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2023 Vol. 44, No. 10
Published: 2023-10-28
 
1479 Feature Point Extraction and Coordinate Transformation Cylindricity Minimum Zone Evaluation
WANG Qiang,WANG Wei
DOI: 10.3969/j.issn.1000-1158.2023.10.01
For the minimum zone method based on the evaluation method, there are problems such as the placement of parts will affect the optimization results when the data extraction of parts is performed and the cumbersome local convergence of the multi-sampling point solution,a new method for evaluating the cylindricity error in the minimum zonen is studied. First, the minimum zone evaluation mathematical model is established. Then, the spatial coordinate transformation projection is carried out to transform the data points of any position of the cylinder into a fixed position, and the spatial multi-sampling point problem is converted into a plane for feature point extraction. Finally, the internal and external scanning area and the replacement of coordinate axes are set up and the results of optimization are reviewed to achieve effective prevention of local optimal solutions. The example test results show that for the dataset with the largest number of data samples, the computational efficiency is improved by 1.5 times, which can effectively handle the cylindricity error of multi-sampling points and sampling points at arbitrary position. Moreover, as the number of sample points in the dataset increases, the computational efficiency improves more significantly, and the solution has a high stability.
2023 Vol. 44 (10): 1479-1486 [Abstract] ( 171 ) HTML (1 KB)  PDF (609 KB)  ( 304 )
1487 The Influence of the Adiabatic Properties of Cryostats on the Realization of the Equilibrium Hydrogen Triple Point
YE Xi-hui,YU Ying,XING Li,FENG Xiao-juan,ZHANG Jin-tao,QIU Ping,SUN Jian
DOI: 10.3969/j.issn.1000-1158.2023.10.02
The triple point of equilibrium hydrogen (13.8033K) is one of the cryogenic fixed points with the lowest temperature specified in ITS-90 and is commonly used for the calibration of capsule standard platinum resistance thermometers(CSPRTs). A cryogen-free cryostat has been used to improve the national primary temperature standard, which can provide an ideal adiabatic environment for the realization of equilibrium hydrogen of sealed triple point, and to perform experiments of realization using calorimetry. Pre-melting of the triple point vessel due to spin-conversion catalysts of equilibrium hydrogen and differences between experimental assembling can lead to variety in the heat capacity of the vessel or the thermal resistance of the system, which can affect the realization. A heat transfer model of the system was developed and experiments were carried out under two different adiabatic conditions. The heat capacity of the assembly and the thermal resistance of the adiabatic shield and assembly were measured and the influence of the adiabatic properties of the cryostat on the realization of triple point of equilibrium hydrogen was analyzed. The results show that by measuring the thermal resistance before the start of the realization and confirming that the system has good adiabatic properties, the standard deviation of four plateau of triple point of equilibrium hydrogen is less than 0.1mK.
2023 Vol. 44 (10): 1487-1493 [Abstract] ( 146 ) HTML (1 KB)  PDF (560 KB)  ( 352 )
1494 Laboratory Calibration and Comparison Verification of Multi-channel Self-calibration Infrared Radiation Thermometer
SUN Yan-dong,HAO Xiao-peng,XIE Chen-yü,ZHOU Jing-jing,ZENG Bing,SONG Jian,LING Ling
DOI: 10.3969/j.issn.1000-1158.2023.10.03
The thermal infrared radiometer is critical for gathering field data and validating remote sensing satellite observation data. The accuracy of its calibration has a direct impact on the accuracy and application level of remote sensing data analysis. The design concept of a multi-channel self-calibration infrared radiation thermometer is primarily discussed. The laboratory calibration and repeatability experiments are performed to validate the level of instrument measurement data under long-term operation, and the uncertainty of instrument radiation brightness temperature is 0.27K. The mainstream radiometer is used for the laboratory test analysis, and the accuracy of the calibration results are compared. The maximum deviation of the multi-channel self-calibration infrared radiation thermometer is 0.26℃, and the overall deviation is within 0.3℃. The measurement level of the instrument is verified through outdoor grassland testing experiments. The results show that the multi-channel self-calibration infrared radiation thermometer has a high level of accuracy, and can meet the requirements of long-term, multi-channel and high-precision work in the field, providing data support for the field calibration.
2023 Vol. 44 (10): 1494-1502 [Abstract] ( 140 ) HTML (1 KB)  PDF (706 KB)  ( 169 )
1503 Development of Ultra-low Temperature Adjustable Thermostat from -180 to -60 ℃
CHANG Jia-qiang,YANG Hong-yan,ZHANG Xiang-yu,QIU Ping,ZHU Tian-yu
DOI: 10.3969/j.issn.1000-1158.2023.10.04
An ultra-low temperature adjustable thermostat device with continuously adjustable temperature function was developed, the design principle, specific structure, testing process, and experimental results of the device were described. In order to verify the performance of the device, the experiment of the device temperature volatility, the inter hole temperature uniformity experiment, and the heating rate tests were performed. The results show that the temperature volatility is better than 2mK/10min, the temperature difference is better than 2mK and the heating rate is better than 1.5℃/min. At the same time, the design of the temperature controller was completed, which can realize switching between multi-stage and single-stage temperature control. The developed ultra-low temperature adjustable thermostat device has a temperature range of -180~-60℃ and a temperature control resolution of 0.001K.
2023 Vol. 44 (10): 1503-1508 [Abstract] ( 153 ) HTML (1 KB)  PDF (543 KB)  ( 273 )
1509 Gas-Liquid Two-Phase Flow Pattern Recognition Based on Multi-domain Feature Extraction
ZHANG Li-feng,WANG Zhi
DOI: 10.3969/j.issn.1000-1158.2023.10.05
A multi-domain feature processing scheme is proposed for the accurate identification of gas-liquid two-phase flow. The electrical resistance tomography (ERT) system is used to obtain the flow data of vertical rising pipeline. From the perspective of measurement data and cross-sectional conductivity distribution image, the time-domain features are extracted after dimensionality reduction of high-dimensional measurement data, and the spatial features of the reconstructed image are extracted by linear back projection (LBP) algorithm. Further, Walsh-Hadamard transform is performed on the image to extract column rate domain features. The uniform manifold approximation and projection (UMAP) algorithm is used to reduce the dimension of the quantized multi-domain features, and finally a support vector machine (SVM) is built to realize flow pattern recognition. The results show that the classification accuracy of bubble flow, bubble-slug transition flow, slug flow and severe slug flow are 98.1%,96.3%,95.2% and 94.8%, respectively.
2023 Vol. 44 (10): 1509-1516 [Abstract] ( 130 ) HTML (1 KB)  PDF (575 KB)  ( 150 )
1517 Non-integer-period Sampling Influence on Rectification Error of Multi-directional Vibration Accelerometer
DONG Xue-ming,WANG Min-lin,DU Mei-lin
DOI: 10.3969/j.issn.1000-1158.2023.10.06
To evaluate the influence of non-integer-period sampling on rectification error caused by vibration acceleration, the mathematical model of rectification error caused by singal directional vibration acceleration under non-integer-period sampling is established. By calculating the average value of vibration signals in all directions, the mathematical model of rectification error caused by multi-directional vibration acceleration under non integral period sampling is deduced. Based on the analysis of multi-directional vibration acceleration model, an approach to reduce the influence of non-integer-period sampling on rectification error is given. In simulation, the relative measurement error of rectification error is introduced to verify the effectiveness of the rectification error model of unidirectional vibration acceleration and multi-directional vibration acceleration under non-integer-period sampling.
2023 Vol. 44 (10): 1517-1525 [Abstract] ( 117 ) HTML (1 KB)  PDF (522 KB)  ( 45 )
1526 Parameter Identification of Linear-angular Vibration Exciter Based on Electromechanical Analogy
YANG Jian-gen,TANG Bo,CHEN Wei,YU Jin-hui
DOI: 10.3969/j.issn.1000-1158.2023.10.07
Aiming at the problem that the dynamic parameters of the electromagnetic linear-angular vibration exciter are difficult to obtain directly, a dynamic parameter identification method based on the principle of electromechanical analogy is proposed, which can obtain the dynamic parameters of uniaxial and coupling vibration of the exciter. Firstly, the structural and working principle of the electromagnetic linear-angular vibration exciter are introduced, and the motion differential equations of uniaxial vibration and coupling vibration are established. Secondly, based on the admittance electromechanical analogy principle, the electromechanical analogy models of uniaxial vibration and coupled vibration with mechanical parameters are established. Finally, the impedance formula containing dynamic parameters is established according to the electromechanical ratio model, and the dynamic parameter identification model of the exciter is obtained by combining the additional mass method. The validity of the model is further verified by numerical simulation. The simulation results show that this method has high identification accuracy and anti-noise ability, and the identification relative errors of each parameter are within 5%.
2023 Vol. 44 (10): 1526-1533 [Abstract] ( 175 ) HTML (1 KB)  PDF (531 KB)  ( 93 )
1534 Based on the GADF-TL-ResNeXt Rolling Bearing Fault Diagnosis Method
HOU Dong-xiao,ZHOU Zi-an,CHENG Rong-cai,YAN Shuang
DOI: 10.3969/j.issn.1000-1158.2023.10.08
To solve the problem that traditional diagnosis methods are difficult to extract fault features effectively, a fault diagnosis method based on Gramian angular field (GAF) and TL-ResNeXt is proposed. Firstly, GAF is used to encode the original vibration signal into a two-dimensional feature map of time series correlation. Then these feature maps are input into a deeper level of packet residual network ResNeXt for automatic recognition and classification. At the same time of model training, transfer learning (TL) module is combined in the last layer of the network to accelerate the feature extraction ability of the model and fast learning. In order to verify the effectiveness of the method, the bearing data of Case Western Reserve University are compared with other methods, and the results show that the method performed best. The bearing fault data collect on the rolling mill simulation test platform show that the method also has good generalization and recognition ability under different working conditions.
2023 Vol. 44 (10): 1534-1542 [Abstract] ( 132 ) HTML (1 KB)  PDF (1060 KB)  ( 73 )
1543 High-intensity Ultrasonic Sound Field Measurement Based on Laser Vibrometry
GAO Chu,GAO Shen-ping,YAO Lei,ZHENG Hui-feng,WU De-lin,WANG Xiao-bo,ZHANG Heng-da
DOI: 10.3969/j.issn.1000-1158.2023.10.09
The radiated sound field of the high intensity focused ultrasonic transducer is measured based on the laser vibration measurement method. Compared with the results measured by the standard hydrophone, the measured values of the fundamental wave signal, the second harmonic and the third harmonic at the focus are basically consistent. The error of the fundamental wave sound pressure is within 10%, and the sound pressure distribution at the focal plane is basically consistent. At the same time, the influence of the thin film on the sound field measurement in the laser vibration measurement method is solved based on the multilayer dielectric impedance transfer method, and the sound pressure transmission coefficient of the thin film at different frequencies is calculated. Experiments are designed to verify the results obtained by the laser vibrometry method and the standard hydrophone measurement method at different frequencies(1MHz、5MHz、10MHz). The results show that the correction of the measurement results of the laser vibrometer method by the sound pressure transmission coefficient can effectively reduce the measurement error.
2023 Vol. 44 (10): 1543-1549 [Abstract] ( 163 ) HTML (1 KB)  PDF (512 KB)  ( 315 )
1550 A Fast and High-precision Frequency Measurement Method of Optical Pump Magnetometer Combined with Smooth Time Window-Least Square Method
TAN Chao,XIN Liang,ZHAI Jing-jing,YANG Long,SUN Qi-hao
DOI: 10.3969/j.issn.1000-1158.2023.10.10
In order to improve the precision and speed of frequency measurement of optical pump magnetometer, a fast and high precision frequency measurement method of optical pump magnetometer combined with smooth time window-least square method is proposed. Firstly, according to the characteristics of the frequency signal of optical pump magnetometer, the measurement principle and realization method of the method are analyzed. Then, the formula of frequency measurement is deduced, and the factors that affect the precision of frequency measurement are analyzed. Finally, experiment and an outdoor magnetic field measurement experiment are designed to verify the proposed method. The experimental results show that the method is obviously better than the multi-period synchronous frequency measurement method, and the mean square error in the frequency range of 80~350kHz is less than 2.2×10-3Hz. In the magnetic field measurement experiment, when the sampling frequency is 200Hz, the noise power spectral density is 0.001nTHz@1Hz。
2023 Vol. 44 (10): 1550-1556 [Abstract] ( 118 ) HTML (1 KB)  PDF (636 KB)  ( 294 )
1557 Design and Experimental Research of Radial Magnetization Electromagnetic Sensor
TANG Bo,GUO Bi-ben,CHEN Wei,TAN Long
DOI: 10.3969/j.issn.1000-1158.2023.10.11
A radially magnetized electromagnetic sensor is proposed for the detection of the defects of the traction steel strip, which can realize the accurate detection of the defects of the traction steel strip in-situ nondestructive. Based on the electromagnetic coupling and the magnetic properties of high magnetic permeability materials, an equivalent model of the radially magnetized electromagnetic sensor is established by using the finite element analysis method. The laws of influence of the magnitude of the magnetic induction at the measurement location of the magnetized electromagnetic sensor. Finally, a radially magnetized electromagnetic sensor is prepared on the basis of numerical simulation and to measure its performance, and it is further applied to the defect detection of traction steel strips. The experimental results show that the system can realize the broken strand with a resolution of 0.5mm. This demonstrated that a feasible solution is provided for the defect detection of traction steel strips.
2023 Vol. 44 (10): 1557-1563 [Abstract] ( 129 ) HTML (1 KB)  PDF (649 KB)  ( 82 )
1564 Overview of Josephson Voltage Standard Research at NIM
LI Hong-hui,,WANG Zeng-min,XU Qing,TIAN Zheng-qi,DUAN Mei-mei,WANG Lei
DOI: 10.3969/j.issn.1000-1158.2023.10.12
To the Josephson quantum voltage based standard established by NIM and its application are reviewed. NIM has established the national quantum voltage reference since 1993, and then has carried out two on-site comparisons at1V and 10V with the International Bureau of Metrology. The relative difference between the comparisons is less than 1.1×10-10. To mainly describes the research work of NIM to establish a programmable quantum voltage reference (PJVS), and the progress of synthesizing AC quantum voltage based on PJVS and the value dissemination of AC standard. Some innovations and applications of PJVS are also introduced.
2023 Vol. 44 (10): 1564-1573 [Abstract] ( 176 ) HTML (1 KB)  PDF (701 KB)  ( 394 )
1574 Research on IC Pin soldering Defect Detection Algorithm Based on Improved PP-YOLOv2
LI Na,WANG Xue-ying,HU Xiao-feng,GUO Bin,LUO Zai
DOI: 10.3969/j.issn.1000-1158.2023.10.13
Aiming at the low detection accuracy of IC pin soldering defects due to small target size and dense pins, an algorithm for IC pin soldering defects detection based on improved PP-YOLOv2 is proposed. By introducing SE attention mechanism behind the backbone network, the importance of different channels in the feature map is distinguished, the key features of the target area are strengthened, and the network feature extraction ability is improved. k-means++ clustering algorithm is used to generate 9 cluster centers to reduce the error impact on the detection results caused by improper random selection of initial cluster centers. The experimental results show that the average accuracy of the improved algorithm for detecting the defects of IC pin soldering short circuit, missing pin, warping pin and little tin is 97.9%, 96.1%, 96.7% and 95.8% respectively. Under the threshold value of 0.5, the average accuracy reaches 96.6%, which is 14.9% and 5.1% higher than YOLOv3 and PP-YOLOv2 respectively. The detection time of the improved algorithm for a single picture is 0.151s, which meets the speed requirements of IC quality inspection and provides a reference value for IC pin soldering defect detection.
2023 Vol. 44 (10): 1574-1581 [Abstract] ( 125 ) HTML (1 KB)  PDF (776 KB)  ( 393 )
1582 Modal Analysis of Particle Amplified Surface Plasmon Resonance Sensor
JIANG Jing-hong, XIN Zi-yi, DUAN Jun-yi, ZHOU Ya-dong
DOI: 10.3969/j.issn.1000-1158.2023.10.14
We analyzed the resonance mode and sensitivity of the surface plasmon resonance (SPR) sensor coupled by two kinds of nanoparticle arrays. Most of the sensors use a Kretschmann structure composed of five layers of materials: namely prism, gold film, SiO2 medium, nanoparticle array and air. The effective dielectric constants of AuNps layer and CSNps layer of core-shell structure were calculated by using Maxwell-Garnett theory. Then their propagation characteristics were analyzed with the generalized reflection coefficient. Firstly, the simulation results show the reflectance and modal field distribution of AuNps array with different thickness and geometry. Secondly,the CSNps array structure shows that multiple resonance modes can be excited under TM polarization,and the inner core radius and shell thickness will affect the sensitivity of the SPR sensor,with the inner core radius having a greater impact on sensitivity.The spacing and size of the nanoparticles will affect the concentration of CSNps in the array layer,thereby affecting sensitivity.
2023 Vol. 44 (10): 1582-1589 [Abstract] ( 122 ) HTML (1 KB)  PDF (754 KB)  ( 367 )
1590 Estimation of NOx Emission Concentration from Coal-fired Boilers of Power Stations Based on Variable Selection
WANG Long-xian,ZHAO Wen-jie
DOI: 10.3969/j.issn.1000-1158.2023.10.15
To study the measurement delay of NOx emission concentration of coal-fired boilers in power stations, a prediction model of NOx emission concentration of coal-fired boilers in power stations based on mutual information (MI) and long short-term memory neural network (LSTM) was proposed. Firstly, the delay time between the candidate input variable and the output variable NOx concentration was calculated using mutual information, and the MRMR algorithm was introduced to screen out the optimal feature subset, and the optimal feature subset was used as the input of LSTM model. The prediction model of NOx emission concentration of boiler is established. The simulation results show that the root mean square error (RMSE) and mean absolute error (MAE) of the proposed model are 4.626mg/m3 and 3.836mg/m3, respectively. Compared with the LSTM model without variable selection and delay consideration, the prediction accuracy is significantly improved.
2023 Vol. 44 (10): 1590-1596 [Abstract] ( 114 ) HTML (1 KB)  PDF (537 KB)  ( 57 )
1597 Feature Identification of EEG Preparatory Response Signals Evoked by Motor Intention
FU Rong-rong,LIANG Hai-feng,MI Rui-fu
DOI: 10.3969/j.issn.1000-1158.2023.10.16
The motor intention contained in the preparation response to electroencephalogram (EEG) signals is extracted and recognized, and the pre-movement EEG patterns is decoded. The experimental results show that using the common spatial pattern (CSP) and extreme learning machines (ELM) can efficiently distinguish the preparation potential of the left and right hands before real movement, and the average recognition accuracy rate of EEG data induced by the preparation before the execution of the brain computer interface (BCI) competition can reach 85.7%. On the decoding problem, compared with motor imagery (MI) EEG signals, the preparatory potential saves the time from consciousness generation to action execution, improves the response efficiency of operational task execution, and provides theoretical basis and technical support for efficient BCI based on motor intention.
2023 Vol. 44 (10): 1597-1601 [Abstract] ( 136 ) HTML (1 KB)  PDF (415 KB)  ( 405 )
1602 Diagnostic Protocol for Mild Cognitive Impairment Based on Dimensional Transformation of EEG Signals
LI Xin,LI Zi-peng,LIU Yi,XIE Ping,WANG Yu-lin
DOI: 10.3969/j.issn.1000-1158.2023.10.17
A spectral entropy dimension transformation method matching the convolutional neural network (CNN) was proposed. The EEG data samples of 26 amnestic mild cognitive impairment patients and 20 healthy subjects were compared and analyzed from three aspects: short-time Fourier transform, wavelet transform and spectral entropy.A novel diagnosis scheme of mild cognitive impairment was constructed by using spectrum entropy and CNN.Then, through the comparison of feedforward neural network, k-nearest neighbor, support vector machine, decision tree, naive Bayes, logistic regression and other models, it was verified that the scheme can effectively completed the pattern recognition of EEG in patients with preclinical Alzheimers disease from two aspects of accuracy and stability.Experimental results show that the proposed method can achieve an accuracy of (92.662±1.216)%, and still has high recognition accuracy and generalization ability for EEG signals with noise interference.
2023 Vol. 44 (10): 1602-1611 [Abstract] ( 109 ) HTML (1 KB)  PDF (850 KB)  ( 305 )
1612 Establishment of Measurement and Verification Method for Sequential Evaluation of Anoikis Effect on Hela Cell
XUE Zhi-chao,ZENG Jia-ming,GONG Xiao-yun,XUE Qian,DAI Xin-hua,ZHAO Yang
DOI: 10.3969/j.issn.1000-1158.2023.10.18
Anoikis effect is a special program death for attachment cells in the body, which plays an important role in body development, tissue homeostasis, disease occurrence, and tumor metastasis. Attachment epithelial cell line Hela was hired as the experiment model to investigate the anoikis effect in detail. Living Hela cells were counted after trypsinization and floating for 5min, 30min, 1h, 2h, 4h, and 8h respectively. The activity of these cells was detected after seeding back for 24h. The results showed that floating time would severely decrease cell counting and activity of HeLa, and the floating time of attachment cell needs to be controlled during cell experiments.
2023 Vol. 44 (10): 1612-1616 [Abstract] ( 143 ) HTML (1 KB)  PDF (501 KB)  ( 630 )
1617 Research Progress on Metrological Evaluation Methods for Sampling Efficiency of Bioaerosol Samplers
LIU Wen-cheng,FU Bo-qiang,LIU Nai-yu,LI Man-li,NIU Chun-yan,WANG Jing,WU Yi-hang,LI Ru,CHENG Huan
DOI: 10.3969/j.issn.1000-1158.2023.10.19
The collection, identification and concentration monitoring of microorganisms in bioaerosols are important steps for assessing the risk of bioaerosols. The effective collection of living microbial particles in aerosols by bioaerosol samplers is the precondition for bioaerosol risk factor analysis. Many metrology researchers began to pay more attention to the metrological evaluation methods for bioaerosol sampling efficiency. The different methods for the performance evaluation of sampling physical efficiency and sampling biological efficiency of bioaerosol samplers are reviewed, in order to provide reference for methodological harmonization and standardization of the evaluation method.
2023 Vol. 44 (10): 1617-1625 [Abstract] ( 183 ) HTML (1 KB)  PDF (455 KB)  ( 361 )
1626 An Equivalent Method for Simulating Anesthetic Gas Based on Infrared Absorption Spectroscopy
DING Xiang,MA Xue-ran,ZHANG Yang,LI Wen-hua,ZHOU Feng
DOI: 10.3969/j.issn.1000-1158.2023.10.20
Calibration of anesthetic gas detector relies on the use of standard anesthetic gases, but its preparation is costly and time consuming. To solve this problem, an equivalent simulation method for anesthetic gases is proposed. Infrared filters are used to simulate the absorption of infrared light by anesthetic gases at different concentrations and serve as standard anesthetic gas. An anesthetic gas detection system is developed. Sevoflurane gases with volume fractions between 0.23%~8.50% and infrared filters with transmittance between 36%~95% are prepared and measured. It is demonstrated that the repeatability error of the equivalent sevoflurane concentration of filters is small than 0.02% and the maximum variation of equivalent concentration induced by the temperature effect is small than 0.02%+1.5%·c (c is the volume fraction of the measured gas). It is proved that infrared filters can be used to simulate standard anesthetic gases.
2023 Vol. 44 (10): 1626-1630 [Abstract] ( 110 ) HTML (1 KB)  PDF (351 KB)  ( 106 )
1631 Research Progress on the Detection Methods of Guanidinoacetic Acid and Creatine in Biological Samples
LIU Ruo-yi,XIE Jie,QIAO Xiao-ting,JIANG You,HUANG Ze-jian,DAI Xin-hua,FANG Xiang,YE Zi-hong
DOI: 10.3969/j.issn.1000-1158.2023.10.21
Guanidineacetic acid (GAA) and creatine (CRE), as endogenous substances of human, themselves and their related metabolites are responsible for important physiological functions, and their content and composition have an impact on human tissues and organs. GAA is the precursor of CRE, and CRE can combine with adenosine triphosphate under the action of creatine kinase to form creatine phosphate, which is the material basis for energy storage and utilization in human body. In addition, GAA and CRE are also related to the occurrence and progression of many genetic metabolic diseases, and their rapid detection is essential for the early detection and treatment of such diseases. The currently known diseases correlated with GAA and CRE and their treatment methods are reviewed systematically. The modern detection methods of GAA and CRE in biological samples are also summarized and reviewed, and their possible developmental trends in the future are prospected.
2023 Vol. 44 (10): 1631-1638 [Abstract] ( 170 ) HTML (1 KB)  PDF (431 KB)  ( 256 )
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