摘要：
Investigations using hot compression tests on a new high-strength weathering steel revealed specific deformation behaviors across different conditions. These tests were performed at temperatures ranging from 850 to 1050°C and at strain rates from 0.01 to 5s(-1). Results indicated that a decrease in the deformation temperature combined with an increase in strain rate notably enhanced both the maximum stress and strain achieved. Notably, above 900°C and with strain rates below 0.1s(-1), the flow stress of the material reached a steady state at certain strain levels. At a strain rate of 1s(-1), irrespective of the temperature, the steel shows a continuous strain hardening behavior, achieving no stable flow stress state. Notably, when the true strain exceeds 0.8, an unusual increase in flow stress occurs, predominantly due to secondary work hardening effects. The microstructural changes in the deformed samples were examined using electron backscatter diffraction (EBSD), which helped elucidate the softening mechanisms inherent in this high-strength steel. Further, processing maps developed from true strains of 0.1-0.9, derived from the experimental flow stress data, suggest controlling the strain within 0.2-0.4 to minimize instability during hot working.
期刊：
Surface and Coatings Technology,2025年503:132030 ISSN：0257-8972
通讯作者：
Changzhe He<&wdkj&>Mao Zhang
作者机构：
[Ying Wang; Changzhe He; Shuobin Chen; Jian Yu; Cheng Nie; Zhigang Hu; Bin Li; Junsheng Yang] School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430023, China;[Yuhua Peng] Artificial Intelligence Institute, Wuchang Institute of Technology, Wuhan 430223, China;[Mao Zhang; Pan Gong] State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
通讯机构：
[Changzhe He; Mao Zhang] S;School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430023, China<&wdkj&>State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China
摘要：
This study comprehensively investigates the corrosion mechanism of laser-cladded FeCoNiCrCu high-entropy alloy (HEA) coatings fabricated with varying initial powder particle sizes in a 3.5 % NaCl solution. Subsequent to orthogonal experimental optimization, optimal laser cladding parameters were obtained to generate fine coatings with exceptional quality. It's noteworthy that finer initial powder particles possess higher specific surface energy, promoting the formation of coatings with fewer defects. Aside from that, steady increases in corrosion current density and decreases in corrosion potential were observed with coarser initial powder particles, accompanied by lower charge transfer resistance. Corrosion preferentially initiates at surface defects, with more severe defects directly degrading corrosion resistance. The Cu accumulation at these defects generates a less extensively protective passivation film, which hinders the formation of Cr oxides. As evidently demonstrated by XPS analysis, smaller powder particles form protective films with more Cr oxides and fewer Cu oxides in comparison with those formed by larger particles. To sum up, coatings prepared from finer initial powder particle sizes display superior corrosion resistance.
This study comprehensively investigates the corrosion mechanism of laser-cladded FeCoNiCrCu high-entropy alloy (HEA) coatings fabricated with varying initial powder particle sizes in a 3.5 % NaCl solution. Subsequent to orthogonal experimental optimization, optimal laser cladding parameters were obtained to generate fine coatings with exceptional quality. It's noteworthy that finer initial powder particles possess higher specific surface energy, promoting the formation of coatings with fewer defects. Aside from that, steady increases in corrosion current density and decreases in corrosion potential were observed with coarser initial powder particles, accompanied by lower charge transfer resistance. Corrosion preferentially initiates at surface defects, with more severe defects directly degrading corrosion resistance. The Cu accumulation at these defects generates a less extensively protective passivation film, which hinders the formation of Cr oxides. As evidently demonstrated by XPS analysis, smaller powder particles form protective films with more Cr oxides and fewer Cu oxides in comparison with those formed by larger particles. To sum up, coatings prepared from finer initial powder particle sizes display superior corrosion resistance.
摘要：
Fractionation allows the separation of components in beef tallow. This study compared the physicochemical characteristics and cholesterol content of beef tallow and its liquid fraction, evaluating their frying performance as potential deep-fat frying oils against plant oils. Results showed effective separation of unsaturated components from beef tallow through fractionation. Beef tallow exhibited superior physicochemical properties during frying, with lower deterioration levels than plant oils. Benzo[ a ]pyrene content increased in plant oils but remained low in beef tallow and its liquid fraction. The liquid fraction had a significantly shorter oxidative induction time of 0.38 h compared to 5.85 h and 5.24 h for plant oils. This study revealed that alterations were observed in beef tallow and its liquid fraction when used as frying oils, with beef tallow demonstrating stronger antioxidative properties compared to the liquid fraction, which exhibited lower levels of cholesterol and saturated fatty acids.
Fractionation allows the separation of components in beef tallow. This study compared the physicochemical characteristics and cholesterol content of beef tallow and its liquid fraction, evaluating their frying performance as potential deep-fat frying oils against plant oils. Results showed effective separation of unsaturated components from beef tallow through fractionation. Beef tallow exhibited superior physicochemical properties during frying, with lower deterioration levels than plant oils. Benzo[ a ]pyrene content increased in plant oils but remained low in beef tallow and its liquid fraction. The liquid fraction had a significantly shorter oxidative induction time of 0.38 h compared to 5.85 h and 5.24 h for plant oils. This study revealed that alterations were observed in beef tallow and its liquid fraction when used as frying oils, with beef tallow demonstrating stronger antioxidative properties compared to the liquid fraction, which exhibited lower levels of cholesterol and saturated fatty acids.
通讯机构：
[Chen, Y ] W;Wuhan Polytech Univ, Coll Mech Engn, Wuhan 430048, Hubei, Peoples R China.
关键词：
3D point cloud;Genetic algorithm-based wavelet neural network;Mean absolute percentage error;Poultry viscera;Root mean square error
摘要：
In order to avoid damaging viscera during poultry evisceration and enhance the economic value of poultry products, this paper proposes a predictive method for poultry carcass visceral dimensions based on 3D point cloud and a Genetic Algorithm-based Wavelet Neural Network (GA-WNN). In this study, a data set of poultry carcasses was obtained through the use of 3D point cloud scanning equipment combined with reverse engineering software. The inputs and predicted targets of the model were determined through correlation analysis of various carcass dimensions. Then, a prediction model of poultry visceral size (GA-WNN) was built by K-fold cross validation method, Genetic Algorithm and Wavelet Neural Network (WNN). By comparing the prediction results and analyzing Mean Absolute Percentage Error (MAPE) and Root Mean Square Error (RMSE) of the six models, it was determined that the GA-WNN model had the best prediction results. Finally, in order to verify the generalizability of the method, generalizability experiments were conducted on different breeds of poultry, which proved that the method of this study had superior generalizability ability. In the comparative analysis of the six models, the MAPE and RMSE of the GA-WNN model for the prediction of the three visceral dimensions were the lowest except for the RMSE for the prediction of visceral length. Compared with the largest of the two kinds of errors, the MAPE and RMSE for the prediction of the position of the upper end of the left liver by the method of this study were lower by 5.56% and 0.915 cm, respectively, and the prediction effect had a significant advantage. The experimental results showed that the model built in this paper based on 3D point cloud and GA-WNN network can accurately predict the size of the viscera of poultry carcasses, thus providing theoretical references for the automated evisceration technology without damaging the viscera.
In order to avoid damaging viscera during poultry evisceration and enhance the economic value of poultry products, this paper proposes a predictive method for poultry carcass visceral dimensions based on 3D point cloud and a Genetic Algorithm-based Wavelet Neural Network (GA-WNN). In this study, a data set of poultry carcasses was obtained through the use of 3D point cloud scanning equipment combined with reverse engineering software. The inputs and predicted targets of the model were determined through correlation analysis of various carcass dimensions. Then, a prediction model of poultry visceral size (GA-WNN) was built by K-fold cross validation method, Genetic Algorithm and Wavelet Neural Network (WNN). By comparing the prediction results and analyzing Mean Absolute Percentage Error (MAPE) and Root Mean Square Error (RMSE) of the six models, it was determined that the GA-WNN model had the best prediction results. Finally, in order to verify the generalizability of the method, generalizability experiments were conducted on different breeds of poultry, which proved that the method of this study had superior generalizability ability. In the comparative analysis of the six models, the MAPE and RMSE of the GA-WNN model for the prediction of the three visceral dimensions were the lowest except for the RMSE for the prediction of visceral length. Compared with the largest of the two kinds of errors, the MAPE and RMSE for the prediction of the position of the upper end of the left liver by the method of this study were lower by 5.56% and 0.915 cm, respectively, and the prediction effect had a significant advantage. The experimental results showed that the model built in this paper based on 3D point cloud and GA-WNN network can accurately predict the size of the viscera of poultry carcasses, thus providing theoretical references for the automated evisceration technology without damaging the viscera.
关键词：
porous high-entropy alloy;corrosion resistance;Cr element content;immersion corrosion
摘要：
The effects of different Cr contents on the corrosion resistance of FeCoNiMnCrx (x = 0.5;1;1.5) porous high-entropy alloys (HEAs) in 3.5 wt.% NaCl solution on corrosion resistance was investigated. With the increase in Cr content, the total porosity and permeability of the porous HEA increased. The increase in porosity improves the interconnectivity between the pores and enhances the contact area with the corrosion solution. The pore-making mechanism is mainly a powder compaction, and Kirkendall holes are caused by different elements due to different diffusion rates. With the increase in Cr content, the icorr increases, and the Ecorr decreases in the porous HEAs of FeCoNiMnCrx (x = 0.5;1;1.5). The corrosion resistance of FeCoNiMnCrx (x = 0.5;1;1.5) porous HEAs decreases with the increase in the Cr element. With the increase in Cr content, the weight gain rate of FeCoNiMnCrx porous HEA increases gradually after immersion for 168 h, and the average pore size and permeability of the sample decrease gradually. The corrosion resistance of FeCoNiMnCrx porous HEA decreases with increasing Cr content.
摘要：
This paper investigated the high-temperature oxidation behavior of gas-atomized CoCrFeNiCu high-entropy alloy (HEA) powders at 800–1000 °C via techniques including SEM, XRD, and TEM. The results indicated that the oxidation kinetics of HEA powders is highly sensitive to temperature and the oxidation kinetics undergo a tripartite evolution through distinct phases: initially following a power function law, transitioning to a logarithmic law, and culminating in a linear law with temperature rising. The oxide growth patterns shift from external oxidation to internal oxidation. Reducing the powder particle size accelerates the oxidation rate and promotes more thorough oxidation. Multilayered oxides form on powder surfaces and interpenetrate to form continuous oxide scales between adjacent particles.
This paper investigated the high-temperature oxidation behavior of gas-atomized CoCrFeNiCu high-entropy alloy (HEA) powders at 800–1000 °C via techniques including SEM, XRD, and TEM. The results indicated that the oxidation kinetics of HEA powders is highly sensitive to temperature and the oxidation kinetics undergo a tripartite evolution through distinct phases: initially following a power function law, transitioning to a logarithmic law, and culminating in a linear law with temperature rising. The oxide growth patterns shift from external oxidation to internal oxidation. Reducing the powder particle size accelerates the oxidation rate and promotes more thorough oxidation. Multilayered oxides form on powder surfaces and interpenetrate to form continuous oxide scales between adjacent particles.
期刊：
SEPARATION AND PURIFICATION TECHNOLOGY,2025年354:128753 ISSN：1383-5866
通讯作者：
Juan Zhao
作者机构：
[Luo, Qiang; Sun, Changlin; Pan, Zhilong] School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430048, China;[Zhao, Juan] School of Mathematics & Computer Science, Wuhan Polytechnic University, Wuhan 430048, China;[Cai, Qizhou] State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China
通讯机构：
[Juan Zhao] S;School of Mathematics & Computer Science, Wuhan Polytechnic University, Wuhan 430048, China
摘要：
Traditional advanced oxidation processes (AOPs) for the removal of toxic and refractory ethylenethiourea (ETU) is uneconomical because of the demand for continuous chemical input and full-scale systems. Herein, ETU was efficiently mineralized without sacrificial reagents for the first time through the utilization of ZnO nano-photocatalysts which were synthesized by the adjustment of ratio between the precursor ZnCl 2 and alkaline source KOH during hydrothermal process. Compared to other ZnO samples, ZnO-1/3 (1:3 molar (M) ratio of ZnCl 2 to KOH) exhibited higher apparent rate constant (0.00661 min −1 ) towards the degradation of ETU because of more effective electron-hole separation. The optimum conditions for ETU degradation (ZnO-1/3 dosage of 0.4 g/L, initial ETU concentration of 10 mg/L and photocatalytic reaction temperature of 35 °C) were acquired according to the outcome of the response surface methodology (RSM) based on the Box-Behnken design (BBD), and the predicted maximum removal efficiency of ETU reached 93.17 % and was consistent with the experimental results under this optimum conditions. The h + and •OH were proved to the main reactive species during the photocatalytic process by the free radical capture experiments and electron spin resonance (ESR) analysis. Furthermore, the possible degradation pathways of ETU were suggested based on the identified degradation intermediates, and the reduced toxicity of intermediates was also demonstrated through the quantitative structure–activity relationship (QSAR) prediction and the growth of mung bean seedlings. Hence, photocatalysis with ZnO can be regarded as a promising alternative for ETU elimination.
Traditional advanced oxidation processes (AOPs) for the removal of toxic and refractory ethylenethiourea (ETU) is uneconomical because of the demand for continuous chemical input and full-scale systems. Herein, ETU was efficiently mineralized without sacrificial reagents for the first time through the utilization of ZnO nano-photocatalysts which were synthesized by the adjustment of ratio between the precursor ZnCl 2 and alkaline source KOH during hydrothermal process. Compared to other ZnO samples, ZnO-1/3 (1:3 molar (M) ratio of ZnCl 2 to KOH) exhibited higher apparent rate constant (0.00661 min −1 ) towards the degradation of ETU because of more effective electron-hole separation. The optimum conditions for ETU degradation (ZnO-1/3 dosage of 0.4 g/L, initial ETU concentration of 10 mg/L and photocatalytic reaction temperature of 35 °C) were acquired according to the outcome of the response surface methodology (RSM) based on the Box-Behnken design (BBD), and the predicted maximum removal efficiency of ETU reached 93.17 % and was consistent with the experimental results under this optimum conditions. The h + and •OH were proved to the main reactive species during the photocatalytic process by the free radical capture experiments and electron spin resonance (ESR) analysis. Furthermore, the possible degradation pathways of ETU were suggested based on the identified degradation intermediates, and the reduced toxicity of intermediates was also demonstrated through the quantitative structure–activity relationship (QSAR) prediction and the growth of mung bean seedlings. Hence, photocatalysis with ZnO can be regarded as a promising alternative for ETU elimination.
关键词：
Rice grain pile;Heat and humidity transfer;Simulation test;Simulated granary;Water migration
摘要：
This study addresses the challenge of developing effective strategies to prevent and control the deterioration of stored grain quality caused by biological activities and heating. The unclear mechanisms of water migration and humidity distribution within rice grain piles subjected to localized high temperatures complicate this effort. Using COMSOL simulation and model granaries, the study examines temperature fields, humidity fields, and water migration in high temperature and humidity areas. Results show that within 24 to 48 hours of high-humidity rice exposure to high temperatures, the surrounding grain's temperature rises rapidly, with relative humidity increasing significantly within 48 to 72 hours. The temperature peaks at around 96 hours. The influence of high-humidity grain on its surroundings is minimal within the first 36 hours, but as temperature increases, the relative humidity of the surrounding grain pile rises faster. The micro-airflow caused by temperature differences drives moist air to migrate to cooler areas, leading to a rise in moisture content in these regions. Therefore, interventions like ventilation and grain turnover should be implemented within 24 hours of detecting high-temperature grain, with continuous monitoring of moisture content in adjacent low-temperature areas to prevent further deterioration.
This study addresses the challenge of developing effective strategies to prevent and control the deterioration of stored grain quality caused by biological activities and heating. The unclear mechanisms of water migration and humidity distribution within rice grain piles subjected to localized high temperatures complicate this effort. Using COMSOL simulation and model granaries, the study examines temperature fields, humidity fields, and water migration in high temperature and humidity areas. Results show that within 24 to 48 hours of high-humidity rice exposure to high temperatures, the surrounding grain's temperature rises rapidly, with relative humidity increasing significantly within 48 to 72 hours. The temperature peaks at around 96 hours. The influence of high-humidity grain on its surroundings is minimal within the first 36 hours, but as temperature increases, the relative humidity of the surrounding grain pile rises faster. The micro-airflow caused by temperature differences drives moist air to migrate to cooler areas, leading to a rise in moisture content in these regions. Therefore, interventions like ventilation and grain turnover should be implemented within 24 hours of detecting high-temperature grain, with continuous monitoring of moisture content in adjacent low-temperature areas to prevent further deterioration.
摘要：
This study proposed a novel detection method for crayfish weight classification based on an improved Swin-Transformer model. The model demonstrated a Mean Intersection over Union (MIOU) of 90.36% on the crayfish dataset, outperforming the IC-Net, DeepLabV3, and U-Net models by 17.44%, 5.55%, and 1.01%, respectively. Furthermore, the segmentation accuracy of the Swin-Transformer model reached 99.0%, surpassing the aforementioned models by 1.25%, 1.73%, and 0.46%, respectively. To facilitate weight prediction of crayfish from segmented images, this study also investigated the correlation between the projected area and the weight of each crayfish part, and developed a multiple regression model with a correlation coefficient of 0.983 by comparing the total projected area and the relationship between the projected area and the actual weight of each crayfish part. To validate this model, a test set of 40 samples was employed, with the average prediction accuracy reaching 98.34% based on 10 representative data points. Finally, grading experiments were carried out on the crayfish weight grading system, and the experimental results showed that the grading accuracy could reach more than 86.5%, confirming the system's feasibility. The detection method not only predicts the weight based on the area but also incorporates the proportional relationship of the area of each part to improve the accuracy of the prediction further. This innovation makes up for the limitations of traditional inspection methods and shows higher potential for application. This study has important applications in industrial automation, especially for real-time high-precision weight grading in the aquatic processing industry, which can improve production efficiency and optimize quality control.
摘要：
The influence of calcium chloride (2% (w/v), 3% (w/v), 4% (w/v) or 5% (w/v)) as crosslinker on the performance of sodium alginate (SA) and anthocyanin extracted from black wolfberry (BWA) based films was observed. The results showed that after CaCl(2) treatment, the elongation at break reduced, but the water resistance, thermal stability, and tensile strength of SA/BWA films were significantly improved and they increased with the increase of CaCl(2) concentration. In which, 5%-CaCl(2) treatment endowed the films with optimal performance, which was specifically manifested by a decrease in the swelling ratio from complete dissolution to 163.4% within 60 minutes, water content from 24.9% to 13.1%, water vapor permeation (WVP) from 6.1 g·cm(-1)·cm(-2)·s(-1)·Pa(-1)·10(-12) to 1.6 g·cm(-1)·cm(-2)·s(-1)· Pa(-1)·10(-12), and an increase in water contact angle from 2.19° to 43.85°, tensile strength from 0.76 MPa to 13.15 MPa. Interestingly, CaCl(2) treatment slightly weakened the antioxidant activity (p < 0.05) but also had around 80% of DPPH radical scavenging rate and improved the visual color change of the film to pH. The films treated by 5%-CaCl(2) monitored the freshness of pork well. Therefore, comparing with traditional SA-based films, the CaCl(2) treated SA/BWA film is a better candidate for active and intelligent packaging application.
关键词：
Stiffness matching;Graded scaffold;Laser powder bed fusion;Mechanical properties;Gyroid structure
摘要：
Stress shielding is a leading cause of bone resorption, loosening, and implant failure. Addressing this challenge, this paper proposes an innovative graded scaffold design strategy to achieve local stiffness matching. This study is grounded in the Gibson-Ashby modulus model of the uniform network Gyroid lattice structure. The elastic modulus values from different regions of the frontal bone are utilized as input data, and a polynomial scaffold model for stiffness matching is established using a polynomial fitting method. Ti6Al4V samples were manufactured through laser powder bed fusion technology. The mechanical performance of the scaffold is analyzed through quasi-static compression experiments and finite element simulations. Heat treatment induces changes in the sample's microstructure, leading to a decrease in elastic modulus and enhanced plasticity and structural stability. In comparison to the frontal bone modulus, the heat-treated polynomial scaffold achieves a minimal difference of 7.9 %. When compared to the uniform scaffold (difference: 25.13 %), the polynomial scaffold demonstrates superior stiffness matching. The proposed design strategy holds significant potential for orthopedic implants and personalized medicine applications.
Stress shielding is a leading cause of bone resorption, loosening, and implant failure. Addressing this challenge, this paper proposes an innovative graded scaffold design strategy to achieve local stiffness matching. This study is grounded in the Gibson-Ashby modulus model of the uniform network Gyroid lattice structure. The elastic modulus values from different regions of the frontal bone are utilized as input data, and a polynomial scaffold model for stiffness matching is established using a polynomial fitting method. Ti6Al4V samples were manufactured through laser powder bed fusion technology. The mechanical performance of the scaffold is analyzed through quasi-static compression experiments and finite element simulations. Heat treatment induces changes in the sample's microstructure, leading to a decrease in elastic modulus and enhanced plasticity and structural stability. In comparison to the frontal bone modulus, the heat-treated polynomial scaffold achieves a minimal difference of 7.9 %. When compared to the uniform scaffold (difference: 25.13 %), the polynomial scaffold demonstrates superior stiffness matching. The proposed design strategy holds significant potential for orthopedic implants and personalized medicine applications.
摘要：
This study investigated the corrosion behavior of TC18 titanium alloy with different initial microstructures in neutral salt spray environment by microstructural analysis, corrosion composition analysis, and electrochemical test in 3.5 wt% NaCl solution. In addition, the pitting mechanism of TC18 titanium alloy in salt spray corrosion was analyzed. Through SEM and Sensofar Neox 3D morphology observation, it was found that alloys with different microstructural morphologies exhibited different levels of corrosion resistance during the salt spray corrosion process, and that the pitting pit of TC18 titanium alloy with different initial microstructure tended to remain stable with increasing salt spray treatment time. The local dissolution of the passivation film was identified as the primary corrosion mechanism during the salt spray process of TC18 titanium alloy with different initial microstructures, as determined by XPS and EDS compositional analysis. The pitting corrosion resistance of TC18 titanium alloy can be effectively enhanced by its initial equiaxed microstructure, which has a smaller grain size, as evidenced by microstructural analysis, electrochemical impedance spectroscopy (EIS) results, and complementary evaluation analysis of Tafel polarization curves. Finally, a comprehensive discussion of the salt spray corrosion mechanism of TC18 titanium alloy is provided. This comprehensive study provides critical insights into the durability of marine equipment and the efficacy of preventive measures to mitigate the occurrence of pitting corrosion.
This study investigated the corrosion behavior of TC18 titanium alloy with different initial microstructures in neutral salt spray environment by microstructural analysis, corrosion composition analysis, and electrochemical test in 3.5 wt% NaCl solution. In addition, the pitting mechanism of TC18 titanium alloy in salt spray corrosion was analyzed. Through SEM and Sensofar Neox 3D morphology observation, it was found that alloys with different microstructural morphologies exhibited different levels of corrosion resistance during the salt spray corrosion process, and that the pitting pit of TC18 titanium alloy with different initial microstructure tended to remain stable with increasing salt spray treatment time. The local dissolution of the passivation film was identified as the primary corrosion mechanism during the salt spray process of TC18 titanium alloy with different initial microstructures, as determined by XPS and EDS compositional analysis. The pitting corrosion resistance of TC18 titanium alloy can be effectively enhanced by its initial equiaxed microstructure, which has a smaller grain size, as evidenced by microstructural analysis, electrochemical impedance spectroscopy (EIS) results, and complementary evaluation analysis of Tafel polarization curves. Finally, a comprehensive discussion of the salt spray corrosion mechanism of TC18 titanium alloy is provided. This comprehensive study provides critical insights into the durability of marine equipment and the efficacy of preventive measures to mitigate the occurrence of pitting corrosion.
通讯机构：
[Li, B ] W;Wuhan Polytech Univ, Sch Mech Engn, Wuhan 430023, Hubei, Peoples R China.
关键词：
Deep eutectic solvent;In situ polymerization;Composite hydrogel;Self-healing;Pressure sensitivity
摘要：
This study utilized choline chloride (ChCl) as the hydrogen bond acceptor, while acrylamide (AM) and urea functioned as hydrogen bond donors. A P(AM-Urea) composite hydrogel was successfully synthesized using a ternary deep eutectic solvent (DES) system and in-situ polymerization. The effects of varying AM/Urea molar ratios on the swelling behavior, mechanical properties, self-healing abilities, and pressure sensitivity of the hydrogels were systematically analyzed. The results indicated that an increase in AM content significantly enhanced both the swelling capacity and mechanical strength of the hydrogels. The SP5 sample (AM/Urea molar ratio 1.5:0.5) exhibited optimal performance, achieving a tensile strength of 4.86 MPa and a compressive strength of 5.6 MPa, which were 7.5 and 4.55 times higher, respectively, than those of the SP1 sample. Self-healing experiments revealed that the SP3 hydrogel, with an AM/Urea molar ratio of 1:1, achieved a healing efficiency of 80% within 20 h. Additionally, in pressure sensitivity tests, the SP1 hydrogel with lower AM content exhibited superior piezoelectric performance, with a capacitance change rate of 59.98%, which was 3.2 times greater than that of the SP5 sample. The P(AM-Urea) composite hydrogel developed in this study exhibits exceptional swelling, mechanical strength, self-healing capabilities, and pressure-responsive characteristics, highlighting its potential applications in sensing, biomedicine, and environmental engineering.
摘要：
W-Mo-V high-speed steel (HSS) is a high-alloy high-carbon steel with a high content of carbon, tungsten, chromium, molybdenum, and vanadium components. This type of high-speed steel has excellent red hardness, wear resistance, and corrosion resistance. In this study, the alloying element ratios were adjusted based on commercial HSS powders. The resulting chemical composition (wt.%) is C 1.9%, W 5.5%, Mo 5.0%, V 5.5%, Cr 4.5%, Si 0.7%, Mn 0.55%, Nb 0.5%, B 0.2%, N 0.06%, and the rest is Fe. This design is distinguished by the inclusion of a high content of molybdenum, vanadium, and trace boron in high-speed steel. When compared to traditional tungsten-based high-speed steel rolls, the addition of these three types of elements effectively improves the wear resistance and red hardness of high-speed steel, thereby increasing the service life of high-speed steel mill-roll covers. JMatPro (version 7.0) simulation software was used to create the composition of W-Mo-V HSS. The phase composition diagrams at various temperatures were examined, as well as the contents of distinct phases within the organization at various temperatures. The influence of austenite content on the martensitic transformation temperature at different temperatures was estimated. The heat treatment parameters for W-Mo-V HSS were optimized. By studying the phase equilibrium of W-Mo-V high-speed steel at different temperatures and drawing CCT diagrams, the starting temperature for the transformation of pearlite to austenite (A(c1) = 796.91 °C) and the ending temperature for the complete dissolution of secondary carbides into austenite (A(ccm) = 819.49 °C) during heating was determined. The changes in carbide content and grain size of W-Mo-V high-speed steel at different tempering temperatures were calculated using JMatPro software. Combined with analysis of A(c1) and A(ccm) temperature points, it was found that the optimal annealing temperatures were 817-827 °C, quenching temperatures were 1150-1160 °C, and tempering temperatures were 550-610 °C. The scanning electron microscopy (SEM) examination of the samples obtained with the aforementioned heat treatment parameters revealed that the martensitic substrate and vanadium carbide grains were finely and evenly scattered, consistent with the simulation results. This suggests that the simulation is a useful reference for guiding actual production.
作者机构：
[Ji-Zhen Liu; Yong-Jing Liu] Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics, School of Science, Wuhan University of Technology, Wuhan 430070, China;[Zi-Bin Lin; Yu-Gui Peng; Xue-Feng Zhu] School of Physics and Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China;[Bin Li] School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan, Hubei 430023, China. Electronic address: lb420@whpu.edu.cn;[Shi-Lin Yan] Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics, School of Science, Wuhan University of Technology, Wuhan 430070, China. Electronic address: yanshl@whut.edu.cn;[Xue-Feng Zhu] Key Laboratory of Biomedical Imaging Science and System, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China. Electronic address: xfzhu@hust.edu.cn
通讯机构：
[Bin Li; Xue-Feng Zhu] S;[Shi-Lin Yan] H;School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan, Hubei 430023, China<&wdkj&>Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics, School of Science, Wuhan University of Technology, Wuhan 430070, China<&wdkj&>School of Physics and Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China<&wdkj&>Key Laboratory of Biomedical Imaging Science and System, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
摘要：
Acoustic energy harvesting assisted by metamaterial devices, deemed as a promising way of utilizing green energy, has been extensively investigated in the science and engineering communities during the past years, considering the ubiquitous sound waves in nature. To date, one of the biggest challenges in the acoustic energy harvesting lies in the improvement of efficiency and output power. In this work, we propose to use the phase reversal Fresnel zone plate (PR-FZP) for efficient acoustic energy harvesting in aquatic environment instead of using the traditional FZP. We first show in simulations that the PR-FZP generates a focusing with much larger intensity than traditional FZP at different operation frequencies and focal lengths. Then we conduct experiments and demonstrate a 141% enhancement in output power of the piezo-receiver by using PR-FZP, in comparison to the FZP case. Here the capacitor charging tests show a 162.5% enhancement in the average charging rate and a 249.3% enhancement in average charging power, in contrast to the FZP case. With the harvested acoustic energy stored in the battery, we can drive a propeller to rotate which can further induce motion underwater. Our research has significant implications for the development of sound-driven devices with versatile functionalities.
Acoustic energy harvesting assisted by metamaterial devices, deemed as a promising way of utilizing green energy, has been extensively investigated in the science and engineering communities during the past years, considering the ubiquitous sound waves in nature. To date, one of the biggest challenges in the acoustic energy harvesting lies in the improvement of efficiency and output power. In this work, we propose to use the phase reversal Fresnel zone plate (PR-FZP) for efficient acoustic energy harvesting in aquatic environment instead of using the traditional FZP. We first show in simulations that the PR-FZP generates a focusing with much larger intensity than traditional FZP at different operation frequencies and focal lengths. Then we conduct experiments and demonstrate a 141% enhancement in output power of the piezo-receiver by using PR-FZP, in comparison to the FZP case. Here the capacitor charging tests show a 162.5% enhancement in the average charging rate and a 249.3% enhancement in average charging power, in contrast to the FZP case. With the harvested acoustic energy stored in the battery, we can drive a propeller to rotate which can further induce motion underwater. Our research has significant implications for the development of sound-driven devices with versatile functionalities.
摘要：
In this study, the chitosan (CS) was combined with purple tomato anthocyanin (ATH) and epsilon-polylysine (PL) to prepare CS/ATH/PL films with PL concentrations of 0%, 1%, 3%, 5%, or 7%. In which, ATH and PL were used as the pH indicator and the antimicrobial agent, respectively. The effect of PL content on the physiochemical properties of CS/ATH/PL films, as well as the application in pork packaging, was investigated. Adding PL improved the color stability of ATH in the films. For instance, at 40 degrees C, the retention index of ATH increased from 82.13% (for CS/ATH/0%-PL) to 91.01% (for CS/ATH/7%-PL); under UV radiation, it increased from 62.56% (for CS/ATH/0%-PL) to 88.23% (for CS/ATH/7%-PL). The doped PL significantly improved the elongation at break, antioxidant and antibacterial properties, and barrier properties against water vapor, while PL had no significant effect on the water content of the films. Compared with the control, the pH, total viable count (TVC), and total volatile basic nitrogen (TVB-N) of pork packaged by CS/ATH/PL films were effectively delayed during storage. The CS/ATH/7%-PL film had the best preservative effect on the pork, and the most significant visual color change for monitoring the pork freshness on 0-4 days. Therefore, the CS/ATH/PL films with higher content of PL content have potential application prospects in active and intelligent packaging.Highlights epsilon-Polylysine (PL) improved the color stability of anthocyanins in chitosan-based films. Barrier, antioxidant, and antibacterial properties of films increased with PL content. PL-7% films are promising for active and intelligent packaging for pork.
摘要：
Beef tallow, prized for its unique aroma, is subjected to essential refining procedures to generate high-quality tallow by eliminating impurities and preserving the flavor profile. An innovative refining technique for beef tallow was introduced in this study, with a focus on flavor preservation through the utilization of enzymatic degumming, alkali deacidification, and adsorbent bleaching technologies. These methods led to reductions in phospholipid levels (< 45 mg/kg), free fatty acids (93.0 %), and pigments (up to 85.6 %). Alterations in fatty acid profiles were observed, accompanied by a significant 41.1 % reduction in tocopherol antioxidants, resulting in a decreased oxidation induction time of 2.58 h during beef tallow refining. Following refinement, cholesterol content decreased by 34.2 % to 30.4 mg/100 g. Minimal alterations in the flavor profile of beef tallow were identified through further assessment using electronic nose and HS-SPME-GC–MS methodologies, offering valuable insights into beef tallow refining techniques and its distinctive flavor characteristics.
Beef tallow, prized for its unique aroma, is subjected to essential refining procedures to generate high-quality tallow by eliminating impurities and preserving the flavor profile. An innovative refining technique for beef tallow was introduced in this study, with a focus on flavor preservation through the utilization of enzymatic degumming, alkali deacidification, and adsorbent bleaching technologies. These methods led to reductions in phospholipid levels (< 45 mg/kg), free fatty acids (93.0 %), and pigments (up to 85.6 %). Alterations in fatty acid profiles were observed, accompanied by a significant 41.1 % reduction in tocopherol antioxidants, resulting in a decreased oxidation induction time of 2.58 h during beef tallow refining. Following refinement, cholesterol content decreased by 34.2 % to 30.4 mg/100 g. Minimal alterations in the flavor profile of beef tallow were identified through further assessment using electronic nose and HS-SPME-GC–MS methodologies, offering valuable insights into beef tallow refining techniques and its distinctive flavor characteristics.
摘要：
This study proposed an ammonia-to-hydrogen- proton exchange membrane fuel cell (PEMFC) and hydrogen-doped internal combustion engine (ICE) hybrid system and investigated its application of this system in a large-scale mobile power scenario. The study analyzed how the total hydrogen supply to the PEMFC and ICE, as well as the distribution ratio of the PEMFC, affects the hybrid system’s performance by simulation. Two regulation strategies—constant and step regulation were proposed, and 12 regulation schemes were formulated. Seven performance indices are used to evaluate and optimize these schemes: system efficiency, battery work time, battery capacity, peak power of the battery, remaining battery power, ammonia consumption, and work efficiency. Compared to the baseline scheme, optimization using the constant regulation strategy improved system efficiency from 48.3 % to 54.57 % and reduced battery capacity by 3.46kWh. Optimization using the step regulation strategy results in a battery capacity reduction of up to 7.08kWh and a decrease in remaining battery power by 7.38kWh. Comprehensive evaluation shows that the step regulation strategy has a more significant impact on overall system performance than the constant regulation strategy.
This study proposed an ammonia-to-hydrogen- proton exchange membrane fuel cell (PEMFC) and hydrogen-doped internal combustion engine (ICE) hybrid system and investigated its application of this system in a large-scale mobile power scenario. The study analyzed how the total hydrogen supply to the PEMFC and ICE, as well as the distribution ratio of the PEMFC, affects the hybrid system’s performance by simulation. Two regulation strategies—constant and step regulation were proposed, and 12 regulation schemes were formulated. Seven performance indices are used to evaluate and optimize these schemes: system efficiency, battery work time, battery capacity, peak power of the battery, remaining battery power, ammonia consumption, and work efficiency. Compared to the baseline scheme, optimization using the constant regulation strategy improved system efficiency from 48.3 % to 54.57 % and reduced battery capacity by 3.46kWh. Optimization using the step regulation strategy results in a battery capacity reduction of up to 7.08kWh and a decrease in remaining battery power by 7.38kWh. Comprehensive evaluation shows that the step regulation strategy has a more significant impact on overall system performance than the constant regulation strategy.
通讯机构：
[Li, B ] W;[Hu, H ] H;Wuhan Polytech Univ, Sch Mech Engn, Wuhan 430023, Hubei, Peoples R China.;Huazhong Agr Univ, Coll Food Sci & Technol, Wuhan, Hubei, Peoples R China.
关键词：
Bigel;Oleogel;Hydrogel;Eutectic
摘要：
In the preparation of bigels, wax is commonly used to create oleogels. However, oleogels made with wax typically have high melting points, which restrict their applicability and performance in practical applications. This study investigates the eutectic phase behavior of beeswax (BW) and rice bran wax (RBW) in bigels after ultrasonic treatment by varying their ratio. A bigel with a lower melting point was also prepared. The results indicated that eutectic phase behavior occurred between beeswax (BW) and rice bran wax (RBW) at a 6:4 ratio, reducing the gel's melting point to 53.4 °C. This was approximately 13.07 °C lower than that of wax mixtures with other ratios. X-ray diffraction (XRD) results showed that the β′-type crystal structure in the oleogels was often used in the food field. Fourier transform infrared spectroscopy (FTIR) analysis showed that the eutectic phase behavior enhanced the formation of intermolecular hydrogen bonds. Rheological analysis revealed that the bigel exhibited shear thinning behavior and gel network characteristics during the frequency sweep. Notably, the eutectic phase behavior significantly enhanced the gel strength and stability.
In the preparation of bigels, wax is commonly used to create oleogels. However, oleogels made with wax typically have high melting points, which restrict their applicability and performance in practical applications. This study investigates the eutectic phase behavior of beeswax (BW) and rice bran wax (RBW) in bigels after ultrasonic treatment by varying their ratio. A bigel with a lower melting point was also prepared. The results indicated that eutectic phase behavior occurred between beeswax (BW) and rice bran wax (RBW) at a 6:4 ratio, reducing the gel's melting point to 53.4 °C. This was approximately 13.07 °C lower than that of wax mixtures with other ratios. X-ray diffraction (XRD) results showed that the β′-type crystal structure in the oleogels was often used in the food field. Fourier transform infrared spectroscopy (FTIR) analysis showed that the eutectic phase behavior enhanced the formation of intermolecular hydrogen bonds. Rheological analysis revealed that the bigel exhibited shear thinning behavior and gel network characteristics during the frequency sweep. Notably, the eutectic phase behavior significantly enhanced the gel strength and stability.
摘要：
As the critical performance index of ball screws, the contact characteristics have a significant influence on the lubricant properties, tribological properties, and wear properties of ball screws, which further directly affect the service life of ball screws. The non-uniform load distribution induced by geometric errors results in imbalances among balls along the nut, negatively impacting the service life of ball screws. This study focuses on the load distribution of single-nut ball screws under low-speed working conditions. This paper proposes a self-adjustable model of load distribution that considers the flexibility of the screw and nut with respect to the determination of the non-bearing ball. A refined model for axial stiffness is proposed to systematically analyze the influence of geometric errors on stiffness variations under various loading conditions. The results confirm the ability of the proposed model to reveal the static load distribution in view of geometric errors. The greatest discrepancy observed between the theoretical predictions and the experimental data was 9.22%. The numerical simulations demonstrate variation trends in the normal contact load, the loaded-ball number, and the axial deformation of a nut with geometric errors. Furthermore, the relationship between the axial stiffness of a single-nut ball screw and the geometric error is obtained. The self-adjustable model of load distribution is helpful for studying the carrying capacity of a single-nut ball screw. The findings of the study provide a definite reference for optimization of structural design and wear life prediction.
