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Improvement in shape control performance of finishing mills in endless rolling production line

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Journal of Iron and Steel Research International 2023年第2期30卷 267-276页

作者： Zhao-yang Li Zhi Qi Lan-tian Guo Shu-huan Wang guan-yu Zhou Chi-huan yao Ding-guo Zhao An-rui He School of Metallurgy and Energy North China University of Science and TechnologyTangshan063210HebeiChina Tangshan Donghua Steel Enterprise Group Co. Ltd.Tangshan063210HebeiChina National Engineering Research Center for Advanced Rolling Technology University of Science and Technology BeijingBeijing100083China

Donghua steel continuous casting-rolling(DSCCR)production line is an endless rolling production line independently integrated and developed by a Chinese *** solve the problem of out-of-control shape caused by insufficient adjustment ability of work roll bending force of DSCCR finishing mills,the backup roll contours of the finishing mill were optimized considering multi-objectives,and varying contact length backup roll(VCR)contours matching the concave work rolls were designed based on the rapid rolls-strip deformation calculation model,which integrated the elastic deformation of the rolls and the fast plastic deformation of the rolled *** simulation results showed that VCR configuration can significantly enhance the control efficiency of the work roll bending force and increase the transverse stiffness of rolling mill compared with the conventional roll *** addition,VCR backup roll can improve the contact state between backup roll and work *** industrial production showed that the bending force setup value was more reasonable and the strip crown control accuracy was improved.

关键词： Endless rolling Profile control Flatness control Bending force Roll contour Varying contact rolling

Fast Liquid Phase Epitaxial Growth for Perovskite Single Crystals

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Chinese Physics Letters 2020年第1期37卷 97-100页

作者： yu-Wei Li Xin Wang guan-Wen Li yao Wu yu-Zhu Pan yu-Bing Xu Jing Chen Wei Lei Joint International Research Laboratory of Information Display and Visualization School of Electronic Science and EngineeringSoutheast UniversityNanjing 210096

Semiconductors grown by the solution-processed method have shown low-cost,facile fabrication process and comparable ***,there are many reasons why it is difficult to achieve high quality *** example,lattice constant mismatch is one of the problems when photovoltaic devices made of organ metallic *** this work,MAPbBr^(MA=CH3NH3^+)perovskites single crystals grown on the surface of MAPbBr2.5 CI0.5 perovskites single crystals via liquid epitaxial growth method is *** is found that when the lattice constants of the two perovskite single crystals are matched,another crystal can be grown on the surface of one crystal by epitaxial *** whole epitaxy growth process does not require high heating temperature and long heating time.X-ray diffraction method is used to prove the lattice plane of the substrate and the epitaxial grown layer.A scanning electron microscope is used to measure the thickness of the epitaxial *** with perovskite-based photodetectors without epitaxial growth layer,perovskite-based photodetectors with epitaxial growth layer have lower dark current density and higher optical responsibility.

关键词： Crystal perovskite epitaxial

Impacts of channel dredging on hydrodynamics and sediment dynamics in the main channels of the Jiaojiang River Estuary in China

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Acta Oceanologica Sinica 2023年第9期42卷 132-144页

作者： Yanming yao Xueqian Chen Jinxiong yuan Li Li Weibing guan Ocean College Zhejiang UniversityZhoushan 316021China Hangzhou Xi’ao Environmental Science and Technology Company Limited Hangzhou310011China State Key Laboratory of Satellite Ocean Environmental Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310058China

Channel dredging in estuaries increases water depth and subsequently impacts sediment dynamics and morphology. The Jiaojiang River Estuary is dredged frequently owing to heavy shipping demands. In this study,the effects of different dredging schemes on siltation were assessed through numerical modeling. The sediment model of the Jiaojiang River Estuary utilized an optimized bottom boundary layer model that considered the bed sediment grain size and fluid mud, and this model was calibrated using field data. Result reveal that channel dredging modifies the flow velocity inside and around the channel by changing the bathymetry;subsequently, this affects the residual current, bed stress, suspended sediment concentration, and sediment fluxes. Increasing the dredging depth and width increases the net sediment fluxes into the channel and dredging depth has a greater influence on the channel siltation thickness. When the dredging depth is 8.4 m or11.4 m, the average siltation thickness of the channel is 0.07 m or 0.15 m per mouth respectively. The parallel movement of the channel has small effects on the siltation volume during the simulation period. The sediment deposits in the channel primarily originates from the tidal flats, through bottom sediment fluxes. Vertical net circulation has a dominant impact on siltation because the difference of horizontal current of each layer on the longitudinal section of the channel increases, which intensifies the lateral sediment transport between the shoal and channel. The influence of vertical frictional dissipation on the lateral circulation at the feature points accounts for more than 50% before dredging, while the non-linear advective term is dominant after dredging. Tidal pumping mainly affects the longitudinal sediment fluxes in the channel. These results can be used for channel management and planning for similar estuaries worldwide.

关键词： sediment dynamics channel dredging bottom boundary layer siltation Jiaojiang River Estuary

A simple method for determining independent fracture toughness and tensile strength of rock

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International Journal of Mining Science and Technology 2022年第4期32卷 707-726页

作者： Junfeng guan yulong Zhang Jiangfeng Meng Xianhua yao Lielie Li Shuanghua He School of Civil Engineering and Communication North China University of Water Resources and Electric PowerZhengzhou 450045China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China

This paper develops a model that only requires two sets of small-size rock specimens with the ratio of the structural geometry parameter maximum to minimum ae,max:ae,min≥3:1 to determine the rock fracture and strength parameters without size effect and predict the actual structural performance of *** of three-point-bending,four-point-bending,or a combination of the above two specimen types,fracture toughness KICand tensile strength ftof rock were determined using only two sets of specimens with ae,max:ae,min≥3:*** values KICand ftwere consistent with those determined using multiple sets of *** full structural failure curve constructed by two sets of small-size specimens with ae,max:ae,min≥3:1 can accurately predict large-size specimens fracture failure,and±10%upper and lower limits of the curve can encompass the test results of large-size *** peak load prediction curve was constructed by two sets of specimens with ae,max:ae,min≥3:1,and±15%upper and lower limits of the peak load prediction curve can cover the small-size specimen tests *** model and method proposed in this paper require only two sets of small-size specimens,and their selection is unaffected by the specimen type,geometry,and initial crack length.

关键词： Rock Size effect Boundary effect Structural geometry parameter Fracture toughness Tensile strength

Collision free 4D path planning for multiple UAVs based on spatial refined voting mechanism and PSO approach

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Chinese Journal of Aeronautics 2019年第6期32卷 1504-1519页

作者： Yang LIU Xuejun ZHANG yu ZHANG Xiangmin guan School of Information Science&Electric Engineering Shandong Jiaotong UniversityJinan 250357China School of Electronic&Information Engineering Beihang UniversityBeijing 100083China College of Air Traffic Control Civil Aviation University of ChinaTianjin 300350China College of Transportation Engineering Tongji UniversityShanghai 200092China School of General Aviation Civil Aviation Management Institute of ChinaBeijing 100102China

In this paper, a four-dimensional coordinated path planning algorithm for multiple UAVs is proposed, in which time variable is taken into account for each UAV as well as collision free and obstacle avoidance. A Spatial Refined Voting Mechanism(SRVM) is designed for standard Particle Swarm Optimization(PSO) to overcome the defects of local optimal and slow *** each generation candidate particle positions are recorded and an adaptive cube is formed with own adaptive side length to indicate occupied regions. Then space voting begins and is sorted based on voting results, whose centers with bigger voting counts are seen as sub-optimal positions. The average of all particles of corresponding dimensions are calculated as the refined solutions. A time coordination method is developed by generating specified candidate paths for every UAV, making them arrive the same destination with the same time consumption. A spatial-temporal collision avoidance technique is introduced to make collision free. Distance to destination is constructed to improve the searching accuracy and velocity of particles. In addition, the objective function is redesigned by considering the obstacle and threat avoidance, Estimated Time of Arrival(ETA), separation maintenance and UAV self-constraints. Experimental results prove the effectiveness and efficiency of the algorithm.

关键词： 4D path planning Collision free Multiple UAVs Obstacle avoidance Particle swarm optimization Spatial refined voting mechanism

Vacuum residue coking process simulation using molecular-level kinetic model coupled with vapor-liquid phase separation

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Chinese Journal of Chemical Engineering 2022年第1期35卷 301-310页

作者： Zhengyu Chen Xinhui yao Dong guan Suoqi Zhao Linzhou Zhang Chunming Xu State Key Laboratory of Heavy Oil Processing Petroleum Molecular Engineering Center(PMEC)China University of PetroleumBeijing 102249China

In this work,a molecular-level kinetic model was built to simulate the vacuum residue(VR)coking process in a semi-batch laboratory-scale reaction kettle.A series of reaction rules for heavy oil coking were summarized and formulated based on the free radical reaction ***,a large-scale molecularlevel reaction network was automatically generated by applying the reaction rules on the vacuum residue *** order to accurately describe the physical change of each molecule in the reactor,we coupled the molecular-level kinetic model with a vapor–liquid phase separation *** vapor–liquid phase separation model adopted the Peng-Robinson equation of state to calculate vapor–liquid equilibrium.A separation efficiency coefficient was introduced to represent the mass transfer during the phase *** used six sets of experimental data under various reaction conditions to regress the model *** tuned model showed that there was an excellent agreement between the calculated values and experimental ***,we investigated the effect of reaction temperature and reaction time on the product *** a comprehensive evaluation of the reaction temperature and reaction time,the optimal reaction condition for the vacuum residue coking was also obtained.

关键词： Kinetic modeling Molecular engineering Vapor-liquid equilibrium Vacuum residue coking

Circulating RNA ZFR promotes hepatocellular carcinoma cell proliferation and epithelial-mesenchymal transition process through miR-624-3p/WEE1 axis

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Hepatobiliary & Pancreatic Diseases International 2024年第1期23卷 52-63页

作者： Li Zhang Sai He Hao guan yao Zhao Di Zhang Department of General Surgery the Second Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710004China Department of Breast Cancer Shaanxi Provincial Cancer HospitalXi’an 710000China

Background:Hepatocellular carcinoma(HCC),the most common type of primary liver cancer,is the fourth leading cause of cancer-related deaths *** evidence shows that the expression of circulating RNA ZFR(circZFR)is upregulated in HCC ***,the molecular mechanism of circZFR in HCC is ***:Quantitative reverse transcriptase polymerase chain reaction(qRT-PCR)was employed to detect the expression of circZFR,microRNA-624-3p(miR-624-3p)and WEE1 in HCC tissues and *** R assay and actinomycin D treatment assay were used to analyze the characteristics of *** functional analysis,the capacities of colony formation,cell proliferation,cell apoptosis,migration and invasion were assessed by colony formation assay,5-ethynyl-2-deoxyuridine(EdU)assay,flow cytometry assay and transwell *** blot was used to examine the protein levels of WEE1 and epithelial-mesenchymal transition(EMT)-related *** interactions between miR-624-3p and circZFR or WEE1 were validated by dual-luciferase reporter assay and RNA immunoprecipitation(RIP)*** models were established to determine the role of circZFR in ***:circZFR and WEE1 were upregulated,while miR-624-3p expression was reduced in HCC tissues and *** could sponge miR-624-3p,and WEE1 was a downstream gene of *** of circZFR significantly reduced the malignant behaviors of HCC and that co-transfection with miR624-3p inhibitor restored this *** of WEE1 abolished the inhibitory effect of miR624-3p mimic on HCC ***,circZFR acted as a competitive endogenous RNA(ceRNA)to regulate WEE1 expression by targeting ***,in vivo studies have illustrated that circZFR knockdown inhibited tumor ***:circZFR knockdown reduced HCC cell proliferation,migration and invasion and promoted apoptosis by regulating the miR-624-3p/WEE1 axis,suggesting that the circZFR/miR-624-3p/WEE1 axis might

关键词： Hepatocellular carcinoma circZFR miR-624-3p WEE1 Liver cancer

Vibration Analysis of a Simply Supported Beam Traversed by Uniform Distributed Moving Load

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上海交通大学学报 2004年第Z2期38卷 155-160页

作者： yu YANG Nian-guan TENG Yian-feng TENG School of Civil Engineering and Mechanics Shanghai Jiaotong Univ. Shanghai200030 China School of Civil Engineering and Mechanics Shanghai Jiaotong Univ. Shanghai200030 China School of Civil Engineering and Mechanics Shanghai Jiaotong Univ. Shanghai200030 China

Considering the engineering background of some transportation system like maglev, vertical vibration of the simply supported beam is investigated. The length of the vehicle is assumed to be longer than the beam span. The model of moving distributed load with constant speed is established .The beam can be taken as Euler-Bernoulli beam model and the right side of the control equation is simplified by using a moving status function. Duhamel integral and mode superposition method is used to solve the dynamic behavior of the beam. In this aspect deflection and acceleration are included. The results of different parameters such as the span of beam, velocity of load and ratio vehicle-Beam masses are compared. All results show that the dynamic response of the beam is tied up with these factors: the frequency of the beam, the moving frequency of the load and the ratio of vehicle-beam mass.

关键词： simply supported seam vertical vibration moving load

Finite Element Simulation of Flexible Roll Forming with Supplemented Material Data and the Experimental Verification

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Chinese Journal of Mechanical Engineering 2016年第2期29卷 342-350页

作者： YAN yu WANG Haibo LI Qiang guan Yanzhi School of Mechanical and Material Engineerin North China University of Technology

Flexible roll forming is a promising manufacturing method for the production of variable cross section products. Considering the large plastic strain in this forming process which is much larger than that of uniform deformation phase of uniaxial tensile test, the widely adopted method of simulating the forming processes with non-supplemented material data from uniaxial tensile test will certainly lead to large error. To reduce this error, the material data is supplemented based on three constitutive models. Then a finite element model of a six passes flexible roll forming process is established based on the supplemented material data and the original material data from the uniaxial tensile test. The flexible roll forming experiment of a B pillar reinforcing plate is carried out to verify the proposed method. Final cross section shapes of the experimental and the simulated results are compared. It is shown that the simulation calculated with supplemented material data based on Swift model agrees well with the experimental results, while the simulation based on original material data could not predict the actual deformation accurately. The results indicate that this material supplement method is reliable and indispensible, and the simulation model can well reflect the real metal forming process. Detailed analysis of the distribution and history of plastic strain at different positions are performed. A new material data supplement method is proposed to tackle the problem which is ignored in other roll forming simulations, and thus the forming process simulation accuracy can be greatly improved.

关键词： 3D Flexible roll forming constitutive model material data supplementation finite element method experiment verification