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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 147-153页

作者： junjie li Wenbo Yu Zhenyu Sun Weichen Zheng liangwei Zhang Yanling Xue Wenning liu Shoumei Xiong Center of Materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Traffic&Transportation Engineering Central South UniversityChangsha 410075China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile *** can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated ***,the development of non-heat treatment Al alloys is becoming the hot *** addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of *** achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and *** influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic *** results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased ***,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical *** introduction of Ce resulted in the poisoning effect and reduced mechanical properties.

关键词： aluminium alloy high-pressure die-casting externally solidified crystals non-heat treatment

Detecting large-scale underwater cracks based on remote operated vehicle and graph convolutional neural network

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Frontiers of Structural and Civil Engineering 2022年第11期16卷 1378-1396页

作者： Wenxuan CAO junjie li Faculty of Infrastructure Engineering Dalian University of TechnologyDalian 116024China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China

It is of great significance to quickly detect underwater cracks as they can seriously threaten the safety of underwater *** to date has mainly focused on the detection of above-water-level cracks and hasn’t considered the large scale *** this paper,a large-scale underwater crack examination method is proposed based on image stitching and *** addition,a purpose of this paper is to design a new convolution method to segment underwater *** improved As-Projective-As-Possible(APAP)algorithm was designed to extract and stitch keyframes from *** graph convolutional neural network(GCN)was used to segment the stitched *** GCN’s m-IOU is 24.02%higher than Fully convolutional networks(FCN),proving that GCN has great potential of application in image segmentation and underwater image *** result shows that the improved APAP algorithm and GCN can adapt to complex underwater environments and perform well in different study areas.

关键词： underwater cracks remote operated vehicle image stitching image segmentation graph convolutional neural network

Efficient Identification of water conveyance tunnels siltation based on ensemble deep learning

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Frontiers of Structural and Civil Engineering 2022年第5期16卷 564-575页

作者： Xinbin WU junjie li linlin WANG Faculty of Infrastructure Engineering Dalian University of TechnologyDalian 116024China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China

The inspection of water conveyance tunnels plays an important role in water diversion *** is an essential factor threatening the safety of water conveyance *** and efficient identification of such siltation can reduce risks and enhance safety and reliability of these *** remotely operated vehicle(ROV)can detect such ***,it needs to improve its intelligent recognition of image data it *** paper introduces the idea of ensemble deep *** on the VGG16 network,a compact convolutional neural network(CNN)is designed as a primary learner,called Silt-net,which is used to identify the siltation *** the same time,the fully-connected network is applied as the meta-learner,and stacking ensemble learning is combined with the outputs of the primary classifiers to obtain satisfactory classification ***,several evaluation metrics are used to measure the performance of the proposed *** experimental results on the siltation dataset show that the classification accuracy of the proposed method reaches 97.2%,which is far better than the accuracy of other ***,the proposed method can weigh the accuracy and model complexity on a platform with limited computing resources.

关键词： water conveyance tunnels siltation images remotely operated vehicles deep learning ensemble learning computer vision

Recent progress on sulfide infrared nonlinear optical materials with large SHG response and wide band gap

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Chinese Journal of Structural Chemistry 2023年第1期42卷 22-29页

作者： linan Wang Qi Sun junjie li Research Center for Crystal Materials CAS Key Laboratory of Functional Materials and Devices for Special EnvironmentsXinjiang Technical Institute of Physics&ChemistryCASUrumqi830011China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China

As the core device of all-solid-state laser,infrared(IR)nonlinear optical(NLO)material plays a critical role in exploring new coherent lights by frequency conversion technologies,which are widely used in noninvasive medical diagnostics,spectroscopy,environmental monitoring and long-distance laser *** satisfy the growing demand of current laser technology in IR regions,high performance NLO materials with large second-harmonic generation(SHG)response,high laser-induced damage threshold(liDT)and wide transparency range are highly ***,numerous efforts and advances have been achieved in sulfide *** review highlights the progress of high-performance sulfide IR NLO materials with a good balance between strong SHG response(≥1.0×AgGaS_(2))and wide band gap(≥3.0 eV)since *** chemical synthesis,crystal structure,optical properties and structure-property relationship of 13 high performance metal sulfide IR NLO materials are summarized and reviewed in ***,the potential opportunities and challenges in IR NLO materials are discussed.

关键词： Infrared NLO material s Sulfide Structure-property relationship Optical property

Wing aeroelasticity analysis based on an integral boundary-layer method coupled with Euler solver

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Chinese Journal of Aeronautics 2016年第5期29卷 1262-1272页

作者： Ma Yanfeng He Erming Zeng Xianang li junjie School of Aeronautics Northwestern Polytechnical University Xi'an Shaanxi 710072 China AVIC Xi'an Aircraft Design and Research Institute Xi'an Shaanxi 710089 China

An interactive boundary-layer method, which solves the unsteady flow, is developed for aeroelastic computation in the time domain. The coupled method combines the Euler solver with the integral boundary-layer solver （Euler/BL） in a ＂semi-inverse＂ manner to compute flows with the inviscid and viscous interaction. Unsteady boundary conditions on moving surfaces are taken into account by utilizing the approximate small-perturbation method without moving the computational grids. The steady and unsteady flow calculations for the LANN wing are presented. The wing tip displacement of high Reynolds number aero-structural dynamics （HIRENASD） Project is simulated under different angles of attack. The flutter-boundary predictions for the AGARD 445.6 wing are provided. The results of the interactive boundary-layer method are compared with those of the Euler method and experimental data. The study shows that viscous effects are significant for these cases and the further data analysis confirms the validity and practicability of the coupled method.

关键词： Aeroelasticity Flutter Integral boundary-layer Transonic flow Unsteady flow

A Comparison Study of Synkinematic Illite Isolation,Quantitative X-ray Powder Diffraction,and K-Ar Dating for Direct Fault Gouge Analyses

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Acta Geologica Sinica(English Edition) 2023年第2期97卷 636-650页

作者： ZHENG Yong li Haibing li junjie ZHANG Guohe SI Jialiang Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Jiangsu Donghai Continental Deep Hole Crustal Activity National Observation and Research Station DonghaiJiangsu 222300China Beijing Research Institute of Uranium Geology Beijing 100029China Military and Civilian Integration Geological Survey Center Chengdu 610000China

K-Ar dating of synkinematic illite is increasingly recognized as a central method to constrain the timing of shallow crustal *** of efficient sample preparation and quantitative identification of illite polytypes are critical to acquiring K-Ar isotope data for authigenic *** this respect,we compared the commonly used clay size separation method through centrifugation with vacuum filtration technology,showing that the former is prone to extract fractions with finer particle sizes under similar conditions,thus improving the error in the authigenic end-member ***,we demonstrated that the side-packed mounting method for X-ray diffraction analysis can significantly enhance the randomness in powder samples,thus improving the quantification accuracy compared with the front-packed and back-packed *** validity of our quantification method was confirmed by comparing Profex■modeling patterns with a suite of synthetic mixtures of known compositions,yielding an average analytical error of 3%.Dating results of these artificial mixtures and the reference materials indicated that a large range in percentages of detrital illite and a sufficient amount of age data will produce reliable results for ages of both extrapolated ***,if the range is limited,the extrapolated age close to those of datasets is still reliable.

关键词： illite polytypes fault gouge clay size separation mounting method Profex■ extrapolated K-Ar age

On Ti6Al4V Microsegregation in Electron Beam Additive Manufacturing with Multiphase-Field Simulation Coupled with Thermodynamic Data

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Acta Metallurgica Sinica(English Letters) 2022年第3期35卷 425-438页

作者： Yujian Wang Shuo Chu Zhijun Wang junjie li Jincheng Wang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China

Electron beam additive manufacturing is an effective method for the fabrication of complex metallic *** rapid solidification,the characteristics of microsegregation within the interdendritic region are interesting and important for the subsequent phase transformation and final mechanical ***,in view of the microsecond lifetime and the small length scale of the molten pool,experimentally investigating microsegregation is challenging,even with electron probe *** this study,a multiphase-field model coupled with the real thermodynamic data of Ti6Al4V alloy was successfully developed and applied to simulate the rapid solidification of columnarβgrains via electron beam additive *** thermal gradient(G)and cooling rate(R)were obtained from a 3D powder-scale multiphysics simulation and provided as inputs to a multiphase-field *** eff ects of the electron beam process parameters and thermal conditions on the columnarβgrains were *** films and droplets were observed to have solute enrichment in the intercellular *** size of the liquid film increased at a lower scanning speed and energy *** the scanning speed and energy power refined the columnarβgrains and decreased the liquid film *** extent of microsegregation considerably increased at lower energy power,whereas the change in scanning speed had little eff ect on the *** results also indicate that solute vanadium results in significant solute trapping and microsegregation during the rapid solidification of the Ti6Al4V alloy.

关键词： Ti6Al4V alloy Microsegregation Electron beam additive manufacturing Multiphase-field model

Review on charging model of sand particles due to collisions

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Theoretical & Applied Mechanics Letters 2020年第4期10卷 276-285页

作者： li Xie junjie li Yakui liu College of Civil Engineering and Mechanics Lanzhou UniversityLanzhou 730000China Key Laboratory of Western Disaster and Environmental Mechanics Attached on Education Ministry of ChinaLanzhou UniversityLanzhou 730000China

In this paper, the models describing the charge transfer between two sand particles due to collisions are reviewed. By comparing the experimental results and the calculated results by the models carried on an individual particle due to a single collision, it indicates the Mosaic model is more reasonable to describe the collision charging mechanism. The Mosaic model cannot only describe the dependence of the collision charges on the relative collision speed and the particle size, but also reveal the relationship between the collision charges with the environmental temperature, the relative humidity and the material parameters, e.g., the absorption energy. Based on the Mosaic model, the model to describe the charges transfer due to multiple collisions is also developed, which can be used to calculate the charges carried by sand particles due to multiple collisions in the wind blown sand flux.

关键词： Charging model Sand particles Contact electrification

PdPtBi networked nanowires derived from Pd nanosheets as efficient catalysts for ethanol oxidation

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Nano Research 2023年第7期16卷 9125-9131页

作者： Ningkang Qian liang Ji junjie li Hui Zhang Deren Yang State Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China Zhejiang Provincial Key Laboratory of Power Semiconductor Materials and Devices ZJU-Hangzhou Global Scientific and Technological Innovation CenterHangzhou 311200China

Direct ethanol fuel cells(DEFCs)have received increasing attention as one of the most promising energy conversion ***,developing catalysts with high activity,long durability and strong anti-poisoning ability for ethanol oxidation is still ***,using Pd nanosheets as sacrificial templates,we have successfully synthesized PdPtBi networked nanowires(NWs)to improve the activity and stability for ethanol oxidation reaction(EOR)due to the addition of *** functional theory(DFT)calculations demonstrated the downshift of d-band center of Pd,which is beneficial to suppress CO poisoning and boost reaction kinetics for ***,the PdPtBi networked NWs exhibited the highest activity(11.08 A·mg_(Pd+Pt)^(-1)and 92.52 mA·cm^(-2))with an enhancement of 4.4 and 17.5 times relative to those of Pd/C,respectively and best stability with a 47.2%left versus only a 5.8%left for Pd/C of mass activity after 3,600 s towards *** work deepens the understanding of controllable preparation of networked NWs and provides an effective strategy to design advanced catalysts with high activity and stability.

关键词： trimetallic palladium platinum network nanowire ethanol oxidation

Blockchain Meets Generative Behavior Steganography:A Novel Covert Communication Framework for Secure IoT Edge Computing

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Chinese Journal of Electronics 2024年第4期33卷 886-898页

作者： Yuanlong CAO junjie li Kailin CHAO Jianmao XIAO Gang LEI School of Computer Information Engineering Jiangxi Normal University Jiangxi Blockchain Data Security and Governance Engineering Research Center Jiangxi Normal University School of Software Jiangxi Normal University

The rapid development of Internet of things(Io T) and edge computing technologies has brought forth numerous possibilities for the intelligent and digital future. The frequent communication and interaction between devices inevitably generate a large amount of sensitive information. Deploying a blockchain network to store sensitive data is crucial for ensuring privacy and security. The openness and synchronicity of blockchain networks give rise to challenges such as transaction privacy and storage capacity issues, significantly impeding their development in the context of edge computing and Io T. This paper proposes a reliable fog computing service solution based on a blockchain fog architecture. This paper stores data files in the inter planetary file system(IPFS) and encrypts the file hash values used for retrieving data files with stream cipher encryption. It employs a steganographic transmission technique leveraging Alpha Zero's Gomoku algorithm to discretely transmit the stream cipher key across the blockchain network without a carrier, thus achieving dual encryption. This approach aims to mitigate the storage burden on the blockchain network while ensuring the security of transaction data. Experimental results demonstrate that the model enhances the transmission capacity of confidential information from kilobytes(KB) to megabytes(MB) and exhibits high levels of covert and security features.

关键词： Steganography Ciphers Privacy Data privacy Blockchains Encryption Internet of Things