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Transverse Bending Characteristics in U-channel Forming of Tailor Rolled Blank

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Journal of Iron and Steel Research International 2016年第12期23卷 1249-1254页

作者： Hua-wei ZHANG Ying-ping GUAN jia-lu wu Xiang-hua LIU School of Control Engineering Northeastern University at Qinhuangdao College of Mechanical Engineering Yanshan University Research Institute of Science and Technology Northeastern University

Research on the formability of tailor rolled blank （TRB） is of good practical significance and application value because of the enormous potential of TRB in the aspect of automobile lightweight. However, the forming of TRB is problematic because of the varying properties; especially, springback is a main challenge. The transverse bending （bending axis is perpendicular to the rolling direction） of TRB U channel was studied through simulation and experiment. The forming characteristics of TRB U channel during transverse bending were analyzed. The mechanisms of forming defects, including bending springback and thickness transition zone （TTZ） movement, were revealed. On this basis, effects of blank geometric parameters on springbaek and TTZ movement were discussed. The results indicate that springback and TTZ movement happen during transverse bending of TRB U-channel. Nonuni form stress distribution is the most fundamental reason for the occurrence of springback of TRB during transverse bending. Annealing can eliminate nonuniform stress distribution, and thus diminish springbaek of TRB, especially springback on the thinner side. Therefore, springback of the whole TRB becomes more uniform. However, annealing can increase the TTZ movement. Blank thickness and TTZ position are the main factors affecting the formability of TRB U-channel during transverse bending.

关键词： tailor rolled blank transverse bending springback U-channel annealing thickness transition zone

Study on Nonuniform Deformation of Tailor Rolled Blank During Uniaxial Tension

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Acta Metallurgica Sinica(English Letters) 2015年第9期28卷 1198-1204页

作者： Hua-Wei Zhang Xiang-Hua Liu Li-Zhong Liu Ping Hu jia-lu wu School of Mechanical Engineering and Automation Northeastern University Research Institute of Science and Technology Northeastern University School of Automotive Engineering Dalian University of Technology

The deformation characteristics of tailor rolled blank （TRB） in the course of uniaxial tension were studied by means of analysis, test and simulation. The mechanical analytical model of TRB during uniaxial tension was set up, and the deformation formulae for the thinner side and for the thicker side were derived to quantify the deformation of TRB. On this basis, uniaxial tension tests on TRB and ordinary blanks （the thinner side and the thicker side of TRB） were conducted. Lagrange polynomial interpolation method was adopted to construct the stress-strain fields of unannealed and annealed TRBs for solving TRB material parameters, and then, uniaxial tension simulation on TRB was completed. Deformations and properties of unannealed TRB were compared with those of annealed TRB, and the thinner side and the thicker side were also compared. Finally, the research results were explained by metallurgical structure. The results show that nonuniform deformation happens in TRB during uniaxial tension, and the necking occurs on the thinner side. The agreement of analysis, test and simulation confirms the correctness of the analytical model and the deformation formulae. The findings of this paper can lay the foundation for the future study on TRB stamping formability and provide a way for TRB modeling.

关键词： Tailor rolled blank (TRB) Nonuniform deformation Uniaxial tension Annealing Metallographical

Forming Limit and Thickness Transition Zone Movement for Tailor Rolled Blank during Drawing Process

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Journal of Iron and Steel Research International 2016年第3期23卷 185-189页

作者： Hua-wei ZHANG Xiang-hua LIU Li-zhong LIU Ping HU jia-lu wu School of Control Engineering Northeastern University at Qinhuangdao Research Institute of Science and Technology Northeastern University School of Automotive Engineering Dalian University of Technology

The process of automobile lightweight can be promoted by the application of tailor rolled blank（TRB）in the automobile ***,research on the formability of TRB is of good practical significance and application value because of the enormous potential of TRB in the aspect of automobile *** at the present condition of lack of researches on the influence of characteristic parameters on TRB drawing process,the drawing formability of TRB was studied with a combination method of simulation and experiment by taking square box as the research ***,drawing simulation and experiment of TRB were carried ***,effects of thickness transition zone（TTZ）position and blank size on the drawing formability of TRB were *** limit and TTZ movement for TRB square box during the drawing process were respectively discussed,when transition zones of TRB were located at different positions and blanks were of different *** results indicate that lubrication condition exerts greater influence on TRB forming limit in comparison with TTZ movement,and the smaller blank size and TTZ being located at the blank center or slightly offset to the thinner side are preferable for acquiring greater forming limit and smaller TTZ movement.

关键词： tailor rolled blank square box forming limit thickness transition zone movement drawing formability

Molecular Evolution of Protein Sequences and Codon Usage in Monkeypox Viruses

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Genomics, Proteomics & Bioinformatics 2024年第1期22卷 89-97页

作者： Ke-jia Shan Changcheng wu Xiaolu Tang Roujian lu Yaling Hu Wenjie Tan jian lu State Key Laboratory of Protein and Plant Gene Research Center for BioinformaticsSchool of Life SciencesPeking UniversityBeijing 100871China Sinovac Biotech Ltd. Beijing 100085China NHC Key Laboratory of Biosafety National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 100052China

The monkeypox virus(mpox virus,MPXV)epidemic in 2022 has posed a significant public health ***,the evolutionary principles of MPXV remain largely ***,we examined the evolutionary patterns of protein sequences and codon usage in *** first demonstrated the signal of positive selection in OPG027,specifically in the CladeⅠlineage of ***,we discovered accelerated protein sequence evolution over time in the variants responsible for the 2022 ***,we showed strong epistasis between amino acid substitutions located in different *** codon adaptation index(CAI)analysis revealed that MPXV genes tended to use more non-preferred codons compared to human genes,and the CAI decreased over time and diverged between clades,with CladeⅠ>Ⅱa andⅡb-A>Ⅱ*** the decrease in fatality rate among the three groups aligned with the CAI pattern,it remains unclear whether this correlation was coincidental or if the deoptimization of codon usage in MPXV led to a reduction in fatality *** study sheds new light on the mechanisms that govern the evolution of MPXV in human populations.

关键词： Mpox virus Positive selection OPG027 Accelerated evolution Codon usage bias

Cutting performance of saw blades with microtextured rougher and finisher sawteeth

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Advances in Manufacturing 2024年第2期12卷 317-334页

作者： Yang lu jian-Xin Deng Zhi-Hui Zhang jia-Xing wu Ran Wang Yi-Chen Bao Key Laboratory of High Efficiency and Clean Mechanical Manufacture of MOE School of Mechanical EngineeringShandong UniversityJinan250061People’s Republic of China

The problems of severe sawtooth wear,harsh sawing noise,and low surface quality during the processing of circular saw blades need to be *** improve the cutting performance of TiC-based cermet saw blades,microtextures parallel to the cutting edge were fabricated on rough and fine sawteeth by laser *** cutting tests were performed on a sawing platform under lubricated *** of the sawing arc length and working sawtooth cutting force variations were developed for sawing steel pipes,and the accuracy of the sawing force model was verified *** results indicate that the variations in the sawing force are proportional to the sawing arc *** circular saw blades with microtextures that did not penetrate the sawtooth rake face exhibited the lowest cutting force,sawing noise,and highest machined surface ***,the worn-out distance of the rougher and finisher sawteeth was reduced by approximately 7.4%and 44.1%,respectively,compared with conventional circular saw *** main failure modes of sawteeth were tip wear,rake face adhesion,and oxidative *** addition,the mechanism by which the textures improve the cutting and wear properties of TiC-based circular saw blades was *** study provided a significant concept for enhancing the cutting performance of circular saw blades and improving the machined surface quality.

关键词： Circular saw blades Micro textures Cutting performance Wear performance

Inimitable 3D pyrolytic branched hollow architecture with multi-scale conductive network for microwave absorption

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Journal of Materials Science & Technology 2024年第6期173卷 170-180页

作者： jiajun Li Qianqian Zhu jiahui Zhu Yuhang Cheng Zirui jia Feng lu Chao Wang Guanglei wu Institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao266071China College of Chemistry and Chemical Engineering Qingdao UniversityQingdao266071China Technical Center of Qingdao Customs Qingdao266002China

To solve the electromagnetic pollution problem,the reasonable structure design and component control of the electromagnetic absorber is *** this work,three-dimensional(3D)pyrolytic branched hollow architecture carbon PBHAC/MoS_(2)composites were prepared via a hydrothermal and calcination two-step *** narrow-gap nano-size MoS_(2)acquired after vulcanization and micro-size 3D branched carbon skeleton PBHAC possess intensified conduction ***,the presence of potential differences between different phases creates a space charge region at the heterogeneous interface,resulting in strong interfacial *** resulting 3D branched hollow PBHAC/MoS_(2)composites exhibit optimized impedance matching and multiple loss ***,the 3D branched hollow carbon PBHAC/MoS_(2)composites have the best electromagnetic wave(EMW)absorption *** minimum reflection loss(RLmin)is-57.8 dB at 1.93 mm and the maximum effective absorption bandwidth(EAB_(max))is 6.08 GHz at 2 mm,which indicates the excellent EMW absorption performance of the ***,this composite is expected to be a microwave absorber with the characteristics of“thin,light,wide,and strong”.

关键词： Dielectric loss MoS_(2) Impedance matching Schottky barrier Microwave absorption

Progress in preparation of AlN-reinforced magnesium matrix composites:A review

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China Foundry 2024年第1期21卷 1-10页

作者： lu Chen Shu-lin Lü Di-jia Zhao Wei Guo jian-yu Li Shu-sen wu State Key Lab of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

As a ceramic material,AlN has very good thermophysical and mechanical *** addition,AlN is an effective refining agent for Mg alloys because it has a lattice constant similar to that of ***,AlN is an ideal reinforcement for magnesium matrix composites(MMCs),and is attracting increasing *** review addresses the development of preparation technologies for AlN-reinforced Mg matrix *** mainstream preparation techniques include stir casting,melt infiltration,powder metallurgy,and in-situ *** addition,the advantages and disadvantages of these techniques are analyzed in depth,and it is pointed out that the next direction for the preparation of high-performance AlN-reinforced MMCs is less aluminization and multiple technologies integration.

关键词： AlN MMCs preparation thermophysical property mechanical property

Ballistic performances of the hourglass lattice sandwich structures under high-velocity fragments

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Defence Technology（防务技术） 2024年第1期31卷 312-325页

作者： He-xiang wu jia Qu Lin-zhi wu Key Laboratory of Advanced Ship Materials and Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbin150001China School of Civil Engineering Northeast Forestry UniversityHarbin150040China

In this paper,the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of *** is paid to elucidating the influences of rod cross-section dimensions,structure height,structure layer,and rod inclination angle on the deformation mode,ballistic performances,and ability to change the ballistic direction of *** results show that the ballistic performances of hourglass lattice sandwich structures are mainly affected by their structural *** this respect,structural parameters optimization of the hourglass lattice sandwich structures enable one to effectively improve their ballistic limit velocity and,consequently,ballistic performances.

关键词： Hourglass lattice sandwich structures Ballistic performances high-velocity Finite element analysis

Experimental observation of spontaneous symmetry breaking in a quantum phase transition

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 34-39页

作者： Wen Ning Ri-Hua Zheng jia-Hao lu Fan wu Zhen-Biao Yang Shi-Biao Zheng Fujian Key Laboratory of Quantum Information and Quantum Optics College of Physics and Information EngineeringFuzhou UniversityFuzhou 350108China Hefei National Laboratory Hefei 230088China

Spontaneous symmetry breaking(SSB)plays a central role in understanding a large variety of phenomena associated with phase transitions,such as superfluid and *** far,the transition from a symmetric vacuum to a macroscopically ordered phase has been substantially *** process bridging these two distinct phases is critical to understanding how a classical world emerges from a quantum phase transition,but so far remains unexplored in *** here report an experimental demonstration of such a process with a quantum Rabi model engineered with a superconducting *** move the system from the normal phase to the superradiant phase featuring two symmetry-breaking field components,one of which is observed to emerge as the classical *** results demonstrate that the environment-induced decoherence plays a critical role in the SSB.

关键词： quantum phase transition Rabi model spontaneous symmetry breaking superconducting circuit Schrodinger cat states