最新刊期
卷 59 ， 期 2 ， 2025
- 摘要：To accurately assess the impact of offshore wind (OW) fluctuations on the performance of the underwater compressed air energy storage (UWCAES) system, an advanced adiabatic UWCAES was employed as the subject of investigation, firstly, a thermodynamic model of OW-UWCAES was established, followed by the introduction of a design methodology for key operational parameters, and finally the energy conversion characteristics of the UWCAES system were analyzed under rated and variable working conditions in this paper. The results show that: As the ratio of thermal oil to air mass flow rate (κo,a) increased, the heat losses in the underwater gas pipeline and cold oil tank exhibited opposite trends. An optimal κo,a existed that minimized the system's heat loss, corresponding to the highest round-trip efficiency (ηrt). The optimal κo,a under the study's design conditions is 1.41, resulting in an ηrt of 60.3%. Under the design condition, thermal storage and heat exchange units exhibited the highest exergy losses, accounting for 36.6% of the total exergy losses. For stable wind speeds, deviations from the design wind speed decreased the efficiency of the compressor and expander, leading to a reduction in ηrt. For disturbing wind speeds, as the maximum value of the disturbing wind component (vd,max) increased, its impact on average power generation transitioned through a rapidly increasing region, an increasing deceleration region, and a decreasing region due to limitations from the rate wind speed and cut-out speed. In all three regions, the ηrt is lower than the design value under rated stable conditions. This study can provide a theoretical guidance for the integrated application of underwater compressed air energy storage and offshore wind power.关键词：underwater compressed air energy storage;offshore wind power;wind fluctuation;energy conversion1080|6|0更新时间：2026-01-06
- 摘要：To address prolonged attachment of bubbles to the photoelectrode surface of photoelectrochemical water splitting reactor, which leads to smaller effective activation area and lower gas production efficiency, an experimental platform was constructed for the visualization of the dynamics of bubbles in photoelectrochemical water splitting for hydrogen production with coupled vibration system, and a method was proposed to accelerate the detachment of bubbles from the photoelectrode surface by applying vibrations with different amplitudes and frequencies to the electrodes in this paper. Firstly, the electrical signals and geometrical parameters during the evolution of individual bubbles on the stationary electrode surface were recorded. Next, the changes in the current and potential during bubble growth at different frequencies and amplitudes were compared. Finally, the effect of vibration on the geometrical properties of the bubbles was analyzed. The results show that the larger the vibration frequency and amplitude, the larger the photocurrent of the reaction and the smaller the overpotential, that is, the reaction resistance decreased. Increasing the vibration frequency and amplitude could significantly reduce the size of bubble detachment, thus accelerating the bubble detachment. At a vibration frequency of 70 Hz, the detachment diameter of bubbles was reduced by a maximum of 321 μm compared with no vibration, a reduction of about 48%. After vibration application, the bubble diameter was a power function of the growth time, and the bubble growth was controlled by inertia and chemical reaction in turn. This study can provide insights for optimizing the design of photocatalytic water-splitting reactors.关键词：bubble detachment;vibration frequency;photoelectrochemical water splitting;amplitude328|6|0更新时间：2026-01-06
- 摘要：To show the complex flow and phase change in the condensation of swirling steam jet, an experimental study was conducted in this paper. Firstly, a novel X-type swirl pressure nozzle was employed to achieve the swirling flow of the steam jet. Next, the condensation regimes of swirling bubbles and the evolution of related parameters were analyzed at various mass flow rates, and these parameters included bubble radius, growth rate, collapse rate, maximum migration speed of the bubble center, and collapse frequency. The results show that there were three condensation regimes: smooth grown bubble regime, transition regime, and rough grown bubble regime. Under the influence of centrifugal force, typical behaviors such as neck torsion and irregular deformation of the jet bulge at the top of bubbles may occur during the condensation process. As the mass flow rate increased, the bubble condensation time decreased, the growth rate increased, and both bubble radius and collapse rate exhibited nonlinear changes. The maximum migration speed of the bubble center ranged from 24.3 m/s to 73.23 m/s, while the bubble collapse frequency varied between 20 Hz and 302 Hz. At the same mass flow rate, bubbles may condense in different directions and display a zigzag motion trajectory. An increasing in the deviation angle of the bubble center relative to the central axis of the nozzle helps reduce the rebound number during the collapse, exerting a nonlinear impact on the bubble growth rate, collapse rate, and maximum migration speed of the bubble center. This study can provide a theoretical support to some extent for the development and optimization of condensation technologies in related industrial fields.关键词：swirling steam jet;X-type swirl pressure nozzle;bubble condensation characteristics144|5|0更新时间：2026-01-06
- 摘要：To improve the performance of parabolic trough solar thermal power generation systems, a parabolic trough solar thermal power generation system model with double-stage concentrated heat collection (the double-stage system) was developed by coupling mirror fields with both high and low concentration ratios and combining two types of heat transfer fluids. The system was benchmarked against typical solar thermal power generation systems to explore the mechanisms for the improved heat collection and transfer performance, as well as the reasons for reduced exergy losses in critical processes of the double-stage system. Meanwhile, detailed energy and exergy analyses were conducted on the double-stage system, revealing the energy and exergy flow in the double-stage system and the distribution patterns of energy and exergy losses on both the mirror field section and the power generation section. The results show that coupling mirror fields effectively improved heat collection performance, while combining two types of heat transfer fluids improved the heat transfer process. As for the distribution of losses, the optical loss was still a significant factor contributing to heat collection losses in the system, and a large proportion of exergy losses stemmed from the solar-to-heat conversion process, highlighting a significant potential for improvement. The double-stage system could reach a thermal efficiency of 27.35% and an exergy efficiency of 28.84%, with increases of 0.9%—1.5% in both thermal and exergy efficiency over traditional systems using a single concentration ratio and sole heat transfer fluid. Moreover, the double-stage approach reduced the mirror field area by 4%—6% at the same power output. This study proposes an improved strategy for parabolic trough solar thermal power generation systems, providing a theoretical basis for further research and optimization.关键词：parabolic trough solar thermal power generation;concentration ratios;heat transfer fluid;thermal efficiency;exergy loss142|6|0更新时间：2026-01-06
- 摘要：To investigate the effect of state of charged air on the thermodynamic parameters of air storage device during charging process of compressed air, the existing thermodynamic model was modified and two dimensionless numbers related to the mass change rate were established on the basis of the macroscopic mass and energy equations of compressed humid air in air storage device by taking into account the effects of various physical properties and state parameters related to the mass change rate in water phase transition. On the basis of comparing and verifying the calculation accuracy of the model with experimental data, the model was used to calculate the charging process of four different moisture (moisture content refers to the mass fraction of gaseous water in humid air, and the study range is 0 to 0.03.) content of air. The results show that the inlet air moisture content of the air storage device had little effect on the pressure of humid air inside the device, but had a greater impact on temperature; condensation occurred after the humid air filled into the air storage device reached the saturated state, and the combined effect of air convection and the increase of environmental pressure led to the evaporation of the liquid water generated, and the condensation water in the air storage device was much greater than the evaporated water; the increase in exergy in the device, which was affected by phase change, was higher than that when it was charged with dry air for 50 minutes. Therefore, the rate of condensation and the proportion of water in different phases in the air storage device can be evaluated respectively according to the respective expressions and physical meanings of the two dimensionless numbers proposed to ultimately calculate the effect of inlet air moisture content on the exergy in the air storage device.关键词：air storage device;humid air;charging process;evaporation;condensation131|13|0更新时间：2026-01-06
- 摘要：To address the unclear internal and external flow interaction and cooling characteristics of curvature double-walls, the conjugate heat transfer numerical simulation method with experimental validation was used in this paper, and the internal and external flow interaction and overall cooling characteristics of planar, concave, and convex double-wall structures were compared under three typical blowing ratios (0.4, 0.6 and 0.8). The study analyzed the mutual influences of internal and external flows in curvature double-wall structures and revealed the overall cooling characteristics resulting from the combined effects of internal and external flows. The results show that curvature feature significantly changed the characteristics of hole ingestion, impingement chamber crossflow, and outer wall attachment in double-wall structures. At low blowing ratios, the concave double-wall structure had the largest film hole outflow area, with significantly enhanced crossflow intensity and heat transfer in the impingement stagnation region. The averaged overall cooling effectiveness of the outer wall can reach 0.54. The convex double-wall structure showed enhanced downstream film cooling and impingement cooling, while mainstream ingestion can reach the lower side of the film holes. At high blowing ratios, the concave double-wall structure had the largest secondary vortex area in the coolant outflow region below the film holes. The increased injection angle resulted in slightly lower cooling effectiveness downstream of film holes. The convex double-wall structure had the weakest upstream backflow in the impingement chamber, thereby achieving the strongest crossflow accumulation effect. The averaged overall cooling effectiveness of the convex wall surface can reach 0.73 at the fourth row holes. This study can provide insights for the design of double-wall structural layouts in curved components, e.g., turbine blades.关键词：curvature double-wall;flow interaction;film cooling;impingement cooling162|6|0更新时间：2026-01-06
- 摘要：To enhance the cooling performance of the double-wall cooling system and strengthen its cooling advantages, the solid pin fin structure of the system was replaced with a pin fin with porous medium, and the performance enhancement by the porous medium was investigated by using the conjugate heat transfer method. The differences in flow and heat transfer characteristics between porous medium and solid structures were studied in terms of different blowing ratios, pin fin diameters and pin fin heights. The results show that the velocity and temperature distributions between the inner and outer walls were more uniform under the high permeability properties of the porous medium. After the replacement, the overall cooling effectiveness was significantly improved, with an increase from 3.08% to 5.03% in area-averaged overall cooling effectiveness, while the pressure loss did not change much. As the diameter of the pin fin with the porous medium increased, the overall cooling effectiveness exhibited an increasing trend, ranging from 2.13% to 3.03%. The height of the pin fin had a weaker effect on the cooling performance. The applicability of porous media pin fins in a double-wall cooling system was verified.关键词：conjugate heat transfer;double-wall cooling;porous medium;pin fin;overall cooling effectiveness161|7|0更新时间：2026-01-06
- 摘要：To clarify the interaction mechanism between syngas and nitrogen oxides (NOx), the oxidation characteristics of typical coal-derived syngas doped with NOx at different pressures (0.19, 1.80 MPa) and initial mole fractions of NOx (0, 0.092 5%, 0.185%) were measured and analyzed in a high-pressure flow reactor over a temperature range of 623 to 1 273 K. Simulations were conducted using six previously published kinetic models, and the CRECK-2019 model was updated based on experimental results and the latest calculated reaction rate constants. This updated model was used for a detailed kinetic analysis, revealing key reactions in the oxidation process of syngas/NOx. The experimental results show that increased pressure enhanced the low-temperature oxidation of syngas as NOx doping increased. NOx doping had no significant effect on the low-temperature oxidation of syngas at 0.19 MPa, whereas it promoted low-temperature oxidation at 1.80 MPa and inhibited oxidation at medium and high temperatures across different pressures. The reaction H2+NO2=H+HONO contributed significantly to the oxidation of syngas/NOx at high pressure. Additionally, the reactions HNO+NO2=HONO+NO, HNO+H=NO+H2, and HNO+OH=NO+H2O strongly influenced the generation of OH at medium and high temperatures. This study can provide a theoretical foundation for the design and pollutant emission control of syngas turbine.关键词：syngas;nitrogen oxides;high-pressure flow reactor;oxidation characteristic;kinetic model128|4|0更新时间：2026-01-06
- 摘要：Based on the multilayer structure of metal substrate-dielectric layer-metal array with triangular column-cylindrical metal array as the core, a chromium-based metamaterial absorber-emitter pair was proposed to synchronously realize solar energy full-spectrum absorption and spectral modulation. An optical-thermal coupling computational model was established around its absorption and emission performance of light waves and the evolution of its temperature field, and a systematic study was carried out. Firstly, the absorption performance was simulated under the conditions with an incident solar energy wavelength of 300—2 500 nm, a side length of absorber triangular column of 50—300 nm and a height of the column of 10—100 nm. Next, the emission performance was simulated under the conditions with a side length of the transmitter base of 1 000—2 000 nm, a height of the triangular column of 10—500 nm and a height of the column of 30—500 nm. Finally, the evolution of the temperature field was calculated at an incident power of 3—15 MW·m－2. The results show that the spectral absorptivity of absorber matched with the solar AM1.5, and the overall absorptivity was between 0.88 and 0.90, and there was no obvious change with the array column geometry and material, which was conducive to the reduction of the manufacturing cost and process difficulty; the spectral emissivity of emitter matched basically with the blackbody radiative forcing curves at 1 500—2 000 K, and the emissivity efficiency in 1 450—2 000 nm was 0.50—0.99, and the spectral modulation was realized, in which the height of the triangular column and the temperature of the emitter itself were the key factors affecting its emission efficiency; the absorber-emitter pair had an overall spectral modulation efficiency of 0.18—0.67; the fundamental way to improve the spectral modulation efficiency was to increase the temperature of the emitter by strengthening the absorption on the basis of the rational design of the emitter surface geometrical structure. This study can provide a reference for the design and operation of spectral modulation elements.关键词：solar energy;metamaterial;spectral modulation;absorber;emitter;optical-thermal coupling118|4|0更新时间：2026-01-06
- 摘要：To suppress the heat generation mechanisms in rotor-bearing systems and clarify the temperature distribution characteristics of the journal under different whirl conditions, a method to analyze thermal effect of rotor-bearing system considering synchronous whirling of journal was proposed in this paper. Based on the thermal effect analysis model, a user-defined function was developed in C++ to incorporate the temperature-viscosity model. The unsteady dynamic mesh updating approach based on structured grids was used, enabling automatic iteration of the journal center during synchronous whirling. The effectiveness of the proposed mathematical model and solution method were verified by validation through case studies and comparison with Kucinschi's experimental results. The influence of eccentricity, synchronous whirl frequency, and whirl amplitude on the circumferential temperature and pressure distribution characteristics of the journal was studied under three different whirling orbits. The results show that with a fixed eccentricity of 0.5 and an increase in synchronous whirl frequency from 50 Hz to 200 Hz, the maximum circumferential temperature difference was observed under a straight-line orbit, with the maximum relative deviations from the circular and elliptical orbits reaching 11.51% and 14.01%, respectively and that with a fixed synchronous whirl frequency of 159.17 Hz and an increase in the eccentricity from 0.1 to 0.5, the maximum circumferential temperature difference was again observed under the straight-line orbit, with relative deviations from the circular and elliptical orbits ranging from 10% to 25%. A phase difference was observed between the circumferential temperature distribution and the oil film viscous shear force distribution of the journal. This study can provide a theoretical reference for suppressing rotor thermal-induced synchronous vibration instability.关键词：heat generation mechanism;whirling orbit;temperature distribution;pressure distribution93|8|0更新时间：2026-01-06
- 摘要：Since the existing models exhibit a limited ability in predicting the sharply changing viscosity with changing compositions and working conditions in CO2-carbon capture, use and storage for enhanced oil recovery technology, a modified residual entropy scaling viscosity model was proposed, while the inner link between the thermodynamic parameters and viscosity property were explored. This study focused on the characteristics of viscosity for the highly asymmetric CO2/higher hydrocarbons mixtures. The density, vapor liquid equilibrium and entropy properties of the mixtures were obtained by using the perturbed chain statistical associating fluid theory equation of state. Further, a new entropy variable and a viscosity reference term were constructed, and a single-valued relationship between the dimensionless viscosity of the target mixture and the residual entropy of the fluid was verified. The results show that the proposed model can describe the changing law of viscosity properties of highly asymmetric mixtures more accurately than the extended corresponding states and friction Theory models which are both limited in predictive ability. The overall absolute average deviations between the calculated results using the above two viscosity models with introducing extra correction factor and experimental data were 33.49% and 12.71%, respectively. The predictive performance would deteriorate further with the increase of the number of carbon atoms of alkane and the enhancement of the asymmetry between the components of the mixture. The proposed model could make accurate predictions of the consequence of working condition change with overall absolute average deviation of 6.03%. Besides that, no obvious systematic errors could be observed in the comparison. It is verified that system was reliable and stable. This study can provide basic thermophysical data for revealing the CO2 oil displacement mechanism and developing the technology of numerical simulation.关键词：viscosity model;carbon capture;oil displacement;storage108|6|0更新时间：2026-01-06
- 摘要：To effectively remove organic impurities from waste salt for better waste salt recycling and environmental protection, a pyrolysis reactor model based on a parabolic trough concentrator and a tubular reactor was established in this paper. The effects of reflector depth, focal length, and reactor outer diameter on the energy distribution and the organics pyrolysis characteristics were investigated through photothermal coupling. The results show that as the reflector depth increased from 100 mm to 1000 mm, the average concentration ratio of the concentrator increased by 7.34 while the optical efficiency decreased by 0.52%; both the maximum temperature Tmax and minimum temperature Tmin of the reactor increased, with a temperature difference ΔT of the reactor about 100 K; the pyrolysis reaction time was shortened, and the thermal efficiency of the system increased by about 10.71%. As the focal length increased from 100 mm to 1 000 mm, the heat flow density became more concentrated, resulting in a 21.03 increase in the maximum concentration ratio and a 0.53% decrease in optical efficiency; the Tmin did not change significantly, but the Tmax and ΔT exhibited a linear increase, with the ΔT increasing from 31.45 K to 222.56 K; the system reaction rate and thermal efficiency increased. As the reactor outer diameter increased from 14 mm to 104 mm, the heat flow density decreased, the Rave decreased from 34.75 to 4.71, and the optical efficiency increased by 0.53%. The Tmax and Tmin exhibited a decreasing trend, while ΔT increased from 52.13 K to 114.32 K. The reaction rate and thermal efficiency decreased, but the pyrolysis time of per unit volume waste salt decreased from 5.26 s·cm－3 to 1.29 s·cm－3. The study results presented in this paper are significant for the parameter design and optimization of solar waste salt pyrolysis reactor.关键词：solar reactor;energy distribution;photothermal coupling;organics pyrolysis99|5|0更新时间：2026-01-06
- 摘要：To address the influence of X-ray on the detection of high-energy gamma rays in inertial confinement fusion and the challenges associated with the complex control thresholds of gas Cherenkov radiators and the fixed thresholds of some Cherenkov radiators, a novel approach was proposed in this paper to utilize silica aerogel as a Cherenkov radiator for gamma-ray detection. Firstly, a transmittance measurement platform was constructed, and the transmittance of a 1 cm thick silica aerogel with a density of 410 mg/cm3 within the wavelength range of 250 nm to 800 nm was measured, along with its absorption and scattering coefficients. Subsequently, the refractive index of silica aerogel was determined using the minimum deviation angle method, followed by fitting across the wavelength range from 250 nm to 800 nm. These derived parameters absorption and scattering coefficients, as well as the refractive index were integrated into the Geant4 software. The Geant4 software was then used to simulate the different gamma energy responses of the silica aerogel detection system. Finally, the luminous intensity of both silica aerogel and quartz glass was measured respectively using a system based on a 60Co source at the Northwest Institute of Nuclear Technology. The results show that the net signal for silica aerogel was 11.67 nA with a 3.8% uncertainty, while the net signal for quartz glass was 373.67 nA with a 3.2% uncertainty. This proved the feasibility of the silica aerogel Cherenkov detection system for gamma-ray detection. These results demonstrate the potential of silica aerogels as Cherenkov radiators for high-energy gamma-ray diagnostics in ICF experiments.关键词：inertial confinement fusion;gamma-ray detection;Cherenkov radiator;silica aerogel91|7|0更新时间：2026-01-06
- 摘要：To address the critical challenge of accurately and dynamically forecasting the humidity distribution in frost-free refrigerators equipped with active humidification capabilities, a general model integrating commercial simulation software and self-programming was proposed in this paper for dynamic simulation of humidity distribution in frost-free refrigerator and humidity uniformity improvement. Initially, a physical model was constructed, focusing on a specific frost-free refrigerating chamber as the subject of investigation. Subsequently, a mathematical model of the evaporator was developed based on the distribution parameter method and the porous media model to calculate pressure drop, heat exchange, and frost accumulation as wet air flows through the evaporator. Additionally, simulation models for the humidifier, fan, and other components were established, reflecting the actual operational conditions of the frost-free refrigerator. Finally, a control program was crafted based on the control strategy of refrigerating chamber to couple the mathematical models of various components with the physical model of the refrigerating chamber. This enabled dynamic simulation of the humidity distribution, and the experimental data was used to verify models. The results show that the general model proposed could precisely forecast the dynamic changes in temperature and humidity in the refrigerating chamber of a frost-free refrigerator. Compared with experimental data, the average temperature deviation was below 0.7 ℃, while the average relative humidity deviation was less than 5.1% during a start-stop cycle. Moreover, by using the new design of relocating the humidifier to the middle of the door, the humidity uniformity in the refrigerating chamber was significantly improved with a reduction of the coefficient of variation for humidity from 0.55 to 0.41. The study results are of significance for the forecast of temperature and humidity distribution in the pre-design stage of frost-free refrigerators and the improvement of design efficiency.关键词：frost-free refrigerator;temperature distribution;humidity distribution;dynamic simulation;humidity uniformity87|8|0更新时间：2026-01-06
- 摘要：To improve the prediction accuracy of stock price indexes and enhance the performance of statistical modeling and the design of quantitative trading strategy based on the characteristics of indexes, a quantitative model was proposed, which was based on gated recurrent unit and deep evolution strategy (GRU-DES) and effectively integrated index prediction with quantitative trading strategies. Firstly, RNN, LSTM, and GRU neural network predictive models were established to forecast the SSE mega cap, SSE mid cap and SSE small cap indexes, respectively. Next, the proposed DES model was employed to backtest the predicted values and true values of the three indexes. By comprehensively comparing the backtesting metrics and trading details of the predicted results with the true results under the same strategy, after determining the network structure and strategy parameters, the DES was optimized. Finally, the GRU-DES model was developed on basis of the optimized strategy, and the model effectiveness was verified through out-of-sample backtesting of these indexes again. The results show that the proposed GRU-DES model was 14% higher than the LSTM-DES model and RNN-DES model in backtesting metrics, effectively avoiding the randomness and overfitting problems of statistical prediction indexes. According to the backtesting results over 7 years from 2016 to 2024, the proposed GRU-DES model sufficiently demonstrates the stability and effectiveness in all backtesting metrics compared to reinforcement learning model.关键词：stock index;quantitative model;long short term memory;gated recurrent unit;returns90|5|0更新时间：2026-01-06
- 摘要：To address the difficulty in fully identifying pavement defects of different sizes caused by insufficient multi-scale feature extraction capability of existing networks, a pavement disease detection model based on multi-scale feature reinforcement was proposed in this paper. Firstly, a fast spatial pyramid pooling module based on mixed dilated convolution was constructed, and by stacking dilated convolutions with different dilation coefficients, the network receptive field was further expanded to capture a larger range of contextual information and preserve more spatial information. Next, a multi-path feature fusion network was designed to achieve cross level feature capture and reduce information loss during the feature fusion process through multiple branches and skip connections. The K-means clustering algorithm was used together with the Intersection over Union to obtain reasonable anchor boxes. In addition, a penalty term for area was designed in the loss function and a descent gradient was set up to improve the accuracy and efficiency of the predicted box regression. Finally, efficient attention through cross channel interaction was introduced to achieve interaction between important channels in the model. Experimental results show that in terms of detection accuracy, the proposed model was 4.0% higher than the original model YOLOv5s and 1.0% to 17.9% higher than classical models such as Faster R-CNN and CenterNet and advanced models such as YOLOv8s and YOLOv7n-tiny. After optimization with TensorRT acceleration engine, the detection speed on NVIDIA Jetson TX2 and NVIDIA Jetson Nano embedded platforms nearly doubled without compromising the detection accuracy.关键词：pavement disease detection;multi-scale feature reinforcement;mixed dilated convolution;feature fusion network;efficient channel attention;embedded platform180|8|0更新时间：2026-01-06
- 摘要：To solve the problem of accuracy decrease in facial recognition caused by the loss of facial structural information in the case of facial occlusion, an occluded face recognition algorithm based on fine-grained deep feature mask estimation was proposed. Firstly, the face image was fed into feature pyramid network (FPN) to obtain multi-scale deep semantic features. Next, the features extracted from the FPN were processed by the atrous convolution and fused with shallow features extracted using MobileNetV3; a pixel-wise binary mask was used as label to train the network to obtain the fine-grained deep feature mask; this deep feature mask was multiplied with the deep features to suppress the corrupted feature produced by occlusion and to obtain the better face representation. Finally, CosFace loss and mask estimation loss were jointly used to train the network to improve the performance of occluded face recognition algorithm. Three face occlusion datasets with mask, scarf, and center occlusion were created based on the LFW dataset, respectively. The experimental results show that on four different datasets, the proposed algorithm was more accurate than existing algorithms and obtained very stable face recognition results under different occlusion situations. The recognition accuracy on LFW and LFW-mask-occlusion datasets reached 99.38% and 98.42%, respectively and that on LFW-scarf-occlusion and LFW-center-occlusion datasets reached 98.72% and 98.65%, respectively, outperforming the algorithms compared.关键词：face recognition;fine-grained;mask estimation;occluded;feature mask112|7|0更新时间：2026-01-06
- 摘要：To improve the accuracy of intra chroma prediction in H.266/versatile video coding (VVC), a cross-component prediction method based on lightweight convolutional neural network was proposed in this paper. The luma module and chroma module were designed to extract features from luma and chroma reference samples, and the attention module was designed to leverage the attention mechanism to construct the spatial correlation between the current luma reference samples and the boundary luma reference samples. Finally, the attention mask was applied to the boundary chroma reference samples to generate chroma prediction value. To reduce the encoding and decoding complexity, the feature fusion and prediction in the network were achieved in two dimensions, the existing training strategy with shared parameters to handle variable block sizes was improved, and slimmable convolutions were introduced to adjust network parameters according to different block sizes. The experimental results show that the proposed algorithm achieved 0.30%/2.46%/2.25% BD-rate reduction on the Y/Cb/Cr component, respectively, compared with the H.266/VVC test model VTM18.0. Compared with other convolutional neural networks-based cross-component prediction methods, the proposed method effectively reduced the network parameters and inference complexity, saving 10% encoding time and 19% decoding time.关键词：versatile video coding;cross-component prediction;lightweight convolutional neural network;attention mechanism;slimmable convolution84|5|0更新时间：2026-01-06
- 摘要：To analyze the dark-field microscopy imaging characteristics of wear debris for direct-reflection online visual ferrograph (OLVF), a new dark-field microscopy imaging model was proposed. By taking Lambert's cosine law and light backscattering theory as references, a reflection light irradiance superposition model was presented for direct-reflection OLVF microscopy system to quantitatively evaluate the dark-field microscopy imaging sharpness of wear debris. On the basis of Matlab simulation and calculation of contrast transmittance on CMOS image plane, how the changes in optical magnification, oil attenuation coefficient, and backscattering angle affect the contrast transmittance of dark-field microscopy imaging sharpness of wear debris were investigated, by which the numerical optimum of optical magnification can be calculated and ascertained correctly to be 2.2 and the oil attenuation coefficient for direct-reflection OLVF debris detection was determined to be more than 2.0. It was definite that the contrast transmittance on CMOS image plane fluctuated within the range of 0.210 to 0.846. Moreover, the high-resolution wear debris images can be obtained by using the dark-field microscopy imaging detection of direct-reflection OLVF, whose detecting accuracy was about 10 μm. Finally, an experimental test of debris image acquisition was carried out. The results show that not only the visual information of wear debris can be reliably obtained from the diesel engine oil and crude oil with more than 2.28 oil attenuation coefficient by using the dark-field microscopy imaging of direct-reflection OLVF, but also the reflected ferrograms of wear debris can be effectively captured from the hydraulic oil and gearbox oil with less than 2.0 oil attenuation coefficient. In this way, metal wear debris in different oils can be detected, and the wear of oil extraction equipment can be monitored online.关键词：direct-reflection online visual ferrograph;dark-field microscopy imaging;contrast transmittance;crude oil;wear debris142|4|0更新时间：2026-01-06
- 摘要：To address the problems of power balance and vibration noise caused by the complex coupling of the hydraulic drive system and hydrogen pressurization system in the ionic liquid hydrogen compressor, a multi-system coupling dynamics model of three-stage ionic liquid compressor was constructed based on SimulationX, and the transient dynamic properties of the hydraulic drive system and hydrogen pressurization system were investigated. The dynamic properties of the piston under the action of hydraulic oil and hydrogen in the start-up stage and stable operation stage were obtained through multi-cycle simulation. The tangential and normal resultant forces of the crankshaft were calculated to analyze the influence of piston forces at all levels on the imbalance of the crankshaft. The system was operated under variable operating conditions, and the non-uniformity of the motor speed was investigated under different inlet pressures. It is found that frequent changes in valve opening and compressibility of hydraulic oil caused fluctuations in the speed of the compression piston, a sudden change in the resultant external force occurred at the upper and lower dead centers of the piston, and the balance of the crankshaft could be effectively improved by reducing the secondary piston force. As the inlet pressure decreased from 30 bar to 15 bar, the non-uniform coefficient of the motor speed was less than 1% under various operating conditions, the change in inlet pressure caused instability in the operation of the system, thus affecting the energy consumption of the system. The study results can provide a reference for the design optimization of ionic liquid hydrogen compressors.关键词：hydrogen compressor;hydrogen pressurization system;hydraulic drive system;multi-system coupling;transient dynamic properties217|5|0更新时间：2026-01-06
- 摘要：《西安交通大学学报》是西安交通大学主办的自然科学综合性学术理论刊物,以促进科学技术发展、培育科技人才、为社会主义现代化建设服务为宗旨,坚持以“出精品、创名牌、办一流学报,争时效、促交流、举科技人才”为目标,主要登载机械、能源、动力、工程力学、电气、材料、电子、信息与控制、计算机等主学科,以及化学工程、生物医学工程、建筑、管理工程、数学、物理等学科方向的最新研究成果,重点突出机电特色。本刊为月刊,国际标准开本,国内外公开发行,为了保证刊物的质量,根据国家的有关标准和本刊的实际,特制定本简则。1来稿要求1.1本刊以校内师生的稿件为主,同时接收校外省(部)级以上政府基金资助项目的本刊主学科领域的研究论文,以及国内外专家教授的特约稿件,发稿重点为机电类学科。11|2|0更新时间：2026-01-06
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