最新刊期
卷 59 ， 期 1 ， 2025
- 摘要：To promptly and effectively devise topological reconfiguration strategies for distribution networks to boost rapid load recovery capabilities, an elastic post-disaster topological reconfiguration method for distribution networks using a hybrid quantum-classical (HQC) algorithm is introduced, with a specific focus on the advantages of quantum computing. Firstly, a post-disaster topology reconfiguration model for distribution network based on HQC algorithm is established to facilitate interactive processes among real-world scenarios, optimization problems, and embedded algorithm modules in both quantum and classical computing environments. Then, the topological reconfiguration problem for distribution networks is structured into discrete unconstrained optimization sub-problems and continuous constrained optimization sub-problems. A quantum annealing-embedded alternating direction method of multipliers (QA-ADMM) algorithm is proposed, which maps discrete sub-problems into quantum-interpretable Ising models. This algorithm is implemented on the D-Wave quantum annealing computer and iteratively solved on classical computers for continuous sub-problems. An adaptive penalty factor adjustment mechanism is utilized to hasten algorithm convergence. Through analyses of various distribution systems, including IEEE 14, 33, 69, 123 and an enhanced 205-node distribution system, the effectiveness, stability, and scalability of the QA-ADMM algorithm are validated. The findings suggest that penalty factors, penalty term coefficients, and quantum annealing sampling read times influence the accuracy and convergence speed of the algorithm. The computational benefits of the hybrid quantum-classical algorithm become more pronounced with larger optimization problem scales. In the case of a 205-node distribution system, computational efficiency using the hybrid approach can be boosted by around 34% compared to classical computing.关键词：resilient distribution network;topology reconfiguration;hybrid quantum-classical algorithm;quantum computing;quantum annealing1290|6|0更新时间：2026-01-06
- 摘要：An overview and analysis of the current status of energy storage participation in domestic and international electricity markets is provided to address the challenge posed by the gradual decrease in the proportion of synchronous resources in the power system affecting system frequency security. Commencing with the genuine need for energy storage to engage in rapid frequency regulation and bolster system frequency security, a derivation is carried out based on a clearing model for the electrical energy and reserve markets with energy storage involvement. This study systematically analyzes the system's frequency response processes with and without energy storage involvements, sets the criteria for energy storage to offer rapid frequency regulation and secondary frequency regulation, creates a joint clearing model for the electrical energy and reserve markets with independent energy storage participation and the frequency regulation ancillary service market (incorporating fast frequency regulation), and establishes the pricing mechanisms for electrical energy, operating reserves, rapid frequency regulation, and secondary frequency regulation within this model. The proposed model encompasses four crucial stages: inertia response, rapid frequency regulation, primary frequency regulation, and secondary frequency regulation, showcasing the comprehensive frequency security attributes of the power system. The simulation outcomes reveal that compared to the joint clearing model lacking energy storage participation, the proposed model reduces system operational expenses by approximately 0.72% and 0.47% in the case of the IEEE-30 and NREL-118, respectively, thereby fortifying system frequency security while cutting down operational costs.关键词：fast frequency response;energy storage;regulating ancillary service;electricity market;frequency response184|7|0更新时间：2026-01-06
- 摘要：To accurately analyze the armature-rail contact characteristics of high-speed enhanced electromagnetic energy propulsion devices, a method that combines numerical calculations with experimental measurements is proposed for dynamic analysis. Firstly, a mathematical model is established between contact resistance and physical quantities such as muzzle voltage, rail current, and magnetic field. Experiments are designed to measure parameters like muzzle voltage, rail current, armature speed, and spatial magnetic field. Subsequently, the armature-rail contact resistance of the enhanced electromagnetic energy propulsion device is calculated using experimental data on muzzle voltage and rail current as well as finite element numerical simulation results. Further analysis of the armature-rail contact characteristics at different stages is conducted based on the calculated contact resistance and armature speed characteristic curve. Finally, the serviced rails are disassembled and morphologically scanned to provide validation of the reliability of the contact characteristic analysis at different stages through the scan images. The research results reveal that the armature-rail contact resistance peak at 8.5 mΩ during the initial stage, leading to severe rail damage. As the acceleration progresses to medium and high speeds, the contact resistance stabilizes around 0.78 mΩ, indicating a consistent and stable armature-rail contact state. However, at the high-speed exit stage, the contact resistance exhibits significant fluctuations, resulting in poor electrical contact stability. This research offers fundamental data and a reliable reference for further research on rail wear and system performance enhancement in high-speed electromagnetic propulsion devices.关键词：electromagnetic propulsion devices;high-speed conditions;contact resistance;rail morphology;armature-rail contact76|8|0更新时间：2026-01-06
- 摘要：To address the challenges posed by complex structures in fault location within hybrid three-terminal high voltage direct current (HVDC) transmission lines, a fault location method based on enhanced convolutional neural network (CNN) is proposed. Firstly, the fault current data of the hybrid three-terminal HVDC transmission system is acquired by modeling the system using PSCAD/EMTDC software, with the fault current being decoupled using the Clarke transform to obtain the line-mode components of the fault current. Secondly, variational mode decomposition (VMD) is applied to decompose the line-mode components into multiple intrinsic mode function (IMF) components, with the most informative IMF component being chosen as input for the VMD-CNN model. Then, an efficient classification model, support vector machine (SVM), is employed to classify the fault occurrence region by training on the extracted IMF components as inputs for SVM, ensuring precise identification of the fault region. Finally, a VMD-CNN model is developed for fault location, extracting fault information from traveling wave signals and optimizing CNN hyperparameters using the sparrow search algorithm to achieve accurate fault location in hybrid three-terminal HVDC transmission lines. The simulation results reveal that with a transition resistance of 100 Ω, the relative error in fault location is below 0.17% for various fault locations; at a fault position of 460 km, the relative error is under 0.25% for different transition resistance scenarios; and with a transition resistance of 50 Ω, the relative error remains below 0.3% for different fault types. The proposed method enhances fault location accuracy under diverse fault locations, transition resistances, and fault types.关键词：hybrid three-terminal DC transmission lines;fault location;variational mode decomposition;convolutional neural network;sparrow search algorithm74|7|0更新时间：2026-01-06
- 摘要：To investigate the alternative application characteristics of 3D printed regenerative-cooling channels in the thrust chamber of liquid rocket engines, 3D printed stainless steel 304 rectangular minichannels with sinusoidal wave internal surface structures and varying roughness levels are developed. These minichannels feature a cross-sectional dimension of 2.0 mm×2.0 mm, with specified roughness values of 6.3, 25.0, and 100.0 μm, while the measured actual roughness (Ra) values are 11.88, 12.70, and 17.53 μm, respectively. By utilizing a combination of the high-temperature resistivity method and pixel method, the actual inner diameters and wall thicknesses of three types of 3D printed channels are acquired. This process corrects the internal wall temperature and heat flux density associated with the flow of rocket kerosene. Subsequently, an experimental research method is developed to investigate the heat transfer characteristics of rocket kerosene within 3D printed rough channels. Experimental parameters include a pressure range of 15—20 MPa, mass flow rates between 12 450 and 24 900 kg·m－2·s－1, heat flux densities from 5 to 15 MW·m－2, and fluid temperatures from ambient to －150 ℃. The research indicates that the heat transfer characteristics of rocket kerosene flow are influenced by heat flux density, fluid temperature, and mass flow rate. The heat transfer coefficient increases by approximately 25%—33% for fluid temperatures ranging from 50 to 135 ℃. With heat flux densities varying from 5.0 to 15.0 MW·m－2, the heat transfer coefficient increases by 8.3%. Additionally, for mass flow rates within the range of 12 450—24 900 kg·m－2·s－1, the heat transfer coefficient shows a significant increase of 60.2%. Enhancing roughness improves the heat transfer of rocket kerosene flow, with an increase in roughness from 11.88 μm to 17.53 μm resulting in over a 20% enhancement in heat transfer.关键词：3D printing;rectangle channel;heat transfer;roughness;rocket kerosene141|10|0更新时间：2026-01-06
- 摘要：In high-temperature and high-pressure flow conditions, accurately determining cavitation states and extracting useful information from pressure fluctuation signals pose significant challenges. To address these issues, cavitation experiments are conducted with high-temperature and high-pressure water flowing through orifices, and an adaptive variational mode decomposition (AVMD) algorithm based on a genetic algorithm is proposed. This algorithm combines techniques such as the central frequency method, genetic algorithm, power spectral entropy, and relative energy to adaptively determine the hyperparameters of the variational mode decomposition and effectively remove noise from the signals, thus improving the precision of cavitation feature extraction. The results show that the AVMD algorithm can accurately capture the onset and development of cavitation phenomena in high-temperature, high-pressure water flowing through orifices, and can identify the initiation points, transition points, and variations in cavitation intensity. When high-temperature, high-pressure water passes through the orifice, cavitation occurs when the dimensionless frequency of pressure fluctuations falls within the range of 0.04 to 0.35, and the dimensionless amplitude is between 0.014 and 0.067. As cavitation intensity increases, the pressure fluctuation amplitude and frequency within the pipe generally increase. The initiation and severe transition points of cavitation are closely related to the inlet pressure and the subcooling degree of the working fluid at the entrance. The AVMD algorithm effectively improves the accuracy of cavitation characteristic analysis, particularly in cavitation prediction under complex flow conditions, providing theoretical support and references for the stable operation of pressurized water reactor (PWR) coolant systems and high-pressure steam systems.关键词：high-temperature and high-pressure water;cavitation characteristics;adaptive variational mode decomposition;orifice plates78|11|0更新时间：2026-01-06
- 摘要：A frequency domain mathematical model is proposed to address the instability of gas-liquid two-phase flow in water-cooled wall pipelines of supercritical circulating fluidized bed boilers during deep peak shaving, suitable for various operating conditions. The transfer function characterizing the stability of gas-liquid flow within the tubes is derived by linearizing the mass, energy, and momentum equations with small disturbances and applying Laplace transform. The stability of the working fluid flow in the tubes is assessed using Nyquist diagram interpretation. Using this model, the instability boundary of the water wall tube segment of a 350 MW supercritical circulating fluidized bed boiler is calculated, and the impact of different parameters on the flow instability characteristics is investigated. The results show that the heat loads at which flow instability occurs during 20% and 50% of the boiler's maximum continuous evaporation rate are 76.09 kW·m－2 and 113.52 kW·m－2, respectively, indicating the stability and safety of the water wall tube flow. The effect of inlet subcooling on critical heat flux density exhibits a non-monotonic relationship. Increasing the mass flow rate reduces the density difference between the inlet and outlet fluids, promoting flow stability. Moreover, raising the inlet throttling coefficient can dampen flow pulsations at the inlet, further enhancing flow stability. Altering the tilt angle of the tube section under different operational conditions leads to varying effects on flow stability.关键词：deep peak shaving;flow instability;frequency domain method;supercritical circulating fluidized bed boiler70|5|0更新时间：2026-01-06
- 摘要：In response to the unclear thermal mixing mechanism between hot and cold fluids in the circular T-junctions of marine power platforms and ship power devices, the large eddy simulation method is employed to investigate fluid thermal mixing under high temperature and high pressure conditions. This study examines different branch pipe arrangements with a working pressure of 10 MPa, an inlet fluid temperature difference of 275 K, and a swing Reynolds number of 41 500, all under multi-force field coupling conditions. The proposed mixing coefficient is employed to quantitatively assess the fluid mixing effect within the circular T-junction, while the root mean square temperature is used to evaluate temperature fluctuations at the wall of the circular T-junction, under different branch pipe configurations. The results reveal a temporal and spatial synergistic mechanism between the vortex structure and temperature field in the shear layer and wake region. Notably, the vortex shedding frequency aligns closely with the temperature fluctuation frequency at corresponding positions, with a shedding frequency of 19.3 Hz. The additional inertial force induces periodic changes in both the vortex structure and temperature field within the circular T-junction, accelerating the fluid mixing process. This effect mitigates the thermal stratification phenomenon caused by buoyancy and gravity, resulting in increased temperature fluctuations in the fluid domain, with a characteristic length of approximately 10.2D. Compared to static conditions, mixing coefficients increase by 10.8%, 18.3%, and 27.8% for branch pipes arranged vertically upwards, horizontally, and vertically downwards under swing conditions, respectively. The maximum peak of the root mean square temperature for T-junctions arranged vertically downwards under swinging conditions reaches 0.16, approximately double that of stationary conditions. Therefore, when branch pipes are arranged vertically upwards, the thermal mixing effect is optimal, and thermal stratification is minimized, making this arrangement preferable for practical applications.关键词：circular T-junction;buoyancy;rolling motion;thermal mixing mechanism;large eddy simulation167|8|0更新时间：2026-01-06
- 摘要：To achieve low-carbon transformation and energy efficiency improvement of data centers, a distributed multi-energy system that incorporates various renewable energy sources and energy storage devices is introduced as their energy supply system. Firstly, an optimization objective system comprising life cycle costs, carbon emissions, energy consumption, grid electricity purchase rate, and heat waste rate is established. Subsequently, two operation strategies considering load characteristics are developed, and an improved multi-objective grasshopper optimization algorithm is employed to determine the system capacity configuration. To analyze the impact of optimization objectives and operation strategies on system optimization, various optimized design schemes are formulated by combining different optimization objectives and operation strategies. The analytic hierarchy process and entropy weight method are used to assign weights to evaluation criteria, and the vlseKriterijumska optimizacija I kompromisno resenje (VIKOR) method is applied for evaluation ranking. A case study on a data center in Qinghai province is conducted to obtain its energy system optimal design and operation scheme. The results indicate that the capacities of the absorption chiller and the ground source heat pump are influenced by the operation strategy, while the capacity of the energy storage device is affected by the optimization objective. Under the same operation strategy, increasing the number of optimization objectives can enhance the overall performance of the system. The values of the fundamental optimization objectives such as life cycle costs, carbon emissions, and energy consumption show minor variations across different schemes, whereas the grid electricity purchase rate and heat waste rate exhibit significant changes. Through the implementation of five-objective optimization, which integrates heat waste rate and grid electricity purchase rate with the basic optimization objectives, the system's overall performance is notably enhanced. Specifically, the heat waste rate and grid electricity purchase rate are reduced by 62.30% and 25.92%, respectively, while renewable energy generation sees a 2% increase.关键词：data center;distributed multi-energy system;optimal design;operation strategy;improved multi-objective grasshopper optimization algorithm86|12|0更新时间：2026-01-06
- 摘要：To optimize the coolant air development space and enhance overall cooling performance, a plug structure positioned within the cooling chamber is proposed for swirl cooling structures used at the leading edges of turbine blades. Based on a simplified swirl cooling structure, the effect and mechanism of the plug structure on the heat transfer coefficient, comprehensive cooling performance, flow distribution and flow structure of the swirl cooling target surface are investigated using the numerical simulation method. The results show that by incorporating the plug structure, within the jet Reynolds number range of 5 000 to 20 000, the average Nusselt number on the swirl cooling structure's target surface increases by 5.9% to 8.3%, the overall cooling effectiveness factor rises by 5.2% to 6.6%, the Nusselt number on the suction side experiences a significant increase of 14.8% to 16.6%, and the maximum difference in flow between adjacent nozzles decreases from 18% to 5%. The plug structure reduces the development space of the upstream jets at the cooling chamber axis, thereby inhibiting the formation of swirl backflow and vortex cores. This reduction minimizes the interference of upstream coolant on fresh jets and strengthens the weakening effect of swirl on the wall boundary layer. Consequently, the plug structure effectively enhances the consistency of the swirl structure and improves the strength and uniformity of the heat transfer coefficient of the target surface.关键词：swirl cooling;turbine blades;internal cooling;Nusselt number;jetting Reynolds number44|5|0更新时间：2026-01-06
- 摘要：In response to the challenge where current focus evaluation methods struggle to accurately assess image focus amidst fluctuations in image scene content, a focus evaluation method, fully equivalent to Gaussian blur standard deviation, is introduced based on the “classification + fitting” concept. Firstly, a dataset for image focus classification, annotated with finite Gaussian blur standard deviations, is established. Subsequently, an asymmetric kernel convolution neural network (AKC-net) is developed to derive image Gaussian blur standard deviation classification scores. Finally, a cubic spline interpolation function is applied to fit the classification score of the AKC-net fully connected layer output and the corresponding Gaussian blur standard deviation, using the standard deviation linked to the maximum score as the focus evaluation for the images. Simulation experiments and real shooting experiment are carried out on the Waterloo dataset and real shooting images respectively. The experimental findings indicate that the proposed method achieves an average classification accuracy of up to 97.7% across various focus images. The root mean square error and mean absolute error between the obtained evaluation results and the true Gaussian blur standard deviation values are less than 0.07. Furthermore, the focus measurement values derived from real shooting images are independent of the image content, enabling the absolute evaluation of the image focus.关键词：degree of focus evaluation;Gaussian blur standard deviation;asymmetric kernel convolution neural network;cubic spline interpolation34|4|0更新时间：2026-01-06
- 摘要：In response to the challenge of precise trajectory tracking control for robot manipulators, influenced by the accuracy of modeling parameters and disturbance uncertainties, a novel control approach that combines non-singular fast terminal sliding mode control with iterative learning control is presented. First, to ensure the convergence speed of tracking errors and prevent singularity issues during convergence, a non-singular fast terminal sliding mode controller employing the law of approach to saturation is designed. Second, to further improve trajectory tracking accuracy, an error iterative learning controller is developed, and the convergence of these controllers is analyzed. Finally, the control system based on the proposed method is implemented in Simulink for iterative and comparative control simulation experiments. Additionally, real-machine experiments for robot manipulator tracking control are carried out. The experimental results show that: in the iterative experiment, the maximum average steady-state error in joints increases by 72%; in the comparative experiment, compared to PD-type iterative learning control and PD-type linear sliding mode control, the maximum average steady-state error rises by 97% and 51%, respectively, while the maximum response adjustment time decreases by 70% and 50%, respectively; in the real-machine experiment, the robot manipulator tracking error stabilizes within the range of [－0.05, 0.05] rad. These findings thoroughly validate the effectiveness and accuracy of the proposed control method, offering an effective control solution for addressing uncertainties in robot manipulator trajectory tracking.关键词：robot manipulators;non-singular fast terminal sliding mode control;iterative learning control;trajectory tracking47|6|0更新时间：2026-01-06
- 摘要：To tackle the issue of parameter redundancy and the challenge of learning comprehensive global contextual information in current deep learning-based super-resolution methods, as well as the limited capacity to reconstruct high-frequency image features, a super-resolution network (RPSRnet) based on receptive field optimization and progressive feature fusion is proposed, delivering exceptional performance in single image reconstruction. By integrating pixel attention mechanisms and large receptive field convolutions, two progressive pathways are devised to interpret inputs as features at varying levels of abstraction. This design enriches the network's capability to grasp contextual information while streamlining parameter redundancy. Through the utilization of hierarchical convolutions and multiple receptive field branches, the network sustains lightweight convolutions and acquires fused features from diverse scales on hierarchical pathways. This process enhances the network's proficiency in reconstructing edge details and intricate texture features. The experimental results reveal that the proposed algorithm achieves a peak signal-to-noise ratio of 32.47 dB on the Set5 benchmark test set and 28.81 dB on the Set14 test set. The algorithm surpasses existing advanced algorithms, utilizing fewer parameters and resulting in a 9% reduction in parameters, effectively validating the algorithm's efficacy.关键词：image super resolution;attention mechanism;receptive field optimization;feature fusion39|8|0更新时间：2026-01-06
- 摘要：To address the challenge of balancing control precision and stability in existing trajectory tracking control methods, a robust control method based on Udwadia-Kalaba (U-K) control theory is introduced. Using the Lagrangian method, a dynamic model for robots is established, dividing dynamic parameters into a deterministic nominal part and an uncertain part. The nominal control torque under ideal motion trajectory constraints for the exoskeleton robot system is determined based on the U-K theory and the nominal parameters. A robust controller is introduced to mitigate the effects of uncertainty, with uncertainty boundaries defined to establish the necessary additional control torque. The simulation results indicate that, compared to traditional PID algorithms, the trajectory tracking accuracy of the hip and knee joint angles for the exoskeleton robot is enhanced by 76.4% and 96.8%, respectively, using the proposed U-K-based robust control method. The results from trajectory tracking comparative experiments using a prototype of the lower limb exoskeleton robot designed based on this method show that the trajectory tracking accuracy for the hip and knee joint angles are 0.467 0° and 0.114 1° for the lower limb exoskeleton, indicating an 82.6% and 86.8% enhancement over the PID algorithm used as a control. Furthermore, the overall system control period is decreased by 56.6%. That control method exhibits enhanced synchronization, control precision and stability.关键词：lower limb exoskeleton robots;Udwadia-Kalaba theory;robust controller;trajectory tracking control45|11|0更新时间：2026-01-06
- 摘要：To address the conflict between damping effectiveness and control energy consumption in active suspension systems, an ideal twin dynamic deflection tracking control strategy for active air suspension systems is introduced. The strategy is founded on the research concept of “digital twins, virtual-to-real control, and energy-efficient damping”. Firstly, taking the vehicle seat active air suspension system as an example, a genuine air suspension system's ideal digital twin is formulated using a quasi-zero stiffness system, alongside the development of a parameter matching design methodology for this digital twin. Subsequently, with the air spring gas pressure control as a key point. An outer-loop position fuzzy non-singular fast terminal sliding mode controller and an inner-loop air pressure controller considering the nonlinear flow characteristics of the solenoid valve during air spring inflation and deflation processes are designed to achieve the tracking of the twin body deflection under actual excitations by the real suspension system. Finally, through bench simulation experiments and comprehensive vehicle ride comfort simulations, the efficacy and progressiveness of the proposed control strategy are validated. The results show that, compared to the traditional control strategy aiming at reducing the acceleration, the proposed strategy showcases reduced root mean square values of vertical vibration acceleration of the seat under random road conditions and a reduction exceeding 65.0% in the root mean square value of control energy consumption. Furthermore, under impact road conditions, the vertical vibration amplitude of the seat is diminished, with a maximum reduction in active control force exceeding 45.5%. The proposed strategy significantly outperforms the traditional strategy, effectively enhancing the damping capabilities of the suspension system while markedly significantly reducing the active control energy consumption. This strategy adeptly resolves the aforementioned conflict and can be broadly implemented across various active suspension systems, offering a novel research trajectory for energy-efficient damping.关键词：vehicle;air suspension;energy saving and vibration reduction;ideal twin dynamic deflection36|7|0更新时间：2026-01-06
- 摘要：In response to the prevalent challenges of the wide frequency ranges and complexity of electromagnetic interference (EMI) sources during the design process of electric vehicle onboard chargers, a method based on port impedance testing for equivalent circuit modeling and system-level collaborative simulation is introduced. Initially, impedance testing and three-dimensional electromagnetic simulations are performed on various components of the on-board charger system to develop models for passive devices, port filters, and high-voltage shielded cables, extracting high-frequency parasitic parameters from key printed circuit board. Subsequently, simulation program with integrated circuit equivalent models for active devices are established and validated for accuracy through double pulse experiments. To address the challenge of synchronizing simulation and modeling in the power factor correction circuit's control loop, a co-modeling approach is employed to build the equivalent circuit model of the entire system. Finally, the individual component models are integrated to develop a comprehensive conducted EMI prediction model for the on-board charger system. Simulations and experiments are performed in accordance with relevant testing standards. The results reveal that within the 150 kHz to 30 MHz frequency range, the prediction accuracy deviates by less than 9 dB from the actual results, indicating strong consistency. This suggests that the model can accurately predict the conducted interference levels at the high-voltage AC side of the on-board charger system, thereby offering valuable insights for electromagnetic compatibility design.关键词：on-board charger;port impedance testing;electromagnetic interference;co-simulation34|5|0更新时间：2026-01-06
- 摘要：To enhance the performance and safety of energetic materials (CL-20), microfluidic technology has been widely used in the microsphere preparation process. By integrating droplet microfluidics with surface acoustic wave technology, ethyl acetate droplets with exceptional uniformity in size are created. Subsequently, micrometer-sized CL-20/NC energetic microspheres are fabricated using a solvent-nonsolvent recrystallization approach. The droplet generation process is monitored employing a high-speed camera. The results demonstrate that surface acoustic wave technology can effectively regulate the transition of droplet generation modes, averting uncontrollable shifts caused by material precipitation and channel obstructions, thereby ensuring consistent and uninterrupted droplet generation. The morphologies of microspheres with varying particle size, CL-20 contents and NC contents are characterized by field emission scanning electron microscopy (SEM). The findings suggest that diminishing CL-20 content, augmenting NC content, or increasing microsphere size can diminish surface roughness and minimize defects. With the support of surface acoustic wave technology, the coefficient of variation in microsphere size decreases significantly from 39.33% to 7.51%, notably enhancing uniformity. The crystal structure and thermodynamic traits of CL-20/NC microspheres of different sizes are characterized using X-ray diffractometry and thermal analysis. The results indicate that microspheres with a median particle size of 20 μm display superior thermal stability, with a decomposition peak temperature of 229.04 ℃, surpassing that of microspheres with a median particle size of 7 μm at 228.22 ℃. Microspheres with a median size of 7 μm exhibit heightened reactivity and energy density, manifesting a higher mass loss rate (84.3%) and heat release (12.05 mW/mg) compared to their 20 μm counterparts, which demonstrate a mass loss rate of 80.2% and heat release of 8.84 mW/mg.关键词：acoustofluidics technology;CL-20/NC energetic microspheres;coefficient of variation of particle size;thermodynamic properties45|6|0更新时间：2026-01-06
- 摘要：To address the issue of limited sensor reliability in extreme environments due to thermal stress, leading to sensor zero drift, temperature drift and even failure, a thermal stress calculation method and finite element model for high-temperature piezoelectric force sensors based on thermal-structural coupling. Based on the equilibrium equation and the thermal-elastic theory, the physical equation of thermoelastic mechanics of the sensor is established, and the impact of packaging material and temperature on the thermal stress of the piezoelectric force sensor is analyzed. By examining the thermal stress distribution of the piezoelectric force sensor in high-temperature environments, the areas of stress concentration within the sensor are identified. Tracing back the thermal stress of the sensor reveals that thermal mismatch stress arises from the disparity in the thermal expansion coefficients between the packaging material and the crystalline material. The random vibration power spectral density is converted into an acceleration time-domain signal, and the sensor's thermal stress is analyzed using a multi-physics coupling method, yielding a maximum stress of 134.61 MPa, which is below the material's yield strength by 300 MPa, confirming the sensor's reliability in high-temperature, high-pressure, and random vibration environments. An examination of the impact of alumina and zirconia insulation on the sensor's maximum thermal stress shows that at 420 ℃, the maximum thermal stress of the alumina-insulated sensor is 9.18 MPa lower than that of the non-insulated sensor and 79.31 MPa lower than that of the zirconia-insulated sensor. The research provides insights for reducing thermal stress in sensors in high-temperature environments.关键词：high-temperature sensors;thermal stress;multiphysical fields;piezoelectric50|8|0更新时间：2026-01-06
- 摘要：In order to address the scientific challenge of predicting the remaining useful life of materials damaged by cavitation erosion, a life prediction method that integrates convolutional neural network technology is introduced. Specifically, the residual network (ResNet) model is utilized and enhanced with a coordinate attention mechanism (CA). Through optimization of the convolution, channel number and down-sampling method in the model, an improved coordinate residual network (CA-ResNet) model is developed to accurately predict the remaining useful life of 17-4PH material damaged by cavitation erosion. Initially, the cavitation characteristic curve is obtained from ultrasonic cavitation tests. Then, the cavitation stages are quantitatively segmented using a Logistic equation, defining the life coefficient ζ. Meanwhile, with the assistance of a super-depth-of-field microscope, microscopic images of the material at various post-damage time points are captured to establish a microscopic image database correlated with the life coefficient ζ. The results demonstrate that the improved CA-ResNet network model achieves a verification accuracy of 92.2% on the CIFAR10 public dataset and 93.2% on the collected cavitation damage dataset of 17-4PH material. This represents a 1.5% and 3.5% accuracy improvement over the ResNet18 network model, respectively. By fine-tuning hyperparameters like learning rate and batch size, the accuracy on the cavitation damage dataset is elevated to 95.0%. In this paper, an end-to-end data-driven approach is adopted to achieve accurate prediction from cavitation damage morphology to post-cavitation life.关键词：ResNet;coordinate attention mechanism;cavitation erosion;life prediction22|8|0更新时间：2026-01-06
- 摘要：To accurately assess the fatigue reliability of fillet welds at the bottom of molten salt tanks during service, a fatigue reliability assessment method based on the stress-strength interference theory is introduced. This method involves randomizing stress-influencing factors and fatigue model parameters. The range of typical molten salt liquid level variations and their occurrence frequencies are obtained through the rainflow counting method. A numerical model of fillet welds, accurately representing their dimensions, is created to analyze stress distribution. By utilizing a normal distribution model for stress-influencing factors such as fillet weld size and load, the Latin hypercube sampling technique enables the statistical sampling necessary to establish the distribution model of equivalent structural stress at the fillet weld toe. The primary stress-life curve parameters within the fatigue life model as per the ASME BPVC.Ⅷ.2—2023 standard is randomized. Based on the stress-strength interference theory, a fatigue reliability assessment model for fillet welds is established. An illustrative analysis of the fatigue reliability of fillet welds at the bottom of a low-temperature molten salt tank of a solar thermal device reveals six typical operational scenarios for liquid level fluctuations within a quarter, with peak variations spanning from 1.55 m to 12.39 m. The highest stress on the fillet weld is identified at the inner weld toe, measuring 301.5 MPa. The average fatigue lifespan of fillet welds subjected to various loads is calculated at 46 a. Following 3 a of service, the probability of fatigue failure of the fillet weld stands at 0.040 6, escalating to 0.335 9 after 30 a of operational service.关键词：molten salt tank;fillet weld;stress-strength interference model;fatigue reliability70|10|0更新时间：2026-01-06
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