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Hybrid Finite Element Method Based on Polygon-Quadtree Meshes for Heat Transfer and Thermal Elastic Analysis

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Acta Mechanica Solida Sinica 2023年第5期36卷 745-753页

作者： lihui wang Rui Zhang Ran Guo Jiangbo Tao Faculty of Civil Engineering and Mechanics Kunming University of Science and TechnologyKunming 650000China

A steady-state thermal hybrid element model is proposed to calculate particle-reinforced composites divided by an improved quadtree *** functional of hybrid flux finite element method(HF-FEM)is constructed using the weighted residual *** functional independently assumes a heat flux field in the cell domain and a temperature field along cell *** construction of a universal heat flux function is put forward,which is approximated by a complete polynomial,and the temperature at the cell boundary is obtained by linear ***,the hybrid stress finite element method(HS-FEM)is constructed to solve the thermal *** this paper,an improved quadtree grid that can accurately describe the shape of elliptical inclusions is *** comparing several numerical examples with the traditional FEM,it is demonstrated that the hybrid element of the thermal analysis proposed in this paper is practical.

关键词： Hybridﬂux method Hybrid thermal stress method Improved quadtree grid Steady-state

Study on rolling process optimization of high carbon steel wire

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Journal of University of Science and Technology Beijing 2007年第5期14卷 431-436页

作者： Yu-An Jing Lin Hu lihui wang Jingtao Han School of Materials Science and Engineering University of Science and Technology Liaoning Anshan 114044 China Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China AnGang New Steel Company Limited Anshan 114003 China

The existing problems in the manufacture of SWRH82B high carbon steel wire were discussed by sampling and testing the microstructure and properties of the steel from the workshop. To solve the problems, the experimental parameters for thermal simulation were optimized, and the thermal simulating experiments were carded out on a Gleeblel500 thermal simulator. The process parameters for the manufacture were optimized after analysis of the data, and the productive experiments were performed after the water box in front of the no-twist blocks was reconstructed, to control the temperature of the loop layer. The results from the productive experiments showed that the cooling rate of 10-15℃/s was reasonable before phase transformation, about 5℃/s during phase transformation, and 600-620℃ was the suitable starting temperature for phase transformation. The ultimate strength of the Ф11.0 mm wire was increased to 1150-1170 MPa with an increase of 20-30 MPa, the percentage reduction of section was to 34%-36% with an increase of 1%-3% by testing the finished products after reconstruction.

关键词： high-carbon steel wire SWRH82B microstructure thermal simulation phase transformation

An mmWave Dual-Band Integrated Substrate Gap Waveguide Single Cavity Filter with Frequency Selectivity

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China Communications 2024年第1期21卷 188-199页

作者： Qiuhua Lin Dongya Shen lihui wang Zhiyong Luo School of Electronics and Communication Engineering Sun Yat-sen UniversityShenzhen 518107China School of Information Science and Engineering Yunnan UniversityKunming 650091China Pengcheng Laboratory Shenzhen 518107China Shenzhen Key Laboratory of Navigation and Communication Integration Shenzhen 518107China

A novel dual-band ISGW cavity filter with enhanced frequency selectivity is proposed in this paper by utilizing a multi-mode coupling *** cavity is designed to control the number of modes,and then the ports are determined by analyzing the coupling relationship between these selected *** synthesizing the coupling matrix of the filter,a nonresonating node(NRN)structure is introduced to flexibly tune the frequency of modes,which gets a dualband and quad-band filtering response from a tri-band filter no the ***,a frequency selective surface(FSS)has been newly designed as the upper surface of the cavity,which significantly improves the bad out-of-band suppression and frequency selectivity that often exists in most traditional cavity filter designs and *** results show that its two center frequencies are f01=27.50 GHz and f02=32.92GHz,*** with the dual-band filter that there is no the FSS metasurface,the out-of-band suppression level is improved from measured 5 dB to18 dB,and its finite transmission zero(FTZ)numbers is increased from measured 1 to 4 between the two designed *** with the tri-band and quadband filter,its passband bandwidth is expanded from measured 1.17%,1.14%,and 1.13% or 1.31%,1.50%,0.56%,and 0.57% to 1.71% and 1.87%.In addition,the filter has compact,small,and lightweight characteristics.

关键词： coupling topology frequency selectivity non-resonating node(NRN) out-of-band suppression single ISGW cavity filter

Gaze Estimation via a Differential Eyes’Appearances Network with a Reference Grid

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Engineering 2021年第6期7卷 777-786页

作者： Song Gu lihui wang Long He Xianding He Jian wang Chengdu Aeronautic Polytechnic Chengdu 610100China Department of Production Engineering KTH Royal Institute of TechnologyStockholm 10044Sweden

A person’s eye gaze can effectively express that person’s ***,gaze estimation is an important approach in intelligent manufacturing to analyze a person’s *** gaze estimation methods regress the direction of the gaze by analyzing images of the eyes,also known as eye ***,it is very difficult to construct a person-independent model that can estimate an accurate gaze direction for every person due to individual *** this paper,we hypothesize that the difference in the appearance of each of a person’s eyes is related to the difference in the corresponding gaze *** on this hypothesis,a differential eyes’appearances network(DEANet)is trained on public datasets to predict the gaze differences of pairwise eye patches belonging to the same *** proposed DEANet is based on a Siamese neural network(SNNet)framework which has two identical branches.A multi-stream architecture is fed into each branch of the *** branches of the DEANet that share the same weights extract the features of the patches;then the features are concatenated to obtain the difference of the gaze *** the differential gaze model is trained,a new person’s gaze direction can be estimated when a few calibrated eye patches for that person are *** personspecific calibrated eye patches are involved in the testing stage,the estimation accuracy is ***,the problem of requiring a large amount of data when training a person-specific model is effectively avoided.A reference grid strategy is also proposed in order to select a few references as some of the DEANet’s inputs directly based on the estimation values,further thereby improving the estimation *** on public datasets show that our proposed approach outperforms the state-of-theart methods.

关键词： Gaze estimation Differential gaze Siamese neural network Cross-person evaluations Human–robot collaboration

Monitoring Multiple Cropping Index of Henan Province, China Based on MODIS-EVI Time Series Data and Savitzky-Golay Filtering Algorithm

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Computer Modeling in Engineering & Sciences 2019年第5期119卷 331-348页

作者： lihui wang Feng Qi Xin Shen Jinliang Huang Key Laboratory of Environment and Disaster Monitoring and Evaluation Institute of Geodesy and GeophysicsChinese Academy of SciencesWuhan430077China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan430079China Collaborative Innovation Center of Geospatial Technology Wuhan UniversityWuhan430079China.

Multiple cropping index(MCI)is a very important indicator in crop production and agricultural intensification,which represents the utilizing degree of agriculture resources at time scale and the effective utilization situation of arable *** objective of this paper is monitoring multiple cropping index of Henan province of China according to the time series of MODIS(Moderate-Resolution Imaging Spectroradiometer)EVI(Enhanced Vegetation Index)after Savitzky-Golay filter processing from the year 2006 to *** results revealed that this method could provide an effective way to monitor multiple cropping index,and the method of no additional authentication data is independent and *** result was accurate and stable,the slope of linear regression of the multiple cropping index between the statistical results and the remote sensing results was 1.0136(R2=0.779).The precision of sample areas validation was 97.91%.Suggesting that the time series MODIS-EVI which after Savitzky-Golay filtering processed,could provide an effective way to extract spatial information of multiple cropping index for management department of agriculture.

关键词： Multiple cropping index time Series of MODIS-EVI Savitzky-Golay filtering Henan Province

Examining the Factors Affecting Personal Income： An Empirical Study Based on Survey Data in Chinese Cities

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2017年第4期12卷 515-544页

作者： lihui wang Junyi Shen Graduate School of Economics Kobe University Nada Kobe 657-8501 Japan Research Institute for Economics and Business Administration Kobe University Nada Kobe 657-8501 Japan

This paper empirically analyzes the factors affecting personal income in urban China using survey data of the ＂Preference and Life Satisfaction Survey＂ conducted by the Global COE project of Osaka University from 2009 to 2013. We consider education level as an endogenous variable, and both ordinary least squares （OLS） regression and instrumental variable （IV） regression are performed. We find a number of factors, such as sex, age, education, and marriage that significantly affect personal income. In addition, differences between different occupations are also investigated.

关键词： personal income earning function urban China discrimination

Total loads modeling and geological adaptability analysis for mixed soil-rock tunnel boring machines

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Underground Space 2022年第3期7卷 337-351页

作者： Wencong Qi lihui wang Siyang Zhou Yilan Kang Qian Zhang Key Laboratory of Modern Engineering Mechanics School of Mechanical EngineeringTianjin UniversityTianjin 300350China Department of Military Vehicle Academy of Military TransportationTianjin 300161China

Rock-soil interface mixed ground(RSI)is often encountered in tunnel *** excavation loads of tunnel boring machines(TBMs)are controlled by the interaction characteristics between TBM and rock/soil *** different properties of rock and soil cause the varying interaction range and stress ***,there have been several studies available to estimate excavation loads under RSI,and the conclusion is that the total loads increase with increasing the rock layer proportion in the excavation ***,the previous studies cannot take the difference of rock/soil properties into account,except for the calculation of cutters ***,the interaction characteristics between RSI and TBM is *** paper analyzes the interaction characteristics between TBM’s main components and complex geological conditions(e.g.,layered soil,layered rock,and RSI condition).A model is proposed to calculate the total thrust and total torque assuming quasi-static equilibrium of the tunneling *** rationality and applicability of the model are discussed and verified by two typical ***,the geological adaptability is discussed in terms of the excavation difficulty and the matching relationship between total torque and total *** results indicate that when the rock layer proportion in the excavation face increases,the reduction of overall extrusion and friction loads is 1.5 times higher than the increase of disc cutters breaking *** total loads and the ratio of the total torque to total thrust decrease approximately *** is a power function relationship between the excavation difficulty index and the penetration *** results of this study provide an important reference for the total loads design of equipment propulsion systems and the parameter adjustment during tunnel construction.

关键词： Rock-soil interface mixed ground Tunnel boring machine Total loads prediction Thrust and torque Geological adaptability analysis

Digital Twins and Cyber Physical Systems toward Smart Manufacturing and Industry 4.0:Correlation and Comparison

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Engineering 2019年第4期5卷 653-661页

作者： Fei Tao Qinglin Qi lihui wang A.Y.C.Nee School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100083China Department of Production Engineering KTH Royal Institute of TechnologyStockholm SE-10044Sweden Department of Mechanical Engineering National University of SingaporeSingapore 117575Singapore

State-of-the-art technologies such as the Internet of Things(IoT),cloud computing(CC),big data analytics(BDA),and artificial intelligence(AI)have greatly stimulated the development of smart *** important prerequisite for smart manufacturing is cyber-physical integration,which is increasingly being embraced by *** the preferred means of such integration,cyber-physical systems(CPS)and digital twins(DTs)have gained extensive attention from researchers and practitioners in *** feedback loops in which physical processes affect cyber parts and vice versa,CPS and DTs can endow manufacturing systems with greater efficiency,resilience,and *** and DTs share the same essential concepts of an intensive cyber-physical connection,real-time interaction,organization integration,and in-depth ***,CPS and DTs are not identical from many perspectives,including their origin,development,engineering practices,cyber-physical mapping,and core *** order to highlight the differences and correlation between them,this paper reviews and analyzes CPS and DTs from multiple perspectives.

关键词： Cyber–physical systems(CPS) Digital twin(DT) Smart manufacturing Correlation and comparison

Optical and electronic properties of single modulation doped GaAs/AlGaAs V-grooved quantum wire modified by ion implantation

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Science China(Physics,Mechanics & Astronomy) 2005年第3期48卷 361-370页

作者： HUANG Shaohua CHEN Zhanghai BAI lihui wang Fangzhen SHEN Xuechu Surface Physics Laboratory Department of Physics Fudan University Shanghai 200433 China Surface Physics Laboratory Department of Physics Fudan University Shanghai 200433 China Surface Physics Laboratory Department of Physics Fudan University Shanghai 200433 China Surface Physics Laboratory Department of Physics Fudan University Shanghai 200433 China Surface Physics Laboratory Department of Physics Fudan University Shanghai 200433 China

Single GaAs/Al0.5Ga0.5As V-grooved quantum wire modified by selective ion-implantation and rapid thermally annealing was investigated by spatially-resolved microphotoluminescence and magneto-resistance measurement. Spatially-resolved photoluminescence results indicate that the ion-implantation induced quantum well intermixing raises significantly the electron subband energies of the side quantum wells and vertical quantum wells, and more efficient accumulation of electrons in the quantum wires is achieved. Furthermore, the polarization properties of the photoluminescence from the quantum wires show large linear polarization degree up to 63%. Magneto- transport investigation on the ion implanted quantum wire samples presents the quasi-one dimensional intrinsic motion of electrons, which is important for the design and optimization of one dimensional electronic devices.

关键词： GaAs/AlGaAs V-grooved quantum wire, ion-implantation, photoluminescence, polarization,magneto-resistance