Loading...

Archive

    For Selected: Toggle Thumbnails
    Information & Control
    A Transfer Learning Framework for EEG Emotion Recognition
    ZHAO Hai, WANG Xiang, SHI Han, CHEN Jia-wei
    2023, 44 (7):  913-921.  DOI: 10.12068/j.issn.1005-3026.2023.07.001
    Abstract ( 691 )   HTML ( 14)   PDF (655KB) ( 413 )  
    As the most representative signal of human emotion, EEG signal is becoming the mainstream signal source of emotion recognition. Transfer learning can overcome the problem of distribution difference between physiological signal source domain and target domain. The traditional transfer learning will have a negative impact on the transfer effect due to the lack of the selection process of samples and features, resulting in a low recognition rate. In order to improve the migration effect, this paper optimizes the migrated data in two aspects: samples and characteristics. A case selection method based on like value and an automatic feature selection method based on particle swarm optimization are introduced. Using JDA, a transfer learning framework for emotion recognition is proposed. Finally, two transfer learning tasks are constructed on the SEED dataset for verification. The results show that the framework can effectively improve the transfer effect and improve the accuracy of cross domain emotion recognition.
    References | Related Articles | Metrics
    Multi-constraint Optimal Puncture Path Planning Algorithm for Liver Cancer Ablation
    LIU Xiao-xi, JIANG Hui-yan, LUO Min
    2023, 44 (7):  922-930.  DOI: 10.12068/j.issn.1005-3026.2023.07.002
    Abstract ( 540 )   HTML ( 10)   PDF (1619KB) ( 326 )  
    Aiming at the problem that the classic puncture path planning algorithm does not consider the area around the path when quantifying the path, new constraints condition are proposed to make up for the lack of quantification of the information around the path. A strict constraint condition was proposed based on the blood vessel position information (the surrounding area avoids the blood vessel), and based on bone density, blood vessel density, and diameter information, three soft constraints (bone density, blood vessel density, and blood vessel risk) were proposed, and the surrounding information was added to the quantification of the path to improve the safety of the puncture path. In order to adapt to the specificity of patients, a soft constraint optimization degree scoring algorithm is proposed, and the weight is set according to the optimization degree of soft constraints, and the puncture path corresponding to the maximum optimization degree is taken as the optimal puncture path. In order to verify the effectiveness of the algorithm, experiments were carried out on the public dataset 3D-IRCADb. The experimental results show that the algorithm proposed in this paper can quickly calculate the optimal puncture path that meets the clinical needs.
    References | Related Articles | Metrics
    A Reconstruction Algorithm for Electromagnetic Vascular Tomography Image Based on Fractal-DenseNet
    YANG Dan, WANG Yu-jia, XIN Cai-ning, XU Bin
    2023, 44 (7):  931-937.  DOI: 10.12068/j.issn.1005-3026.2023.07.003
    Abstract ( 378 )   HTML ( 3)   PDF (1721KB) ( 158 )  
    In view of the lack of underdetermination and pathology in electromagnetic vascular tomography image reconstruction, a Fractal-DenseNet based vascular tomography image reconstruction algorithm is proposed. With the principle of vascular tomography image reconstruction based on the magneto-electric coupling effect of blood flow, combining FractalNet’s fractal idea with DenseNet’s dense connection idea, a Fractal-DenseNet network model suitable for the inversion of blood flow velocity distribution was built for the reconstruction of vascular tomography image. Based on the magneto-electric coupling measurement model of human forearm ulnar artery flow, the corresponding data pairs of vessel section velocity and voltage signal caused by magneto-electric effect of blood flow were established, which were respectively used as the input and the output of the network model. Through supervised learning, the image reconstruction based on the flow velocity distribution of the vessel is realized. The results show that the root mean square error and correlation coefficients of Fractal-DenseNet reconstruction are 0.0078 and 99.28%, respectively. The proposed model has good anti-noise performance and can be used to reconstruct vascular tomography images under complex boundary conditions.
    References | Related Articles | Metrics
    Materials & Metallurgy
    A Kinetic Model for Ferrite-Austenite Transformation
    LAN Hui-fang, LIU Ze-yang, WU Meng-ru
    2023, 44 (7):  938-943.  DOI: 10.12068/j.issn.1005-3026.2023.07.004
    Abstract ( 513 )   HTML ( 8)   PDF (628KB) ( 287 )  
    In this paper,based on the concepts of mixed model and Gibbs energy balance model, a simple Gibbs energy balance model was established to simulate the ferrite-austenite transformation of Fe-C-Mn low carbon steel during the intercritical annealing at 780℃. The effects of Gibbs free energy, effective grain size and alloying distribution on the transformation were studied. The results show that the initial effective grain size and interfacial mobility greatly affected the kinetics of phase transformation, while they had little effect on the final volume fraction of the austenite. The dissipation energy caused by the Mn enrichment at the interface during phase transformation slowed down the transformation kinetics and reduced the final volume fraction of the austenite. It is found that the modelling results above are in good accordance with the experimental ones.
    References | Related Articles | Metrics
    Dehydration, Decarburization and Digestion Performance of Gibbsitic Bauxite by Low-Temperature Roasting
    YANG Hu, PAN Xiao-lin, WU Hong-fei, YU Hai-yan
    2023, 44 (7):  944-952.  DOI: 10.12068/j.issn.1005-3026.2023.07.005
    Abstract ( 525 )   HTML ( 5)   PDF (1472KB) ( 186 )  
    The gibbsite bauxite pretreated by low-temperature roasting, the effects of roasting temperature and time on the dehydration and decarbonization of gibbsite ore and the digestion performance of calcined alumina were systematically studied by means of XRF, XRD and SEM. The results show that the ore quality greatly reduces after roasting and the obvious cracks are observed on the ore surface with lamellar structures. The gibbsite phase decreases and gradually changes to the boehmite, while the goethite changes to the hematite. When the roasting temperature is 400℃ and the roasting time is 30min, the mass fraction of crystal water in the ore is 7.54%, the dehydration ratio is 62.52%, the mass fraction of carbon is down to 0.11%, and the decarbonization ratio is 85.73%. When the digestion temperature of calcined ore is 145℃, the digestion time is 30 min, the mass concentration of circulating mother liquor caustic soda is 170g/L, and the actual digestion ratio of alumina is 81.51%, which is higher than that of the raw ore. The digestion kinetics results of calcined ore show that the digestion process of alumina is mainly controlled by internal diffusion, and the apparent activation energy is 42.71kJ/mol.
    References | Related Articles | Metrics
    Mechanical Engineering
    Gesture Recognition in the Complex Environment Based on Gan-St-YOLOv5
    HAO Bo, YIN Xing-chao, YAN Jun-wei, ZHANG Li
    2023, 44 (7):  953-963.  DOI: 10.12068/j.issn.1005-3026.2023.07.006
    Abstract ( 665 )   HTML ( 11)   PDF (2690KB) ( 272 )  
    During the human-computer interaction of gesture recognition in the complex environment of intelligent industrial production, gesture features are affected by local occlusion, strong illumination and small distant targets, leading to the reduction of gesture features recognized in the process of target detection and recognition, and even classification errors. Given that improving the accuracy of gesture recognition in the complex environment has become an urgent problem to be solved in human-computer interaction tasks, an innovative Gan-St-YOLOv5 model is proposed. On the basis of YOLOv5, GAN and Swin Transformer modules are integrated into SENet channel attention mechanism, and Confluence detection box selection algorithm is used to enhance the accuracy of model detection. In order to verify the superiority of the model, the YOLOv5 model is used for comparison and it is concluded that the mAP_0.5 of Gan-St-YOLOv5 is up to 96.1% on the fully visible test set, as high as 92.3% in the intense illumination test set, as high as 86.6% in the partial occlusion test set, and as high as 96.4% in the remote small target test set, all of which are superior to the YOLOv5 target detection algorithm and achieve higher accuracy with less efficiency loss.
    References | Related Articles | Metrics
    Life Analysis of Coupling Damage Between Sliding Wear and Contact Fatigue Based on Morris Method
    YAN Yu-tao, JIANG Cheng, GAO Lian-qi
    2023, 44 (7):  964-971.  DOI: 10.12068/j.issn.1005-3026.2023.07.007
    Abstract ( 486 )   HTML ( 2)   PDF (1180KB) ( 131 )  
    Aimed at a secondary system on the coupling damage of sliding wear and contact fatigue in linear contact, combining the modified Archard’s wear model, the critical plane method and the virtual crack extension method, an analysis model of the coupling damage between sliding wear and contact fatigue is developed. Based on the Morris sensitivity method, the contribution ratio of contact fatigue sensitivity is established. Furthermore, a life prediction method of the coupling damage of both sliding wear and contact fatigue is proposed based on the sensitivity contribution ratio. The results show that the coupling damage life is obviously less than the single damage life. The sensitivity of coupling damage is significantly affected by contact pressure, contact width and curvature radius, and the contribution ratio of contact fatigue damage is basically linear with key parameters. The coupling damage life prediction result is in good agreement with the calculation result, which verifies the usability of the prediction model for coupling damage life.
    References | Related Articles | Metrics
    Study on Tooth Surface Wear and Pitting Corrosion of Carbon Steel Gears Under Different Lubrication Conditions
    ZHANG Sheng-nan, SUN Zhi-li, GUO Fan-yi, WANG Jian
    2023, 44 (7):  972-981.  DOI: 10.12068/j.issn.1005-3026.2023.07.008
    Abstract ( 410 )   HTML ( 8)   PDF (2884KB) ( 217 )  
    The electrochemical corrosion will form Fe-free inclusions on the tooth surface, and the crevice corrosion between the inclusions and the surface of the Fe matrix may become the initiation position of pitting corrosion. Due to the periodic pressure of the lubricating oil, the crevices will continue to expand and form pitting corrosion. Under the condition of dry friction, the incidence of pitting corrosion is the lowest and the wear is the most serious. High temperature oxidation corrosion occurs on the tooth surface and an oxide layer is formed on the tooth surface. Under the condition of oil lubrication, the lubricating oil is adhered to the tooth surface in the form of oil film, the incidence and area of pitting corrosion increase with the improvement of lubrication conditions, and the wear degree decreases with the improvement of lubrication conditions. Under the condition of dry friction, tooth surface wear is the main failure mode, and under the sufficient lubrication condition, tooth surface pitting becomes the main failure mode. When the lubricating oil supply decreases, the minimum wear depth will shift from the node position to the tooth root direction.
    References | Related Articles | Metrics
    Analysis of Micro Cutting Forces in the Helical Milling of CFRP
    WANG Hai-yan, WU Ye, FU Qi-lin, ZHOU Zhi-tong
    2023, 44 (7):  982-988.  DOI: 10.12068/j.issn.1005-3026.2023.07.009
    Abstract ( 456 )   HTML ( 5)   PDF (1517KB) ( 128 )  
    In order to accurately predict the variation of cutting forces in the helical milling of CFRP, the effects of anisotropy of CFRP materials and fiber direction angle are emphatically considered in the modeling of cutting forces. The orthogonal cutting analysis of CFRP mesoscopic units is carried out according to different damage areas. On this basis, combining the machining principle of the helical milling and considering the cutting force generated by the periphery edges and bottom edges respectively, the change of cutting forces under different fiber direction angles is analyzed, and the theoretical model of cutting forces for helical milling is established. Through the helical milling experiment of CFRP, based on the measured periodic fluctuation values of the three-way cutting forces, the theoretical values of the cutting forces under the specific revolution angles are solved. The results show that the fitting error between the theoretical and experimental values of cutting forces is less than 16%, which verifies the correctness of the theoretical model of cutting forces in the helical milling of CFRP.
    References | Related Articles | Metrics
    Research on Optical Vacuum Measurement Technology Based on Fabry-Perot Cavity
    FAN Dong, LI De-tian, XI Zhen-hua, LIU Kun
    2023, 44 (7):  989-995.  DOI: 10.12068/j.issn.1005-3026.2023.07.010
    Abstract ( 379 )   HTML ( 4)   PDF (732KB) ( 195 )  
    Based on the ab initio theory, the physical parameters such as molar polarization, molar susceptibility and Virial coefficient of argon gas were calculated, and the theoretical parameter model of gas pressure about refractive index was established by combining the Virial equation of state and Lorentz-Lorenz equation. The optical vacuum measuring device based on the Fabry-Perot cavity was used to accurately measure the resonant frequency change of the laser in the Fabry-Perot cavity to obtain the gas refractive index and gas pressure. At 105Pa, the relative uncertainty of the refractive index is 1.8×10-11, and the relative uncertainty of the gas pressure is 4.4×10-6. The measured pressures obtained by the optical vacuum measuring device based on the Fabry-Perot cavity and the capacitance film vacuum gauge were compared and analyzed. The results showed that the Fabry-Perot cavity based optical vacuum measuring method has higher stability and accuracy.
    References | Related Articles | Metrics
    Resources & Civil Engineering
    Accurate Detection of Goaf in Open-pit Iron Mine Based on 3D High-density Resistivity Method
    WANG En-de, SHEN Jian, LI Bin, YUAN Kun
    2023, 44 (7):  996-1001.  DOI: 10.12068/j.issn.1005-3026.2023.07.011
    Abstract ( 469 )   HTML ( 5)   PDF (1956KB) ( 204 )  
    Aiming at the technical problem of accurate detection of underground hidden goaf in open-pit iron mines, based on the geological characteristics of actual ore deposits in an open-pit iron mine and the resistivity values of different rock ore bodies, three anomaly identification models were established to analyze the abnormal response characteristics of goaf under the condition of uneven transverse electrical properties, and the distribution rule of geoelectric field was obtained, the application research was carried out through the field test. The results show that the anomaly identification model can simulate the geoelectric field distribution accurately. In large area detection work, 3D high-density resistivity method can effectively overcome the interference of the volume effect of 2D high-density resistivity method on the accurate location discrimination of goaf and weaken the abnormal expansion effect.
    References | Related Articles | Metrics
    Flocs Formation Mechanism in Hydrophobic Flocculation Flotation of Fine Wolframite
    MENG Qing-you, YUAN Zhi-tao, YANG Jian-chao
    2023, 44 (7):  1002-1008.  DOI: 10.12068/j.issn.1005-3026.2023.07.012
    Abstract ( 344 )   HTML ( 3)   PDF (1086KB) ( 141 )  
    The flocs formation mechanism of fine wolframite is systematically studied by hydrophobic flocculation experiments, atomic force microscope analyses, and numerical simulations. The results show that sodium oleate induces the surface hydrophobicity of wolframite and further generate hydrophobic flocculation within pH 8.0~8.5, and the apparent particle size D50 of the hydrophobic flocs of fine wolframite is positively correlated with sodium oleate concentration and stirring strength. There is a strong adhesion force between wolframite particles in the sodium oleate system, and the hydrophobic force is the main contribution component to the formation of hydrophobic flocs. The strong turbulent fluid environment formed in the stirring device contributes to the mutual contact and energy transfer of mineral particles, increasing the particle collision adhesion probability. The combination of high shear force and sodium oleate induced hydrophobic force can promote the formation of large and stable flocs of fine wolframite. The WO3 recovery in the hydrophobic flocculation flotation of wolframite slimes increases by 12.04% compared with the conventional flotation.
    References | Related Articles | Metrics
    Effects of Grinding Aids Glycerol and Sodium Pyrophosphate on Kinetic Parameters of Quartz Grinding
    WANG Ze-hong, TIAN Peng-cheng, MAO Yong
    2023, 44 (7):  1009-1018.  DOI: 10.12068/j.issn.1005-3026.2023.07.013
    Abstract ( 366 )   HTML ( 3)   PDF (772KB) ( 198 )  
    The effects of two grinding aids, glycerol and sodium pyrophosphate, on the grinding kinetic behavior of 0.074~2mm quartz pure mineral in the material were systematically investigated by using batch wet ball milling experiments. Based on the grain size distribution characteristics of grinding products, m order grinding kinetic models of quartz in the grinding process were established. The influence of the amount of grinding aid on the kinetic parameters and grinding speed of quartz was analyzed. The results show that the quartz grinding process conformes to the m order grinding dynamics model.With the increase of the dosage of glycerol and sodium pyrophosphate, the kinetic parameter k decreases first and then increases, and the kinetic parameter m increases first and then decreases. The maximum value is reached when the dosage of grinding aids is 0.3%~0.5%. Under the same grinding conditions, the grinding speed of 0.45~1mm particle size is the maximum.
    References | Related Articles | Metrics
    Effect of Hydroxyethyl on Cationic Collector of Quaternary Ammonium Salts
    LIU Wen-bao, TONG Ke-lin, LIU Wen-gang, ZHAO Pan-xing
    2023, 44 (7):  1019-1025.  DOI: 10.12068/j.issn.1005-3026.2023.07.014
    Abstract ( 394 )   HTML ( 5)   PDF (701KB) ( 114 )  
    In order to systematically study the influence of the introduction of hydroxyethyl on the performance of quaternary ammonium salt collectors, flotation test, contact angle test, toxicity test, degradation test, surface tension test, Zeta potential test, molecular dynamics analysis and other methods were adopted in this paper. The performance differences of dodecyl dihydroxyethyl methyl ammonium bromide (BHMDB) and dodecyl trimethyl ammonium bromide (DTAB) were studied, and the influence mechanism of hydroxyethyl on the performance of collector quaternary ammonium salts was analyzed. Compared with DTAB, BHMDB has better collection capacity, flotation selectivity, pH adaptability and hydrophobicity. The introduction of hydroxyethyl reduces the toxicity and critical micelle concentration of the solution, but makes the degradation worse. Through the analysis of the mechanism of the collector, it can be seen that the introduction of hydroxyethyl group strengthens the hydrogen bond between the agent and the mineral surface, increases the cross-sectional area of the polar group of the agent, and makes it more selective.
    References | Related Articles | Metrics
    Explosion Hazard of Floating Dust from Fermented Waste Mash in Low Concentration Alcoholic Atmosphere
    RUAN Meng, XU Kai-li, LU Bai-cheng, LIU Bo
    2023, 44 (7):  1026-1033.  DOI: 10.12068/j.issn.1005-3026.2023.07.015
    Abstract ( 361 )   HTML ( 3)   PDF (1542KB) ( 103 )  
    The floating dust at different heights in the warehouse where the fermented waste mash is stacked is selected, and the three kinds of dust in the upper, middle, and lower layers are named floating dust U(Upper), floating dust M(Middle) and floating dust L(Lower) respectively. The physical characteristics of three kinds of floating dust were studied to analyze the change in dust explosion characteristics. It was found that the maximum explosion pressure Pmax increased with the increase of volatile content and the decrease of ash content. In addition, the change rules of explosion overpressure, minimum ignition energy, lower explosion limit, and flame propagation velocity of floating dust M in 1%, 2%, and 3% alcoholic atmosphere were investigated. It was found that alcohol acted as a volatile component in this mixed explosion system, which not only enhanced the explosion intensity but also enhanced the explosion sensitivity. Finally, with the change of explosion constant, it is pointed out that the dust explosion hazard level changes from St1 to St2 due to the presence of the alcoholic atmosphere.
    References | Related Articles | Metrics
    Effect of Acid-Base Interaction Corrosion on Properties of Aramid Filter
    LIU Jing-xian, DAI Feng, MAO Ning
    2023, 44 (7):  1034-1040.  DOI: 10.12068/j.issn.1005-3026.2023.07.016
    Abstract ( 332 )   HTML ( 3)   PDF (1322KB) ( 129 )  
    Industrial high-temperature flue gas often contains trace amounts of SOx and is weakly acidic. During denitrification treatment, ammonia escape will make it slightly alkaline with fluctuation, which will cause acid-base interactive corrosion of bag-type dust filter material, resulting in the failure of filter bag. In order to explore the effect of acid-base interaction corrosion on the filtration performance of the filter material, the mechanical properties, surface morphology, chemical composition and filtration performance of the aramid filter with different experimental treatment methods were studied. The results show that 20% NaOH solution and 35% H2SO4 solution are secondary interactively corroded. The strength retention rates of warp and zonal are 53.76%, 41.26%, respectively. The elongation retention rate at break are 40.23%, 63.69%, respectively. The thickness is increased by 6.55% and the surface density is decreased by 5.18%. After treatment, the fiber surface becomes rough, with longitudinal grooves and transverse cracks. The essential reason for the damage caused by acid-base interaction corrosion on the performance of aramid filter is that the amide group in the filter is destroyed, so that the macromolecular chain is broken, and the degree of damage varies with the mass fraction of acid and alkali in the solution and the change in the order of acid-base corrosion.
    References | Related Articles | Metrics
    Analytical Solution of Pore Pressure in Foundation Pit Seepage Field Under Groundwater Level Fluctuation
    YU Jun, ZHANG Zhi-zhong, DENG Peng-bing, HE Zhen
    2023, 44 (7):  1041-1048.  DOI: 10.12068/j.issn.1005-3026.2023.07.017
    Abstract ( 421 )   HTML ( 4)   PDF (689KB) ( 117 )  
    The pore pressure response of a two-dimensional seepage field in an isotropic soil layer under the condition of periodic fluctuation of groundwater level is studied analytically. The soil around the pit is divided into four regular regions, and the expressions of the series solution form of the pore pressure response in each region are obtained by applying the superposition principle and the method of separation of variables, and the explicit analytical solution of the pore pressure of the seepage field around the pit is solved by combining the continuous conditions between the regions. The results of the analytical solution are compared with the results of numerical software and semi-analytical solutions to verify the correctness of the analytical solution method in this paper. Based on this solution, the influence of the variation of engineering parameters such as water level inside and outside the pit on the pore pressure response distribution and phase lag is analyzed. The results show that the pore pressure response and phase lag are influenced by the engineering parameters of the pit, and the influence on the far-field pore pressure response and the phase lag inside the pit is more obvious.
    References | Related Articles | Metrics
    Management Science
    Feel at Ease and Revitalize the Company: Influencing Mechanism of Inclusive Leadership to Employees’ Intrapreneurship
    JIA Jian-feng, ZHANG Li-teng, LIU Zhi
    2023, 44 (7):  1049-1056.  DOI: 10.12068/j.issn.1005-3026.2023.07.018
    Abstract ( 454 )   HTML ( 7)   PDF (496KB) ( 181 )  
    Based on the social cognitive theory, the influencing mechanism of inclusive leadership on employees’ intrapreneurship was interpreted, especially the mediating effect of employees’ psychological security between inclusive leadership and employees’ intrapreneurship, and the contingency effect of employees’ entrepreneurial proclivity between employees’ psychological security and their intrapreneurship. Based on 179 pieces of 3-stage survey data, Mplus 7.0 software was used to test the hypothesis using path analysis, Bootstrap analysis, simple slope test and other methods. The results showed that inclusive leadership has a significant positive impact on employees’ intrapreneurship, inclusive leadership has a significant positive impact on employees’ psychological security, and employees’ psychological security has a significant positive mediation effect between inclusive leadership and employees’ intrapreneurship. Employees’ entrepreneurial proclivity significantly positively moderates the impact of employees’ psychological security on employees’ intrapreneurship.
    References | Related Articles | Metrics
    Directors’ Network Position, Social Trust and Corporate Risk-taking
    WU Li, WANG Di, YUAN Zhi-zhu
    2023, 44 (7):  1057-1064.  DOI: 10.12068/j.issn.1005-3026.2023.07.019
    Abstract ( 424 )   HTML ( 7)   PDF (444KB) ( 177 )  
    The social network analysis technology is used, and the data of A-share listed companies in Shanghai and Shenzhen stock markets from 2007 to 2019 are selected to test the impact of directors’ network position on corporate risk-taking and the moderating effect of social trust on the relationship between them. It is found that directors’ network position is significantly positively correlated with corporate risk-taking, and social trust strengthens the promoting role of directors’ network position on corporate risk-taking. Further tests find that under different social trust levels, directors’ network position can promote the risk-taking of state-owned and non-state-owned enterprises, but the moderating effect of social trust only exists in non-state-owned enterprises. Regardless of the degree of industrial competition, directors’ network position can promote corporate risk-taking, but social trust only plays a moderating effect when the degree of industrial competition is high.
    References | Related Articles | Metrics