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：
Degumming, a critical process in the edible oil industry, is essential for removing phospholipids. Traditional methods such as water-degumming and acid-degumming have limitations in this regard. This study aimed to assess the efficacy of different degumming techniques, including acid, single and multi-enzyme methods, on rice bran oil (RBO). The investigation also focused on the impact of these techniques on the physicochemical characteristics and preservation of micronutrients in RBO during the degumming process. The primary phospholipids identified were phosphatidylethanolamine (29.51 %), phosphatidylcholine (37.00 %), and phosphatidylinositol (24.49 %). Acid degumming removed 84.23 % of phospholipids, while a significantly higher removal rate of 98.7 % was achieved with the combination of phospholipase A1 & phospholipase C. The degumming process effectively inhibited oxidation in RBO, leading to a substantial increase in the oxidation induction time from 5.7 to 10.0 hours. Furthermore, multi-enzyme degumming showed slightly greater radical-scavenging activity compared to single enzyme degumming in RBO. However, the levels of micronutrients such as phenols, sterols, tocopherols, squalene, and oryzanol were reduced by 6.27–22.17 %. This study provides a comprehensive analysis of the effects of different degumming processes on the physicochemical properties, fatty acid profiles, antioxidant capacities, and preservation of micronutrients in RBO.
Degumming, a critical process in the edible oil industry, is essential for removing phospholipids. Traditional methods such as water-degumming and acid-degumming have limitations in this regard. This study aimed to assess the efficacy of different degumming techniques, including acid, single and multi-enzyme methods, on rice bran oil (RBO). The investigation also focused on the impact of these techniques on the physicochemical characteristics and preservation of micronutrients in RBO during the degumming process. The primary phospholipids identified were phosphatidylethanolamine (29.51 %), phosphatidylcholine (37.00 %), and phosphatidylinositol (24.49 %). Acid degumming removed 84.23 % of phospholipids, while a significantly higher removal rate of 98.7 % was achieved with the combination of phospholipase A1 & phospholipase C. The degumming process effectively inhibited oxidation in RBO, leading to a substantial increase in the oxidation induction time from 5.7 to 10.0 hours. Furthermore, multi-enzyme degumming showed slightly greater radical-scavenging activity compared to single enzyme degumming in RBO. However, the levels of micronutrients such as phenols, sterols, tocopherols, squalene, and oryzanol were reduced by 6.27–22.17 %. This study provides a comprehensive analysis of the effects of different degumming processes on the physicochemical properties, fatty acid profiles, antioxidant capacities, and preservation of micronutrients in RBO.
作者机构：
[Tahir, Muhammad; Tahir, M; Ahmad, Waheed; Dai, Jun; Dai, J] Beijing Inst Technol, Sch Mechatron Engn, Beijing 100081, Peoples R China.;[Bibi, Batoul] Ghazi Univ, Dept Chem, DG Khan 32200, Pakistan.;[Peng, Zhen; He, L; Xiong, Yibo; Khan, Arif Ullah; He, Liang; Ul Nisa, Fazal; Ma, Zeyu; Naseem, Mizna] Sichuan Univ, Sch Mech Engn, State Key Lab Intelligent Construct & Hlth Operat, Chengdu 610065, Peoples R China.;[Gong, Fengming] Sichuan Univ, West China Hosp 2, Dept Gynecol & Obstet, Dev & Related Dis Women & Children Key Lab Sichuan, Chengdu 610041, Peoples R China.;[Tang, Hui] Univ Elect Sci & Technol China, Sch Mat & Energy, Chengdu 611731, Peoples R China.
通讯机构：
[He, L ] S;[Tahir, M; Dai, J ] B;Beijing Inst Technol, Sch Mechatron Engn, Beijing 100081, Peoples R China.;Sichuan Univ, Sch Mech Engn, State Key Lab Intelligent Construct & Hlth Operat, Chengdu 610065, Peoples R China.
关键词：
Zeolitic imidazolate frameworks;Metal-organic frameworks;Electrochemical gas sensors
摘要：
Zeolitic imidazolate framework-8 (ZIF-8), a subgroup of metal-organic frameworks, has garnered significant focus due to its remarkable structural tunability, chemical stability, and high surface area. These attributes make ZIF-8 and its derivatives desirable materials for drug delivery, catalysis, absorption of different gases, and gas sensing applications. This review comprehensively explains the current advances in the synthesis of ZIF-8 and its derivatives, emphasizing the various approaches, including solvothermal, mechanochemical, sonochemical, and seed-assisted methods, etc. The influence of critical parameters like linkers, solvents, pH, temperature, reaction flow rate, viscosity, interfacial tension, and reaction conditions on the morphology and performance of ZIF-8 is systematically analyzed. Furthermore, it explores the roles of ZIF-8-based materials in electrochemical sensing, highlighting their performance in sensing gases such as CO 2 , NH 3 , H 2 S, volatile organic compounds, NO 2 , and H 2 . The mechanisms behind the sensing capabilities of pure, composite, and hybrid ZIF-8 are explained, emphasizing the structure-property relationship and the development of composites. Challenges such as reproducibility, scalability, and environmental stability are also addressed, alongside prospects for integrating ZIF-8 into next-generation gas sensors. This review provides insight into the synthesis-application nexus, aiming to guide future research towards the rational design of ZIF-8-based gas sensors with improved performance and practical utility.
Zeolitic imidazolate framework-8 (ZIF-8), a subgroup of metal-organic frameworks, has garnered significant focus due to its remarkable structural tunability, chemical stability, and high surface area. These attributes make ZIF-8 and its derivatives desirable materials for drug delivery, catalysis, absorption of different gases, and gas sensing applications. This review comprehensively explains the current advances in the synthesis of ZIF-8 and its derivatives, emphasizing the various approaches, including solvothermal, mechanochemical, sonochemical, and seed-assisted methods, etc. The influence of critical parameters like linkers, solvents, pH, temperature, reaction flow rate, viscosity, interfacial tension, and reaction conditions on the morphology and performance of ZIF-8 is systematically analyzed. Furthermore, it explores the roles of ZIF-8-based materials in electrochemical sensing, highlighting their performance in sensing gases such as CO 2 , NH 3 , H 2 S, volatile organic compounds, NO 2 , and H 2 . The mechanisms behind the sensing capabilities of pure, composite, and hybrid ZIF-8 are explained, emphasizing the structure-property relationship and the development of composites. Challenges such as reproducibility, scalability, and environmental stability are also addressed, alongside prospects for integrating ZIF-8 into next-generation gas sensors. This review provides insight into the synthesis-application nexus, aiming to guide future research towards the rational design of ZIF-8-based gas sensors with improved performance and practical utility.
作者机构：
[Xie, Jun; Xie, J; Cai, Song] Hunan First Normal Univ, Sch Intelligent Mfg, Changsha 410205, Peoples R China.;[Zhang, Yi] TravelSky Technol Ltd, Beijing 100000, Peoples R China.;[Tang, Yun] Hunan Univ Sci & Technol, Sch Phys & Elect Sci, Xiangtan 411201, Peoples R China.;[Ji, Yi; Cai, Song] Wuhan Polytech Univ, Sch Mech Engn, Wuhan 430074, Peoples R China.
通讯机构：
[Xie, J ] H;Hunan First Normal Univ, Sch Intelligent Mfg, Changsha 410205, Peoples R China.
摘要：
This paper presents a novel mechanistic explanation for microwave-assisted LIBS to mitigate self-absorption effects. A set of plasma characteristic equations in cylindrical coordinates, including plasma isothermal expansion and modified adiabatic expansion kinetics equations, were formulated. These equations were subsequently coupled with microwave electric field equations to develop a microwave energy-assisted model. These models were employed to numerically analyze the plasma dimensions, velocity, and spatial distribution characteristics of plasma concentration, as well as the energy consumption during plasma expansion and the microwave-assisted energy. This analysis aims to explain the self-absorption mechanism and uncover how microwave-assisted LIBS mitigates self-absorption. LIBS experiments, both with and without microwave assistance, were conducted. An improved Saha-Boltzmann planar method was proposed to quantify the degree of self-absorption in the spectral lines of Al, Si, and Ca. Based on the measured spectral data, the plasma temperature of Al was calculated using this improved method, while the electron densities of Si, Ca, and Al plasmas were determined independently of self-absorption effects, as no spectral line intensity information was involved. The evolution of plasma expansion was captured using an intensified charge-coupled device (ICCD). The experiments confirmed that microwave- assisted LIBS did not alter plasma electron temperature or electron density, but provides sufficient energy for uniform plasma expansion, thereby reducing self-absorption. This finding offers a theoretical reference for mitigating jitter following femtosecond laser wire formation. Furthermore, the experiments demonstrated that microwaves effectively reduce self-absorption and enhance spectral intensity, validating both the accuracy and feasibility of the plasma characteristic equations and the microwave energy-assisted model. These results provide theoretical guidance and experimental optimization for plasma characteristics in LIBS applications.
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.
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.
摘要：
With rising living standards, the demand for health and nutrition has increased, sparking interest in food antioxidants. Known for neutralizing free radicals, antioxidants protect cells from oxidative damage, potentially aiding in disease prevention and anti-aging. In the food industry, they also enhance preservation and quality. Thus, studying food antioxidant mechanisms, detection methods, and applications holds theoretical and practical value. This review mainly discusses the mechanisms, detection methods, and applications of food antioxidants in nutrition. Firstly, the main research status and development trends of food antioxidants are described. Then, the action mechanisms of food antioxidants are introduced. Food antioxidants can effectively remove free radicals and prevent free radicals from causing damage to human cells, thus delaying aging and preventing disease. Secondly, the methods of detecting food antioxidants are discussed, including liquid chromatography, liquid chromatography-tandem mass spectrometry, gas chromatography, and gas chromatography-mass spectrometry. These methods can be used to analyze antioxidant components in various samples of foods, drugs, plants, etc. Finally, the research progress of plant antioxidants is discussed, including the applications of a variety of highly effective antioxidant components extracted from different plants. This review provides the theoretical basis and application reference for the research of food antioxidants.
摘要：
The broken rice rate (BR) is a critical metric which influences the appearance, processing, and economic value of rice. However, current machine vision and machine learning approaches engender significant errors when calculating BR. This study introduces a novel restoring method for identifying BR by leveraging grading and morphological features. A three-class classification model using Convolutional Neural Network (CNN) was devised to distinguish broken rice types of crescent head, elliptical tail, and quadrilateral midst based on their morphological characteristics. After training, the accuracy of classfication model is over 98.7%. Taking the longest 10% of rice grains in the image to be identified as head rice references, the broken grains are filtered by calculating the length proportion to the head rice via machine vision. The filtered broken grains are classified to one of three morphological categories with the trained CNN. The broken grains are virtually ‘restored' to head rice equivalents based on the classified shape and the grading size. Finally, the BR is determined by comparing the counts of original and restored grains. The results of two testing conditions which including all and lacking some broken grains demonstrate that the proposed method can accurately and effectively identify the BR in real-time (2.5s).
The broken rice rate (BR) is a critical metric which influences the appearance, processing, and economic value of rice. However, current machine vision and machine learning approaches engender significant errors when calculating BR. This study introduces a novel restoring method for identifying BR by leveraging grading and morphological features. A three-class classification model using Convolutional Neural Network (CNN) was devised to distinguish broken rice types of crescent head, elliptical tail, and quadrilateral midst based on their morphological characteristics. After training, the accuracy of classfication model is over 98.7%. Taking the longest 10% of rice grains in the image to be identified as head rice references, the broken grains are filtered by calculating the length proportion to the head rice via machine vision. The filtered broken grains are classified to one of three morphological categories with the trained CNN. The broken grains are virtually ‘restored' to head rice equivalents based on the classified shape and the grading size. Finally, the BR is determined by comparing the counts of original and restored grains. The results of two testing conditions which including all and lacking some broken grains demonstrate that the proposed method can accurately and effectively identify the BR in real-time (2.5s).
期刊：
OPTICS AND LASER TECHNOLOGY,2025年181:111727 ISSN：0030-3992
通讯作者：
Hui Li<&wdkj&>Shengnan Shen
作者机构：
[Ma, Rongzhe; Chen, Jiahong; Wang, Minjie] School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China;[Zhu, Wenkang] The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China;Hubei Provincial Engineering Research Center of Generic Technologies for Integrated Circuit Packaging and Integration, Wuhan University, Wuhan 430072, China;[Tu, Hua; Jiang, Yajun] School of Mechanical Engineering, Wuhan Polytechnical University, Wuhan 430048, China;[Li, Hui] School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China<&wdkj&>The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China<&wdkj&>Hubei Provincial Engineering Research Center of Generic Technologies for Integrated Circuit Packaging and Integration, Wuhan University, Wuhan 430072, China
通讯机构：
[Hui Li; Shengnan Shen] S;School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China<&wdkj&>The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China<&wdkj&>Hubei Provincial Engineering Research Center of Generic Technologies for Integrated Circuit Packaging and Integration, Wuhan University, Wuhan 430072, China<&wdkj&>School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China<&wdkj&>The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
摘要：
In the laser powder bed fusion (L-PBF) process, the incorporation of in-situ monitoring systems plays a vital role in guaranteeing the quality of the additive manufacturing (AM) process. Nevertheless, the monitoring system based on high-speed cameras is hindered by the high cost of the required high-speed cameras, making it difficult to achieve accurate in-situ monitoring. This paper studies in-situ video frame interpolation and super resolution reconstruction for accurate monitoring of L-PBF process. It introduces a novel in-situ video frame interpolation algorithm, termed CS-EMA-VFI, aiming to improve the temporal resolution of monitoring video. The visual transformer-based video super resolution (ViTSR) algorithm was employed to enhance the spatial resolution of the interpolated video. A U-Net algorithm was utilized for extracting the geometric characteristics of the molten pool during the L-PBF process subsequent to video frame interpolation and super resolution reconstruction. Comparing the CS-EMA-VFI with seven state-of-the-art video frame interpolation methods, the CS-EMA-VFI achieves the highest peak signal-to-noise ratio (PSNR) of 28.16 dB and the highest structural similarity index measure (SSIM) of 0.917 while being lightweight. The ViTSR achieved PSNR of 28.18 dB and 25.31 dB on the original video sequence and interpolated video sequence, respectively. The inference time for the CS-EMA-VFI with fixed timestep, ViTSR, and U-Net were recorded as 18.5 ms, 48.0 ms, and 20.5 ms, respectively. The total inference time of the three-stage strategy varies from 87.0 ms to 142.5 ms, depending on the temporal resolution enhancement multiples. Additionally, the proposed three-stage method achieves a segmentation accuracy of 90.15 % with fixed timestep interpolation, simultaneously enhancing temporal and spatial resolution, thus enabling accurate and real-time monitoring. This paper promotes the wide adoption of in-situ monitoring system in the AM field.
In the laser powder bed fusion (L-PBF) process, the incorporation of in-situ monitoring systems plays a vital role in guaranteeing the quality of the additive manufacturing (AM) process. Nevertheless, the monitoring system based on high-speed cameras is hindered by the high cost of the required high-speed cameras, making it difficult to achieve accurate in-situ monitoring. This paper studies in-situ video frame interpolation and super resolution reconstruction for accurate monitoring of L-PBF process. It introduces a novel in-situ video frame interpolation algorithm, termed CS-EMA-VFI, aiming to improve the temporal resolution of monitoring video. The visual transformer-based video super resolution (ViTSR) algorithm was employed to enhance the spatial resolution of the interpolated video. A U-Net algorithm was utilized for extracting the geometric characteristics of the molten pool during the L-PBF process subsequent to video frame interpolation and super resolution reconstruction. Comparing the CS-EMA-VFI with seven state-of-the-art video frame interpolation methods, the CS-EMA-VFI achieves the highest peak signal-to-noise ratio (PSNR) of 28.16 dB and the highest structural similarity index measure (SSIM) of 0.917 while being lightweight. The ViTSR achieved PSNR of 28.18 dB and 25.31 dB on the original video sequence and interpolated video sequence, respectively. The inference time for the CS-EMA-VFI with fixed timestep, ViTSR, and U-Net were recorded as 18.5 ms, 48.0 ms, and 20.5 ms, respectively. The total inference time of the three-stage strategy varies from 87.0 ms to 142.5 ms, depending on the temporal resolution enhancement multiples. Additionally, the proposed three-stage method achieves a segmentation accuracy of 90.15 % with fixed timestep interpolation, simultaneously enhancing temporal and spatial resolution, thus enabling accurate and real-time monitoring. This paper promotes the wide adoption of in-situ monitoring system in the AM field.
通讯机构：
[Pei, HC ] W;Wuhan Polytech Univ, Sch Mech Engn, 36 Huanhu Middle Rd, Wuhan 430048, Hubei, Peoples R China.
关键词：
Dead-ended PEMFC;oxygen circulation;water management;density distribution
摘要：
Dead-ended proton exchange membrane fuel cells (PEMFCs) using pure hydrogen and oxygen can improve fuel efficiency and cell performance, making them widely applicable in enclosed spaces. However, dead-ended PEMFCs are prone to flooding, which reduces cell performance and service life. To address this issue, an oxygen recirculation system utilizing oscillating flow generated by pressure differences is designed in this study. This system not only achieves close to 100% fuel utilization but also optimizes water management and enhances current density uniformity. The optimal oxygen cycling conditions were selected based on current density uniformity and cell performance enhancement. The results show that a larger pressure difference amplitude improves water removal from the cell; however, excessively large pressure differences can lead to unstable cell operation. The oscillating flow generated by pressure differences significantly improved current density uniformity, particularly at higher output load currents. Current density uniformity improved by 16.29% at a current of 75 A. The experiment demonstrates that the best current density uniformity is achieved when managing water using a pressure difference at 4-minute intervals, as longer or shorter oscillation intervals are unsuitable for dead-ended performance.
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.
关键词：
点云配准, 随机采样一致性, 图形处理器, 体素化广义迭代最近点, point cloud registration, random sample consensus, graphics processing unit, voxelized generalized iterative closest point
摘要：
针对现有点云配准算法对不同场景的点云进行配准时存在适用性弱、鲁棒性差及配准效率低下等问题，本文提出面向模型和室内外点云的高效配准算法。首先，采用体素网格滤波对点云进行下采样，并使用内部形态描述子（ISS）提取点云特征。然后，由快速点特征直方图（FPFH）对特征点进行特征描述，采用随机采样一致性（RANSAC）算法对点云进行粗配准。最后，通过图形处理器（GPU）并行加速的体素化广义迭代最近点（VGICP）算法实现精配准。实验结果表明，在含有噪声点的三维模型、室内及低重叠率室外点云中，本文算法在达到较高配准精度的同时仅耗时0.118 s、0.306 s和0.648 s。相比于现有的配准算法，配准效率提高了79.12%、82.41%和88.28%。本文算法在不同的应用场景下均具有较高的配准精度和配准效率，且适用性更强、鲁棒性更高。 您的浏览器不支持 audio 元素。 AI语音播报 In response to the problems of weak applicability, low registration efficiency and poor robustness of existing point cloud registration algorithms when registering point clouds from different scenes, this paper proposes an efficient registration algorithm for models, indoor scene and outdoor scene point clouds. Firstly, voxel grid filtering is used to downsample the point cloud, and intrinsic shape signatures (ISS) is used to extract point cloud features. Then, fast point feature histograms (FPFH) are used to describe the feature points, and random sample consensus (RANSAC) algorithm is used for rough registration of point clouds. Finally, the voxelized generalized iterative closest point (VGICP) algorithm accelerated by a graphics processing unit (GPU) is used to achieve precise registration. Experimental results show that in the three-dimensional model, indoor and low overlap outdoor point clouds with noise, the proposed algorithm achieves high registration accuracy while only consuming 0.118 s, 0.306 s, and 0.648 s, respectively. Compared with existing registration algorithms, the registration efficiency is improved by 79.12%, 82.41%, and 88.28%, respectively. The proposed algorithm has high registration accuracy and efficiency in different application scenarios, and has stronger applicability and higher robustness.
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：
Surface-enhanced Raman scattering (SERS) is a frontier technology for high-sensitivity analysis of molecules and chemical substances, and a useful tool in the sensing field relying on fingerprint recognition ability, high sensitivity, multiple detection, biocompatibility, and so forth. SERS substrates have been well concerned attributed to their ability to enhance Raman signals, which makes them useful in various applications, including sensing and detection. At the same time, flexible SERS substrates enable sample loads to meet requirements and, therefore, have high sensitivity for Raman detection, but the detection capacity is still limited. In this paper, the basic principle and method of SERS were reviewed, and some new trends of micro- and nanostructured SERS substrates were reviewed from the aspects of material, matrix type, preparation, and application.
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：
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.
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.
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.
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 CaCl2 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 CaCl2 concentration. In which, 5%-CaCl2 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<middle dot>cm(-1)<middle dot>cm(-2)<middle dot>s(-1)<middle dot>Pa-1<middle dot>10(-12) to 1.6 g<middle dot>cm(-1)<middle dot>cm(-2)<middle dot>s(-1)<middle dot> Pa-1<middle dot>10(-12), and an increase in water contact angle from 2.19 degrees to 43.85 degrees, tensile strength from 0.76 MPa to 13.15 MPa. Interestingly, CaCl2 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%-CaCl2 monitored the freshness of pork well. Therefore, comparing with traditional SA-based films, the CaCl2 treated SA/BWA film is a better candidate for active and intelligent packaging application.
