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Online diagnosis platform for tomato seedling diseases in greenhouse production

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 80-89页

作者： Xin jin xiaowu Zhu jiangtao ji Mingyong li Xiaolin Xie Bo Zhao College of Agricultural Equipment Engineering Henan University of Science and TechnologyLuoyang 471003HenanChina Science&Technology Innovation Center for Completed Set Equipment Longmen LaboratoryLuoyang 471023HenanChina Institute of Mechatronics Technology and Application China Mechanized Agriculture Science Research Institute Group Co.LtdBeijing 100020China

The facility-based production method is an important stage in the development of modern agriculture,lifting natural light and temperature restrictions and helping to improve agricultural production *** address the problems of difficulty and low accuracy in detecting pests and diseases in the dense production environment of tomato facilities,an online diagnosis platform for tomato plant diseases based on deep learning and cluster fusion was proposed by collecting images of eight major prevalent pests and diseases during the growing period of tomatoes in a facility-based *** diagnostic platform consists of three main parts:pest and disease information detection,clustering and decision-making of detection results,and platform diagnostic ***,based on the You Only Look Once(YOLO)algorithm,the key information of the disease was extracted by adding attention module(CBAM),multi-scale feature fusion was performed using weighted bi-directional feature pyramid network(BiFPN),and the overall construction was designed to be compressed and lightweight;Secondly,the k-means clustering algorithm is used to fuse with the deep learning results to output pest identification decision values to further improve the accuracy of identification applications;Finally,a detection platform was designed and developed using Python,including the front-end,back-end,and database of the system to realize online diagnosis and interaction of tomato plant pests and *** experiment shows that the algorithm detects tomato plant diseases and insect pests with mAP(mean Average Precision)of 92.7%,weights of 12.8 Megabyte(M),inference time of 33.6 *** with the current mainstream single-stage detection series algorithms,the improved algorithm model has achieved better performance;The accuracy rate of the platform diagnosis output pests and diseases information of 91.2%for images and 95.2%for *** is a great significance to tomato pest control research and t

关键词： pest and disease detection YOLO diagnosis platform k-means clustering facility production base

Improving Fatigue Properties of 316L Stainless Steel Welded Joints by Surface Spinning Strengthening

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 840-854页

作者： Dongqiqiong Wang Qiang Wang xiaowu li Zhefeng Zhang Department of Materials Physics and Chemistry School of Materials Science and Engineeringand Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education)Northeastern UniversityShenyang 110819China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China College of light Industry Liaoning UniversityShenyang 110036China

The surface spinning strengthening(3S)mechanism and fatigue life extension mechanism of 316L stainless steel welded joint were systematically elucidated by microstructural analyses and mechanical *** indicate that surface gradient hardening layer of approximately 1 mm is formed in the base material through grain fragmentation and deformation twin strengthening,as well as in the welding zone composed of deformedδ-phases and *** fatigue strength of welded joint after 3S significantly rises by 32%(from 190 to 250 MPa),which is attributed to the effective elimination of surface geometric defects,discrete refinement ofδ-Fe phases and the appropriate improvement in the surface strength,collectively mitigating strain localization and surface fatigue damage within the gradient strengthening *** redistributed fineδ-Fe phases benefited by strong stress transfer of 3S reduce the risk of surface weak phase cracking,causing the fatigue fracture to transition from microstructure defects to crystal defects dominated by slip,further suppressing the initiation and early propagation of fatigue cracks.

关键词： 316L stainless steel Welded joint Surface spinning strengthening Nanotwin Fatigue life

Physiological and transcriptome analyses of Chinese cabbage in response to drought stress

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Journal of Integrative Agriculture 2024年第7期23卷 2255-2269页

作者： lin Chen Chao li jiahao Zhang Zongrui li Qi Zeng Qingguo Sun xiaowu Wang limin Zhao Lugang Zhang Baohua li State Key Laboratory for Crop Stress Resistance and High-Efficiency Production College of HorticultureNorthwest A&F UniversityYangling 712100China Institute of Vegetables and Flowers Chinese Academy of Agricultural SciencesBeijing 100081China

Chinese cabbage is an important leafy vegetable crop with high water demand and susceptibility to drought *** explore the molecular mechanisms underlying the response to drought,we performed a transcriptome analysis of drought-tolerant and-sensitive Chinese cabbage genotypes under drought stress,and uncovered core drought-responsive genes and key signaling pathways.A co-expression network was constructed by a weighted gene coexpression network analysis(WGCNA)and candidate hub genes involved in drought tolerance were ***,abscisic acid(ABA)biosynthesis and signaling pathways and their drought responses in Chinese cabbage leaves were systemically *** also found that drought treatment increased the antioxidant enzyme activities and glucosinolate contents *** results substantially enhance our understanding of the molecular mechanisms underlying drought responses in Chinese cabbage.

关键词： Chinese cabbage drought stress abscisic acid weighted gene co-expression network analysis glucosinolate

A molecular insight into coke formation process of vacuum residue in thermal cracking reaction

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Petroleum Science 2024年第3期21卷 2130-2138页

作者： ji-Guang li Xin Guo Huan-Di Hou Heavy Oil Processing Department Sinopec Research Institute of Petroleum Processing Co.LtdBeijing100083China

Understanding the coking behaviors has been considered to be really essential for developing better vacuum residue processing technologies.A battery of thermal cracking tests of typical vacuum residue at 410℃ with various reaction time were performed to evaluate the coke formation *** total yields of ideal components including naphtha,atmospheric gas oil(AGO)and vacuum gas oil(VGO)of thermal cracking reactions increased from 10.89%to 40.81%,and the conversion ratios increased from8.05%to 43.33%with increasing the reaction time from 10 to 70 *** asphaltene content increased from 12.14%to a maximum of 22.39%and then decreased,and this maximum of asphaltene content occurred at the end of the coking induction *** asphaltenes during the coking induction period,at the end and after coking induction period of those tested thermal cracking reactions were characterized to disclose the structure changing rules for coke formation process,and the coke formation pathways were discussed to reveal the coke formation process at molecular level.

关键词： Vacuum residue Thermal cracking Asphaltene Coking induction period Sulfur Nitrogen

Forced boiling of nonazeotropic immiscible mixture in a supercapillary microchannel array for ultra-high heat flux removal with chip junction temperature below 85℃

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Science China(Technological Sciences) 2024年第5期67卷 1364-1380页

作者： SUN Bo BAO YuChen TIAN Tong li ji School of Engineering Science University of Chinese Academy of SciencesBeijing100049China Laboratory of Advanced Thermal Management Technologies School of Engineering ScienceUniversity of Chinese Academy of SciencesBeijing100049China

In this study,a structure-optimized two-phase microchannel heat sink with sintered submicron nucleation sites was developed and *** copper-based microchannels had a rectangular cross-section with an equivalent hydraulic diameter of 222μ*** subcooled flow boiling characteristics were comprehensively compared between pure HFE-7100 and a non-azeotropic,immiscible binary mixture of HFE-7100 and water,considering heating areas of 1 and 5 cm^(2).The total heating power input to the test section were 100–1500 and 250–3000 W for a 1 and 5 cm^(2)heat source,respectively,with a flow rate ranging from 50 to150 L/*** to pure HFE-7100,the non-azeotropic immiscible binary mixture of HFE-7100/water in the sintered porous microchannels exhibited a much higher overall heat transfer coefficient and lower power *** maintain the junction temperature of a high power electronic chip below 85℃,the proposed supercapillary microchannel heat sink could effectively dissipate the heat flux of 1275 W/cm^(2)over 1 cm^(2)heat source and 500 W/cm^(2)over 5 cm^(2)heat *** addition,the volume ratio of the binary mixture strongly influence the two-phase flow heat transfer *** optimal volume ratio exist in terms of the thermal resistance–pumping power minimization(HFE-7100:water=2:8 is recommended in this study).The findings of this investigation on the flow boiling properties of non-azeotropic immiscible mixtures help fill a gap in the related field.

关键词： microchannel sintered powder coating submicron nucleation cavities nonazeotropic immiscible ultra-high heat flux

Building Feedback-Regulation System Through Atomic Design for Highly Active SO_(2)Sensing

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Nano-Micro Letters 2024年第7期16卷 343-357页

作者： Xin jia Panzhe Qiao xiaowu Wang Muyu Yan Yang Chen Bao-li An Pengfei Hu Bo Lu jing Xu Zhenggang Xue jiaqiang Xu NEST Lab Department of ChemistryCollege of SciencesShanghai UniversityShanghai 200444People’s Republic of China Shanghai Synchrotron Radiation Facility Zhangjiang LabShanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204People’s Republic of China School of Chemistry and Materials Science University of Science and Technology of ChinaHefei 230026People’s Republic of China Key Laboratory of Organic Compound Pollution Control Engineering(MOE) School of Environmental and Chemical EngineeringShanghai UniversityShanghai 200444People’s Republic of China Shanghai University Instrumental Analysis&Research Center of Shanghai UniversityShanghai 200444People’s Republic of China

Reasonably constructing an atomic interface is pronouncedly essential for surface-related gas-sensing ***,we present an ingen-ious feedback-regulation system by changing the interactional mode between single Pt atoms and adjacent S species for high-efficiency SO_(2)*** found that the single Pt sites on the MoS_(2)surface can induce easier volatiliza-tion of adjacent S species to activate the whole inert S ***,the activated S species can provide a feedback role in tailoring the antibonding-orbital electronic occupancy state of Pt atoms,thus creating a combined system involving S vacancy-assisted single Pt sites(Pt-Vs)to synergistically improve the adsorption ability of SO_(2)gas ***-more,in situ Raman,ex situ X-ray photoelectron spectroscopy testing and density functional theory analysis demonstrate the intact feedback-regulation system can expand the electron transfer path from single Pt sites to whole Pt-MoS_(2)supports in SO_(2)gas *** with wireless-sensing modules,the final Pt1-MoS_(2)-def sensors array can further realize real-time monitoring of SO_(2)levels and cloud-data storage for plant *** a fundamental understanding of the intrinsic link between atomic interface and sensing mechanism is thus expected to broaden the rational design of highly effective gas sensors.

关键词： Feedback-regulation system Atomic interface SO_(2)sensor Single-atom sensing mechanism Intelligent-sensing array

Experimental and numerical investigation of two blended blade and endwall configurations

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CHINESE JOURNAL OF AERONAUTICS 2024年第9期37卷 150-163页

作者： Meng, Tongtong li, Xin Zhou, ling ji, Lucheng Tsinghua Univ Inst Aero Engine Beijing 100084 Peoples R China Beijing Inst Technol Sch Aerosp Engn Beijing 100081 Peoples R China

The Blended Blade and Endwall (BBEW) technique has proven to be effective in controlling the intersection of boundary layer in corner region of the compressor endwall. In this study, the experiment and analysis of two different BBEW designs are emphasized. First, based on a linear cascade with 0.7 Mach number inflow, two different configurations, BBEW 1 and BBEW 2, are well conducted. Then, according to the experimental result, control effects of these two BBEW configurations are validated and compared subsequently under various working conditions. The results demonstrate a reduction in total pressure loss of 12.8% and 29% at the design point for BBEW 1 and BBEW 2, respectively. Consequently, the BBEW technique proves effective in suppressing the development of the boundary layer and preventing corner separation. Followed by detailed numerical analysis, improvements around the corner region, especially for the boundary layer, are extracted to show the mechanisms and distinctions between the two configurations. The results indicate that BBEW 1 significantly restrains the development of boundary layer before separation occurs, while BBEW 2 directly controls the strength and scale of the corner separation. (c) 2024 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.

关键词： Aerodynamic Computational fluid dynamic Experiment Corner separation Blended Blade and Endwall (BBEW) COMPRESSOR DESIGN SUCTION FLOW

Machine learning model based on non-convex penalized huberized-SVM

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Journal of Electronic Science and Technology 2024年第1期22卷 81-94页

作者： Peng Wang ji Guo lin-Feng li School of Finance and Economics Xizang Minzu UniversityXianyang712082China Research Center for Quality Development of Xizang Special Industries Xianyang712082China School of Computer Science and Technology Xinjiang UniversityUrumqi830017China

The support vector machine(SVM)is a classical machine learning *** the hinge loss and least absolute shrinkage and selection operator(LASSO)penalty are usually used in traditional ***,the hinge loss is not differentiable,and the LASSO penalty does not have the Oracle *** this paper,the huberized loss is combined with non-convex penalties to obtain a model that has the advantages of both the computational simplicity and the Oracle property,contributing to higher accuracy than traditional *** is experimentally demonstrated that the two non-convex huberized-SVM methods,smoothly clipped absolute deviation huberized-SVM(SCAD-HSVM)and minimax concave penalty huberized-SVM(MCP-HSVM),outperform the traditional SVM method in terms of the prediction accuracy and classifier *** are also superior in terms of variable selection,especially when there is a high linear correlation between the *** they are applied to the prediction of listed companies,the variables that can affect and predict financial distress are accurately filtered *** all the indicators,the indicators per share have the greatest influence while those of solvency have the weakest *** companies can assess the financial situation with the indicators screened by our algorithm and make an early warning of their possible financial distress in advance with higher precision.

关键词： Huberized loss Machine learning Non-convex penalties Support vector machine(SVM)

Threshold Selection and Resource Allocation for Quantized Identification

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Journal of Systems Science & Complexity 2024年第1期37卷 204-229页

作者： WANG Ying li Xin ZHAO Yanlong ZHANG ji-Feng Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

This paper is concerned with the optimal threshold selection and resource allocation problems of quantized identification, whose aims are improving identification efficiency under limited resources. Firstly, the first-order asymptotically optimal quantized identification theory is extended to the weak persistent excitation condition. Secondly, the characteristics of time and space complexities are established based on the Cramér-Rao lower bound of quantized systems. On these basis, the optimal selection methods of fixed thresholds and adaptive thresholds are established under aperiodic signals, which answer how to achieve the best efficiency of quantized identification under the same time and space complexity. In addition, based on the principle of maximizing the identification efficiency under a given resource, the optimal resource allocation methods of quantized identification are given for the cases of fixed thresholds and adaptive thresholds, respectively, which show how to balance time and space complexity to realize the best identification efficiency of quantized identification.

关键词： Quantized output resource allocation system identification threshold selection.