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    Information & Control
    Operation Fault Diagnosis of High-Pressure Grinding Roll Using Adaptive Reconstruction Features with Parameter Optimization
    Hong-shuo SUN, Dan-wei ZHANG, Quan XU, Tian-you CHAI
    2025, 46 (11):  1-11.  DOI: 10.12068/j.issn.1005-3026.2025.20240087
    Abstract ( 20 )   HTML ( 1)   PDF (3368KB) ( 16 )  

    The operating environment of the high-pressure grinding roll is complicated, and the signal is easily polluted by noise. Traditional algorithms find it difficult to extract the fault characteristics of high-pressure grinding rolls effectively and select the parameters of the stochastic resonance system. To address these issues, an operation fault diagnosis method of high-pressure grinding roll based on adaptive reconstruction features with parameter optimization was proposed. First, the ensemble empirical mode decomposition (EEMD) method was employed to decompose the high-pressure grinding roll’s vibration signal into several intrinsic mode function (IMF) components. Secondly, the mixed criterion of correlation coefficient and mutual information was used to adaptively screen the component signals with the strongest abnormal operation characteristics and reconstruct them. Then, the salp swarm algorithm (SSA) was introduced to build the adaptive stochastic resonance (SR) parameter optimization mechanism by combining the population probabilistic mutation mechanism. Finally, an operation fault diagnosis algorithm of high-pressure grinding roll based on an adaptively selected component reconstruction signal was proposed. Simulation results verify the effectiveness of the proposed method.

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    Research on Heavy Vehicle Rollover Stability Based on Fast Model Predictive Control
    Hong-wei WANG, Qing-qing ZHANG, Xun WANG
    2025, 46 (11):  12-18.  DOI: 10.12068/j.issn.1005-3026.2025.20240092
    Abstract ( 8 )   HTML ( 1)   PDF (1484KB) ( 5 )  

    In order to solve the problem that heavy vehicles are prone to rollover, an active safety control method based on fast model prediction was proposed. Firstly, a nonlinear dynamic model of the heavy vehicle was established, and the nonlinear system was transformed into a linear system by the T-S fuzzy method. A hierarchical control strategy was adopted, where the upper layer was designed to obtain the optimal yaw moment by the model predictive control (MPC) anti-rollover controller, and the lower layer utilized the unilateral wheel control method for the allocation of the braking force. Then, in order to reduce the computational burden of the controller, the Laguerre function was introduced to reconstruct the control input sequence, and the constraints were handled by the primal-dual interior point method to solve the quadratic programming function efficiently in real time. Finally, the co-simulation of MATLAB/Simulink and TruckSim was carried out under typical working conditions, and the results show that compared with the traditional MPC controller, the proposed fast MPC controller can effectively improve the computational efficiency while guaranteeing the performance and can avoid the vehicle rollover instability.

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    Foreign Object Detection Method for Dehydrated Vegetables Based on Improved YOLOv8
    Bo HU, Hua-de XIONG, Yao LIU, Yong-jun ZHANG
    2025, 46 (11):  19-29.  DOI: 10.12068/j.issn.1005-3026.2025.20249020
    Abstract ( 8 )   HTML ( 0)   PDF (12524KB) ( 5 )  

    Problems such as heavy workload, low manual detection efficiency, and inconsistent quality inspection standards of workers during the production process of dehydrated vegetables exist. To address these issues, a foreign object detection method based on improved YOLOv8, namely YOLOv8n-BCS, was proposed. This method could assist workers in improving quality inspection efficiency and reducing labor intensity. The YOLOv8n-BCS model introduced ShuffleNetV2 and BoTNet (bottleneck transformer network) into the backbone network and incorporated the simple attention module (SimAM) attention mechanism and lightweight upsampling operator content-aware reassembly of features (CARAFE) into the neck structure. The similarity intersection over union (SIoU) function was also used to calculate regression loss. By using an NVIDIA GeForce RTX 3080 server for training and testing, the experimental results show that the YOLOv8n-BCS model has an accuracy P of 96.8%, a recall R of 94.7%, a harmonic mean F1 of 95.7%, a mean average accuracy (mAP) of 97.1%, a frame rate of 231 f/s, and a model volume of 6.1 MB. Compared with the control model, the YOLOv8n-BCS model has reduced capacity, as well as improved detection speed and average accuracy, providing a technical reference for optimizing intelligent detection and sorting systems for dehydrated vegetables.

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    CT Image Quality Classification Based on Stacking Ensemble Learning
    Yi-wen LIU, Tao WEN, Yuan-guo BI, Hong-bo ZHU
    2025, 46 (11):  30-36.  DOI: 10.12068/j.issn.1005-3026.2025.20240225
    Abstract ( 12 )   HTML ( 1)   PDF (1887KB) ( 13 )  

    Computed tomography (CT) imaging has become an important form of medical imaging due to its low cost and high efficiency. However, the decline in image quality causes serious interference to diagnosis and prognosis. The limited performance of a single classifier cannot meet the requirements of high-precision CT image quality classification. To address this issue, a method based on Stacking ensemble learning was designed for artifact recognition. Based on classification diversity and individual classifier performance, random forest (RF), back propagation neural network (BPNN), and Inception v3, all of which are heterogeneous, were selected as the base classifiers. Extreme gradient boosting (XGBoost) was used as the meta-learner. The experimental results show that the accuracy of this method reaches 99.2%, which ensures the classification effect of the model and can meet the high accuracy requirements for CT image quality classification under the condition of an unbalanced dataset.

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    Fine-Tuned Large Language Model EcoPowerGPT for Multi-energy Power Generation Field
    Wen-jun TAN, Yan-liang GUO, Rui-ting QU, Qing SONG
    2025, 46 (11):  37-47.  DOI: 10.12068/j.issn.1005-3026.2025.20240187
    Abstract ( 10 )   HTML ( 0)   PDF (1072KB) ( 13 )  

    To address the issues of poor question answering (QA) performance due to the lack of high-quality datasets in the multi-energy power generation field, as well as the current limitations in the generalization capability of Chinese responses, a fine-tuned large language model called EcoPowerGPT based on the Llama architecture was proposed for the multi-energy power generation field. By organizing literature and reports in the multi-energy power generation field, the model employed classification filtering and multi-dimensional scoring methods for data processing, thereby constructing a fine-tuned dataset for multi-energy power generation. This dataset was then used to fine-tune the large language model. Comparative experiments were conducted between EcoPowerGPT and six other dialogue models on multi-energy power generation QA test sets and test sets of multiple-choice questions with a single correct answer. The results demonstrate that EcoPowerGPT outperforms existing dialogue models in terms of both the accuracy and comprehensiveness of its responses.

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    Dual-Stage Deep Learning-Based Image Inpainting Method
    Tian-qi WANG, Di ZHANG, Xin-yu ZHANG, Yi-ming ZHANG
    2025, 46 (11):  48-57.  DOI: 10.12068/j.issn.1005-3026.2025.20250072
    Abstract ( 8 )   HTML ( 0)   PDF (6043KB) ( 6 )  

    In view of the shortcomings of existing image inpainting methods in handling complex damage and relying on paired training samples, an end-to-end dual-stage self-supervised image inpainting method was proposed. The method included degradation simulation, edge restoration, and color reconstruction; synergistic restoration of structure and color was achieved through cooperative optimization. Experiments were conducted on a historical image dataset from archives, and evaluation was performed using four metrics: peak signal-to-noise ratio(PSNR), learned perceptual image patch similarity(LPIPS), Fréchet inception distarce(FID)and Colorfulness Scare. Experimental results demonstrate that the proposed method outperforms existing mainstream methods in terms of image restoration accuracy, perceptual quality, and color performance, exhibiting good practical value and robustness.

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    Materials & Metallurgy
    Influence of Controlled Rolling on Microstructure and Performance of High-Manganese and High-Nitrogen Austenitic Steels
    Chu-heng ZHANG, Yan-mei LI, Xiang-tao DENG, Zhao-dong WANG
    2025, 46 (11):  58-65.  DOI: 10.12068/j.issn.1005-3026.2025.20240078
    Abstract ( 8 )   HTML ( 0)   PDF (6755KB) ( 10 )  

    To improve the yield strength of high-manganese and high-nitrogen austenitic steels, characterization methods such as scanning electron microscope (SEM) and electron backscatter diffraction (EBSD) were used, and the influence of the controlled rolling process on the microstructure evolution and mechanical properties of high-manganese and high-nitrogen austenitic steels in the Fe-Mn-Cr-N system was systematically investigated. The evolution characteristics of the microstructure and properties of the experimental steels were analyzed in two rolling processes at different temperatures: rolling in the recrystallization zone and the non-recrystallization zone. When the finish rolling temperature decreased from 1 040 ℃ to 973 ℃, the average grain size of the experimental steels decreased, and a small amount of deformation microstructures appeared. Accordingly, the strength, plasticity, and toughness were slightly improved. When the finish rolling temperature dropped to 849 ℃ in the non-recrystallization zone, the experimental steels were filled with deformed austenite grains with higher dislocation density, and the yield strength and tensile strength increased significantly. Low-temperature rolling in the non-recrystallization zone could overcome the limitations of insufficient yield strength of traditional high-manganese austenitic steels and obtain better comprehensive mechanical properties.

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    Research on Mechanism and Influencing Factors of TiO2 Carbothermal Reduction
    Guo-peng ZHANG, Feng-man SHEN, Wei-ling ZHANG, Hai-yan ZHENG
    2025, 46 (11):  66-72.  DOI: 10.12068/j.issn.1005-3026.2025.20240111
    Abstract ( 8 )   HTML ( 0)   PDF (1955KB) ( 4 )  

    Excessive reduction of TiO2 in the process of smelting vanadium-bearing titanomagnetite in the blast furnace has a great effect on the smooth operation of the blast furnace. Based on the thermodynamic calculation of the carbothermal reduction of TiO2, the effects of the temperature, atmosphere, and the type of reductant on the carbothermal reduction process of TiO2 were explored by the loss-in-weight method. The results indicate that the starting reaction temperature of Ti(C x,N y ) solid solution increases with the increase in the mole fraction of TiC. The mole fraction of TiN in Ti(C x,N y ) increases with the increase in the partial pressure of N2 at the same temperature. The reduction degree of TiO2 increases with the increase in temperature within the same reaction time. TiO2 can be reduced to produce TiC or TiN with graphite under the atmospheres of Ar or N2, while in the air and CO2 atmosphere, graphite will be oxidized with O2 and CO2. Of all the reductants, TiO2 has the greatest difficulty in undergoing carbothermal reduction with graphite. Increasing the graphitization degree of the coke in the blast furnace is conducive to inhibiting the excessive reduction of TiO2 in the blast furnace.

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    Mechanical Engineering
    Dynamic Modeling and Vibration Analysis of Cylindrical Roller Bearings with Local Defects
    Xiao-peng LI, Xue-dong LI, Bin LIU, Bai-tao LI
    2025, 46 (11):  73-81.  DOI: 10.12068/j.issn.1005-3026.2025.20240108
    Abstract ( 5 )   HTML ( 0)   PDF (3976KB) ( 2 )  

    To analyze the influence of the raceway groove on the dynamic performance and vibration characteristics of cylindrical roller bearings, the cylindrical roller bearings of the traction motor were taken as the research object, and the shaft current damage model of the cylindrical roller bearings with a corrugated groove was established. Firstly, the additional displacement caused by the local defect of the bearing raceway was described by the piecewise function, and the damage model of the local defect of the bearings was established. Secondly, based on the simplified spring-mass model of cylindrical roller bearings, the bearing dynamic model considering raceway defects was established. Finally, through simulation and experiment, the influence of different damage degrees on bearing vibration characteristics and bearing load distribution was studied, and the reliability of the developed bearing model was determined. The results show that the bearing model effectively reflects the impact excitation and periodic change law caused by shaft current damage. With the increase of local defect damage degree, the vibration response and load distribution fluctuation of the bearings constantly increase, and the rotation of the bearings tends to be unstable.

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    Surface Roughness of 17-4PH Products by Metal Fused Filament Fabrication
    Shi-jie JIANG, Fei WANG, Shu-guang LI, Zi-zhao XU
    2025, 46 (11):  82-89.  DOI: 10.12068/j.issn.1005-3026.2025.20240042
    Abstract ( 7 )   HTML ( 0)   PDF (2308KB) ( 15 )  

    Due to the layer-by-layer accumulation and the influence of the debinding/sintering process, the surface of products by metal fused filament fabrication(MFFF)has obvious defects. Optimization of processing parameters is one of the effective methods to improve the surface quality. Firstly, MFFF green/sintered samples were prepared based on the Box-Behnken design principle, and the surface roughness of different parts was experimentally determined. The individual and interaction effects of the processing parameters were then analyzed according to the response surface method, and a variance analysis was conducted on the experimental results to determine the significant factors. Finally, the statistical model and optimized combination of processing parameters were obtained by regression analysis and experimentally verified. The results show that the optimization of processing parameters can effectively improve the surface quality of MFFF products. Extrusion multiplier has the greatest effect on the surface roughness of the sample, and the printing speed has the least effect. Appropriately increasing the extrusion multiplier is helpful to improve the surface quality of green parts.

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    Characteristics Analysis of Spherical Spiral Groove Bearings Considering Fluid Inertia
    Zhong LUO, Hao-tian HAO, Xuan-rui WU, Bao-bing LIANG
    2025, 46 (11):  90-97.  DOI: 10.12068/j.issn.1005-3026.2025.20240077
    Abstract ( 8 )   HTML ( 0)   PDF (2553KB) ( 8 )  

    Spherical spiral groove bearings (SSGBs) serve as an important bearing and vibration control structure of the rotor system in a flywheel energy storage device, and their stiffness and damping directly affect the vibration behavior of the rotor system, thus controlling the performance and efficiency of the flywheel energy storage device. To study the lubrication characteristics of the bearings, based on the Reynolds equation considering fluid inertia in the spherical coordinate system, the perturbation pressure equation was derived by using the perturbation method. Then, the partial differential equations were solved by using the finite volume and the finite difference methods to obtain the pressure distribution of the oil film. Furthermore, the pressure, load-carrying capacity, and dynamic characteristics of the oil film considering the fluid inertia and disregarding fluid inertia were analyzed by numerical calculations. The results show that when the rotational speed and eccentricity are larger, the fluid inertia has an obvious influence; the oil film pressure, load-carrying capacity, and damping considering fluid inertia are larger, and the stiffness is smaller.

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    Preparation of Microcylindrical Array Tool Electrode with Large Aspect Ratio
    Li-ya JIN, Ya-dong GONG, Rong-di ZHU, Hong-fei GAO
    2025, 46 (11):  98-105.  DOI: 10.12068/j.issn.1005-3026.2025.20240107
    Abstract ( 7 )   HTML ( 0)   PDF (3515KB) ( 4 )  

    In view of the difficulty and complexity in the preparation of microcylindrical array electrodes with a large aspect ratio, a new process method with multiple iterations based on the special phenomenon of rounded cross-section caused by galvanic corrosion of micro-normal tetragonal electrodes was proposed, so as to achieve high-quality and high-efficiency preparation of microcylindrical array electrodes with a large aspect ratio.The feasibility of the method was verified experimentally, and the effects of different electrode materials (copper and copper-tungsten alloy) on the processing performance were compared.The results show that fewer iterations are required for the iterative preparation of microcylindrical array electrodes for copper electrodes compared with copper-tungsten alloys.The large aspect ratios of the prepared 6×6 microcylindrical array electrodes of prepared copper and copper-tungsten alloy are 6.08 and 8.81, respectively, and the standard deviations of the diameters of circular holes in the processed array are 8.48 μm and 8.18 μm, respectively.

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    Resources & Civil Engineering
    Calculation Method and Its Numerical Verification of Mid-span Deflection of Fish-Bellied Beam Support
    Cheng-fei WANG, Shu-hong WANG, Shi-hui JIAO, Ming-zhu REN
    2025, 46 (11):  106-114.  DOI: 10.12068/j.issn.1005-3026.2025.20240085
    Abstract ( 9 )   HTML ( 0)   PDF (2270KB) ( 8 )  

    The deformation calculation of fish-bellied beam support is a highly statically indeterminate problem, involving complex relationships between stress and strain. Therefore, a theoretical method suitable for the deformation of the fish-bellied beam support structure was needed. Based on the reduction of the force and deformation characteristics of the fish-bellied beam support, a calculation method for the mid-span deflection of the fish-bellied beam support structure was proposed. By comparing various working conditions using finite element software, the theoretical assumption error was corrected. A highly accurate calculation method for the mid-span deflection of fish-bellied beam support was obtained. This method can be used for calculating the deformation of fish-bellied beam support and can efficiently predict the mid-span deformation of fish-bellied beam support. Verification by various methods shows that this method has small errors and conforms to the rules, providing a reference for related engineering projects.

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    Numerical Simulation on Tunneling Parameter Optimization of Shield Machine in Cutting Obstacle Piles in Existing Stations
    Peng JIA, Bin-yu SUN, Li ZHU, Li-min SONG
    2025, 46 (11):  115-124.  DOI: 10.12068/j.issn.1005-3026.2025.20240242
    Abstract ( 11 )   HTML ( 0)   PDF (4774KB) ( 11 )  

    When the shield machine encounters obstacle piles while tunneling beneath an existing station, it often needs to directly cut through the piles. During this process, the control of the shield machine’s tunneling parameters is crucial for ensuring the safety and stability of the existing upper structure. For the pile-cutting construction of the Shenyang Metro passing beneath existing stations, ABAQUS finite element numerical simulation software was used to simulate the dynamic cutting process of the cutterhead through the obstacle piles. The results show that during the pile-cutting process, whether the shield machine is advancing towards or away from the station, both the field penetration index (FPI) and the tunneling specific energy increase with the advancing speed. The length of the rebar cut during the pile-cutting process also increases with the advancing speed and cutterhead rotation speed. When the advancing speed is less than 0.35 mm/s, the number of rebars with lengths shorter than 350 mm is relatively high. However, when the cutterhead rotation speed exceeds 0.140 rad/s, the number of long rebars increases significantly. As the advancing speed increases, the disturbance degree to the surrounding piles also increases, and the disturbance degree notably increases when the advancing speed exceeds 0.4 mm/s.

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    IWOA-Elman Neural Network and Its Application to Backfill Strength Prediction
    Hao-ran GAO, Hong-lei LIU, De-fu CHE, Tian-xing LAN
    2025, 46 (11):  125-133.  DOI: 10.12068/j.issn.1005-3026.2025.20240105
    Abstract ( 9 )   HTML ( 1)   PDF (3493KB) ( 13 )  

    Uniaxial compressive strength of mine backfill is critical for stope stability. In response to the problem of low efficiency and long time consumption in traditional testing methods, an improved whale optimization algorithm (IWOA) incorporating chaotic mapping, adaptive weighting, and Levy flight was proposed. IWOA was used to optimize the weights and thresholds of an Elman neural network, and an IWOA-Elman prediction model was constructed. Based on backfill proportioning data from a mine, the model was trained and tested with mass fractions of cement, fly ash, and tailings as inputs and compressive strength as output. Comparative analysis with Elman, PSO-Elman, and WOA-Elman models demonstrates superior convergence of IWOA. The root mean square error (RMSE) and mean absolute percentage error (MAPE) of the IWOA-Elman model are 0.050 7 and 3.326 9, respectively, indicating higher accuracy. The model provides a valuable reference for backfill strength prediction and intelligent backfill design.

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    Mechanism and Experimental Study on Deterioration of Collapsible Loess Performance Induced by Irrigation
    Shi-xiong MA, Shu-hong WANG, Zhi LIU
    2025, 46 (11):  134-142.  DOI: 10.12068/j.issn.1005-3026.2025.20240106
    Abstract ( 8 )   HTML ( 0)   PDF (11489KB) ( 7 )  

    In order to investigate the mechanism of performance deterioration in collapsible loess under the influence of irrigation, laboratory tests with varying irrigation and evaporation cycles under different salt mass fraction conditions were conducted. A deterioration model of remolded loess collapsibility affected by irrigation and evaporation cycles was established, along with proposed evaluation indices for deterioration performance. The microstructural evolution characteristics were obtained through scanning electron microscopy (SEM) tests. Results indicate that the collapsibilify coefficient exhibits defferent growth patterns with increasing irrigation and evaporation cycles and rising salt mass fraction. The coupled effects of irrigation and evaporation and salt erosion render the loess skeletal structure more porous and weaker, providing additional pore space for collapsibility. When the salt mass fraction is below 0.3%, the deterioration rate caused by irrigation and evaporation exceeds that from salt erosion. Conversely, when the salt mass fraction exceeds 0.6%, the deterioration rate from salt erosion surpasses that caused by irrigation and evaporation. This research can serve as a reference for hazard assessment and prediction of performance deterioration in collapsible loess within the Loess Plateau region.

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    Electrochemical Experimental Study on Passivation Behavior of Steel Bars Embedded in Fly Ash Cement Paste
    Ying-fang FAN, Yu-xuan SU, Qiu-chao LI, Hao CHEN
    2025, 46 (11):  143-153.  DOI: 10.12068/j.issn.1005-3026.2025.20249028
    Abstract ( 7 )   HTML ( 0)   PDF (5664KB) ( 13 )  

    In order to investigate the passivation process of steel bars embedded in fly ash(FA)cement paste, five FA dosages(0, 10%, 20%, 30% and 40%) were taken into consideration. The cement paste-cylindrical steel bar specimens were prepared. Open-circuit potential and electrochemical impedance spectroscopy methods were applied to monitor the formation of the passivation film on the steel bar during the cement hydration process. The impedance spectra of cement paste-steel bar specimens with different FA dosages were obtained during the cement hydration process. Based on the equivalent circuit model R(Q(R(QR))), the electrochemical parameters such as the resistance of the passivation film, the charge transfer resistance, and the apparent interface capacitance of the specimens were recorded. The results indicate that the passivation film is formed on the steel bars embedded in the FA cement pastes within seven days. The R(Q(R(QR)))equivalent circuit model can effectively fit the electrochemical impedance spectral curves of the FA cement paste-steel bar specimens. The chi-square test results are less than 10-4. FA delays the passivation of the steel bars embedded in the cement paste. When 20% FA is added, the passivation film of steel bars embedded in the cement paste is more stable, and it has a better protective effect on the steel bars.

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    Experimental Study on Physiological and Subjective Thermal Responses of Different Age Groups Under Stepwise Temperature Changes
    Xiao-meng SI, Jiu-hong ZHANG, Jiang AN, Ming-xiao MA
    2025, 46 (11):  154-162.  DOI: 10.12068/j.issn.1005-3026.2025.20240209
    Abstract ( 8 )   HTML ( 0)   PDF (2516KB) ( 10 )  

    Taking Shenyang shopping malls as the research subject, this study investigated the temporal variations in physiological parameters and subjective evaluations among different age groups under stepwise temperature changes during moderate activity. A total of 60 participants were recruited. The experiment involved cold exposure at -12 ℃ and indoor exposures at 18 ℃ and 24 ℃. Participants underwent three successive phases for experimental research: hot, cold, and hot exposure. The results show that it takes approximately 18 minutes for the human body to reach a new physiological steady state after cold exposure, with children demonstrating quicker recovery time. Blood pressure varies significantly under stepwise temperature changes, with the variation range in the children group approximately 2.5 times that of the middle-aged group. LF/HF (low frequency/high frequency) shows significant differences among different age groups. The LF/HF value is significantly influenced by different age groups and environmental temperature conditions and can be used as a potential indicator for evaluating thermal comfort of the human body under various environmental conditions.

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