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2023 Vol. 44, No. 8
Published: 2023-08-28
 
1159 Design of Optical Resonant Cavities for Inductive Type Optical Superconducting Transition Edge Detector Devices
WANG Zhen-yu,ZHONG Qing,ZENG Jiu-sun,LI Jin-jin,XU Xiao-long,WANG Xue-shen
DOI: 10.3969/j.issn.1000-1158.2023.08.01
To improve the detection efficiency of the inductive optical superconducting transition edge detector devices, a resonant cavity structure based on an Al total reflection layer, SiO2 and SiNx anti-reflection layer is designed and fabricated on a 15nm niobium (Nb) film photon absorber layer for the 633nm wavelength. The reflectivity is simulated with the Concise Macleod software and the layer structure of the resonant cavity for the lowest reflectivity is selected. The resonant cavity is prepared by a magnetron sputtering process and a following chemical vapor deposition process with an end point detection. The reflectivity is characterized by a spectrophotometer, which shows that the prepared resonant cavity can reduce the reflectivity at 633nm to be only 0.9%, and also has good anti reflection effect, the reflectivity for from 506nm to 690nm to be <1%.
2023 Vol. 44 (8): 1159-1162 [Abstract] ( 157 ) HTML (1 KB)  PDF (398 KB)  ( 381 )
1163 Application of Line Laser in Constructing Optical Mirror Testing Path
JI Bo,XU Chen,TANG Jin
DOI: 10.3969/j.issn.1000-1158.2023.08.02
To investigate the application of line laser in the construction of the optical testing path which based on its ability to no-contract output continuous reference datum, the assistant role of the line laser in testing different types of mirrors has been studied, such as plane mirror testing, spherical mirror testing, Ritchey-Common testing, aspheric mirror testing etc, and the operational guidance in the adjustment has been proposed, that scientifically and systematically demonstrate its special advantages in spatial position and optical axis correction, also the interference of its error to the testing and the corresponding correction measures has been discussed, then verified the advantages by experimental comparison with the traditional equipment. The results show that the line laser can replace the traditional auxiliary alignment equipment and methods, and it has good adaptability for different types of optical mirror testing.
2023 Vol. 44 (8): 1163-1168 [Abstract] ( 107 ) HTML (1 KB)  PDF (616 KB)  ( 143 )
1169 Fabrication and Test of High Quality Factor MgF2 Crystal Microcavity
QU Zhi-er,PAN Yi-jie,LIU Xian-wen,ZHANG Cheng,WANG Jin,QU Ji-feng
DOI: 10.3969/j.issn.1000-1158.2023.08.03
Based on a linear motor, a high precision scale and a mechanical feedback unit, a precision automatic grinding and polishing system was developed. The system enabled accurately control the size, thickness and shape of the crystal microcavities during preparation. The trapezoidal micro-disk cavity of magnesium fluoride crystal with high quality factor was fabricated by preforming, rough grinding, rough polishing and fine polishing. The surface roughness of magnesium fluoride crystal after precision polishing was characterized to be 2.84nm using a white light interferometer. By setting up a taper fiber and crystal microcavity coupling testing system, the quality factor of the prepared crystal microcavity was measured to be 4.55×108 at 1550nm by the optical cavity ring-down method.
2023 Vol. 44 (8): 1169-1175 [Abstract] ( 168 ) HTML (1 KB)  PDF (776 KB)  ( 384 )
1176 Reserches on High Stability Infrared Planar Blackbody Radiation Source
FENG Guo-jin,WU Zhi-feng,ZHENG Chun-di
DOI: 10.3969/j.issn.1000-1158.2023.08.04
In order to meet the requirements of infrared radiation calibration of infrared instrument in the complex environment on site, two sets of portable infrared thermal radiation sources were developed with high stability and the effective radiation surface is 400mm×400mm. One of them adopted the principle of temperature control based on closed fluid, and mainly worked in a relatively low temperature working area 10℃ lower than the ambient temperature, which was used as a reference low temperature point for environmental radiation. The other set adopted the principle of large-area TEC temperature control, which mainly worked in a relatively high temperature working area 10℃ higher than the ambient temperature. The surface emissivity of the two sets of infrared radiation sources was higher than 0.97, the temperature control stability was better than 0.01℃/h, and the surface temperature uniformity of the infrared radiation source was better than 0.2℃.
2023 Vol. 44 (8): 1176-1181 [Abstract] ( 123 ) HTML (1 KB)  PDF (697 KB)  ( 82 )
1182 Improved SIFT Feature Matching Algorithm with Geometric Feature Constraints
ZHANG Xi-min,ZHAN Hai-sheng,YU Qi-ying
DOI: 10.3969/j.issn.1000-1158.2023.08.05
The accuracy of image registration directly affects the accuracy of machine vision dimension detection. Aiming at the fact that scale-invariant feature transform(SIFT) feature transform algorithm was less involved the geometric relationship between feature points, and it was easy to generate mismatch points for the capture image with smooth varied grayscale, such as small widget, an improved SIFT feature matching algorithm with geometric feature constraints was proposed. Firstly, the target contour profile was extracted by the image tracking algorithm based on boundary topology analysis. Secondly, the SIFT algorithm was constrained by geometric contour profiles of images, and the Random sample consensus(RANSAC) algorithm was taken to remove outlier point pairs. Finally, image accurate registration transformation was performed by calculated transformation matrix. A machine vision precision detection and measurement system were developed based on high-resolution industrial camera and high-performance computer, and experiments were carried out on the USB interface plug-in parts of mobile phone as samples. The experimental results showed that the accuracy of image registration of this algorithm can reach 95.31%. Compared with SIFT algorithm and SIFT+RANSAC algorithm, the registration accuracy was greatly improved. The algorithm has been applied to develop an automation dimension detection and measurement system.
2023 Vol. 44 (8): 1182-1187 [Abstract] ( 125 ) HTML (1 KB)  PDF (529 KB)  ( 317 )
1188 Research on the Layout of Calibration Points for Laser Tracking Multilateral Asynchronous Measurement System
YAN Yang,XIA Wen-jie,LIN Hu
DOI: 10.3969/j.issn.1000-1158.2023.08.06
To improve the calibration accuracy of the base station of laser tracking multilateral asynchronous measurement system, the layout of calibration points is studied. Firstly, simulation experiments are carried out under different calibration point layouts based on the principle of laser tracking multilateral method, and the results show that the calibration accuracy of the base station is different under different calibration point layouts with different values of position dilution of precision (PDOP). Secondly, based on PDOP, the study of the layout of calibration points in different dimensions is done. The results shows that the calibration accuracy of the base station is poor when the calibration points are laid out in a straight line, and the calibration accuracy of the base station improves when the calibration points are laid out in the plane or in the space range with the layout expansion and the points number increase. Finally, the experiments for measured points demonstrat that the PDOP can quantitatively characterize the pros and cons of the calibration points layout. When the calibration points are laid out in a three-dimensional space area, the PDOP value corresponding to the base station is <3, the spatial distance between the coordinates of the measured point and the reference coordinates is ≤4.4μm and the calibration accuracy of the base station and the measurement accuracy of the measured points are higher.
2023 Vol. 44 (8): 1188-1195 [Abstract] ( 107 ) HTML (1 KB)  PDF (619 KB)  ( 52 )
1196 Research on Resolution Evaluation Method of Nano-Positioning Stage Based on Laser Interference and Capacitive Sensor Composite Calibration Technology
YAN Han,ZHANG Shu,PI Lei,MA Ying-han,HU Jia-cheng,SHI Yu-Shu
DOI: 10.3969/j.issn.1000-1158.2023.08.07
When measuring nanometer resolution with laser interferometer, the interference measurement is limited due to environmental factors. Capacitive sensor can resist this kind of interference well, but it has the disadvantages of untraceable and nonlinear error.In order to realize the measurement traceability of nanoscale resolution and ensure the accuracy of the measurement value, we use laser interferometer to calibrate the capacitor sensor, so as to form a complete traceability chain of nanometer microtable-capacitance sensor-laser interferometer. The maximum deviation of the measured value between the capacitance sensor and the laser interferometer at 10nm step is 0.8nm, and the resolution of the nano stages is 2nm in the capacitance sensor resolution calibration experiment.The above results show that the calibration method is feasible and practical.
2023 Vol. 44 (8): 1196-1201 [Abstract] ( 122 ) HTML (1 KB)  PDF (529 KB)  ( 139 )
1202 The Method to Measure Small Angle by Two-arm Non-common Path Non-localized Interference of Point Light Source
ZHANG Bao-wu,CUI Jian-jun,OUYANG Ye-feng,CHEN Kai,FANG Zhen-yuan
DOI: 10.3969/j.issn.1000-1158.2023.08.08
In order to enhance the measurement precision of the small angle, a method to measure small angle by two-arm non-common path non-localized interference of point light source is presented. In the method, the angle measurement system is built by establishing the theoretical model of small angle measurement, and the interference concentric rings are recorded by the CCD without lens and small pixs on the large target surface. The principle of the method is to fit a series of rings and circle center positioning method by multi-ring regression with both dark ring and bright ring. The method can measure the lateral shift of the center of the circle with high precision, and complete the comparison measurement experiment with the laser interference small angle measuring instrument. For the proposed angle system, the results show that the maximum fluctuation of the stability is -2.46″ in the x direction, and -1.92″ in the y direction within three hours; the repeatability had good agreement with the small angle laser interference within ±0.50″ which has a maximum deviation of -0.45″.
2023 Vol. 44 (8): 1202-1207 [Abstract] ( 110 ) HTML (1 KB)  PDF (566 KB)  ( 48 )
1208 Investigation on Calibration Method of NTC Thermistor Thermometer Applied to Integrated Circuit Research on Calibration Method of NTC Thermistor Thermometer Used in Integrated Circuit
LI Jia-hao,SUN Jian-ping,LI Ting,WANG Hong-jun,WANG Guang-yao,CHEN Ze-chuan,GAO Chuan-ji
DOI: 10.3969/j.issn.1000-1158.2022.08.09
Aiming at the requirement of near mK temperature measurement accuracy of intgrated circuit (IC) in the range of 21～23℃, the influence of the calibration method of negtive temperature coefficient (NTC) thermistor thermometer on the temperature measurement accuracy of IC is studied. The coefficients of the Basic, Hoge-1, and Steinhart-Hart equations are calculated using the least-squares method, and the interpolation residuals of the calibration eqution are analyzed to evaluate the feasibility of the low-order accurate calibration equation for high-quality temperature measurement and control of IC fabrication processes. The results show that the standard deviations of the residuals of the Basic equation, Steinhart-Hart equation, and Hoge-1 equation are 2.29mK, 0.63mK, and 0.65mK, respectively; the Basic exponential eqution with two calibration points has the worst performance, and the Hoge-1 equation with three calibration points shows the best interpolation performance, which is valuable for accurate temperature measurement in narrow temperature regions of IC.
2023 Vol. 44 (8): 1208-1213 [Abstract] ( 146 ) HTML (1 KB)  PDF (476 KB)  ( 245 )
1214 Research on Automatic Calibration System of Multiple Digital Thermo-hygrometers Based on Machine Vision
ZHOU Yi,PAN Yong-gao,MIN Qi-tao,YAO Jian,LI Jun,CHEN Lu,MIAO Wen-jiao
DOI: 10.3969/j.issn.1000-1158.2023.08.10
In order to solve the problems of low working efficiency of the traditional calibration device for digital thermo-hygrometers which is unable to meet the growing demand and the data by manual record cannot be rechecked and traced. Using machine vision technologies such as image segmentation, processing, character recognition and so on. An automatic calibration system for multi-meter digital thermo-hygrometers is designed based on LabVIEW. More than 10 models and a total of 30 digital thermo-hygrometers were used for automatic calibration experiments. The experimental results show that the recognition accuracy of the automatic calibration system is more than 99.3% and the calibration results can be ensured to be correct through manual recheck, which verified the reliability of the automatic calibration device and system.
2023 Vol. 44 (8): 1214-1221 [Abstract] ( 130 ) HTML (1 KB)  PDF (1112 KB)  ( 297 )
1222 Image Reconstruction of Planar Electrical Capacitance Tomography Based on Compressed Sensing Algorithm
ZHANG Li-feng,ZHANG Bo-xiong,HUA Hui-chun
DOI: 10.3969/j.issn.1000-1158.2023.08.11
Image reconstruction algorithm based on compressed sensing theory is proposed for planar electrical capacitance tomography (PECT). According to the relation between capacitance measurements of the planar array electrode and the distance between the electrode pairs,the number of independent measurements is cut down. Based on the ill conditioned characteristics of image reconstruction and the sparsity of dielectric constant of defect model,the gradient projection (GPSR-BB) algorithm based on compressive sensing theory is applied to PECT. The simulation and experiment of composite defect detection are carried out using GPSR-BB algorithm and compared with LBP algorithm,Tikhonov regularization algorithm and Landweber algorithm. Results show that the quality of reconstructed images is obviously improved.
2023 Vol. 44 (8): 1222-1228 [Abstract] ( 115 ) HTML (1 KB)  PDF (747 KB)  ( 419 )
1229 Experimental Investigation of a Reciprocating Double-plunger Gas Flow Standard Device
XU Chun-wei,ZHANG Gao-ming,XU Zhi-peng
DOI: 10.3969/j.issn.1000-1158.2023.08.12
To solve the problems of restricted dimension of cylinder and limited flow range of the plunger gas flow standard devices, a reciprocating double-plunger gas flow standard device was developed, operating modes including single-cylinder, parallel double-cylinder and tandem double-cylinder modes were explored. For different operating modes, the repeatability and accuracy of the device were verified by the calibration experiment of a sonic nozzle with the nominal flow rate of 0.06m3/h. Results revealed that the repetitive rate of the device was less than 0.02% at different modes, the errors of the device at single-cylinder and parallel double-cylinder modes were less than 0.02%, while the error of the device at tandem double-cylinder mode was less than 0.05%.
2023 Vol. 44 (8): 1229-1234 [Abstract] ( 114 ) HTML (1 KB)  PDF (786 KB)  ( 49 )
1235 Minimum-deviation Demodulation Algorithm for Measurement of Fiber Optic Pressure Sensors
SHEN Ya-feng,JIANG Yi,SUI Guang-hui
DOI: 10.3969/j.issn.1000-1158.2023.08.13
When the gas pressure measurement is performed with fiber optic pressure sensors based on EFPI structures, a high-resolution cavity length measurement method is required, because the sensor structure determines that the dynamic range of the cavity length is relatively small. A high precision minimum-deviation cavity-length demodulation algorithm is proposed and experimentally demonstrated. The absolute cavity length of an optical fiber pressure sensor based on EFPI structure is recovered by using the demodulation algorithm. Through sealing an EFPI fiber optic pressure sensor in a pressure standard source, the real-time measurement of gas pressure is realized. The experimental results show that the cavity length of the EFPI fiber pressure sensor has a good linear relationship and repeatability with the change of pressure. The repeatability of cavity length measurement is±1nm, the nonlinear error is 0.1496%,the repeatability of pressure measurement is 0.12%, and the accuracy of pressure measurement is better than 0.5%.
2023 Vol. 44 (8): 1235-1239 [Abstract] ( 141 ) HTML (1 KB)  PDF (539 KB)  ( 315 )
1240 Prediction of Residual Life of Rolling Bearing Based on N-BEATS Neural Network
SHI Pei-ming,SU Shi-min,MA Hui-zhong,XU Xue-fang,HAN Dong-ying
DOI: 10.3969/j.issn.1000-1158.2023.08.14
In order to effectively predict the remaining service life of the bearing, and to solve the problem of complex and unstable signal sequences collected during the prediction, resulting in low prediction accuracy and performance, the empirical mode decomposition is used to adaptively decompose the signal sequence, the dynamic time warping algorithm is used to screen the main degradation features, and the trend features of the signal sequence are extracted. The deep neural network N-BEATS with residual principle is used for prediction. For the problem of less prediction history data, the prediction structure combining recursion and direct is used to predict the remaining life in multiple steps. Comparing N-BEATS with long-term and short-term memory neural network and grey prediction model, the results show that the average absolute error of the prediction results of the proposed method is increased by 3.2% and 3.3% respectively compared with LSTM and grey prediction model under different working conditions, the relative root mean square error increased by 3.5% and 3.1% respectively.
2023 Vol. 44 (8): 1240-1247 [Abstract] ( 115 ) HTML (1 KB)  PDF (843 KB)  ( 147 )
1248 Research on Intermediate Checks Scheme of Automatic Verification System of Electric Energy Metering Instruments Based on INSGA-Ⅱ
LI Liang-bo,XIE Jin-fang,GENG Rui,TIAN Tian
DOI: 10.3969/j.issn.1000-1158.2023.08.15
In order to achieve the multi-objective requirements of high quality, high efficiency and low cost of the automatic verification system of electric energy metering instruments intermediate checks, a mathematical model was established to minimize the comprehensive verification cost and maximize verification efficiency. To solve the model, an improved fast non-dominated multi-objective optimization algorithm (INSGA-Ⅱ) was proposed, which improved the searching ability of the population by designing a multi-point crossover mutation strategy, and using perturbation population to improve the diversity of the population and prevent the population from falling into local optimum. The effectiveness and feasibility of the model and algorithm were verified by example simulation and algorithm comparison. The results showed that INSGA-Ⅱ algorithm can effectively obtain the non-dominated solution of the problem, which is of guiding significance to improve the verification quality, verification efficiency and reduce the verification cost. Finally, the optimal solution of the model was applied to the intermediate checks of the automatic verification system of low-voltage current transformer in Hubei Electric Power Metering Center of State Grid, and the control chart was drawn to monitor the operation status of the verification system online, which ensured that the measurement process was always in the state of statistical control.
2023 Vol. 44 (8): 1248-1255 [Abstract] ( 140 ) HTML (1 KB)  PDF (642 KB)  ( 47 )
1256 Rapid Screening Method of High Moisture Content Contraband Based on ECT and Deep Learning
HE Yong-bo,ZHANG Shu-hao
DOI: 10.3969/j.issn.1000-1158.2023.08.16
In order to realize the non-invasive and rapid screening of high moisture content contraband by the customs, a detection method combining electrical capacitance tomography (ECT) technology and deep learning is proposed, and the feasibility study is carried out in the simulation environment. Firstly, the ECT sensor suitable for installation on the conveyor is designed, and different package models containing normal objects and contraband with high moisture content are constructed; Then, the capacitance signal data of different package models are obtained by capacitance sensor, and the two-dimensional and three-dimensional image reconstruction are carried out; Finally, in order to make up for the high error rate of manually observed package reconstruction image, a one-dimensional convolutional neural network (1D-CNN) model for adaptive extraction of capacitance signal features is constructed to predict and classify the package model. The experimental results show that the detection accuracy of the proposed method can reach over 98%, and the detection time of a single model is only 10-3 seconds, which can achieve rapid screening of high moisture content prohibited substances.
2023 Vol. 44 (8): 1256-1263 [Abstract] ( 85 ) HTML (1 KB)  PDF (660 KB)  ( 124 )
1264 Research on Pipeline Crack Detection Based on Microwave Circular Antenna Arrays
QIU Guo-hua,TIAN Shan-shan,YUAN Qin-wen
DOI: 10.3969/j.issn.1000-1158.2023.08.17
A fast nondestructive testing method based on microwave circular antenna arrays has been proposed. It is used to detect longitudinal and transverse joints of pipes. The inner diameter of the pipe used in the experiment was 5.4cm and 8cm respectively. Firstly, the HFSS simulation software is used for simulation to determine the single-mode transmission of microwaves in TE11 mode. Thereafter, the experimental systems were built, the antenna arrays transmit the signal generated by the vector network analyzer into the pipeline, and the antenna arrays receive the reflected wave from the detection pipeline and turn to the vector network analyzer. Pipes with two diameters were detected by different circular antenna arrays. The results indicate that an array of two antenna arrays can detect cracks in pipes with a inner diameter of 5.4cm, and six antenna arrays can clearly detect cracks in pipes with a inner diameter of 8cm. The detection effect of the antenna array is better than that of single-rod antenna. It is a useful exploration for the antenna array to detect pipeline cracks.
2023 Vol. 44 (8): 1264-1271 [Abstract] ( 116 ) HTML (1 KB)  PDF (740 KB)  ( 285 )
1272 Research on Saturation Absorption Frequency Stabilization System Based on Rb MEMS Vapor Cell
LIU Ya-lei,JIA Shuo,JIANG Zhi-yuan,WANG Jin,WANG Jian-bo,YUAN De-cheng,LIN Ping-wei,MA Ai-wen,QU Ji-feng
DOI: 10.3969/j.issn.1000-1158.2023.08.18
A microfabricated rubidium (Rb) atomic vapor cell is fabricated through micro-electro-mechanical system (MEMS) fabrication technology, which is applied to saturated absorption spectra and laser frequency stabilization. To achieve the three cavities glass-silicon-glass ‘sandwich’ structure, deep reactive ion etching and anodic bonding processes are adopted. Saturated absorption spectra frequency stabilization system based on Rb MEMS atomic vapor cell is built with an external cavity semiconductor laser with at 780nm. The MEMS vapor cell is heated and temperature controlled, and the saturated absorption spectra at different temperatures and optical powers are analysed. The experiment adopts the beat frequency method by two lasers after the laser frequency is locked through lock-in amplifier to evaluate the performance of the system. Experimental result shows that frequency stability of 1s and 100s integration time is 2.7×10-11 and 6.3×10-12.
2023 Vol. 44 (8): 1272-1276 [Abstract] ( 144 ) HTML (1 KB)  PDF (696 KB)  ( 412 )
1277 Study on the Measurement of Low Energy X-ray Air Kerma Based on Proportional Counter
QIN Feng,WU Jin-jie,LI Meng-yu,LU Ping-zhou,QU Bing-bing,JIAO Zhi-wei,TANG Xian-qiang,ZHU Wei-feng,ZHAO Rui
DOI: 10.3969/j.issn.1000-1158.2023.08.19
In order to accurately measure low-energy and low-dose-rate X-ray, based on 10~60kV X-ray machine, seven reference radiation quality were established by adding additional filtration on the basis of low air kerma series radiation quality. The energy spectrum of radiation quality by Monte Carlo simulation program were obtained, and half-value layer and average energy were calculated. The proportional counter was used to complete the measurement of the energy spectrum. The results showed that the relative deviation between the simulated energy spectra and measured spectra does not exceed 6%. By used PTW34047 ionization chamber, the measurement of air kerma rate was completed by successive substitution method. The proportional counter was calibrated and the energy spectrum-dose conversion function was obtained. Finally, the energy spectrum-dose conversion function was verified, and the deviation from the results obtained by the ionization chamber method is not more than 3.8%. Verified by AT1123 survey meter, the relative deviation is within 9%.
2023 Vol. 44 (8): 1277-1283 [Abstract] ( 128 ) HTML (1 KB)  PDF (521 KB)  ( 86 )
1284 Selection and Application of Spectral Data Preprocessing Strategy
SUN Jia-hao,ZHANG Wei,SHI Jian-qin,LI Yan-kun
DOI: 10.3969/j.issn.1000-1158.2023.08.20
Spectral pre-processing is an important link in the establishment of spectral measurement metrology model, and at present, many spectral preprocessing methods have appeared. Based on the purpose and effect of the pretreatment, the origin, developments, theories, characterizes and actual application examples of common spectral preprocessing methods in scatter correction, scaling, smoothing, baseline correction and noise filtering areas were reviewed. According to the problems existing in the application of preprocessing methods, the principle, developments and characteristics of the ensemble strategy of preprocessing methods were discussed, and its research trend and development prospect were analyzed, for providing basis and references for the selection of spectral preprocessing methods and strategies.
2023 Vol. 44 (8): 1284-1292 [Abstract] ( 158 ) HTML (1 KB)  PDF (458 KB)  ( 526 )
1293 Evaluation of the Uncertainties of Continuous Measurement for Methane in the Atmosphere
CUI Hu-xiong,CHAI Wen-xuan,WANG Ying,FU Qing-yan
DOI: 10.3969/j.issn.1000-1158.2023.08.21
The global climate change caused by the increase of methane concentration in the atmosphere has become a hot spot in the world. In order to accurately study the variation of methane concentration in the atmosphere, it is extremely important to understand and master the uncertainty of methane measurement. On-line gas chromatography is used to measure methane in the atmosphere, the main sources of uncertainty in the measurement process are analyzed, and each uncertainty component is quantified and evaluated. The results show that the expanded uncertainty is 100nmol/mol(k=2, P=95%) when methane concentration is 2000nmol/mol. According to the analysis, it is found that the uncertainty of online measurement of methane in the atmosphere are mainly introduced by the dilution and preparation of standard gases and the fitting of standard curves
2023 Vol. 44 (8): 1293-1297 [Abstract] ( 131 ) HTML (1 KB)  PDF (343 KB)  ( 226 )
1298 Measurement of the Purity of Oxytocin by Quantitative Nuclear Magnetic Resonance Method with Deconvolution
HUANG Ting,ZHANG Wei,LI Hong-mei
DOI: 10.3969/j.issn.1000-1158.2023.08.22
Oxytocin is an important peptide, and it was chosen as the target analyte of the purity metrological international comparison, representing the type of peptide with molecular weight <5000, cross-linking, and non-modification. A quantitative nuclear magnetic resonance method with deconvolution was established to measure the purity of the oxytocin sample containing many structurally similar impurities. Appropriate internal standard (acesulfame potassium), solvent (deuterium oxide), quantitative peak (phenyl protons at chemical shift=7.1) and experimental parameters were selected. Through deconvolution analysis, the areas of three impurity peaks overlapping with the quantitative peak were obtained. After deducting the areas of impurity peaks, the purity of the oxytocin sample was accurately determined. The mentioned method was applied to participate in that international comparison, and its result (785.8mg/g, with expanded uncertainty of 15.4mg/g) was consistent with the reference value of the comparison (787.2mg/g, with expanded uncertainty of 12.9mg/g). Moreover, compared with other common methods, the method has the advantages of simple operation, short analysis time and low cost. The results show that the mentioned method is an accurate, rapid and simple method for peptide purity determination.
2023 Vol. 44 (8): 1298-1302 [Abstract] ( 99 ) HTML (1 KB)  PDF (447 KB)  ( 51 )
1303 ConvOS:An Interpretable Diagnostic Model for COVID-19 X-ray Imaging
JIAN Xian-zhong,YOU Guo-da,ZHANG Tao,ZHANG Zhen-wen
DOI: 10.3969/j.issn.1000-1158.2023.08.23
In order to improve the diagnostic accuracy of deep learning model in X-ray diagnosis of COVID-19 and improve the models interpretability, a novel visual diagnosis (ConvOS) model was designed by combining bilateral perturbation comprehensive Gradient significance graph optimization (IGOS++) algorithm and improved ConvNeXt network model. An efficient channel attention (ECA) module was introduced into the residual block of ConvNeXt network model, and IGOS++ was used to analyze the output characteristics of the improved ConvNeXt network model. The optimal insertion loss hyperparameters were obtained, and high-precision saliency maps were generated to improve the performance of visual interpretation and diagnosis of COVID-19 X-ray images. The experimental results on COVIDx dataset show that the accuracy, recall, accuracy and F1-score of ConvOS model reach 93.7%, 92.6%, 96.2% and 94.4%, respectively. Compared with other diagnostic models, the classification performance index is better, the region of interest (ROI) of significance graph is more accurate, and the diagnostic confidence of the model is higher.
2023 Vol. 44 (8): 1303-1309 [Abstract] ( 126 ) HTML (1 KB)  PDF (670 KB)  ( 336 )
1310 Exploration and Practice of Strengthening the Construction of Interdisciplinary Integration of Metrology and Related Disciplines
HUANG Le-fu,SONG Ming-shun,BAO Fu-bing,XU Hua
DOI: 10.3969/j.issn.1000-1158.2023.08.24
Metrology is the science of measurement and its application. Strengthening the construction of metrology discipline is an important technical talent support for the development of national metrology. Interdisciplinary integration is an effective way to promote the development of metrology discipline construction. Under the background of building a modern advanced measurement system in our country, the construction of metrology and related disciplines is promoted around colleges and universities, and the typical model of interdisciplinary integration is used for reference. Two cross integration modes, paths and examples of "metrology+discipline" and "discipline+metrology" are discussed and analyzed, and some construction experiences of China Jiliang University in the process of promoting practical exploration are introduced. It is hoped that the exploration and practice of cross-integration mode can provide reference and support for relevant universities to layout cross disciplinary fields related to metrology.
2023 Vol. 44 (8): 1310-1316 [Abstract] ( 128 ) HTML (1 KB)  PDF (423 KB)  ( 266 )
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