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2024 Vol. 45, No. 8
Published: 2024-08-28
 
1089 Low Light Level Spectral Responsivity Measurement System
Lü Liang,LUO Yupeng,JIANG Xiaomei,LIN Xiaofeng,PANG Bowen
DOI: 10.3969/j.issn.1000-1158.2024.08.01
To meet the spectral responsivity calibration requirements of photon counting detectors, a low light level spectral responsivity measurement system is established. The feature of this system is that it can achieve spectral comparison measurement at pW monochromatic light power level. An adjustable luminance source is designed, and it is tightly coupled with the dispersion subtractive double grating monochromator to achieve power variable monochromatic light output with six orders, which can be applied to the linear working range of different photon detectors, covering the wavelength range 330～1100nm. The light-tight designation of the light path enables the system to work under normal lighting conditions, reducing the experimental environment requirements. Based on a standard detector integrated with fA grade current amplifier, the spectral responsivity measurement of the photon detectors at 1×106photons/s count rate level is achieved. The controlling and data acquisition software are developed using LabView platform, which realizes the whole process of measurement automation. The characteristics experiment of the system has been carried out, and the relative spectral responsivity of photon detector are calibrated in the wavelength range from 330～1100nm with relative expanded uncertainty is (2.5～3.8)%, k=2.
2024 Vol. 45 (8): 1089-1095 [Abstract] ( 42 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
1096 Electromagnetic Tomography Algorithm Based on MLP-AE Network
JIA Hu,WANG Mingquan,SHANG Aoxue
DOI: 10.3969/j.issn.1000-1158.2024.08.02
Due to the limitations of physical models, the traditional algorithm of electromagnetic tomography (EMT) leads to the lack of reconstruction data, which makes its inverse problem have serious discomfort and pathology. In order to solve the problems of many artifacts and poor quality in the reconstructed images, a composite electromagnetic tomography algorithm based on MLP-AE is proposed. Firstly, the field information of the object to be tested is sent to the self-coding neural network (AE) for learning as input to obtain the encoded data. Then the electromagnetic excitation of the measured object field is carried out to obtain voltage data. The voltage data is taken as input, and the data after encoding the field information of the DUT is sent to the MLP neural network for learning as output. Finally decoding enables end-to-end image reconstruction. The performance of the proposed algorithm is evaluated by mean squared error, structural similarity index and imaging time, and compared with the linear backprojection algorithm, Tikhonov regularization algorithm, and Landweber iterative algorithm. The experimental results show that the proposed algorithm reduces the mean squared error by 28.77%, 22.57% and 23.74% compared with the above traditional algorithms on a single image, the structural similarity index is increased by 17.54%, 14.38% and 15.44%, and the imaging time is 73.78%, 98.63% and 93.86% faster, respectively. It provides an idea for real-time accurate imaging later.
2024 Vol. 45 (8): 1096-1102 [Abstract] ( 25 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1103 The Comparison of Ultraviolet Regular Transmittance
FENG Guojin,ZHANG Qiaoxiang,ZHENG Chundi,GAN Haiyong,WU Houping,LI Yuxiao,LIANG Fengchen
DOI: 10.3969/j.issn.1000-1158.2024.08.03
In order to ensure the consistency of UV transmittance values in China with those in the world, the National Institute of Metrology, China, participated in the first research comparison of ultraviolet regular transmittance organized by COOMET during 2018 to 2019. This comparison uses 4 sets of solutions as comparison samples, the nominal value of transmittance covers 5%～90%, and the wavelength range covers 235nm～350nm. The comparison results show that the measurement results of each reference laboratory are basically equivalent and consistent. When the transmittance is 50%, the deviation between ours and the international reference value can not exceed 0.12%. When the transmittance is near 20%, the deviation between ours and the international reference value is less than 0.08%. For 10% transmittance, the deviates quantity is no more than 0.03%.
2024 Vol. 45 (8): 1103-1107 [Abstract] ( 34 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1108 Research on the Influence of Robot Geometric Parameter Calibration Error Model on Positioning Accuracy
WANG Dongxia,TANG Ying,LI Guocheng,WEN Xiulan,QIAN Kui
DOI: 10.3969/j.issn.1000-1158.2024.08.04
The geometric parameter error of robots is the main factor affecting the positioning accuracy of robots, and the positioning accuracy of robots can be effectively improved by calibrating the geometric parameters.In order to solve the singularity problem of robots in the calibration process, improved Denavit-Hartenberg (MDH) method is adopted to establish the geometric parameter model of robots.Based on the principle of differential error, the full position error, position error, and attitude error models of robot geometric parameter calibration are established.The redundancy of geometric parameters and identifying geometric parameter errors are analyzed by using Levenberg-Marquardt(LM) algorithm and the influence of different error models on robot positioning accuracy are studied.The experimental results show that the accuracy of both position and attitude can be improved by about 75% after the geometric parameters are be calibrated based on the full position error model.And it is suitable for promotion and application in robots with high-precision positioning requirements.
2024 Vol. 45 (8): 1108-1114 [Abstract] ( 36 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1115 Research on Error Compensation and Fitting Algorithms of Wafer Alignment Calibrator
LIU Tundong,CHEN Zengyan,WANG Ruoyu,TANG Zhichen,ZHENG Peng
DOI: 10.3969/j.issn.1000-1158.2024.08.05
Wafer alignment calibrator plays a crucial role in semiconductor manufacturing and inspection processes. However, the accuracy of wafer center positioning can be affected by measurement errors. Consequently, the development of error compensation algorithms is paramount to refining the accuracy of wafer alignment calibrator. To address the impact of wafer carrier surface tilt on sampling accuracy, a physical model of a tilted wafer and its elliptical projection on the horizontal plane is established. An analytical relationship between the ellipse and the wafer center is derived from this model. Subsequently, an elliptical equation is employed for fitting purposes. To further enhance compensation and fitting accuracy, an extended Kalman filter-based ellipse fitting algorithm with a forgetting factor is proposed. This algorithm employs density-based spatial clustering of applications with noise for data preprocessing, coupled with improved progressive consistent sampling to improve the distribution of sample points. Additionally, an iterative reweighted least squares method is applied for ellipse fitting, resulting in high-precision estimation of the wafer center. Experimental results demonstrate that the proposed method achieves a fitting accuracy of 99.95% after error compensation, thus validating its effectiveness.
2024 Vol. 45 (8): 1115-1124 [Abstract] ( 38 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1125 Study on On-site Reproduction Method of Shipborne Miniature Ga-In Eutectic Fixed Point
ZHU Xingfu,PAN Jiang,WANG Guangyao,DIAO Fuguang,SUN Jianping,LI Ting,WANG Pengyu
DOI: 10.3969/j.issn.1000-1158.2024.08.06
Application of fixed point thermometry technology to the field calibration of shipbrone sensors is a key strategy for achieving flattening in temperature measurements and enhancing the accuracy of oceanic temperature measurements. The fixed points defined by ITS90 in the temperature from -5℃ to 35℃ is inadequate, which blocks the accuracy improvement of the marine NTC thermistors. A new miniature Ga-In eutectic fixed point was developed, and the reproducibilities of the fixed point in temperature controlled box and ambient environment were investigated. Two methods including the tangent intersection method and cubic polynomial fitting were used to obtain the values of the temperature plateaus. The results showed that the reproducibility of the miniature Ga-In eutectic fixed point is better than 1mK. In order to obtain better performance, the miniature Ga-In eutectic fixed point should be kept in solid state at temperature below its melting point. Using the tangent intersection method, the phase transition temperature of the miniature Ga-In eutectic fixed point is determined to be 15.6549℃,with an expanded uncertainty of 1.54mK(k=2).
2024 Vol. 45 (8): 1125-1131 [Abstract] ( 13 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1132 Jointly Improved Sparse Regularization ECT Image Reconstruction Algorithm
MA Min,SUN Ni
DOI: 10.3969/j.issn.1000-1158.2024.08.07
To improve the ill-conditioned and ill-posed problem in the inverse problem solving process of electrical capacitance tomography (ECT), a jointly improved sparse regularization image reconstruction algorithm is proposed. Firstly, the sensitivity matrix is optimally preprocessed by the adaptive truncated singular value algorithm to eliminate the redundant information in the matrix. Secondly, in order to enhance the sparsity and stability of the solution, the L1-αL2 sparse regularization is jointly improved based on the optimized sensitivity matrix to construct new convex function terms. Finally, the solution is performed by the fast iterative threshold shrinkage algorithm to accelerate the iterative convergence speed. The improved algorithm achieves an average correlation coefficient of 0.8813 in the reconstructed image, the image error is reduced to 0.2111 on average, and the imaging speed is kept within 0.10s. The simulation and experimental results show that the improved algorithm improves the ill-posed and ill-condition degree and enhances the image reconstruction accuracy while having strong robustness and real-time performance.
2024 Vol. 45 (8): 1132-1138 [Abstract] ( 29 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1139 Image Reconstruction of ECT Based on Multi-scale Adaptive Network
ZHANG Lifeng,CHANG Enjian
DOI: 10.3969/j.issn.1000-1158.2024.08.08
In order to solve the nonlinear ill-posed inverse problem of electrical capacitance tomography (ECT), a multi-scale adaptation network (MSANet) model is proposed, which achieves the fusion of multi-scale features in a more fine-grained dimension and has a relatively small number of model parameters.By constructing a tree structure within a single residual block to form a multi-scale feature fusion module, MSANet achieves more robustness and lower computational parameters. Furthermore,by adding an adaptive spatial threshold module, the reconstruction accuracy of the images is further improved. Compared with linear back projection (LBP) algorithm, Landweber iterative algorithm,and commonly used deep learning methods, this method has the smallest average relative error and the largest average correlation coefficient,with 0.181 and 0.967, respectively.
2024 Vol. 45 (8): 1139-1146 [Abstract] ( 20 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1147 Image Reconstruction of ECT Based on Second-order Hybrid Sensitivity Matrix
CHEN Da,ZHANG Lifeng,FAN Zhenping
DOI: 10.3969/j.issn.1000-1158.2024.08.09
The use of electrical capacitance tomography technology to solve image reconstruction problems is a nonlinear problem. Usually, only the linear part of the sensitivity coefficients is preserved in the derivation process of sensitivity. However, the neglected nonlinear part also contains important imaging information. In order to improve the accuracy of image reconstruction, a second-order hybrid sensitivity matrix is established based on the mathematical definition of the second-order sensitivity coefficient, combined with fuzzy C-means clustering algorithm and electric field center line theory, and the matrix is introduced into the Landweber algorithm, proposing the second-order hybrid Landweber algorithm. Finally, simulation and static experiments are conducted and compared with the traditional Tikhonov and first-order Landweber algorithm, the results show that the second-order hybrid sensitivity matrix can improve the image reconstruction accuracy.
2024 Vol. 45 (8): 1147-1154 [Abstract] ( 17 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1155 OpenFOAM-based Study of Hydrogen Sonic Nozzle Outflow Characteristics
XIANG Yuhan,HUANG Zhenwei,LI Chunhui,CAO Peijuan,XIE Dailiang
DOI: 10.3969/j.issn.1000-1158.2024.08.10
The OpenFOAM numerical simulations, combined with the experimental measurements of the high-pressure pVTt gas flow standard device of the National Institute of Metrology, was conducted for the three sonic nozzles with throat diameters of 0.32mm, 1.01mm and 3.20mm. The effect of flow state and metrological characteristics resulted from gas media were quantitively investigated within the laminar flow range of 4.14×103～8.21×105 throat Reynolds number. The results show that the difference of discharge coefficients between hydrogen and helium is within 1.14%, while the difference of discharge coefficients between hydrogen and air is within 0.45%.
2024 Vol. 45 (8): 1155-1161 [Abstract] ( 29 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1162 Study on Flow Characteristics of Multiphase Flow in Internal Transport of Hydrate Phase Transition
TAO Junao,ZHANG Huoming,CHEN Guoqing,LU Pinglan
DOI: 10.3969/j.issn.1000-1158.2024.08.11
The natural hydrate will decompose due to the change of pressure during the lifting process of the flexible riser, and the phase change process will flow from the solid-liquid two-phase flow at the bottom of the riser to the gas-liquid-solid three-phase flow at the top of the riser. Based on the computational fluid dynamics (CFD) method, the catenary linear flexible riser model was established by FLUENT, and the Euler multiphase flow model was used to simulate the hydrate decomposition process by combining the UDF source term, and the flow characteristics of hydrate in the riser under different influencing parameters were obtained. The results show that the increase of particle volume fraction and suspension angle can increase the gas holding capacity in the riser, thereby reducing the energy consumption of hydrate transportation. The increase of inlet speed can increase the particle velocity at the outlet of the riser, so that the gas holding rate in the pipeline is reduced, and the increase of speed will increase the energy consumption of the required pump. The increase of particle volume fraction increases the gas holding rate in the riser, and the energy consumption of the required pump first decreases and then increases, there is an optimal value for particle volume fraction. In the actual project, the purpose of reducing energy consumption can be achieved by adjusting the relevant parameters according to needs.
2024 Vol. 45 (8): 1162-1169 [Abstract] ( 23 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1170 Performance Analysis and Optimization of Microgram Monomer Weighing Mechanism Based on Elliptical Flexure Hinge
ZHU Jinhui,WANG Jian,JIANG Wensong,LUO Zai
DOI: 10.3969/j.issn.1000-1158.2024.08.12
To improve the sensitivity of single weighing mechanism, the performance of microgram monomer weighing mechanism was analyzed and optimized, and the mathematical model of the weighing mechanism based on elliptical flexure hinge was established. The sensitivity of the weighing mechanism was evaluated by the end displacement of the beam of the weighing mechanism. The influence of elliptical and circular hinge on the sensitivity of the weighing mechanism was verified by changing the hinge thickness in different parts. The accuracy of the model was verified with Ansys Workbench finite element simulation software, and the evaluation basis for the mesh division of flexible hinges was given. The results show that the minimum error of the model is 1.8%, and under 1μg load, the end displacement of elliptical hinge increases by 0.39nm compared with circular hinge.
2024 Vol. 45 (8): 1170-1176 [Abstract] ( 25 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1177 Experimental Study on Volume Determination of Weights by Double Weighting in Air Method
SU Yi,XIONG Zhongqi,ZHENG Xiaolan,CHENG Liyuan
DOI: 10.3969/j.issn.1000-1158.2024.08.13
A comparative experimental study was conducted on the volume determination of standard weights with a mass of 1g~5kg, using the double weighing in air method and the hydrostatic method. A method for measuring the volume of auxiliary weight plates was proposed, which solved the problem of small weights ranging from 1g to 5g that cannot be directly loaded onto the scale plate. The uncertainty of weight volume measurement was evaluated by Monte Carlo method, and it was found that the consistency of the weight volume and its uncertainty measured by the double weighing method and hydrostatic method was very good, and the relative uncertainty of the weight volume decreased with the increase of the nominal mass when the nominal mass of the weights was 1g~1kg, and increased with the increase of the nominal mass when the mass was more than 1kg.
2024 Vol. 45 (8): 1177-1183 [Abstract] ( 24 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1184 Explicit Expression of Load Transferred Law Inside Structure Based on Semi-Analytic Finite Element Method
WANG Zhaohua,LIAN Hui,WU Fenghe,HUANG Bingxiao,YANG Chenglong,SUN Yingbing,WANG Chaoshi
DOI: 10.3969/j.issn.1000-1158.2024.08.14
Aiming at the problem of quantitative expression of load transferred law inside a given structure, a visualization method of load transferred law based on semi-analytical finite element method is proposed. The basic principle of calculating the load transferred amount in the local area is defined. Based on the semi-analytic finite element method, the mathematical expression of the load transferred calculation is derived. The continuous removal and recovery of local materials in the structure is simulated by using the element life and death technology. And the visualization process of load transferred law is given through secondary development. Taking rectangular cantilever plate, plate with hole, three-point bending plate and bending beam as examples, the load transferred law inside the structure are calculated respectively. The quantitative expression of the load transferred law not only gives the size of the load transferred in local region, but also gives the direction of the load.
2024 Vol. 45 (8): 1184-1190 [Abstract] ( 25 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
1191 Sound Level Meter Reading Recognition Method Based on Improved DBNet-CRNN
WANG Jia,ZHU Haijiang,WANG Yinchu,HE Longbiao,YANG Ping,NIU Feng
DOI: 10.3969/j.issn.1000-1158.2024.08.15
In order to improve the work efficiency of the sound level meter calibration work, a reading detection and recognition method based on deep learning neural network for the image of the sound level meter is proposed. The reading detection model is based on DBNet and uses ShuffleNetV2 as the backbone network, significantly reducing the number of model parameters. To improve the accuracy of reading area detection, an efficient channel attention ECA module is introduced to enhance the network's ability to extract channel features. The optimized model reduces the number of parameters to 15.4% and the calculation amount to 67.4% while maintaining accuracy. The reading recognition model is based on the CRNN model, which first adds a batch normalization layer to improve the stability of network training. Then, residual blocks are introduced to replace the original convolutional blocks, improving the network's ability to extract complex features. Applying Dropout to the network to improve its generalization ability. In addition, pre-training the reading recognition model on the synthesized reading dataset effectively increases the accuracy of the model. The improved method achieves an accuracy of 99.7%, which is 2.4% higher than the original method. The experimental results show that this method has strong robustness against factors such as diverse fonts, uneven lighting, and blurring in sound level meter images, and has high recognition accuracy for readings in sound level meter images.
2024 Vol. 45 (8): 1191-1199 [Abstract] ( 34 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1200 Image Denoising Method for Insulator Defect Detection Based on Adaptive BM3D
SHI Peiming,YUAN Qunmao,XU Xuefang,KAN Junming
DOI: 10.3969/j.issn.1000-1158.2024.08.16
Due to the influence of the shooting environment, the acquired image is often mixed with noise, which easily affects the accuracy of insulator defect detection. To solve this problem, an adaptive BM3D noise reduction method is proposed. First, a noise estimation algorithm based on the statistical relationship between the noise level and the eigenvalue of the image block covariance matrix is introduced to solve the problem that the original BM3D algorithm needs prior knowledge. Second, taking the peak signal to noise ratio (PSNR) as the objective function, the optimal parameters of the insulator image under each noise intensity are obtained by quantum genetic algorithm, including the hard threshold parameter and the distance threshold in the basic estimation, and the distance threshold in the final estimation. Finally, taking the noise intensity as the independent variable, the fitting curve of the above three parameters are obtained by polynomial fitting, so as to obtain the optimal parameters combination of the algorithm under each noise intensity, and realize the rapid parameter adaptation of BM3D algorithm under different noise levels. The results of comparative experiments indicate that the proposed method is superior to other methods in terms of visual and objective evaluation indexes. When the noise standard deviation is 25, the proposed method improves PSNR, structural similarity (SSIM) and edge preserve index (EPI) compared with the original BM3D algorithm, especially the EPI value increases by nearly 20%. While improving the noise reduction effect, it can retain more edge details, which is helpful to improve the effect of subsequent insulator identification and defect detection.
2024 Vol. 45 (8): 1200-1208 [Abstract] ( 20 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1209 Joint SOC and Capacity Estimation of Lithium Battery Based on Adaptive H∞ Observer
WU Zhongqiang,CHEN Haijia
DOI: 10.3969/j.issn.1000-1158.2024.08.17
In order to improve the estimation accuracy of lithium battery SOC, based on adaptive H∞ observer a joint estimation method of lithium battery SOC and capacity is proposed. Based on the second-order RC equivalent circuit model of lithium battery, and the coupling relationship between SOC and capacity is considered, the capacity of lithium battery is also observed as the state variable of the system. An adaptive H∞ observer is designed. The parameters of the observer can be adjusted adaptively with the state change of lithium battery. Since the influence of capacity is considered in SOC estimation, the adaptive H∞ observer can realize the simultaneous accurate estimation of SOC and capacity. The experimental results show that the adaptive H∞ observer has high estimation accuracy and strong robustness. The average SOC estimation error of the battery is always within 0.43%. Compared with EKF and H∞ observers, the adaptive H∞ observer has higher estimation accuracy and stability.
2024 Vol. 45 (8): 1209-1215 [Abstract] ( 22 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1216 Calibration Technology of Low-frequency Electric Field Strength Basing on the Method of Standard Field
ZHAO Pinzhang,FENG Tieying,SUN Jianhui,CHEN Yulong,Song Guangming
DOI: 10.3969/j.issn.1000-1158.2024.08.18
In order to realize the calibration of low-frequency electric field measuring instrument, the low-frequency electric field measurement technology based on the standard field method is discussed. The structure and the working principle of the field meter is given, the method of generating the calculable standard electric field by parallel plates is analyzed, then the calibration system is built. The system is applied to carry out calibrating experiment, the sources of error are analyzed, and the uncertainty of measurement result has been evaluated. Another method basing the TEM cell is applied to verify the calibration result, and the comparison data shows that the calibration result of this calibration system is acceptable and reliable, which meets the calibration requirements of typical low-frequency electric field measuring instruments.
2024 Vol. 45 (8): 1216-1221 [Abstract] ( 27 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1222 Research on Battery Capacity Decline Prediction Based on Improved Algorithm of Traceless Particle Filtering
GUO Ruijun,XIN Yongqiang,YANG Jianfeng
DOI: 10.3969/j.issn.1000-1158.2024.08.19
In order to improve the accuracy and applicability of battery capacity prediction, an improved algorithm based on traceless particle filtering is proposed. In order to reduce the observation error of the filtering iteration process, a support vector regression algorithm is introduced to improve it. Since the kernel function and penalty factor in the support vector regression algorithm are difficult to determine, it is proposed to use the optimization ability of the genetic algorithm to solve it, forming a model improved by the genetic algorithm and support vector regression. The performance of this fusion model is evaluated and compared with UPF-SVR and UPF-RVR, and the experimental results show that the mean absolute error EMAand root mean square error SRMSE of the fusion model prediction results are lower than 2.0% and 2.5%, respectively, and the prediction accuracy is higher compared with the other models, and at the same time, the prediction level and convergence are significantly better than other models, which is more effective and feasible.
2024 Vol. 45 (8): 1222-1230 [Abstract] ( 20 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1231 Measurement of Mass Attenuation Coefficients near Zn Absorption Edge
SHU Ziyao,GUO Siming,ZHOU Xing,HUANG Shikui,FAN Lipeng,LI Zhiwei,WANG Zhen
DOI: 10.3969/j.issn.1000-1158.2024.08.20
The exact value of the photon mass attenuation coefficient of a material needs to provide basic data for different fields.The monochromatic X-ray radiation device is an ideal device for the study of mass attenuation coefficient (μ/ρ) because the energy of the device is continuous and can be reconciled with the number of measured photons.The mass attenuation coefficient measurement method of Zn samples in the range of 8~20keV near the K absorption edge (9~11KeV) with 0.1keV step based on a monochromatic X-ray device is studied, and the experimental measurement values are compared with the NIST theoretical values.The results show that there is a maximum deviation near the K absorption edge jump, and the deviation decreases when moving away from the absorption edge.The measured curves are basically consistent with NIST-XCOM and NIST-FFAST curves, and the maximum deviation between the measured values and the theoretical values of NIST-XCOM is less than 10.51%.
2024 Vol. 45 (8): 1231-1235 [Abstract] ( 30 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
1236 Simulation Study of Radiation Energy Spectrum of SRT-100 Superficial X-ray Therapy System
BAO Junxia,ZHAO Rui,TANG Xianqiang,WU Jinjie,DING Weicheng,ZHANG Xiao,CHANG Maoyuan
DOI: 10.3969/j.issn.1000-1158.2024.08.21
Superficial treatment has shown good advantages in the repair of postoperative scars and the treatment of skin lesions. In order to study the radiation quality produced by SRT-100 superficial X-ray therapy system, EGSnrc software was used to simulate the energy spectrum at different tube voltages, and the energy spectrum was compared with the energy spectrum calculated by Spekcalc program. The result showed good agreement between them. The effect of different target angles of the X-ray tube on the half-value layer was studied, and the result showed that the larger the target angle, the smaller the half-value layer. The mean energy and the effective energy were calculated from the simulated energy spectrum. Compared with the results of Spekcalc, results displayed that the maximum deviation of the average energy and the effective energy are 0.7% and 5.8% respectively.
2024 Vol. 45 (8): 1236-1241 [Abstract] ( 28 ) HTML (1 KB)  PDF  (0 KB)  ( 2 )
1242 Study on the Detection of TP53-R273H/R273C Gene Mutation by Digital PCR
ZHANG Jiejie,NIU Chunyan,WANG Xia,YANG Jingya,DONG Lianhua
DOI: 10.3969/j.issn.1000-1158.2024.08.22
TP53 gene is the tumor suppressor gene and commonly used as the targeted detection gene in cancer.R273H and R273C are common hot spot mutations in TP53 gene detection.In order to establish a droplet digital polymerase chain reaction (ddPCR) detection method for these two mutations, two sets of ddPCR methods were designed for the mutation sites, and the specificity of the probe was verified.The annealing temperature and primer probe concentration were optimized.The results showed that the established method had good specificity and repeatability, and the correlation coefficients between ddPCR and weight method were 0.9997 and 0.9996,.The limit of detection of R273H and R273C were both 0.02%, and the limit of quantitation were both 0.05%.The methods can be used to accurately detect TP53-R273H and TP53-R273C gene mutations, providing strong support for clinical application.
2024 Vol. 45 (8): 1242-1248 [Abstract] ( 30 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )
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