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Non-isothermal creep age forming of Al-Cu-Li alloy:Experiment and modelling

Chinese Journal of Aeronautics 2023年第5期36卷 566-581页

作者： Changhui WU Heng LI Tianjun BIAN Chao LEI Liwen ZHANG State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China School of Materials Science and Engineering Xi’an University of TechnologyXi’an 710048China

Non-isothermal Creep Age Forming(CAF),including loading,heating,holding,cooling and springback stages,is an advanced forming technique for manufacturing high performance large integral panels at short production period and low ***,the creep deformation and aging precipitation during heating stage is often neglected in experiments and modeling,leading to low forming *** achieve shape forming and property tailoring simultaneously,a deep understanding of the non-isothermal creep aging behavior and the establishment of predictive models are urgently required.A new five-stage creep feature of Al-Cu-Li alloy during the non-isothermal creep aging is *** microstructural interactions between the dislocations,solute atoms,Guinier Preston zones(GP zones)and T1 precipitates are found to dominate the five-stage creep aging *** physical-based model considering temperature evolution history is established to describe the five-stage creep *** springback and yield strength of non-isothermal creep age formed plates with different thicknesses are predicted and compared by non-isothermal CAF experiments and corresponding *** CAF experiments show that the springback and yield strength of the non-isothermal creep age formed plate are 62.1%and 506 MPa,*** results are in good agreement with experimental *** proposed model broadens the application of traditional CAF models that mainly focus on isothermal conditions.

关键词： Al-Cu-Li alloy Creep aging forming Microstructures Springback Mechanical properties Thickness

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First-principles calculations study of valley polarization in antiferromagnetic bilayer systems

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Physical Review B 2025年第14期111卷 L140404-L140404页

作者： San-Dong Guo Ping Li Guangzhao Wang School of Electronic Engineering Xi'an University of Posts and Telecommunications Xi'an 710121 China State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and Engineering Xi'an Jiaotong University Xi'an Shaanxi 710049 China Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing School of Electronic Information Engineering Yangtze Normal University Chongqing 408100 China

Superior to ferromagnetic (FM) valleytronics, antiferromagnetic (AFM) counterparts exhibit ultradense and ultrafast potential due to their intrinsic advantages of zero stray field, terahertz dynamics, and compensated moments of antiferromagnets. However, the physics of spontaneous valley polarization is mainly rooted in FM hexagonal lattices and is rarely used to explore the simultaneous spin and valley polarizations in AFM materials. Here, we propose a general stacking method to achieve valley polarization in AFM bilayer systems. The hexagonal ferrovalley material is used as the basic building unit, and then the space-inversion centrosymmetric bilayer system with interlayer AFM ordering is constructed by horizontal mirror and twofold rotational operations, which can exhibit spontaneous valley polarization. In this construction process, the rarely explored layer-locked hidden valley polarization, hidden Berry curvature, and layer Hall effect are involved, and an out-of-plane electric field can be used to detect hidden valley polarization and to realize layer-locked anomalous valley Hall effect. We use three examples to illustrate our proposal. First, the Janus GdBrI is used to illustrate concepts and effects involved in our design process. Second, the RuBr2 is used to demonstrate other phenomena, including valley polarization transition and near-ideal quantum spin Hall insulators. Finally, we use our design principles to understand the valley polarization of experimentally synthesized MnSe from a new perspective. Our works establish a robust general scheme to achieve valley polarization in AFM bilayer systems, thereby opening up new avenues for AFM valleytronics.

关键词： Landforms

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Dynamic Hand Gesture-Based Person Identification Using Leap Motion and Machine Learning Approaches

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computers, Materials & Continua 2024年第4期79卷 1205-1222页

作者： Jungpil Shin Md.AlMehedi Hasan Md.Maniruzzaman Taiki Watanabe Issei Jozume School of Computer Science and Engineering The University of AizuAizuwakamatsuFukushima965-8580Japan Department of Computer Science&Engineering Rajshahi University of Engineering&TechnologyRajshahi6204Bangladesh

Person identification is one of the most vital tasks for network security. People are more concerned about theirsecurity due to traditional passwords becoming weaker or leaking in various attacks. In recent decades, fingerprintsand faces have been widely used for person identification, which has the risk of information leakage as a resultof reproducing fingers or faces by taking a snapshot. Recently, people have focused on creating an identifiablepattern, which will not be reproducible falsely by capturing psychological and behavioral information of a personusing vision and sensor-based techniques. In existing studies, most of the researchers used very complex patternsin this direction, which need special training and attention to remember the patterns and failed to capturethe psychological and behavioral information of a person properly. To overcome these problems, this researchdevised a novel dynamic hand gesture-based person identification system using a Leap Motion sensor. Thisstudy developed two hand gesture-based pattern datasets for performing the experiments, which contained morethan 500 samples, collected from 25 subjects. Various static and dynamic features were extracted from the handgeometry. Randomforest was used to measure feature importance using the Gini Index. Finally, the support vectormachinewas implemented for person identification and evaluate its performance using identification accuracy. Theexperimental results showed that the proposed system produced an identification accuracy of 99.8% for arbitraryhand gesture-based patterns and 99.6% for the same dynamic hand gesture-based patterns. This result indicatedthat the proposed system can be used for person identification in the field of security.

关键词： Person identification leap motion hand gesture random forest support vector machine

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RE-SEGNN:recurrent semantic evidence-aware graph neural network for temporal knowledge graph forecasting

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science China(Information sciences) 2025年第2期68卷 103-119页

作者： Wenyu CAI Mengfan LI Xuanhua SHI Yuanxin FAN Quntao ZHU Hai JIN National Engineering Research Center for Big Data Technology and System Services Computing Technology and System LabCluster and Grid Computing LabSchool of Computer Science and TechnologyHuazhong University of Science and Technology

Temporal knowledge graph(TKG) reasoning, has seen widespread use for modeling real-world events, particularly in extrapolation settings. Nevertheless, most previous studies are embedded models, which require both entity and relation embedding to make predictions, ignoring the semantic correlations among different entities and relations within the same timestamp. This can lead to random and nonsensical predictions when unseen entities or relations occur. Furthermore, many existing models exhibit limitations in handling highly correlated historical facts with extensive temporal depth. They often either overlook such facts or overly accentuate the relationships between recurring past occurrences and their current counterparts. Due to the dynamic nature of TKG, effectively capturing the evolving semantics between different timestamps can be *** address these shortcomings, we propose the recurrent semantic evidenceaware graph neural network(RE-SEGNN), a novel graph neural network that can learn the semantics of entities and relations simultaneously. For the former challenge, our model can predict a possible answer to missing quadruples based on semantics when facing unseen entities or relations. For the latter problem, based on an obvious established force, both the recency and frequency of semantic history tend to confer a higher reference value for the current. We use the Hawkes process to compute the semantic trend, which allows the semantics of recent facts to gain more attention than those of distant facts. Experimental results show that RE-SEGNN outperforms all SOTA models in entity prediction on 6 widely used datasets, and 5 datasets in relation prediction. Furthermore, the case study shows how our model can deal with unseen entities and relations.

关键词： knowledge graph reasoning temporal knowledge graph Hawkes process semantic evidence

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Neutrosophic Pseudo-t-Norm and Its Derived Neutrosophic Residual Implication

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Neutrosophic Sets and Systems 2023年 57卷 18-32页

作者： Bu, Hongru Hu, Qingqing Zhang, xiaohong School of Mathematics and Data Science Shaanxi University of Science & Technology Xi’an710021 China School of Electrical and Control Engineering Shaanxi University of Science & Technology Xi’an710021 China School of Mathematics and Data Science Shaanxi University of Science and Technology Xi’an710021 China

First of all, on the basis of complete lattice, the concept of neutrosophic pseudo-t-norm (NPT) is given. Definitions and examples of representable neutrosophic pseudo-t-norms (RNPTs) are given, while unrepresentable neutrosophic pseudo-t-norms (UNPTs) is also given. Secondly, De Morgan neutrosophic triples (DMNTs) consists of three operators: NPTs, neutrosophic negators (NNs) and neutrosophic pseudo-s-norms (NPSs), where NPTs and NPSs are dual about NNs. Again, we study the neutrosophic residual implications (NRIs) of NPTs, as well as their underlying properties. Finally, we give a method to get NPTs from neutrosophic implications (NIs) and construct non-commutative residuated lattices (NCRLs) based on NRIs and NPTs. © (2023). All Rights Reserved.

关键词： Fuzzy logic

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An overview on IRS-enabled sensing and communications for 6G: architectures, fundamental limits, and joint beamforming designs

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science China(Information sciences) 2025年第5期68卷 170-193页

作者： xianxin SONG Yuan FANG Feng WANG Zixiang REN xianghao YU Ye ZHANG Fan LIU Jie XU Derrick Wing Kwan NG Rui ZHANG Shuguang CUI School of Science and Engineering (SSE) Shenzhen Future Network of Intelligence Institute (FNii-Shenzhen)and Guangdong Provincial Key Laboratory of Future Networks of Intelligence The Chinese University of Hong Kong Department of Electrical Engineering City University of Hong Kong School of Information Engineering Guangdong University of Technology Key Laboratory of Wireless-Optical Communications Chinese Academy of Sciences School of Information Science and Technology University of Science and Technology of China Computer School Beijing Information Science and Technology University National Mobile Communications Research Laboratory School of Information Science and Engineering Southeast University School of Electrical Engineering and Telecommunications University of New South Wales School of Science and Engineering Shenzhen Research Institute of Big Data The Chinese University of Hong Kong Department of Electrical and Computer Engineering National University of Singapore

This study presents an overview on intelligent reflecting surface(IRS)-enabled sensing and communication for the forthcoming sixth-generation(6G) wireless networks, in which IRSs are strategically deployed to proactively reconfigure wireless environments to improve both sensing and communication(S&C) performance. First, we exploit a single IRS to enable wireless sensing in the base station's(BS's) non-line-of-sight(NLoS) area. In particular, we present three IRS-enabled NLoS target sensing architectures with fully-passive, semi-passive, and active IRSs, respectively. We compare their pros and cons by analyzing the fundamental sensing performance limits for target detection and parameter estimation. Next, we consider a single IRS to facilitate integrated sensing and communication(ISAC), in which the transmit signals at the BS are used for achieving both S&C functionalities, aided by the IRS through reflective beamforming. We present joint transmit signal and receiver processing designs for realizing efficient ISAC, and jointly optimize the transmit beamforming at the BS and reflective beamforming at the IRS to balance the fundamental performance tradeoff between S&C. Furthermore, we discuss multi-IRS networked ISAC, by particularly focusing on multi-IRS-enabled multi-link ISAC, multi-region ISAC, and ISAC signal routing, respectively. Finally, we highlight various promising research topics in this area to motivate future work.

关键词： integrated sensing and communication (ISAC) intelligent reflecting surface (IRS) non-line-of-sight (NLoS) sensing sensing and communication tradeoff

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General Optimal Trajectory Planning:Enabling Autonomous Vehicles with the Principle of Least Action

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engineering 2024年第2期33卷 63-76页

作者： Heye Huang Yicong Liu Jinxin Liu Qisong Yang Jianqiang Wang David Abbink Arkady Zgonnikov School of Vehicle and Mobility Tsinghua UniversityBeijing 100084China Department of Cognitive Robotics Faculty of MechanicalMaritime and Materials Engineering(3mE)Delft University of TechnologyDelft 2628Netherlands Department of Software Technology Faculty of Electrical EngineeringMathematics and Computer ScienceDelft University of TechnologyDelft 2628Netherlands Xi’an Institute of High-Technology Xi’an 710051China

This study presents a general optimal trajectory planning(GOTP)framework for autonomous vehicles(AVs)that can effectively avoid obstacles and guide AVs to complete driving tasks safely and ***,we employ the fifth-order Bezier curve to generate and smooth the reference path along the road *** coordinates are then transformed to achieve the curvature continuity of the generated *** the road constraints and vehicle dynamics,limited polynomial candidate trajectories are generated and smoothed in a curvilinear coordinate ***,in selecting the optimal trajectory,we develop a unified and auto-tune objective function based on the principle of least action by employing AVs to simulate drivers’behavior and summarizing their manipulation characteristics of“seeking benefits and avoiding losses.”Finally,by integrating the idea of receding-horizon optimization,the proposed framework is achieved by considering dynamic multi-performance objectives and selecting trajectories that satisfy feasibility,optimality,and *** simulations and experiments are performed,and the results demonstrate the framework’s feasibility and effectiveness,which avoids both dynamic and static obstacles and applies to various scenarios with multi-source interactive traffic ***,we prove that the proposed method can guarantee real-time planning and safety requirements compared to drivers’manipulation.

关键词： Autonomous vehicle Trajectory planning Multi-performance objectives Principle of least action

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A Digital Twin Framework for Logical Range

A Digital Twin Framework for Logical Range

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2023 International Conference on Networking and Network Applications, NaNA 2023

作者： Dang, Zheng Chen, Hao Hei, xinhong Liu, Yilong School of Computer Science and Engineering Xi'an University of Technology Xi'an710048 China

ISBN: (纸本)9798350327380

The Logical Range is introduced into the joint flight test because it can call cross-area test resources and improve the utilization rate of test resources. However, the Logical Range also has the problems of low reusability of test resources and low efficiency in cross regional range data acquisition and communication. For this problem, a digital twin framework for logical range is proposed. In the framework, a Logical Range system based on digital twin is built, and the data network communication methods and virtual-real mapping method are designed in detail. The feasibility of this framework has been effectively verified through flight test examples. This study lays a solid foundation for the combination of flight test and digital twin technology. © 2023 IEEE.

关键词： Reusability

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An integrated micromachined flexible ultrasonicinductive sensor for pipe contaminant multiparameter detection

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Microsystems & Nanoengineering 2024年第4期10卷 271-283页

作者： Zheng Yuan xiaoyu Wu Zhikang Li Jiawei Yuan Yihe Zhao Zixuan Li Shaohui Qin Qi Ma Xuan Shi Zilong Zhao Jiazhu Li Shiwang Zhang Weixuan Jing xiaozhang Wang Libo Zhao State Key Laboratory for Manufacturing Systems Engineering International Joint Laboratory for Micro/Nano Manufacturing and Measurement TechnologiesXi’an Jiaotong University(Yantai)Research Institute for Intelligent Sensing Technology and SystemXi’an Jiaotong UniversityXi’an 710049China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China School of Instrument Science and Technology Xi’an Jiaotong UniversityXi’an 710049China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai 265503China

Pipe contaminant detection holds considerable importance within various industries,such as the aviation,maritime,medicine,and other pertinent *** capability is beneficial for forecasting equipment potential failures,ascertaining operational situations,timely maintenance,and lifespan ***,the majority of existing methods operate offline,and the detectable parameters online are relatively *** constraint hampers real-time on-site detection and comprehensive assessments of equipment *** address these challenges,this paper proposes a sensing method that integrates an ultrasonic unit and an electromagnetic inductive unit for the real-time detection of diverse contaminants and flow rates within a *** ultrasonic unit comprises a flexible transducer patch fabricated through micromachining technology,which can not only make installation easier but also focus the sound ***,the sensing unit incorporates three symmetrical solenoid *** a comprehensive analysis of ultrasonic and induction signals,the proposed method can be used to effectively discriminate magnetic metal particles(e.g.,iron),nonmagnetic metal particles(e.g.,copper),nonmetallic particles(e.g.,ceramics),and *** inclusive categorization encompasses nearly all types of contaminants that may be present in a ***,the fluid velocity can be determined through the ultrasonic Doppler frequency *** efficacy of the proposed detection principle has been validated by mathematical models and finite element *** contaminants with diverse velocities were systematically tested within a 14mm diameter *** experimental results demonstrate that the proposed sensor can effectively detect contaminants within the 0.5−3mm range,accurately distinguish contaminant types,and measure flow velocity.

关键词： inductive holds ultrasonic

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Probabilistic Response and Short-Term Extreme Load Estimation of Offshore Monopile Wind Turbine Towers by Probability Density Evolution Method

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China Ocean engineering 2022年第3期36卷 363-371页

作者： ZHANG Hui XU Ya-zhou School of Building Services Science and Engineering Xi’an University of Architecture and TechnologyXi’an 710055China School of Civil Engineering Xi’an University of Architecture and TechnologyXi’an 710055China

A new analysis framework based on probability density evolution method(PDEM)and its Chebyshev collocation solution are introduced to predict the dynamic response and short-term extreme load of offshore wind turbine(OWT)towers subjected to random sea *** regard to the stochastic responses,random function method is employed to generate samples of sea elevation,the probability density evolution equation(PDEE)is solved to calculate time-variant probability density functions of structural *** the probabilistic load estimation,a FAST model of NREL 5MW offshore turbine is established to obtain samples of bending moment at the tower *** equivalent extreme event theory is used to construct a virtual stochastic process(VSP)to assess the short-term extreme *** results indicate that the proposed approach can predict time-variant probability density functions of the structural responses,and shows good agreement with Monte Carlo ***,the predicted short-term extreme load can capture the fluctuation at the tail of the extreme value distribution,thus is more rational than results from the typical distribution ***,the proposed method shows good adaptation,precision and efficiency for the dynamic response analysis and load estimation of OWT towers.

关键词： offshore wind turbine probability density evolution method Chebyshev collocation matrix exponential Monte Carlo

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