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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

Numerical Simulation on Carburizing and Quenching of Gear Ring

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Journal of Iron and Steel Research International 2007年第6期14卷 47-52页

作者： SONG Guang-sheng LIU xiang-hua WANG Guo-dong XU xiang-qiu Materials Engineering Department Shenyang Institute of Aeronautical Engineering Shenyang 110034 Liaoning China State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China Research and Development Center FAW Group Corporation Changchun 100034 Jilin China

The carburizing process of the gear ring was simulated by taking into account the practical carburizing and quenching techniques of the gear ring and by solving the diffusion equation. The carbon content distribution in the carburized layer was obtained. Based on the results, the quenching process of the gear ring was then simulated using the metallic thermodynamics and FEM： it was found that the carburization remarkably affects the quenching process. Microstructures and stress distributions of the gear ring in the quenching process were simulated, and the results are confirmed by experiments.

关键词： carburization FEM quenching martensite transformation residual stress

Permissible Minimum Thickness in Asymmetrical Cold Rolling

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Journal of Iron and Steel Research International 2013年第11期20卷 21-26页

作者： TANG De-lin LIU xiang-hua LI xiang-yu PENG Liang-gui State Key Laboratory of Rolling and Automation Laboratory Northeastern University

The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling force equation by slab method. An implicit expression of the minimum rolling thickness was then derived from the rolling force equation and Hitehcock equation. The results show that permissible minimum rolling thickness of asymmetrical rolling only exists within a specific range of cross-shear ratio, which is termed the cross-shear zone proportion of the whole de- formation zone. Numerical computation was carried out to obtain a discrete solution of the minimum rolling thick- ness. Experiments were designed to investigate the influence factors on cross-shear ratio. Finally, experimental re- sults prove the correctness of the improved formula given.

关键词： asymmetrical roiling minimum permissible thickness cross-shear ratio asymmetrical ratio friction peak value

Relationship Among Microstructure and Properties and Heat Treatment Process of Ultra-High Strength X120 Pipeline Steel

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Journal of Iron and Steel Research International 2011年第3期18卷 59-64页

作者： ZHOU Min DU Lin-xiu LIU xiang-hua State Key Laboratory of Rolling Technology and Automation Northeastern UniversityShenyang 110004LiaoningChina

The variation of heat treatments including directed quenching and tempering off-line after controlled rolling（DQT） and quenching off-line and tempering off-line after controlled rolling（RQT） with microstructure and mechanical properties of a low-carbon microalloyed steel was compared and *** DQT,the quenched steel was obviously banded microstructure,with increasing tempering temperature,lath martensite coarsened,the cusp carbide precipitated at grain boundaries,the yield strength fluctuated slightly,and the fracture-separation was *** impact toughness was better in the steel tempered at 500 ℃ for 1 *** RQT,with increasing tempering temperature,lath martensite degenerated,intragranular and intergranular finer precipitations with smaller than 30 nm precipitated and grew up and were distributed dispersedly,the stripe-like carbides were distributed at grain boundaries,and the yield strength and tensile strengthen decreased *** impact toughness of RQT process was much better than that of DQT process,and the comprehensive mechanical properties were better for the steel tempered at 500 ℃ for 1 h of RQT process.

关键词： X120 pipeline steel heat treatment microstructure mechanical property fracture-separation

Isolation and Manipulation of Quantitative Trait Loci for Disease Resistance in Rice Using a Candidate Gene Approach

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Molecular Plant 2008年第5期1卷 786-793页

作者： Ke-Ming Hu De-Yun Qiu xiang-Ling Shen xiang-hua Li Shi-Ping Wang National Key Laboratory of Crop Genetic Improvement National Center of Plant Gene Research (Wuhan) Huazhong Agricultural University Wuhan 430070 China

Bacterial blight caused by Xanthomonas oryzae pv. oryzae and fungal blast caused by Magnaporthe grisea result in heavy production losses in rice, a main staple food for approximately 50% of the world＇s population. Application of host resistance to these pathogens is the most economical and environment-friendly approach to solve this problem. Quantitative trait loci （QTLs） controlling quantitative resistance are valuable sources for broad-spectrum and durable disease resistance. Although large numbers of QTLs for bacterial blight and blast resistance have been identified, these sources have not been used effectively in rice improvement because of the complex genetic control of quantitative resistance and because the genes underlying resistance QTLs are unknown. To isolate disease resistance QTLs, we established a candidate gene strategy that integrates linkage map, expression profile, and functional complementation analyses. This strategy has proven to be applicable for identifying the genes underlying minor resistance QTLs in rice-Xoo and rice-M, grisea systems and it may also help to shed light on disease resistance QTLs of other cereals. Our results also suggest that a single minor QTL can be used in rice improvement by modulating the expression of the gene underlying the QTL. Pyramiding two or three minor QTL genes, whose expression can be managed and that function in different defense signal transduction pathways, may allow the breeding of rice cultivars that are highly resistant to bacterial blight and blast.

关键词： bacterial blight blast Oryza sativa quantitative resistance QTL.

Alternative non-Gaussianity measures for quantum states based on quantum fidelity

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Chinese Physics B 2022年第3期31卷 192-200页

作者： Cheng xiang Shan-Shan Li Sha-Sha Wen Shao-hua xiang College of Electrical and Information Engineering Huaihua UniversityHuaihua 418008 China Hunan Provincial Key Laboratory of Ecological Agriculture Intelligent Control Technology Huaihua 418008China

We propose three alternative measures for non-Gaussianity of quantum states: sine distance, Bures angle, and Bures distance, which are based on quantum fidelity introduced by Wang [Phys. Lett. A 373 58(2008)]. Using them, we evaluate the non-Gaussianity of some relevant single-mode and two-mode non-Gaussian states and find a good consistency of the three examined measures. In addition, we show that such metrics can exactly quantify the degree of Gaussianity of even Schrödinger-cat-like states of small amplitudes that can not be measured by other known non-Gaussianity measures such as the Hilbert–Schmidt metric and the relative entropy metric. We make a comparative study between all existing nonGaussianity measures according to the metric axioms and point out that the sine distance is the best candidate among them.

关键词： non-Gaussianity quantum fidelity non-Gaussian states sine metric

Self-Learning Algorithm for Coiling Temperature Controlling

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Journal of Iron and Steel Research International 2004年第6期11卷 30-32页

作者： WANG Jun WANG Guo-dong LIU xiang-hua ZHANG Dian-hua Northeastern University

A novel model of the evolution of microstructure during continuous cooling with the formation of proeutectoid ferrite in steel was proposed from a Voronoi construction for the austenite grains, based on the Rappaz′s integral nucleation model and the assumption that the ferrite nucleates at the edges of the original austenite grains and the successive growth of the ferrite grain is radial. The model can be used to calculate the fraction of ferrite as a function of time or temperature during continuous cooling, and to determine the microstructure of ferrite. The calculated results are in agreement with experimental results investigated in 0 38C-0 28Si-0 55Mn-0 92Cr-0 20Mo steel under continuous cooling using a Gleeble 1500 thermomechanical simulator.

关键词： proeutectoid ferrite Voronoi construction integral nucleation model continuous cooling

On the Structure of Quantum Toroidal Superalgebraε_(m|n)

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Acta Mathematica Sinica,English Series 2023年第11期39卷 2117-2138页

作者： xiang hua WU Hong Da LIN Hong Lian ZHANG Department of Mathematics Shanghai UniversityShanghai 200444P.R.China Newtouch Center for Mathematics of Shanghai University Shanghai 200444P.R.China

Recently the quantum toroidal superalgebraε_(m|n)associated with gl_(m|n)was introduced by *** and ***,which is not a quantum Kac-Moody *** quantum toroidal superalgebraε_(m|n)exploits infinite sequences of generators and relations of the form,which are called Drinfeld *** this paper,we use only finite set of generators and relations to define an associative algebraε'_(m|n)and show that there exists an epimorphism fromε'_(m|n)to the quantum toroidal superalgebraε_(m|n).In particular,the structure ofε'_(m|n)enjoys some properties like Drinfeld-Jimbo realization.

关键词： Quantum toroidal superalgebra Drinfeld realization Lie superalgebra

X-Ray Properties of PSR J1811-1925 by Nu STAR

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Research in Astronomy and Astrophysics 2023年第11期23卷 51-59页

作者： Jin-Tao Zheng Ming-Yu Ge xiang-hua Li Department of Astronomy Yunnan UniversityKunming 650090China Key Laboratory for Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

We analyzed the spectral properties and pulse profile of PSR J1811-1925,a pulsar located in the center of composite supernova remnant(SNR)G11.2-0.3,by using high timing resolution archival data from the Nuclear Spectroscopic Telescope Array Mission(NuSTAR).Analysis of archival Chandra data over different regions rules out the SNR shell as the site of the hard X-ray emission while spectral analysis indicates that the NuSTAR photons originate in the pulsar and its *** pulse profile exhibits a broad single peak up to 35 *** jointed spectrum by combining NuSTAR and Chandra can be well fitted by a power-law model with a photon index ofΓ=1.58±*** integrated flux of jointed spectrum over 1-10 keV is 3.36×10^(-12)erg cm^(-2)s^(-1).The spectrum of pulsar having photon indexΓ=1.33±0.06 and a 1-10 keV flux of 0.91×10^(-12)erg cm^(-2)s^(-1).We also performed the phase-resolved spectral analysis by splitting the whole pulse-on phase into five phase *** photon indices of the bins are all around 1.4,indicating that the photon index does not evolve with the phase.

关键词： (stars:)pulsars:individual(PSR J1811-1925) stars:neutron methods:data analysis