通讯机构:
[Li, B ] W;Wuhan Polytech Univ, Sch Mech Engn, Wuhan 430023, Hubei, Peoples R China.
摘要:
Deep eutectic solvent (DES) was synthesized from choline chloride (ChCl) and acrylamide (AM), and P(AM-co-MA) hydrogels were prepared by adding different contents of maleic acid (MA) to DES by frontal polymerization. Fourier infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize the hydrogels at the microscopic level, and the swelling properties, mechanical properties, self-healing properties and electrical properties of the copolymerized hydrogels were also investigated. The results showed that the equilibrium swelling of the hydrogels was significantly enhanced with the increase of pH due to the addition of MA. The hydrogel with the addition of MA has self-healing properties that pure PAM does not have. In terms of electrical conductivity, the increase of MA makes the internal structure of the hydrogel more loose, which is conducive to the passage of free ions. And there is a significant effect of different temperatures and different crosslinker contents on the electrical conductivity. In summary, we prepared a P(AM-co-MA) hydrogel that can produce significant property changes in response to changes in the external environment, which is expected to expand the application of hydrogels in flexible electronic materials.
通讯机构:
[Beihai Wang] C;College of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430023, China<&wdkj&>Author to whom correspondence should be addressed.
摘要:
This is a case study of cooperative development between a college and a corporation to manufacture a carton-filling machine. Specifically, a green cooperative development method was proposed that would match the college’s design capabilities with the manufacturing capacity of the enterprise. This college–enterprise cooperative development represents an extensive collaboration between industry and academia. This method integrates design for manufacturing (DFM) theory and the integrated computer aided manufacturing definition (IDEF) method to establish the IDEF0 (functional) model of manufacturing knowledge that supports the design process. The model clarifies the specific manufacturing knowledge that enterprises should provide at the conceptual design stage, preliminary design stage and detailed design stage. The forms of communication and timing of knowledge provision needed to optimize development planning and design decisions based on the manufacturing capacity of the enterprise were also determined. Through this method, the college–enterprise cooperative development project (in this case, involving a carton-filling machine) was accomplished with less time, fewer design modifications and fewer parts needing to be reworked. The results show that this method can greatly reduce the run-in period of both parties, improve the efficiency of cooperative development and reduce the cost and waste of prototyping.
摘要:
Acrylonitrile butadiene styrene (ABS) polymer refers to a high-molecular-weight amorphous copolymer with a wide softening range and specific viscoelasticity of polymer material. The application of such powder materials in additive manufacturing technology for selective laser sintering (SLS) for forming and its post-processing enhancement are rarely investigated. In this paper, the standard specimens of ABS powder were fabricated by SLS. The dimensional accuracy and the mechanical properties of specimens were examined, and the microstructure of tensile fracture was observed under a scanning electron microscope (SEM). The tensile, flexural, and impact strengths were obtained as 2.44 MPa, 5.10 MPa, and 2.77 kJ/m2, respectively, as indicated by the results of this study. Accordingly, the SLS ABS parts are not suitable as functional prototypes. According to the thermodynamic equation, dissolution equation, capillary permeability formula, and the selection of diluent, the influence of diluent on viscosity, the influence of curing time on viscosity, and the influence of curing agent and viscosity on permeability are studied. Thus, the parts were infiltrated with two different types of epoxy resin (system Y and system W) to enhance the mechanical properties. The mechanical properties of specimens administrated with curing agent W increased 4.57, 3.87, and 1.64 times in terms of tensile, flexural, and impact strength, respectively; the others administrated with curing agent Y increased 6.38, 3.52, and 1.05 times, respectively. Accordingly, the results indicate that the SLS ABS parts enhanced by epoxy resin can serve as function parts, which is a feasible method since the properties of the composites can be readily tailored by changing different infiltration resins.
期刊:
Journal of Energy Resources Technology,2023年145(6):062901 ISSN:0195-0738
通讯作者:
Yang, L
作者机构:
[Li, Yu; Yang, Liu] Wuhan Polytech Univ, Dept Mech Engn, Wuhan 102249, Hubei, Peoples R China.;[Wang, Deguo; Yang, Liu] China Univ Petr, Dept Mech & Transportat Engn, Beijing 102249, Peoples R China.;[Li, Dongyang; Yang, Liu] Univ Alberta, Dept Chem & Mat Engn, Edmonton, AB T6G 1H9, Canada.
通讯机构:
[Yang, L ] W;Wuhan Polytech Univ, Dept Mech Engn, Wuhan 102249, Hubei, Peoples R China.;China Univ Petr, Dept Mech & Transportat Engn, Beijing 102249, Peoples R China.;Univ Alberta, Dept Chem & Mat Engn, Edmonton, AB T6G 1H9, Canada.
关键词:
particles deposition;power-law shearing;CFD simulation;wellbore cleaning;sand bed change;petroleum engineering
摘要:
Particles deposition and plug-in wellbore cause lots of damage and efficiency reduction during oil and gas exploitation. Transportation has been a focus for safety and production improvement. The annular flow field and particles transport behavior have been investigated using computational fluid dynamics with an renormalization group k-e method. Effects of particles volume concentration, washing fluid concentration with power-law shearing, annular eccentricity, flow rate, and rotation speed have been researched to get the mechanism of particles accumulation and transport behavior. The results show that an increase in eccentricity causes velocity reduction of the annular narrow gap area, particles easily deposit, accumulate, and are hard to transport; increasing flow rate and fluid concentration apparently improve particles transportation and reduce deposition, pressure loss increases; inlet particles volume concentration increases deposition starting position and deposition length, the inner pipe rotation facilitates particles' second suspension.
通讯机构:
[Li, B ; Yan, SL ] W;Wuhan Polytech Univ, Sch Mech Engn, Wuhan 430023, Hubei, Peoples R China.;Wuhan Univ Technol, Sch Sci, Wuhan 430070, Hubei, Peoples R China.
关键词:
deep eutectic monomers;eutectic gel;frontal polymerization;ionic conductive;self-healing
摘要:
Preparation principle of eutectic gels. Abstract The development of elastomers from renewable raw material resources, with excellent properties, has been a major and difficult area of research. In this work, ternary polymerizable deep eutectic monomers (DEMs) were synthesized from acrylamide, choline chloride, and glycerol (Gy). A series of mixed hydrogels were prepared in 15 min through thermal initiation in DEM using a frontal chemical change. The eutectic gel exhibited good mechanical and self‐healing properties, and the mechanical and self‐healing properties of the target gel could be regulated by adjusting the proportion of Gy, while the eutectic gel could maintain high elongation and self‐healing efficiency at low temperatures. Additional, eutectic gels could be compressed to a strain of more than 80% and could immediately recover to their original state when the compression force was released. In the cyclic compression test, the eutectic gel cyclic compression curves showed a high degree of overlap, and no significant hysteresis was observed, even at a set strain of 80% and 100 cyclic compression times. In addition, the eutectic gel showed fine ionic conductivity, and both the water content and Gy content could affect its conductivity, giving it the potential to be used in the application of manufacturing pressure‐sensitive sensors.
摘要:
Agricultural mechanization is crucial in enhancing production efficiency, alleviating labor demands, reducing costs, improving agricultural product quality, and promoting sustainable development. However, wear and tear are inevitable when using agricultural machinery. The failure of critical wear-resistant parts is responsible for over 50% of rural machinery breakdowns. For instance, a domestic combine harvester typically only operates trouble-free for 20 to 30 h, and the service life of a rotary plow knife is approximately 80 h. Investigating the wear performance of key farm machinery components reinforces machinery design and maintenance strategies, extends machinery lifespans, enhances agricultural production efficiency, and advances agrarian sustainability. This paper provides a comprehensive overview of the latest research on the wear resistance of crucial agricultural machinery components. It delves into the factors influencing the wear resistance of these components and explores current effective measures to address wear-related issues. Additionally, it also summarizes the challenges and opportunities in researching the wear performance of key components in agricultural machinery and future development directions.
摘要:
This study revolves around the issues raised by the current semiconductor device metal casings (mainly composed of aluminum and its alloys), such as resource and energy consumption, complexity of the production process, and environmental pollution. To address these issues, researchers have proposed an eco-friendly and high-performance alternative material-Al(2)O(3) particle-filled nylon composite functional material. This research conducted detailed characterization and analysis of the composite material through scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The results show that the Al(2)O(3) particle-filled nylon composite material has a significantly superior thermal conductivity, about twice as high as that of pure nylon material. Meanwhile, the composite material has good thermal stability, maintaining its performance in high-temperature environments above 240 °C. This performance is attributed to the tight bonding interface between the Al(2)O(3) particles and the nylon matrix, which not only improves the heat transfer efficiency but also significantly enhances the material's mechanical properties, with a strength of up to 53 MPa. This study is of great significance, aiming to provide a high-performance composite material that can alleviate resource consumption and environmental pollution issues, with excellent polishability, thermal conductivity, and moldability, which is expected to play a positive role in reducing resource consumption and environmental pollution problems. In terms of potential applications, Al(2)O(3)/PA6 composite material can be widely used in heat dissipation components for LED semiconductor lighting and other high-temperature heat dissipation components, thereby improving product performance and service life, reducing energy consumption and environmental burden, and laying a solid foundation for the development and application of future high-performance eco-friendly materials.
摘要:
This study aimed to determine the integrated freshness index (IFI) of eggs using Vis-NIR spectroscopy and optimized support vector regression, which gave the first insight into the freshness quality of eggs from the biochemical essence of quality changes. In this work, Vis-NIR transmission spectra of brown-shell and pink-shell egg samples were analyzed between 500 nm and 900 nm. Standard normal variables (SNV) were used to normalize the spectral data, and the Shuffled Frog Leaping Algorithm (SFLA) and Competitive Adaptive Reweighted Sampling (CARS) were used to choose the optimal wavelengths. The quantitative analysis model of IFI was developed using a support vector regression (SVR) that was optimized using Grid Search (GS), Genetic Algorithm (GA), and Particle Swarm Optimization (PSO). After conducting a comparative analysis, it was determined that the GA-SVR model based on 63 wavelengths screened by the SFLA best predicted IFI with a training set coefficient of determination (R-c (2)) of 0.900, root means square error (RMSEC) of 0.005, a prediction set coefficient of determination (R-p (2)) of 0.816, root mean square error (RMSEP) of 0.012 and relative analysis error (RPD) of 2.077. The results demonstrate that the model can be used to simultaneously perform nondestructive detection of two distinct egg IFI variants, suggesting broader applicability and enhanced model reliability.
通讯机构:
[Bin Li#] S;[Shilin Yan; Yane Ma] H;Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics, Wuhan University of Technology, Wuhan, China<&wdkj&>School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan, China<&wdkj&>Hubei Institute of Specialty Vehicle, Wuhan, China
关键词:
Acoustic radiation;cylindrical shell;porous material;annular plates;finite element method
摘要:
Acoustic radiation through a system of double-walled shells, lined with porous foams, and stiffened by annular plates simultaneously is studied. Based on modeling, the porous foams as absorbent fluid property, acoustic characteristics of structure are presented for various sandwich construction by means of vibro-acoustic finite element method with automatic matching layer technology. It is noted that equipping porous foams and annular plates simultaneously enhances the acoustic insulation of structure in the entire frequency domain. The overall sound power level is modified by the density of shell. Moreover, the increase of structural stiffness is shown to effectively reduce the acoustic radiation via rising the thickness of inner shell and the number of annular plates. The foam cores decrease the peak value of structural sound power level through using polyurethane foam cores and increasing filling ratio.
期刊:
JOURNAL OF ANIMAL PHYSIOLOGY AND ANIMAL NUTRITION,2023年107(1):228-237 ISSN:0931-2439
通讯作者:
Wan, LL;Ai, H
作者机构:
[Feng, Ke; Chen, Yan; Lu, Jianjian] Wuhan Polytech Univ, Sch Mech Engn, Wuhan, Peoples R China.;[Wan, Lili] Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430048, Peoples R China.;[Ai, Hui] Cent China Normal Univ, Sch Life Sci, Wuhan, Peoples R China.
通讯机构:
[Ai, H ] C;[Wan, LL ] W;Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430048, Peoples R China.;Cent China Normal Univ, Sch Life Sci, Wuhan, Peoples R China.
摘要:
The chicken is rich in various proteins, fatty acids, polysaccharides, trace elements, and other human essential nutrients that contribute to its high nutritional value. In this study, the expression levels of nutrition-related genes (acetyl-CoA acyltransferase, ACAA) of native chicken breeds were investigated. The level of GgalACAA1-2 transcripts expression in the liver of chicken was significantly higher than that of muscle and heart. Moreover, three protein extracts were isolated from the muscle, heart, and liver tissues from the chicken, and their nutritional function was evaluated in the present study. These protein extracts had excellent DPPH and hydroxyl radical scavenging capacities and exhibited significant superoxide anion scavenging ability. Moreover, the protein extracts of muscle tissue showed an important mouse splenocyte proliferation activity and could be used as an immunomodulator of natural origin. In addition, this report presented an automatic visual inspection of chicken viscera using the active contour algorithms and the image processing method for eviscerating by the parallel robot. The recognition and positioning rate of chicken viscera obtained by the proposed method could reach 96.45%. These methods provided basic data for automated poultry slaughter and segmentation, avoiding unnecessary health risks by a pathogenic microorganism, such as avian influenza, Newcastle disease virus, and coronavirus. Moreover, the internal organs of the chicken could be fully harvested by the image segmentation of automatic evisceration, which also facilitated the processing value of these internal organs as by-products of poultry.
作者机构:
[Hu, Zhigang; Li, Bin; Li, Dong; Wang, Ying; Yang, Junsheng] Wuhan Polytech Univ, Sch Mech Engn, Wuhan 430000, Peoples R China.;[Gong, Pan; Jin, Junsong; Wang, Xinyun; Zhang, Mao] Huazhong Univ Sci & Technol, Sch Mat Sci & Engn, State Key Lab Mat Proc & Die & Mould Technol, 1037 Luoyu Rd, Wuhan 430074, Peoples R China.
通讯机构:
[Junsong Jin; Junsheng Yang] A;Authors to whom correspondence should be addressed.<&wdkj&>School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430000, China<&wdkj&>Authors to whom correspondence should be addressed.<&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
关键词:
high entropy alloy;grain size;tribological behavior;wear mechanism
摘要:
The effect and mechanism of grain sizes on the tribological behavior of CoCrFeMnNi high entropy alloy (HEA) were studied by friction experiments and wear morphology analysis. Under normal low load and low sliding speed, the primary wear mechanism of the HEA samples is adhesive wear. With the increase in sliding speed, the wear mechanisms of the samples are adhesive wear and oxidation wear. The oxide layer formed under the action of friction heat of the coarse grain (CG) sample is easy to break due to the softening of the CG. With the increase of normal load and sliding speed, the wear mechanisms of the HEA samples are mainly adhesive wear, oxidation wear, and plastic deformation. The oxide layer of CG sample has many cracks, and the worn surface also has plastic deformation, which leads to the increase of friction coefficient and specific wear rate and the decrease of wear resistance. Therefore, the fine grain size HEA sample has better wear resistance than the CG sample due to its high surface strength.
通讯机构:
[Li, B ] W;Wuhan Polytech Univ, Sch Mech Engn, Wuhan 430023, Hubei, Peoples R China.
摘要:
The present study synthesized a deep eutectic solvent (DES) using acrylic acid (AA), acrylamide (AM), and choline chloride (ChCl), and added phytic acid (PA) as a filler. Subsequently, the PA/P(AA-co-AM) composite hydrogel was prepared under ultraviolet irradiation and used a photoinitiator. Characterization of the hydrogels was conducted using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The study aimed to investigate the impact of PA on the mechanical properties, fatigue resistance, and electrical conductivity of the composite hydrogel. The findings demonstrated that as the mass fraction of PA increased, the compressive strength of the composite hydrogel gradually decreased, yet the fatigue resistance of the composite hydrogel increased. Specifically, after 10 cycles of compression, the resilience recovery rate of FP0 dropped from 86.9% to 70.4%, the maximum stress recovery rate of FP1 dropped from 97.9% to 89.4%, the maximum stress recovery rate of FP2 dropped from 94.4% to 86.6%, and the maximum stress recovery rate of FP3 dropped from 97.3% to 93%. Overall, this study offers a straightforward and efficient method for producing composite hydrogels with both fatigue resistance and electrical conductivity.
摘要:
Based on the concept of microstructure control and multiphase doping, a novel strong-textured porous (STP) Cu-Al-Mn (CAM) shape memory alloy was fabricated through multi-stage sintering process. Porosity ranging from 31.1 to 11.4 % and the largest near-elastic deformation approached 8.0% were achieved in the STP Cu71Al18Mn11 alloy. Through in-depth characterization, it is confirmed that STP-CAM has less γ2 phase compared to porous ordinary polycrystalline alloy, and exhibits strong 〈0 0 1〉 and 〈1 0 1〉 -oriented texture along the direction of sintering pressure, as well as low angle grain boundaries, which contributes to the large near-elastic deformation observed in this novel porous SMAs.
摘要:
Accurate classification and identification of chicken parts are critical to improve the productivity and processing speed in poultry processing plants. However, the overlapping of chicken parts has an impact on the effectiveness of the identification process. To solve this issue, this study proposed a real-time classification and detection method for chicken parts, utilizing YOLOV4 deep learning. The method can identify segmented chicken parts on the assembly line in real time and accurately, thus improving the efficiency of poultry processing. First, 600 images containing multiple chicken part samples were collected to build a chicken part dataset after using the image broadening technique, and then the dataset was divided according to the 6:2:2 division principle, with 1200 images as the training set, 400 images as the test set, and 400 images as the validation set. Second, we utilized the single-stage target detector YOLO to predict and calculate the chicken part images, obtaining the categories and positions of the chicken leg, chicken wing, and chicken breast in the image. This allowed us to achieve real-time classification and detection of chicken parts. This approach enabled real-time and efficient classification and detection of chicken parts. Finally, the mean average precision (mAP) and the processing time per image were utilized as key metrics to evaluate the effectiveness of the model. In addition, four other target detection algorithms were introduced for comparison with YOLOV4-CSPDarknet53 in this study, which include YOLOV3-Darknet53, YOLOV3-MobileNetv3, SSD-MobileNetv3, and SSD-VGG16. A comprehensive comparison test was conducted to assess the classification and detection performance of these models for chicken parts. Finally, for the chicken part dataset, the mAP of the YOLOV4-CSPDarknet53 model was 98.86% on a single image with an inference speed of 22.2 ms, which was higher than the other four models of YOLOV3-Darknet53, YOLOV3-MobileNetv3, SSD-MobileNetv3, and SSD-VGG16 mAP by 3.27%, 3.78%, 6.91%, and 6.13%, respectively. The average detection time was reduced by 13, 1.9, 6.2, and 20.3 ms, respectively. In summary, the chicken part classification and detection method proposed in this study offers numerous benefits, including the ability to detect multiple chicken parts simultaneously, as well as delivering high levels of accuracy and speed. Furthermore, this approach effectively addresses the issue of accurately identifying individual chicken parts in the presence of occlusion, thereby reducing waste on the assembly line. PRACTICAL APPLICATION: The aim of this study is to offer visual technical assistance in minimizing wastage and resource depletion during the sorting and cutting of chicken parts in poultry production and processing facilities. Furthermore, considering the diverse demands and preferences regarding chicken parts, this research can facilitate product processing that caters specifically to consumer preferences.
摘要:
In this paper, the random matrix big data analysis model is thoroughly studied and constructed, the ecological model of college students' innovation and entrepreneurship education is analyzed, and the optimization model of college students' Innovation and entrepreneurship education environmental model based on the random matrix big data analysis model is designed. This paper briefly explains the random matrix and its M-P rate theory deduces the idea of feature extraction by the difference of eigenvalue limit spectrum distribution between different nonrandom matrices and random matrices, gives the data matrix representation method of FEMPL and the specific feature composition basis, and describes the steps of FEMPL feature extraction. A performance model for predicting the running time of Hadoop jobs is constructed using a random matrix. In this paper, innovation and entrepreneurship education has been carried out gradually, and the innovation and entrepreneurship education curriculum, platform, and mechanism have been progressively established. However, there is still a gap between the proper level of innovation and entrepreneurship education development. This study takes education ecology as the research perspective, analyzes the ecosystem of typical schools of innovation and entrepreneurship education, summarizes the dimensions and parameters of the invention and entrepreneurship education ecosystem, constructs an ecological model of innovation and entrepreneurship education for college students, and analyzes the problems and causes of the current innovation and entrepreneurship education ecology for college students based on the model, to propose specific strategies to promote the ecological development of innovation and entrepreneurship education for college students.
摘要:
Water management is important for proton exchange membrane fuel cell (PEMFC). To maintain highly efficient and stable operation of PEMFC, water generated in PEMFC needs to be migrated in time. An inner dehumidification technique is proposed to remove the water inside the PEMFC stack. Two inner condensing units are set near the cathode outlet to cooling the moisture gas. Water vapor in the flow channel will transfer directly to the outlet to supplement the vapor loss due to condensing. As a consequence, water flooding is sufficiently mitigated inside PEMFC. The experimental results show that the output voltage of the dead-ended fuel cell stack increases by 9.77% at 1000 mA center dot cm(-2) when the condensing temperatures is 5 degrees C. When the condensing temperature decreases from 20 degrees C to 5 degrees C, the average stack voltage can be increased by 14.3% at 500 mA center dot cm(-2), and the average temperature difference decreases from 3.2 degrees C to 1.8 degrees C. Moreover, the performance and temperature distribution uniformity are all increased with the increasing of the operation temperature due to inner moisture dehumidification.
作者机构:
[Gong, Pan; Wang, Dongliang; Wang, Xinyun; Zhang, Cheng] Huazhong Univ Sci & Technol, Sch Mat Sci & Engn, State Key Lab Mat Proc & Die & Mould Technol, Wuhan 430074, Peoples R China.;[Gong, Pan] Huazhong Univ Sci & Technol Shenzhen, Res Inst, Shenzhen 518057, Peoples R China.;[Wang, Ying] Wuhan Polytech Univ, Sch Mech Engn, Wuhan 430000, Peoples R China.;[Jamili-Shirvan, Zahra] Esfarayen Univ Technol, Esfarayen, North Khorasan, Iran.;[Yao, Kefu] Tsinghua Univ, Sch Mat Sci & Engn, Beijing 100084, Peoples R China.
通讯机构:
[Gong, Pan; Wang, Xinyun] S;State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, China<&wdkj&>Research Institue of Huazhong University of Science and Technology in Shenzhen, Shenzhen, China<&wdkj&>State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, China
摘要:
The corrosion behavior of TiZrHfBeCu(Ni) high-entropy bulk metallic glasses (HE-BMGs) has been investigated. The TiZrHfBeCu(Ni) HE-BMGs exhibited high corrosion resistance in 3.5 wt. % NaCl solution because of accumulation of ZrO2 and TiO2 in the passive film. Ni promoted increases of the ZrO2, TiO2, and HfO2 contents and a decrease of the BeO content, which improved the HE-BMG corrosion behavior. Compared with Zr41.2Ti13.8Ni10Cu12.5Be22.5 BMG, the high-entropy effect of HE-BMGs can significantly reduce the atomic mobility, which inhibits outward migration of Cu, reduces the kinetics of the dissolution reaction, and inhibits inward erosion by Cl−, thereby improving the corrosion performance.