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Journal of Materials Science & Technology 2021年第11期70卷 156-167页

作者： Xiaojie Zhou Yuan Yao Jian Zhang Xiaomin Chen Weiying Huang Jing Pan Haoran Wang Maopeng Weng Hunan provincial key laboratory of intelligent Manufacturing Technology for High-performance Mechanical equipment Changsha University of Science and TechnologyChangsha410114China

A high-performance Mg-4.9Gd-3.2Y-1.1Zn-0.5Zr alloy has been fabricated by multidirectional forging(MDF)after analyzing its compression *** as-homogenized alloy exhibits a high activation energy Q of deformation(~285 kJ/mol).The size of DRXed grains after compression tends to decrease as the Z-H parameter(Z)increases,showing a grain size exponent m of~*** LPSO phases,kinking deformation,and bimodal microstructure are detected at the relatively low compression temperature of 350 and 400℃,while sufficient DRX can be achieved at 500℃,accompanied by the dissolution of lamellar *** to the processing maps,MDF was successfully conducted under an appropriate *** peak-aged at 200℃for 78 h,the MDFed billet exhibits a tensile yield strength(TYS)of 331 and 305 MPa at room temperature and 200℃,*** high strength mainly results from the combination of fine grains,low Schmid factor for basal slip,sufficientβ’ageing precipitates,and directionally arranged interdendritic LPSO phases,*** paper provides a feasible way for the fabrication of high-performance,low-RE-content,and large-scale Mg components for industrial production.

关键词： Mg-Gd-Y-Zn-Zr Deformation behavior Activation energy Forge Dynamic recrystallization Mechanical properties

Fracture mechanism and separation conditions of pineapple fruit-stem and calibration of physical characteristic parameters

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International Journal of agricultural and Biological Engineering 2023年第5期16卷 248-259页

作者： Mutong Li Lin He Dandan Yue Binbin Wang Junlue Li key laboratory of Modern agricultural intelligent equipment in South China Ministry of Agriculture and Rural Affairs of ChinaGuangdong Institute of Modern Agricultural EquipmentGuangzhou 510630China guangdong Hongke agricultural Machinery Research and Development Co. LtdGuangzhou 510555China

At present,the research on the physical composition and properties of pineapple plants is scarce,and the uncertainty of fruit picking method is the key bottleneck factor hindering the research and development of pineapple harvesting *** on the statistics of survey data from many places,this paper analyzes the fruit-stem fracture mechanism and the theoretical conditions for optimal separation through structural modeling,mechanical behavior analysis and function *** this basis,the“pineapple plant fixation bench”and“fruit-stem bending separation torque test equipment”were developed,and large-size,small-size tests and random optimization tests were carried out *** test results showed that the larger of the stem-stalk fixation distance,the more torque and fracture starting angle required for fruit fracture would increase,and the change range was small when the stem-stalk fixation distance was within 50 mm,and the probability of brittle fracture and complete separation was very *** the space between the fracture section and the fruit-stem connecting point is about 5mm,the range of bending moment value required for the fruit-stem fracture is 1.88 to 2.77 N·m,the range of fracture starting angle is 12.2°to 18.1°,and the angular travel range during the separation process is 82.9°to 87.5°.When the stem-stalk fixation distance is about 15 mm,it is the best fruit-stem separation condition and the breaking torque measured in the verification test is about 2.76 N·*** fracture starting angle is about 13.8°,the maximum prediction error is 13.1%,and the elastic modulus near the fruit-stem joint ranges from 16.1 to 23.9 *** conclusion can provide an important design basis for the research and development of pineapple field picking robot and harvesting equipment.

关键词： pineapple harvesting fracture mechanism of fruit and stem separation conditions experiment design reverse calibration

Laser tracking leader-follower automatic cooperative navigation system for UAVs

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International Journal of agricultural and Biological Engineering 2022年第2期15卷 165-176页

作者： Rui Ming Zhiyan Zhou Zichen Lyu Xiwen Luo Le Zi Cancan Song Yu Zang Wei Liu Rui Jiang College of Engineering South China Agricultural University/Guangdong Laboratory for Lingnan Modern AgricultureGuangzhou 510642China College of Computer and Control Engineering Minjiang University/Fujian Provincial Key Laboratory of Information Processing and Intelligent ControlFuzhou 350108China guangdong provincial key laboratory for agricultural Artificial Intelligence(GDKL-AAI) Guangzhou 510642China guangdong Engineering Research Center for agricultural Aviation Application(ERCAAA) Guangzhou 510642China key laboratory of key Technology on agricultural Machine and equipment South China Agricultural UniversityMinistry of Education of P.R.ChinaGuangzhou 510642China

Currently,small payload and short endurance are the main problems of a single UAV in agricultural applications,especially in large-scale *** is one of the important methods to solve the above problems of UAVs by improving operation efficiency through multi-UAV cooperative *** study proposed a laser tracking leader-follower automatic cooperative navigation system for *** leader in the cluster fires a laser beam to irradiate the follower,and the follower performs a visual tracking flight according to the light spot at the relative position of the laser tracking *** on the existing kernel correlation filter(KCF)tracking algorithm,an improved KCF real-time spot tracking method was *** with the traditional KCF tracking algorithm,the recognition and tracking rate of the optimized algorithm was increased from 70%to 95%in indoor environment,and was increased from 20%to 90%in outdoor *** navigation control method was studied from two aspects:the distance coordinate transformation model based on micro-gyroscope and navigation control *** error of spot position was reduced from the maximum(3.12,−3.66)cm to(0.14,0.12)cm by correcting the deviation distance of the spot at different angles through a coordinate correction *** image coordinate conversion model was established for a complementary metal-oxide-semiconductor(CMOS)camera and laser receiving device at different mounting *** laser receiving device was divided into four regions,S0-S3,and the speed of the four regions is calculated using an uncontrollable discrete Kalman *** outdoor flight experiments of two UAVs were carried out outdoors using this *** experiment results show that the average flight error of the two UAVs on the X-axis is 5.2 cm,and the coefficient of variation is *** average flight error on the Z-axis is 7.3 cm,and the coefficient of variation is *** study demonstrated the possibility

关键词： two-UAVs cooperative visual navigation laser tracking

Design and experimental analysis of rice pneumatic seeder with adjustable seeding rate

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International Journal of agricultural and Biological Engineering 2021年第4期14卷 113-122页

作者： He Xing Zaiman Wang Xiwen Luo Ying Zang Siyu He Peng Xu Shuncai Liu key laboratory of key Technology on agricultural Machine and equipment Ministry of EducationSouth China Agricultural UniversityGuangzhou 510642China College of Engineering South China Agricultural UniversityGuangzhou 510642China guangdong provincial key laboratory of agricultural Artificial Intelligence(GDKL-AAI) Guangzhou 510642China

To adapt to the diversity of hybrid rice and meet its requirements of precision seeding,a rice pneumatic seeder with adjustable seeding rates was designed in this *** seeder employed an independent vortex pump to provide the air source for the seed metering *** to the requirements of air flow in the seed metering device,a sub-pipeline and a general pipeline were *** performances of the two types of pipelines were verified by the air pressure uniformity *** results showed that the sub-pipeline can distribute the air pressure more evenly than the general *** coefficient of variation of the sub-pipeline pressure was less than 5%.Wuyou 1179 hybrid rice was selected as the experimental *** field seeding tests were carried out with different negative pressures and different numbers of groups of sucking holes as experimental *** results showed that the average qualified rate of seeding was 93.35%when only 2 groups of sucking holes were working under the seed sucking negative pressure of 2.0 *** average qualified rate of seeding was 87.21%when 3 groups of sucking holes were working under the seed sucking negative pressure of 1.6 *** average qualified rate of seeding was 83.73%when 4 groups of sucking holes were working under the seed sucking negative pressure of 1.6 *** average qualified rate of seeding was 79.86%when 5 groups of sucking holes were working under the seed sucking negative pressure of 1.6 *** main factors affecting the seeding effect were analyzed and the feasibility of a rice pneumatic seeder with adjustable seeding rates was verified by field *** research results can provide a basis for its practical production and application.

关键词： agricultural machinery adjustable seeding rate seeder pneumatic rice pipeline

Determined Reverberant Blind Source Separation of Audio Mixing Signals

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intelligent Automation & Soft Computing 2023年第6期36卷 3309-3323页

作者： Senquan Yang Fan Ding Jianjun Liu Pu Li Songxi Hu School of intelligent Engineering Shaoguan UniversityShaoguan512026China guangdong provincial key laboratory of Technique and equipment for Macromolecular Advanced Manufacturing South China University of Technology510641China

Audio signal separation is an open and challenging issue in the classical“Cocktail Party Problem”.Especially in a reverberation environment,the separation of mixed signals is more difficult separated due to the influence of reverberation and *** solve the problem,we propose a determined reverberant blind source separation *** main innovation of the algorithm focuses on the estimation of the mixing matrix.A new cost function is built to obtain the accurate demixing matrix,which shows the gap between the prediction and the actual ***,the update rule of the demixing matrix is derived using Newton gradient descent *** identity matrix is employed as the initial demixing matrix for avoiding local optima *** the real-time iterative update of the demixing matrix,frequency-domain sources are ***,time-domain sources can be obtained using an inverse short-time Fourier ***-mental results based on a series of source separation of speech and music mixing signals demonstrate that the proposed algorithm achieves better separation performance than the state-of-the-art *** particular,it has much better superiority in the highly reverberant environment.

关键词： Determined mixtures reverberant environment audio signal separation cocktail party problem

Investigations on Fluid Resonance Within A Narrow Gap Formed by Two Fixed Bodies with Varying Breadth Ratios

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China Ocean Engineering 2023年第6期37卷 962-974页

作者： GONG Shu-kai GAO Jun-liang MAO Hong-fei School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China State key laboratory of Hydraulic Engineering intelligent Construction and Operation Tianjin UniversityTianjin 300350China College of Ocean Engineering and Energy Guangdong Ocean UniversityZhanjiang 524000China guangdong provincial key laboratory of intelligent equipment for South China Sea Marine Ranching Guangdong Ocean UniversityZhanjiang 524088China

The resonant motion of the fluid inside a narrow gap between two fixed boxes induced by incident regular waves with various wave heights is investigated by adopting a two-dimensional numerical wave flume based on an opensourced CFD package,*** two boxes have identical draft and height,but the upstream box has a variable *** article focuses on the influences of the breadth ratio,defined as the ratio of the breadth of the upstream box to that of the downstream box,on the following three aspects of hydrodynamic characteristics of gap resonance:(1)the wave height amplifications inside the gap,and in front and at the rear of the structure system,(2)the reflection,transmission,and energy loss coefficients of the structure system,and(3)the response and damping time of the fluid *** is found that the fluid resonant frequency,the amplification factor of the resonant wave height inside the gap and the maximum energy loss coefficient of the structure system are shown to gradually decrease with the increase of the breadth *** response time of gap resonance is shown to first increase and then decrease with the breadth ratio overall,regardless of the incident wave height,and the configuration that the two boxes have the same breadth would bring the largest response time of gap resonance.

关键词： gap resonance wave amplification varying breadth ratios OpenFOAM

Sub-nanosized vanadate hybrid clusters maintain glucose homeostasis and restore treatment response in inflammatory disease in obese mice

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Nano Research 2024年第3期17卷 1818-1826页

作者： Kun Chen Shengqiu Liu Yujun Wei South China Advanced Institute for Soft Matter Science and Technology School of Emergent Soft MatterSouth China University of TechnologyGuangzhou 510641China guangdong provincial key laboratory of Technique and equipment for Macromolecular Advanced Manufacturing South China University of TechnologyGuangzhou 510641China guangdong provincial key laboratory of Functional and intelligent Hybrid Materials and Devices South China University of TechnologyGuangzhou 510641China

Obesity is closely related with insulin resistance and chronic ***,we report that unsaturated lipid-modified polyoxovanadates(ULPOVs)can restrict weight gain of diet-induced obese mice and improve their glycemic control and obesity-associated *** administration of the sub-nanosized ULPOVs at a low dosage for 7 weeks reduces the body weight and almost normalizes the blood glucose levels of obese mice fed on a high-fat *** treatment increases the activity of the nuclear receptor peroxisome proliferator-activated receptorγ(PPARγ)and reduces intestinal caloric intake,which may be the main reason for blood sugar and body weight *** addition to insulin-sensitizing,PPARγactivation induced by ULPOV treatment in obese mice with atopic dermatitis(AD)promotes the type 2 T helper(TH_(2))cell selective responses and therapeutic effects on immune dysregulation caused by *** data suggest sub-nanosized polyoxovanadate clusters as a class of potential candidates to relieve symptoms accompanied by diet-induced obesity.

关键词： polyoxovanadates lipid modification glucose homeostasis obesity inflammatory disease peroxisome proliferator-activated receptorγ(PPARγ)

Analysis of the track system in bumpy unstructured hard road environment by vibration test

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International Journal of agricultural and Biological Engineering 2022年第4期15卷 163-171页

作者： Mutong Li Junlue Li Lin He Jie He Lian Hu Chengxu Lyu key laboratory of Modern agricultural intelligent equipment in South China Ministry of Agriculture and Rural AffairsChina/Guangdong Institute of Modern Agricultural EquipmentGuangzhou 510630China College of Engineering South China Agricultural UniversityGuangzhou 510642China Chinese Academy of agricultural Mechanization Sciences Beijing 100083China

The complex terrain environment in the hilly land directly affects the operational reliability of agricultural *** order to study the impact of road irregularity on walking chassis vibration,the 3CYLZ-750 remote-controlled weeding machine which is applied to orchards was taken as the object of study,and the rear roller was selected as the object of observation to reveal the rules under which the vibration of the track chassis changes as there is a sudden change in road surface elevation.A column-type test-to-pass method based on unit excitation was proposed in this *** excitation behavior and action process were analyzed by category.A critical acceleration prediction model was built and verified by virtual simulation and hard road surface excitation *** results showed that at the forward velocity of 0-2.5 km/h and exciter height of 20-100 mm,the vertical vibration acceleration of the target roller was significantly affected by Track Contact Point Centrifugal Acceleration(TCPCA).As TCPCA increased,the change rate of vertical vibration acceleration decreased,reaching a minimum of[−13.8,28.8];as TCPCA decreased,the vertical vibration acceleration tended to increase positively at a maximum variation range of[−13.3,42.2].The measured and simulated macroscopic change rules were consistent with the theoretical analysis,further verifying the correctness of variable extraction,and providing a research basis for the accurate modification and improvement of the *** research conclusions can lay a theoretical foundation for analyzing the walking reliability of the track chassis,and provide a design basis and technical support for the development of a tracked agricultural robot chassis for the hilly land in the future.

关键词： track system unstructured road vibration test simulation analysis hilly land agricultural robot

Monitoring black tea fermentation quality by intelligent sensors: Comparison of image, e-nose and data fusion

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Food Bioscience 2023年第2期52卷 947-958页

作者： Qiaoyi Zhou Zhenhua Dai Feihu Song Zhenfeng Li Chunfang Song Caijin Ling guangdong provincial key laboratory of Tea Plant Resources Innovation and Utilization Tea Research InstituteGuangdong Academy of Agricultural SciencesGuangzhou 510640China Jiangsu key laboratory of Advanced Food Manufacturing equipment&Technology School of Mechanical EngineeringJiangnan UniversityWuxi214122China

To scientifically and objectively monitor the fermentation quality of black tea,a computer vision system(CVS)and electronic nose(e-nose)were employed to analyze the black tea image and odor eigenvalues of Yinghong No.9 black ***,the variation trends of tea polyphenols,volatile substances,image eigenvalues and odor eigenvalues with the extension of fermentation time were analyzed,and the fermentation process was categorized into three stages for ***,principal component analysis(PCA)was employed on the image and odor eigenvalues obtained by CVS and *** least squares discriminant analysis(PLS-DA)was performed on 117 volatile components,and 51 differential volatiles were screened out based on variable importance in projection(VIP≥1)and one-way analysis of variance(P<0.05),including geraniol,linalool,nerolidol,and α-***,image features and odor features are fused by using a data fusion ***,the image,smell and fusion information were combined with random forest(RF),K-nearest neighbor(KNN)and support vector machine(SVM)to establish the classification models of different fermentation stages and to compare *** results show that the feature-level fusion strategy integrating the SVM was the most efficient approach,with classification accuracy rates of 100%for the training sets and 95.6%for the testing *** performance of Support Vector Regression(SVR)prediction models for tea polyphenol content based on feature-level fusion data outperformed data-level models(Rc,RMSEC,Rp and RMSEP of 0.96,0.48 mg/g,0.94,0.6 mg/g).

关键词： Computer vision Electronic nose(e-nose) Data fusion strategy Black tea fermentation

Laser polishing of a high-entropy alloy manufactured by selective laser melting

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Frontiers of Mechanical Engineering 2024年第5期19卷 73-86页

作者： Xiaojun TAN Haibing XIAO Zihong WANG Wei ZHANG Zhijuan SUN Xuyun PENG Zhongmin LIU Liang GUO Qingmao ZHANG intelligent Manufacturing and equipment School Shenzhen Institute of Information TechnologyShenzhen 518172China Sino-German intelligent Manufacturing School Shenzhen City PolytechnicShenzhen 518116China guangdong provincial key laboratory of Nanophotonic Functional Materials and Devices School of Information and Optoelectronic Science and EngineeringSouth China Normal UniversityGuangzhou 510006China guangdong provincial key laboratory of Industrial Ultrashort Pulse Laser Technology Shenzhen 518055China College of Materials Science and Engineering Chongqing UniversityChongqing 400045China

The selective laser melting(SLM)technique applied to high-entropy alloys(HEAs)has attracted considerable attention in recent ***,its practical application has been restricted by poor surface *** this study,the capability of laser polishing on the rough surface of a Co-free HEA fabricated using SLM was *** show that the initial SLM-manufactured(as-SLMed)surface of the Co-free HEA,with a roughness exceeding 3.0μm,could be refined to less than 0.5μm by laser ***,the microstructure,microhardness,and wear resistance of the laser-polished(LP-ed)zone were *** indicate that compared with the microhardness and wear resistance of the as-SLMed layer,those of the LP-ed layer decreased by 4%and 11%,respectively,because of the increase in grain size and reduction of the BCC *** study shows that laser polishing has an excellent application prospect in surface improvement of HEAs manufactured by SLM.

关键词： laser polishing selective laser melting high-entropy alloy surface roughness mechanical performance