the current total station plus constant and multiplication constant verification process and verification results have no uncertainty analysis and evaluation, and the verification and measurement results lack the description of quantitative parameters. Taking TS06power-2″ total station as an example, the uncertainty transfer method and Monte Carlo method are used to evaluate the uncertainty of the measurement of addition constant and multiplication constant. The research results indicate that the difference between the two evaluation methods in the evaluation results of additive constant and multiplicative constant are 0.04mm and 0.09mm, respectively, and both meet the verification limit requirements, indicating that both evaluation methods are effective and feasible.
		2023 Vol. 44 (9): 1369-1374 [Abstract] ( 110 ) HTML (1 KB) PDF (439 KB) ( 50 )

	1375	Research and Analysis of Automobile Wheel Hub Surface Defect Detection Algorithm based on YOLOv3-spp
		ZHANG Zhen-yu,LIU Yang,LIU Fu-cai
		DOI: 10.3969/j.issn.1000-1158.2023.09.09
		According to the requirements of surface defect detection environment and detection index in the production process of automobile hub, aiming at the problems of low efficiency and low accuracy of traditional manual detection methods, an automatic defect detection method based on YOLOv3-spp (You Only Look Once v3-Spatial Pyramid Pooling Network) network is proposed. In this method, firstly, the defect area is extracted by image slicing, and then the extracted defect image is enhanced to form a data set to train the YOLOv3-spp deep learning network, what's more the hub defects are detected and compared by using different neural networks and data set screening methods. The experimental results show that: On the dataset collected from the industrial site, the trained YOLOv3-spp neural network can accurately locate and identify four types of defects: point-like, linear, oily sludge and pinhole, with an average accuracy of 84.5%, 93.4%, 95.4% and 89.5% respectively. The detection speed of a single image can reach 35ms, meeting the real-time requirements of detection. Furthermore, the detection accuracy is better than two common neural networks: Faster R-CNN(Faster Region-Convolutional Neural Networks) and SSD(Single Shot MultiBox Detector).
		2023 Vol. 44 (9): 1375-1382 [Abstract] ( 140 ) HTML (1 KB) PDF (725 KB) ( 156 )

	1383	Target Tracking Algorithm Based on Normalized Attention Mechanism with Feature Adaptive Fusion
		ZHANG Li-guo,ZHANG Yu-peng,JIN Mei,ZHANG Sheng,GENG Xing-shuo
		DOI: 10.3969/j.issn.1000-1158.2023.09.10
		To solve the difficult problems of image deformation and low resolution in fast moving target tracking. A feature-adaptive fusion target tracking algorithm based on a normalised attention mechanism is proposed based on current siamese networks. Firstly, the less obvious weights are suppressed by a lightweight attention mechanism that imposes a weight sparsity penalty on the attention module. While a path enhancement method is proposed, path strengthening is applied to the last four feature layers of the backbone. Secondly, a plug-in template online update method is proposed in order to capture changes in the appearance of the target during online tracking and improve the robustness of the algorithm. Finally, a regression-enhanced classification method is used to complete the tracking of the target. The experimental results show that the proposed algorithm achieves high success rates of 63.3% and 59.5% on two challenging datasets, OTB100,UAV123, respectively. Also, the algorithm has strong robustness when the illumination changes, the image background is complex and the target is rotated in-plane.
		2023 Vol. 44 (9): 1383-1389 [Abstract] ( 99 ) HTML (1 KB) PDF (659 KB) ( 402 )

	1390	National Measurement Comparison for Verification Ability of Ophthalmometers
		ZHANG Ji-yan,YANG Lei,LIU Wen-li,GAO Ming-liang,CAO Yuan-hang
		DOI: 10.3969/j.issn.1000-1158.2023.09.11
		In order to investigate the accuracy and consistency of measurement values and issued measurement results for ophthalmometers by various laboratories, China National Institute of Metrology, as the pilot laboratory, organized and implemented the national Class A measurement comparison for radius verification ability of ophthalmometer from 2020 to 2021. A total of 33 laboratories participated in this measurement comparison, covering 15 provinces/municipalities directly under the Central Government, and the participating laboratories were highly representative. The comparison results were evaluated by the normalized error En value. With data processing and statistical analysis, the absolute value of En of 33 participated laboratories was between 0 and 0.85, all less than 1. The difference between the measurement results and reference values of each participated laboratory was within reasonable expectations. The results showed that the verification ability of radius of curvature in all participated laboratories met the technical requirements of measurement standards, and effectively ensured the accuracy, consistency and reliability of quantity values of ophthalmometers.
		2023 Vol. 44 (9): 1390-1394 [Abstract] ( 103 ) HTML (1 KB) PDF (552 KB) ( 57 )

	1395	Radiometric Calibration and Field Application of Self-calibrating Infrared Spectrometer
		LING Ling,HAO Xiao-peng,XIE Chen-yu,SUN Yan-dong,SONG Jian,SIMA Rui-heng,ZHOU Jing-jing
		DOI: 10.3969/j.issn.1000-1158.2023.09.12
		To accurately obtain the spectral emissivity and surface temperature of the target site, a self-calibrating Fourier transform infrared spectrometer was developed for the measurement of surface spectral radiance of the outer field and atmospheric radiance of the descending atmosphere. The calibration was carried out in the laboratory. The blackbody was used as the standard radiation source, and radiometric calibration was performed by two-point method and linear multi-point method in the 8～14μm band which is the best for the observation of ground target thermal radiation. Finally, the two-point method can satisfy the requirement of instrument self-calibration. The source of uncertainty in the spectrograph measurement was analyzed, and the synthetic uncertainty is better than 0.22K. A field experiment was carried out, combined with the spectral iterative smoothing temperature and emissivity separation algorithm (ISSTES), the surface temperature and spectral emissivity were separated. By comparing the spectral emissivity obtained with that measured by the multi-channel infrared radiometer in the same field, the measurement accuracy and stability of the self-calibrating infrared spectrometer in the field application are further verified.
		2023 Vol. 44 (9): 1395-1401 [Abstract] ( 98 ) HTML (1 KB) PDF (472 KB) ( 317 )

	1402	Image Reconstruction of Electrical Capacitance Tomography Based on Improved ResNet-18 Network
		ZHANG Li-feng,CHANG En-jian
		DOI: 10.3969/j.issn.1000-1158.2023.09.13
		In order to solve the nonlinear ill-posed inverse problem of electrical capacitance tomography (ECT), the reconstruction method based on a kind of improved ResNet-18 network is presented. The network consists of multiple residual blocks, each of which is grouped and then connected by intra-group residuals to fuse more feature scales. The dataset of flow pattern is constructed by MATLAB simulation experimental platform, and the learning and training of the training set are completed by using the nonlinear mapping ability of the deep residual network. And then, the trained network is evaluated with the test set. After that, static experiment is carried out. Both the results of simulation and static experiments show that the quality of ECT image reconstruction of the presented method is significantly improved and has good generalization ability compared with LBP, Landweber iterative algorithm and unimproved ResNet-18 algorithm.
		2023 Vol. 44 (9): 1402-1408 [Abstract] ( 136 ) HTML (1 KB) PDF (688 KB) ( 350 )

	1409	Research on Modeling Method of Cold Rolling Force Based on LSTM-JITRVM
		SUN Hao,ZHAO Ming-da,LI Jing,WEI Li-xin,HU Zi-yu
		DOI: 10.3969/j.issn.1000-1158.2023.09.14
		In the process of strip cold rolling, the accuracy rolling force directly affects the product quality. In order to further improve the prediction accuracy of rolling force, a rolling force model based on LSTM-JITRVM (long short term memory- just in time relevance vector machine) is proposed. Firstly, the auto-encoding network is used to extract the deep-seated features of the input data. Then the local outlier factor algorithm is used to judge whether the test sample and its neighborhood points belong to the same distribution, and different self-learning regression models are used to fit different distributions. The simulation results show that the prediction accuracy of the model can be controlled within 3%, and the rolling force can be predicted online with high precision.
		2023 Vol. 44 (9): 1409-1416 [Abstract] ( 96 ) HTML (1 KB) PDF (593 KB) ( 224 )

	1417	Laser Interferometry Measurement of Gas Pulse Pressure
		LI Bo,WANG Xia,HUANG Cheng-yu,ZHANG He-yu,ZUO Rui-qi
		DOI: 10.3969/j.issn.1000-1158.2023.09.15
		The non-contact measurement and traceability method of gas dynamic pressure were studied. A device based on laser interferometry for gas pulse pressure measurement was established. The amplitude and pulse width of pulse pressure were calculated by the relationship between optical path and pressure. The dynamic pressure measurement model was established, and the uncertainty of measurement was analyzed.Experimental measurement of gas pulse pressure using laser interferometry was carried out, synchronous measurements using dynamic pressure sensors and laser was conducted. The deviation of the measurement results using laser interferometry is small, which verifies the accuracy of the device measurement. The results showed that the pulse pressure signal generated by the device is stable and reliable. The optical measurement signal has the advantages of real-time, non-contact, traceability and so on. The measurement of the gas pulse pressure can be realized. The relative standard deviation of the measurement is less than 0.8%, and the uncertainty of the measurement result is less than 2% (k=2).
		2023 Vol. 44 (9): 1417-1422 [Abstract] ( 94 ) HTML (1 KB) PDF (522 KB) ( 85 )

	1423	An Improved 1DCNN-GRU for Rolling Bearing Fault Diagnosis
		JIN Hai-long,MA Wu-xu,MENG Zong,SUN Deng-yun,CAO Wei,FAN Feng-jie
		DOI: 10.3969/j.issn.1000-1158.2023.09.16
		To solve the issue that most traditional models of rolling bearing fault diagnosis can not fully exploit the spatial and temporal characteristics of the signals and require lots of expert knowledge, a novel fault diagnosis method based on one-dimensional convolutional neural networks(1DCNN) and gated recurrent neural networks (GRU) was proposed. Firstly, the convolution layers with different convolution kernels were used to maximize the extraction of spatial features in the signal. Secondly, the IReLU was proposed to enhance the feature extraction ability of the network. Then, the stacked GRU was introduced to further extract the temporal features in the output data of the 1DCNN module and complete the fusion of the spatial and temporal features. Finally, the fused features were recognized. The experimental results showed that the fault recognition accuracy of the proposed method is up to 99.96%, and the proposed method has a high identification accuracy and strong generalization performance for datasets under different loads.
		2023 Vol. 44 (9): 1423-1428 [Abstract] ( 112 ) HTML (1 KB) PDF (525 KB) ( 351 )

	1429	Experimental Study on Fitting Sinusoidal Parameter Error Boundaries Resulting From Quantization
		LIANG Zhi-guo
		DOI: 10.3969/j.issn.1000-1158.2023.09.17
		When the sinusoidal waveform parameters legally estimated, the measurement conditions have the error of the fitting parameters to perform the search research. The selected condition variables are the number of A/D bits, the number of signal cycles in sampling sequence, and the sequence length. The error bounds variation versus conditions is performed, and the error bounds of the equipped parameters such as amplitude, frequency, phase, DC offset, and effective bits are obtained with different conditions change. And all of the effects about the number of A/D bits, the waveform cycles contained in the sequence, and the sequence length have been in-depth researched. The error sequence of the fitting parameters has a significant law of the quantified step characteristics as the sequence length change, the variation rules of quantified ladder width and height are given. For the same number of signal cycles in sampling sequence, the variation of each fitting parameter error as the quantum step sequence number m varies on 1/m² regularity; for the quantization error step number m is constant, both the fit frequency error and the fitting phase error are varied according the signal cycles N in sampling sequence as of 1/N₂ regularity. The errors of fitting amplitude, the fitting DC offset, and the effective bits have the same regularity, they are all will decrease as the number of signal cycles N increase. These results can be used to fit the error evaluation and uncertainty estimation of the sinusoidal parameter, or it can also be used to select measurement conditions in the case of setting fitting errors and uncertainties.
		2023 Vol. 44 (9): 1429-1437 [Abstract] ( 96 ) HTML (1 KB) PDF (676 KB) ( 50 )

	1438	Measurement of Microwave Phase Shift Based on Rydberg Atoms
		ZHANG Ying-yun,RUAN Wei-min,FENG Zhi-gang,QU Ji-feng,SONG Zhen-fei
		DOI: 10.3969/j.issn.1000-1158.2023.09.18
		The microwave quantum precision measurement based on Rydberg electromagnetically induced transparency,due to its advantages of high sensitivity,high resolution,broadband and having direct traceability path to the fundamental physical constant,can be used in various applications,including microwave quantum metrology,communication and imaging.A method for microwave phase shift measurement using rubidium Rydberg atoms is presented here.First, heterodyne reception of signal (SIG) microwave field and local oscillator (LO) microwave field is realized by using hot rubidium Rydberg atomic spectrum, and intermediate frequency (IF) signals with the same phase shift as SIG microwave field are obtained; then the measured signal is processed by the lock-in amplification algorithm to realize the detection of phase difference between the IF signal and a reference signal.The reference signal has the same frequency of IF signal.Finally, while keeping the local microwave field and reference signal unchanged, the phase of the SIG microwave is changed by using the displacement stage, and the microwave phase shift is measured by comparing the phase difference measured at different positions. In order to verify the correctness of the phase shift measurement results,the microwave propagation constant of this frequency is calculated by linear fitting of displacement and the measured phase shift,the relative error of measured microwave propagation constant of 6.92GHz to the theoretical value is within 0.2%. By demonstrating the possibility of microwave phase-shift total optical measurement, the application of microwave quantum precision measurement technology in the field of communication and radar has been laid down.
		2023 Vol. 44 (9): 1438-1443 [Abstract] ( 144 ) HTML (1 KB) PDF (455 KB) ( 282 )

	1444	Reproduction of Tissue Absorbed Dose Based on Beta Radiation Source
		HUANG Jian-wei,ZHANG Xuan,LI De-hong,YANG Yang,CHENG Jian-bo,ZHANG Xiao-le,CAO Lei
		DOI: 10.3969/j.issn.1000-1158.2023.09.19
		In order to reproduce the magnitude of the absorbed dose of β-ray tissue, the radiation field based on 90Sr/90Y and 85Kr sources and the extrapolated ionization chamber parameters, as well as the related correction factors of the extrapolated ionization chamber, were obtained through experiments and simulation calculations, and flattening was achieved. The magnitude of the tissue absorbed dose rate under the filter condition was reproduced. It provides a basis for the subsequent participation in the international comparison of β-particle raidation doses and the transfer of β-particle raidation personal dose equivalents Hp(0.07).
		2023 Vol. 44 (9): 1444-1450 [Abstract] ( 91 ) HTML (1 KB) PDF (427 KB) ( 43 )

	1451	Monte Carlo Simulation and Measurement of Detection Efficiency of Proportional Counter
		TANG Xian-qiang,WU Jin-jie,ZHU Wei-feng,XIONG Tao,ZHAO Rui,MA Xiang-zhuang,LI Meng-yu,LU Ping-zhou
		DOI: 10.3969/j.issn.1000-1158.2023.09.20
		Proportional counter is a gas detector widely used in the field of low energy photon measurement. In order to further study the radiation detection characteristics of proportional counter, Geant4 program was used to simulate the detection efficiency of low energy photon in the energy range of (2~90) keV. Proportional counter was used to measure the energy spectrum of standard radioactive sources129I, 152Eu and241Am, and the energy calibration curve and detection efficiency were obtained. The maximum deviation between the experimental measurement results and the simulation results is 2.29%, which is in good agreement, and verifies the accuracy of the simulation energy range (29.67~59.54)keV detection efficiency. The results show that the model of proportional counter established by Geant4 is consistent with the actual situation, which provides an important basis for the subsequent research on the radiation characteristics of proportional counter with Geant4.
		2023 Vol. 44 (9): 1451-1457 [Abstract] ( 132 ) HTML (1 KB) PDF (609 KB) ( 167 )

	1458	SCR Inlet of Thermal Power Plant Based on ARIMA-OSELM Prediction of NOx Concentration
		JIN Xiu-zhang,CHEN Jia-zheng,LI Yang-feng
		DOI: 10.3969/j.issn.1000-1158.2023.09.21
		It is difficult to accurately measure the inlet NOx concentration in selective catalytic reduction flue gas denitration system (SCR) for the combustion system of thermal power plant due to complex operating conditions and large delay. Therefore, a method to predict NOx concentration at SCR inlet of thermal power plant based on ARIMA-OSELM neural network combination model was proposed. The method was compared from two combination perspectives: optimal weight and residual optimization. The above method was applied to the prediction of SCR inlet concentration in a thermal power plant. The results show that the combined model based on ARIMA-OSELM residual optimization has the highest prediction accuracy, and its effect is better than that of ARIMA-OSELM optimal weight combined prediction model and single ARIMA and OSELM neural network prediction model. The obtain evaluation indexes FMAPE, MRMSE and R2 are 0.190, 1.364 and 0.978, respectively.
		2023 Vol. 44 (9): 1458-1466 [Abstract] ( 100 ) HTML (1 KB) PDF (705 KB) ( 205 )

	1467	Study on the Relationship Between Sampling Flow Rate and Cut Size of Different Types of Particulate Matter Cutters
		TIAN Ying,ZHANG Guo-cheng,LIU Jia-qi,SHEN Shang-yi,WU Dan,PAN Yi-ting,JING Wen-jie
		DOI: 10.3969/j.issn.1000-1158.2023.09.22
		The method of static box was used to explore the influence of sampling flow (Q) on the cut size D50 of particulate matter cutter,including a variety of cyclone cutters of BGI and an impaction-type cutter of Chinese brand.The results showed that no matter which type cyclone cutter,the changes of sampling flow resulted in translation of collection efficiency curve.And the greater the flow rate,the smaller D50.In addition, it was found that the PM1.0,PM2.5 and PM4.0 modes could be switched by changing the flow rate in the same whirlwind cutter,and the sampling flow rate was approximately inversely proportional to D50.For the impaction-type cutter,the square root of D50 was approximately inversely proportional to the sampling flow.It could be used as a rapid evaluation method to quickly estimate the corresponding D50 according to the actual flow rate,which has certain application value.
		2023 Vol. 44 (9): 1467-1472 [Abstract] ( 91 ) HTML (1 KB) PDF (564 KB) ( 43 )

	1473	Calibration Device for Insufflator
		WU Si-qi,HONG Bao-yu,HU Zhi-xiong,MA Xue-ran,BIAN Xin,LIU Wen-li
		DOI: 10.3969/j.issn.1000-1158.2023.09.23
		Based on the working principle of insufflator and relevant measurement technical specifications, the research on the calibration method of insufflator is carried out, a simulated abdominal cavity system is established, and the calibration device of insufflator is built. Software and hardware functional architecture of the calibration device of insufflator are elaborated,intelligent calibration of insufflator is realized by utilizing automatic measurement program.A typical insufflator model is calibrated and the uncertainty is evaluated. The expanded uncertainty of air pressure set value error is 77.02Pa(k=2), and the expanded uncertainty of flow display value error is 5.98% (k=2).The results show that the developed calibration device of insufflator can be applied to the performance testing of insufflator.
		2023 Vol. 44 (9): 1473-1478 [Abstract] ( 116 ) HTML (1 KB) PDF (485 KB) ( 61 )

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