期刊：
Food Research International,2023年163:112278 ISSN：0963-9969
通讯作者：
Xiao-Hua Zhang<&wdkj&>Xiao-Li Yin
作者机构：
[Zhang, Xiao-Hua; Zhang, Ya-Qian; Pan, Le-Yuan; Zheng, Jing-Jing; Yang, Kai-Long; Ren, Lu-Meng] Xuchang Univ, Food & Pharm Coll, Henan Key Lab Biomarker Based Rapid detect Technol, Xuchang 461000, Peoples R China.;[Cui, Hui-Na; Yin, Xiao-Li] Yangtze Univ, Coll Life Sci, Jingzhou 434023, Peoples R China.;[Qing, Xiang-Dong] Hunan City Univ, Coll Mat & Chem Engn, Hunan Prov Key Lab Dark Tea & Jin Hua, Yiyang 413049, Peoples R China.
通讯机构：
[Xiao-Hua Zhang] H;[Xiao-Li Yin] C;College of Life Sciences, Yangtze University, Jingzhou 434023, China<&wdkj&>Henan Key Laboratory of Biomarker Based Rapid-detection Technology for Food Safety, Food and Pharmacy College, Xuchang University, Xuchang 461000, PR China
关键词：
Aqueous two-phase systems;Chemometrics;Green tea;HPLC-DAD;Harvesting season
摘要：
The flavor and aroma quality of green tea are closely related to the harvest season. The aim of this study was to identify the harvesting season of green tea by alcohol/salt-based aqueous two-phase system (ATPS) combined with chemometric analysis. In this paper, the single factor experiments (SFM) and response surface methodology (RSM) optimization were designed to investigate and select the optimal ATPS. A total of 180 green tea samples were studied in this work, including 86 spring tea and 94 autumn tea. After the active components in green tea samples were extracted by the optimal ethanol/(NH(4))(2)SO(4) ATPS, the qualitative and quantitative analysis was realized based on HPLC-DAD combined with alternating trilinear decomposition-assisted multivariate curve resolution (ATLD-MCR) algorithm, with satisfactory spiked recoveries (86.00%-112.45%). The quantitative results obtained from ATLD-MCR model were subjected to chemometric pattern recognition analysis. The constructed partial least squares-discriminant analysis (PLS-DA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) models showed better results than the principal component analysis (PCA) model, and the R(2)X(cum) values (>0.835) and R(2)Y(cum) (>0.937) were close to 1, the Q(2)(cum) values were greater than 0.75 (>0.933), and the differences between R(2)Y(cum) and Q(2)(cum) were not larger than 0.2, indicating excellent cross-validation prediction performance of the models. Furthermore, the classification results based on the hierarchical clustering analysis (HCA) were consistent with the PCA, PLS-DA and OPLS-DA results, establishing a good correlation between tea active components and the harvesting seasons of green tea. Overall, the combination of ATPS and chemometric methods is accurate, sensitive, fast and reliable for the qualitative and quantitative determination of tea active components, providing guidance for the quality control of green tea.
摘要：
Reasonable assessment of corrosion initiation probability in existing reinforced concrete structures is an important premise for ensuring the safety and durability of such structures. In this paper, a simplified dual time-dependent chloride diffusion model considering the load effect is established and verified by comparing its results with the experimental data. Then, a modelling method of imprecise random fields is developed. In addition, a novel probabilistic analysis method of corrosion initiation in existing RC structures with imprecise random fields is proposed. The case analysis results show that the corrosion resistance of existing structures will be overestimated without considering the effect of imprecise random fields. In comparison, the upper bound of cumulative probability of corrosion initiation is 2.29 times of that using the existing deterministic method in this case. Parametric analyses show that the imprecise random field of concrete cover (Cd) has the greatest effect on the cumulative probability of corrosion initiation, followed by initial surface chloride concentration (Cs) and chloride diffusion coefficient (Da). Compared with the interval coefficient of variation and correlation length, the cumulative probability of corrosion initiation is more sensitive to the interval mean, especially the interval mean of Cd. Additionally, the effect of interval correlation length of Cs is sequentially greater than that of Cd and Da.
作者机构：
[Chen, Yi; Xue, Yanghao; Zhao, Changjie; Liu, Chang] Guizhou Univ, Sch Civil Engn, Guiyang 550025, Guizhou, Peoples R China.;[Rao, Junying; Rao, JY] Guizhou Univ, Res Ctr Space Struct, Guiyang 550025, Guizhou, Peoples R China.;[Chen, Yi; Xue, Yanghao; Zhao, Changjie; Liu, Chang] Guizhou Prov Key Lab Rock & Soil Mech & Engn Safe, Guiyang 550025, Guizhou, Peoples R China.;[Yin, Quan] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.
通讯机构：
[Rao, JY ] G;Guizhou Univ, Res Ctr Space Struct, Guiyang 550025, Guizhou, Peoples R China.
摘要：
To investigate the mechanical properties of fractured dolomite, this study analyzed the fracture characteristics (dip angle, length, position, quantity) using the Pearson coefficient and MIC coefficient. Subsequently, the data pertaining to fracture characteristics is preprocessed using a third-degree polynomial, and a three-classification strategy is implemented to improve the logistic regression algorithm to establish the strength prediction model of fractured dolomite. Furthermore, the significance order of the impact of fracture characteristics on rock strength was determined using the numerical simulation software PFC3D, and the dip angle effect was explained from the perspective of internal fracture propagation within the rock. The results show that: (1) When the regularization coefficient λ = 10,000, the algorithm has the highest prediction accuracy and the strongest model generalization ability. (2) The numerical simulation analysis software PFC3D can accurately invert rock failure process and characteristics, and the order of influence of fracture characteristics on rock strength is dip angle > length > position.
作者机构：
[Peng, Zhigao; Peng, ZG; Deng, Zongwei; Feng, Haoxiong; Xiao, Ming] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.;[Liu, Shenggui] China Univ Min & Technol Beijing, Sch Mech & Civil Engn, Beijing 100083, Peoples R China.;[Peng, Zhigao; Peng, ZG] Hunan City Univ, Hunan Engn Res Ctr Struct Safety & Disaster Preven, Yiyang 413000, Peoples R China.
通讯机构：
[Peng, ZG ] H;Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.;Hunan City Univ, Hunan Engn Res Ctr Struct Safety & Disaster Preven, Yiyang 413000, Peoples R China.
摘要：
Under specific conditions, moisture in natural coal seams can be adsorbed in the pores of the coal matrix, reducing the amount of methane adsorption sites and the effective area of the transport channels. This makes the prediction and evaluation of permeability in CBM exploitation more challenging. In this paper, we developed an apparent permeability model of coalbed methane coupling viscous flow, Knudsen diffusion, and surface diffusion which considers the effects of adsorbed gas and moisture in the pores of the coal matrix on the permeability evolution. The predicted data of the present model are compared with those of other models, and the results show good agreement, verifying the accuracy of the model. The model was employed to study the apparent permeability evolution characteristics of coalbed methane under different pressure and pore size distribution conditions. The main findings are as follows: (1) moisture content increases with saturation, with a slower increase for smaller porosities and an accelerated non-linear increase for porosities greater than 0.1. (2) Gas adsorption in pores decreases permeability, further weakened by moisture adsorption under high pressure but negligible at pressures below 1 MPa. (3) Higher water saturation weakens gas transport capacity, especially with pore sizes smaller than 10 nm. (4) The non-Darcy effect weakens with higher initial porosity, and neglecting moisture adsorption may significantly deviate from actual values in modeling methane transport in coal seams. The present permeability model can capture the transport characteristics of CBM in moist coal seams more realistically and is more applicable for predicting and evaluating the gas transport performance under dynamic variations of pressure, pore size, and moisture. The results in this paper can explain the transport behavior of gas in moist, tight, porous media and also provide a foundation for coalbed methane permeability evaluation.
摘要：
In this study, we developed a highly active floatable photocatalyst by incorporating BiOCl/BiOBr heterojunctions with abundant oxygen vacancies (OVs) onto fly ash cenospheres (FACs) composites, aiming to enhance the efficiency of tetracycline (TC) removal. The physicochemical properties of resulting composites were analyzed using various characterization techniques. The findings demonstrated the uniform anchoring of nanosheet-arraylike BiOCl, BiOBr, or BiOCl/BiOBr heterojunctions on the surface of FACs. Intriguingly, the BiOCl/BiOBr heterojunctions exhibited an increased content of OVs compared to BiOCl and BiOBr alone. The degradation experiments of TC revealed that the BiOCl/BiOBr@FACs composites displayed optimal photodegradability, which was further enhanced by the assistance of peroxymonosulfate (PMS). Furthermore, through active species capture experiments and ESR analysis, we proposed a synergistic reactive mechanism that differed from single photocatalytic processes and traditional PMS activation. Active species such as h+, 1O2, & BULL;O2- , & BULL;OH and & BULL;SO4- were found to participate in the synergistic process of TC degradation, in which the presence of PMS promoted the production of & BULL;O2- via OVs active sites instead of inhibition. Importantly, the immobilized BiOCl/BiOBr@FACs composites exhibited floatability on the water surface and were readily excited by visible light, making them suitable for reuse and practical applications. This study presents an innovative approach for designing recyclable photocatalysts and achieving efficient wastewater treatment with the assistance of PMS.
摘要：
The thermal performances of lithium-ion cells are significantly influenced by unavoidable uncertainties during manufacturing. However, there is a lack of uncertainty optimization methods to control the thermal performance fluctuations of lithium-ion cells. This paper proposes a robust optimization approach for prismatic lithium-ion cells, aiming to optimize the manufacturing cost and control the thermal performance fluctuations without removing the uncertainties. The cost objective function and thermal robustness constraints are established considering the uncertainties of the manufacturing parameters, thereby formulating the robust optimization model of the prismatic lithium-ion cell. The robust optimization performs a nested optimization by optimizing the parameter standard deviations for an optimal cost and evaluating the cell thermal robustness at each design point. An analytical expression for the cell expansion behaviour is created based on the elastic shell theory. An electrochemical-thermal-mechanics multidisciplinary analysis method with ordinary differential equations is given to evaluate the cell thermal performances such as temperature, pressure, and expansion under thermal abuse. It addresses the efficiency issue in the nested optimization. The robust optimization approach is applied to design problems for two-type lithium-ion cells packaged in pouch and hard-pack. Numerical and experimental results demonstrate the excellent potential of the approach due to its advantages in applicability, accuracy, and efficiency.
期刊：
JOURNAL OF SUPERCOMPUTING,2023年79(6):6560-6582 ISSN：0920-8542
通讯作者：
Weiming Liu
作者机构：
[Liu, Weiming] Hunan City Univ, Coll Art, Yiyang 413000, Peoples R China.
通讯机构：
[Weiming Liu] C;College of Art, Hunan City University, Yiyang, China
关键词：
Deep learning;Neural network;Generative adversarial network;Music generation;Intelligent composition
摘要：
The production of traditional music is too complicated, consuming a lot of financial and human resources. Therefore, this paper aims to use artificial intelligence (AI) for songwriting and to explore the development and application of the Generative Adversarial Network (GAN) in smart music. An improved GAN-based Multi-Track Music (MTM)-GAN is established. The model is validated with the generation of 5 different music tracks for bass, drums, guitar, piano, and strings. The verification results are compared with the music generated by the existing Multi-Track Sequential GAN (MuseGAN) index evaluation method. The results show that many music clips generated by the MTM-GAN model are smooth and have a certain artistic aesthetic effect. Through the comparison of the two convergence curves of MuseGAN and MTM-GAN, when the penalty term is increased, the MTM-GAN of Consistency Term (CT) converges faster, and the training process is more stable. The numerical space of the parameter distribution obtained by the MTM-GAN-based music segment test is significantly smaller than that of MuseGAN. The probability of MTM-GAN overfitting is small. 62.8% of music listeners cannot distinguish the generated melody from the real melody. Therefore, the proposed model has the advantages of a more stable, more realistic, and faster fitting speed in music generation, indicating that the music generation method is effective.
摘要：
In this study, the rectangular pipe-jacking tunnel project of the Liuye Avenue West Extension under the Changzhang Highway is used to study highway pavement settlement and deformation during pipe-jacking construction through on-site monitoring. A three-dimensional numerical simulation method is employed to analyse the factors contributing to the significant settlement and rebound of the pavement. This study identifies the fundamental law governing the development of pavement settlement over time. The findings indicate that settlement increases rapidly when the jacking distance reaches approximately 10 m and then stabilizes at a consistent growth level. Furthermore, completion of the jacking of the left pipe leads to a transition in the surface settlement groove from a "V"-type distribution to a "W"-type distribution. Comparative analysis reveals that horizontal and vertical displacements exhibit similar characteristics, with maximum displacements occurring in the lagging jacking area. On both sides of the axis, the settlement groove curve remains stable within a range of 30-40 m, while the horizontal displacement curve stabilizes within a range of 20-30 m.
摘要：
Corrosion can accelerate the deterioration of the mechanical properties of orthotropic steel bridge decks (OSBDs), seriously affecting the service safety of steel bridges. In this paper, thirty Q345C steel and four OSBD specimens with various corrosion levels are designed to investigate the effect of corrosion on the static behavior of OSBDs. Then, corrosion damage and its influence on mechanical properties are explored by static loading experiments. The constitutive model for Q345C steel is built considering the impact of corrosion. Finally, a numerical analysis considering geometric initial defects is employed to compare the effect of corrosion location on bearing capacity degradation. It is observed from the tested results that the corrosion led to the failure mode of Q345C steel changing from plastic failure to brittle failure. The ultimate bearing capacity of specimens with a local corrosion rate of 7.92%, 12.05%, and 16.24% decreased by 11.08%, 14.45%, and 17.82%, respectively. Corrosion leads to stress concentration in the top plate area, causing local instability of the structure. The degradation degree of the bearing capacity of the top plate is greater than that of the U-rib corrosion corresponding to the same corrosion conditions.
摘要：
The multiple activities of neurons frequently generate several spiking-bursting variations observed within the neurological mechanism. We show that a discrete fractional-order activated nerve cell framework incorporating a Caputo-type fractional difference operator can be used to investigate the impacts of complex interactions on the surge-empowering capabilities noticed within our findings. The relevance of this expansion is based on the model's structure as well as the commensurate and incommensurate fractional-orders, which take kernel and inherited characteristics into account. We begin by providing data regarding the fluctuations in electronic operations using the fractional exponent. We investigate two-dimensional Morris-Lecar neuronal cell frameworks via spiked and saturated attributes, as well as mixed-mode oscillations and mixed-mode bursting oscillations of a decoupled fractional-order neuronal cell. The investigation proceeds by using a three-dimensional slow-fast Morris-Lecar simulation within the fractional context. The proposed method determines a method for describing multiple parallels within fractional and integer-order behaviour. We examine distinctive attribute environments where inactive status develops in detached neural networks using stability and bifurcation assessment. We demonstrate features that are in accordance with the analysis's findings. The Erdös-Rényi connection of asynchronization transformed neural networks (periodic and actionable) is subsequently assembled and paired via membranes that are under pressure. It is capable of generating multifaceted launching processes in which dormant neural networks begin to come under scrutiny. Additionally, we demonstrated that boosting connections can cause classification synchronization, allowing network devices to activate in conjunction in the future. We construct a reduced-order simulation constructed around clustering synchronisation that may represent the operations that comprise the whole system. Our findings indicate the influence of fractional-order is dependent on connections between neurons and the system's stored evidence. Moreover, the processes capture the consequences of fractional derivatives on surge regularity modification and enhance delays that happen across numerous time frames in neural processing.
作者：
Wong, Kelvin K. L.;Ayoub, Muhammad;Cao, Zaijie;Chen, Cang;Chen, Weimin;...
期刊：
Computer Methods and Programs in Biomedicine,2023年240:107677 ISSN：0169-2607
通讯作者：
Wong, KK
作者机构：
[Chen, Weimin; Wong, Kelvin K. L.; Wong, KK] Hunan City Univ, Sch Informat & Elect, Yiyang 413000, Peoples R China.;[Wong, Kelvin K. L.] Deep Red Future Technol Co Ltd, Dept Res, Shenzhen, Peoples R China.;[Wong, Kelvin K. L.; Zhang, Chris W. J.] Univ Saskatchewan, Dept Mech Engn, Div Biomed Engn, Saskatoon, SK, Canada.;[Ayoub, Muhammad; Chen, Cang; Cao, Zaijie] Cent South Univ, Sch Comp Sci & Engn, Changsha, Hunan, Peoples R China.;[Ghista, Dhanjoo N.] Univ 2020 Fdn, San Jose, CA USA.
通讯机构：
[Wong, KK ] H;Hunan City Univ, Sch Informat & Elect, Yiyang 413000, Peoples R China.
关键词：
Cybernetical intelligence;Deep medicine;Diagnosis;Medical imaging;Precision medicine
摘要：
Conceptual Introduction: To introduce the concept of cybernetical intelligence, deep learning, development history, international research, algorithms, and the application of these models in smart medical image analysis and deep medicine are reviewed in this paper. This study also defines the terminologies for cybernetical intelligence, deep medicine, and precision medicine.Review of Methods: Through literature research and knowledge reorganization, this review explores the fundamental concepts and practical applications of various deep learning techniques and cybernetical intelligence by conducting extensive literature research and reorganizing existing knowledge in medical imaging and deep medicine. The discussion mainly centers on the applications of classical models in this field and addresses the limitations and challenges of these basic models.Evaluation and Discussions: In this paper, the more comprehensive overview of the classical structural modules in convolutional neural networks is described in detail from the perspective of cybernetical intelligence in deep medicine. The results and data of major research contents of deep learning are consolidated and summarized. Conclusion: There are some problems in machine learning internationally, such as insufficient research techniques, unsystematic research methods, incomplete research depth, and incomplete evaluation research. Some suggestions are given in our review to solve the problems existing in the deep learning models. Cybernetical intelligence has proven to be a valuable and promising avenue for advancing various fields, including deep medicine and personalized medicine.& COPY; 2023 Published by Elsevier B.V.
期刊：
FRONTIERS IN EARTH SCIENCE,2023年11:1174017 ISSN：2296-6463
通讯作者：
Tang, M
作者机构：
[Tang, Miao; Chen, Jin; Deng, Hao; Mao, Xiancheng; Tang, M; Liu, Zhankun; Wang, Jinli] Cent South Univ, Sch Geosci & Info Phys, Key Lab Metallogen Predict Nonferrous Met & Geol E, Minist Educ, Changsha, Peoples R China.;[Chen, Jin; Deng, Hao; Mao, Xiancheng; Liu, Zhankun; Wang, Jinli] Hunan Key Lab Nonferrous Resources & Geol Hazards, Changsha, Peoples R China.;[Tang, Miao; Tang, M] Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang, Peoples R China.
通讯机构：
[Tang, M ] C;Cent South Univ, Sch Geosci & Info Phys, Key Lab Metallogen Predict Nonferrous Met & Geol E, Minist Educ, Changsha, Peoples R China.;Hunan City Univ, Sch Municipal & Geomat Engn, Yiyang, Peoples R China.
关键词：
association rules analysis;favorable mineralization site;Jiaojia goldfield;metallogenic information extraction;spatial constraints
摘要：
Mesozoic orogenic gold deposits in the Jiaojia goldfield, Eastern China show the features of regular mineralization spatial distribution and have long been captivated the attention of geologists. This study integrates 3D modeling, model space analysis, and association rule analysis to extract the relationship between structural deformation and gold mineralization. The Apriori algorithm with spatial constraints is used to quantify the favorable mineralization sites in the Jiaojia gold field using different combinations of ore-controlling indicators. The first favorable mineralization site has a 44% probability of mineralization and is primarily located in segments of the fault footwall within 25 m of the fault buffer where the transition from steep to gentle occurs (similar to 1-24). Its uniform distribution indicates that the ore-bearing space near the main fault plane is relatively wide, and hydrothermal diffusion is relatively uniform. Site No. 2 has a 45% probability of mineralization and is located in convex segments (6-35 m) between 25 and 55 m of the fault footwall. The equidistant zonal distribution in this area indicates that secondary faults and fractures have facilitated the migration of hydrothermal fluids, resulting in the formation of extensive ore-bearing spaces. Site No. 3 sited in convex segments (similar to 0-6 m) distal to the fault footwall (similar to 55-515 m) of the fault buffer where the dip is gentle (similar to 30 degrees-35 degrees). The binary structure of differing dips formed by the intersection of steeply dipping orebodies and the slowly dipping orebodies in the central and southern parts of the Nanlu-Xinmu deposit exhibit the complex channel away from the main fault. In this study, the correlation between ore-controlling factors and mineralization in Jiaojia fold field is quantitatively expressed as favorable mineralization sites in the form of association rules, it would contribute to a deeper understanding of the underlying mechanisms governing the formation of structure-controlled orogenic gold deposits in the Jiaojia goldfield.
作者机构：
[Ma, Dechong; Pan, Sai; Ma, DC; He, Guowen; Tan, Mingjun] Hunan City Univ, Coll Mat & Chem Engn, Yiyang 413000, Peoples R China.;[Zhao, Jingzhe] Hunan Univ, Coll Chem & Chem Engn, Changsha 410082, Peoples R China.
通讯机构：
[Ma, DC; He, GW ] H;Hunan City Univ, Coll Mat & Chem Engn, Yiyang 413000, Peoples R China.
关键词：
Bi nanostructures;pH values;Photocatalytic activity;Morphology controlled synthesis
摘要：
The catalytic activity of photocatalyst is strongly dependent on the phase structures, grain size and particle morphology of the catalyst. In this paper, the controlled synthesis of bismuth(Bi) with different morphologies (nanoparticles, nanorods, nanocubes and micro-spheres) has been successfully realized by adjusting different experimental parameters. The Bi nanostructures were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET), photoluminescence (PL), UV-vis absorption spectroscopy (UV-Vis). The PL spectra shown that the reduction of the size of Bi nanomaterials can decrease the recombination rate of photoelectrons and holes, which leads to the effective separation of photocharge carriers and the better photocatalytic performance of Bi nanomaterials. The energy gaps of Bi nanoparticles, nanorods, nanocubes and microspheres are 2.57 eV, 2.69 eV, 2.99 eV and 3.16 eV respectively. The degradation activity of Bi nanostructures with different sizes on organic dyes showed that 99.9%, 98.9%, 97% and 68.3% degradation of RhB was observed after 90-min visible light irradiation for Bi nanoparticles (20-50 nm), nanorods (20 nm in diameter and 1 mu m in length) nanocubes (150-200 nm) and micro-spheres (10 mu m), respectively. The results indicated that if the grain sizes of the Bi samples are reduced from micro-size to nano-size, their catalytic activities dramatically increase. At the same time, the achieved results also reveal that Bi2O3 and BiOCl were found in Bi surfaces before and after catalytic degradation, which was confirmed by XPS and FTIR technology. In addition, the catalytic activity of Bi with the same morphology increased with the decrease of pH value. Furthermore, the Bi samples still retained excellent catalytic activity after 40 cycles, the removal rate could also reach 73.5% for the 40th cycling.
通讯机构：
[Jianxin Peng ] P;Professor, Key Laboratory of Bridge Engineering Safety Control by Department of Education, School of Civil Engineering, Changsha University of Science and Technology, Changsha, Hunan, China
摘要：
A test was carried out to study the interface shear strength between carbonated concrete substrate and self-compacting concrete (SCC) overlay. One hundred and fourteen Z-type specimens were designed and subjected to direct shear tests. The influence of four interface treatment methods, three strengthening schemes and SCC strength on interface shear strength were discussed. Two coefficients considering the influence of interface treatment method and strengthening scheme on interface shear strength between carbonated concrete and SCC were developed. The results show that interface shear strength is affected not only by SCC strength but also by the strengthening scheme for the same interface treatment method, which increases with the increase of overlay strength for the same interface treatment method and strengthening scheme. The position of groove has little influence on interface shear strength for grooved specimens. Implanting steel bar is the most effective way to improve interface shear strength. When the carbonation time is around 60 days, the interface shear strength is increased by about 17%. The theoretical interface shear strength obtained by the developed model agreed well with tested values. The mean ratio of tested interface shear strength to theoretical strength is 0.86.
期刊：
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A,2023年41(6):063110 ISSN：0734-2101
通讯作者：
Xiao, BJ
作者机构：
[Xiao, Baijun] Hunan City Univ, Sch Mech & Elect Engn, Yiyang 413000, Hunan, Peoples R China.;[Zhang, Teng Fei] Anhui Univ Technol, Key Lab Green Fabricat & Surface Technol Adv Met M, Minist Educ, Maanshan, Peoples R China.
通讯机构：
[Xiao, BJ ] H;Hunan City Univ, Sch Mech & Elect Engn, Yiyang 413000, Hunan, Peoples R China.
摘要：
Wear resistance is a critical property of tool coatings for high-speed machining, which depends on mechanical properties and oxidation resistance of the coatings. Many works have demonstrated that AlTiSiN coating has good mechanical properties. Additionally, AlCrN coating exhibits excellent oxidation resistance. The multilayered structure has proved to improve comprehensive properties of the coatings. Therefore, AlCrN/AlTiSiN multilayer coating has a high potential to be used in machining applications. This paper focuses on the high-temperature tribological behavior of AlCrN/AlTiSiN multilayer coating. The results show that AlCrN/AlTiSiN coating exhibits good to acceptable wear resistance up to 800 degrees C. Meanwhile, AlCrN/AlTiSiN coating also displays the lowest friction coefficient of similar to 0.5 and a wear rate of 1.8 x 10(-6) mm(3)/N m at 800 degrees C, which is about 58.13% and 64.0% lower than that of AlCrN and AlTiSiN coatings, respectively. The imaging and composition analysis of the high-temperature wear tracks allowed for explaining the differences in wear mechanisms. At 800 degrees C, a dense thin tribofilm is formed on the surface of AlCrN/AlTiSiN coating, which acts as a glaze layer to impede wear. It provides a strategy for enhancing the wear resistance of monolayer coating in high temperatures, which combines the advantages of both high oxidation resistance of one layer and high hardness of the other layer.
关键词：
finite difference time domain (FDTD);reverse time migration (RTM);finite difference time domain reverse time migration (FDTD-RTM);wavelet multi-resolution analysis;super-resolution reconstruction method
摘要：
The finite difference time domain (FDTD) method was used to solve the Maxwell's equation to obtain the reverse time migration (RTM) of ground penetrating radar (GPR) signals, namely, the finite difference time domain reverse time migration (FDTD-RTM). In order to ensure that the correct numerical solution of iterative calculation was achieved, it was necessary to obtain high-resolution signals, which greatly limits the applicability of FDTD-RTM in engineering. Based on the characteristics of wavelet multi-resolution analysis, this study proposed a super-resolution signal reconstruction method to improve signal resolution, with the view to completely solving the problem of FDTD-RTM limitation caused by insufficient signal sampling using GPR. The results of electromagnetic simulation showed that the signals reconstructed by the above method were highly similar to the signals sampled with the same resolution. On this basis, reverse time migration electromagnetic simulation and physical model tests were designed. The results of both experiments showed that the under-sampled GPR signals could achieve FDTD-RTM following super-resolution reconstruction, and that the migration imaging results of the target were basically consistent with the design scheme. The signal super-resolution reconstruction method based on the wavelet theory was thus shown to successfully achieve the overall application of FDTD-RTM in GPR signal analysis.
摘要：
The serial compound fluidized bed gasification process of HMSW (high moisture solid waste) is studied, and the semi-empirical kinetic model is established by combining hydrodynamics and reaction kinetics. The model include combustion sub-model and gasification sub-model, which are divided into dense phase and dilute phase for simulation. The dense phase is simulated by the three-phase bubble bed theory, and the dilute phase is simulated by Wen-Chen entrainment elutriation model combined with the ring-core model. The pyrolysis model is based on the empirical relationship. The effects of gasification temperature, S/HMSW (steam/high moisture solid waste) ratio, HMSW/C (high moisture solid waste/coal) ratio, and moisture on the gasification process are studied. The results show that the gasification temperature of 1000 degrees C, S/HMSW of 1.13, HMSW/C of 3, and moisture of 26% are the optimal gasification parameters. The study can guide the design, operation, and optimization of the serial compound gasification process.
