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Shear band evolution and mechanical behavior of cold-rolled Zr-based amorphous alloy sheets:An in-situ study

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Journal of Materials Science & Technology 2024年第14期181卷 115-127页

作者： C.y.Zhang Z.W.Zhu S.T.li y.y.Wang Z.K.li H.li G.yuan H.F.Zhang School of Metallurgy Northeastern UniversityShenyang 110819China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China The State Key Laboratory of Rolling and Automation(RAL) Northeastern UniversityShenyang 110819China

Cold rolling process can regulate the microstructure and mechanical properties of amorphous alloys,but it is still a challenging task to reveal their microscopic ***,we designed an in-situ SEM observation device for the cold rolling process of amorphous alloy,and visually observed the formation and evolution of shear bands during single-pass and multi-pass rolling process of the Zr_(55)Cu_(30)Al_(10)Ni_(5)amorphous alloy *** is found that the evolution process of shear bands in the rolling process of amorphous alloy shows heritability,which is mainly reflected in two aspects:one is that the shear band formation pattern in the single-pass rolling process is more inclined to inherit the previous shear band formation pattern;the other is that the shear deformation is more likely to occur in the pre-existing shear bands in the multi-pass rolling *** rule can be used to guide the controlled genera-tion of shear bands in amorphous ***,we emphasized the importance of pre-existing shear band orientations and systematically investigated the mechanical behavior of the amorphous alloys with pre-existing shear bands by in-situ SEM *** is found that the mechanical properties of the as-rolled amorphous alloys are determined by the competition between the work-softening of the pre-existing shear band itself and the work-hardening caused by the blocking effect of the pre-existing shear bands on the shear *** on this,we enhance the tensile fracture strength and the tensile ductility of the amorphous alloy by adjusting the orientation of the pre-existing shear bands parallel to the tensile stress axis so that the pre-existing shear bands prevent the linear propagation and destruction of the new shear bands.

关键词： Amorphous alloy Cold rolling Shear band Mechanical behavior In-situ study Plasticity

Gyrofluid Simulation of Ion-Scale Turbulence in Tokamak Plasmas

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Communications in Computational Physics 2008年第10期4卷 1245-1257页

作者： Jiquan li y.Kishimoto Graduate School of Energy Science Kyoto UniversityUjiKyoto 611-0011Japan Institute for Fusion Theory and Simulation ZhejiangUniversityHangzhouChina

An improved three-field gyrofluid model is proposed to numerically simulate ion-scale turbulence in tokamak plasmas,which includes the nonlinear evolution of perturbed electrostatic potential,parallel ion velocity and ion pressure with adiabatic electron *** is benchmarked through advancing a gyrofluid toroidal global(GFT G)code as well as the local version(GFT L),with the emphasis of the collisionless damping of zonal *** nonlinear equations are solved by using Fourier decomposition in poloidal and toroidal directions and semi-implicit finite difference method along radial *** numerical implementation is briefly explained,especially on the periodic boundary condition in GFT L *** a numerical test and also practical application,the nonlinear excitation of geodesic acoustic mode(GAM),as well as its radial structure,is investigated in tokamak plasma turbulence.

关键词： Geodesic acoustic mode(GAM) zonal flow ion temperature gradient(ITG)turbulence gyrofluid simulation tokamak

Performance assessment of innovative seismic resilient steel knee braced frame

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Frontiers of Structural and Civil Engineering 2016年第3期10卷 291-302页

作者： Tony T. y. y.ng yuanjie li International Joint Research Laboratory of Eearthquake Engineering 1239 Siping Road Shanghai 200002 China Department of Civil Engineering University of British Columbia Vancouver BC V6T1Z4 Canada

Buckling restrained knee braced truss moment frame （BRKBTMF） is a novel and innovative steel structural system that utilizes the advantages of long-span trusses and dedicated structural fuses for seismic applications. Steel trusses are very economical and effective in spanning large distance. However, conventional steel trusses are typically not suitable for seismic application, due to its lack of ductility and poor energy dissipation capacity. BRKBTMF utilizes buckling restrained braces （BRBs） as the designated structural fuses to dissipate the sudden surge of earthquake energy. This allows the BRKBTMF to economically and efficiently create large span structural systems for seismic applications. In this paper, a prototype BRKBTMF office building located in Berkeley, California, USA, was designed using performance-based plastic design procedure. The seismic performance of the prototype building was assessed using the state-of-the-art finite element software, OpenSees. Detailed BRB hysteresis and advanced element removal technique was implemented. The modeling approach allows the simulation for the force-deformation response of the BRB and the force redistribution within the system after the BRBs fracture. The developed finite element model was analyzed using incremental dynamic analysis approach to quantify the seismic performance of BRKBTMF. The results show BRKBTMF has excellent seismic performance with well controlled structural responses and resistance against collapse. In addition, life cycle repair cost of BRKBTMF was assessed using the next-generation performance-based earthquake engineering framework. The results confirm that BRKBTMF can effectively control the structural and non-structural component damages and minimize the repair costs of the structure under different ranges of earthquake shaking intensities. This studies conclude that BRKBTMF is a viable and effective seismic force resisting system.

关键词： buckling restrained brace innovative structural system collapse simulation seismic assessment

Photoisomerization of norbornadiene group in a rigid bichromophoric compound initiated by remote keto chromophore: long-distance through-bond triplet energy transfer

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Chinese Journal of Chemistry 1996年第4期14卷 377-380页

作者： Tung, CH Zhang, LP li, y CHINESE ACAD SCI INST PHOTOG CHEMBEIJING 100101PEOPLES R CHINA

A diad compound 3 beta(bicyclo[2,2,1]hepta-2,5-diene-2-methylcarboxylate-3-carboxy)-androst-5-en-17-one (NBD-S-ONE) was synthesized and its photochemistry was examined. Irradiation of NBD-S-ONE in acetonitrile at lambda > 300 nm selectively excited the keto chromophore. After intersystem crossing, the triplet energy of the keto group was transferred to the NBD group with 18.6% efficiency via a through-bond mechanism, resulting in the isomerization of the latter group to the quadricyclane group.

关键词： norbornadiene photoisomerization through-bond triplet energy transfer

Reactive destabilization and bidirectional catalyzation for reversible hydrogen storage of liBH_(4) by novel waxberry-like nano-additive assembled from ultrafine Fe_(3)O_(4) particles

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Journal of Materials Science & Technology 2024年第6期173卷 63-71页

作者： S.Wang M.H.Wu y.y.Zhu Z.L.li y.X.y.ng y.Z.li H.F.liu M.X.Gao Department of Material Science Shenzhen MSU-BIT UniversityShenzhen 518172China State Key Laboratory of Silicon and Advanced Semiconductor Materials&School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China Institute of Resources Utilization and Rare Earth Development State Key Laboratory of Rare Metals Separation and Comprehensive UtilizationGuangdong Provincial Key Laboratory of Rare Earth Development and ApplicationGuangdong Academy of SciencesGuangzhou 510650China Institute of Science and Technology for New Energy Xi’an Technological UniversityXi’an 710021China National Supercomputing Center in Shenzhen Shenzhen 518055China

liBH_(4) containing 18.5 wt.%H_(2) is an attractive high-capacity hydrogen storage material,however,it suffers from high operation temperature and poor ***,a novel and low-cost bifunctional additive,waxberry-like Fe_(3)O_(4) secondary nanospheres assembled from ultrafine primary Fe_(3)O_(4) nanoparticles,is synthesized,which exhibits significant destabilization and bidirectional catalyzation towards(de)hydrogenation of liBH_(4).With an optimized addition of 30 wt.% waxberry-like Fe_(3)O_(4),the system initiated dehydrogenation below 100℃ and released a total of 8.1 wt.%H_(2) to 400℃.After 10 cycles,a capacity retention of 70% was achieved,greatly superior to previously reported oxides-modified *** destabilizing and catalyzing mechanisms of waxberry-like Fe_(3)O_(4) on liBH_(4) were systematically analyzed by phase and microstructural evolutions during dehydrogenation and hydrogenation cycling as well as density functional theory(DFT)*** present work provides new insights in developing advanced nano-additives with unique structural and multifunctional designs towards liBH4 hydrogen storage.

关键词： liBH_(4) Hydrogen storage Waxberry-like Fe_(3)O_(4) Destabilization Catalysis

EFFECT　OF　ANNEAling　ON　MICROSTRUCTURE　OF　AROMATIC　liQUID　CRySTALliNE　COPOLyESTERS

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Chinese Chemical Letters 1996年第1期7卷 73-74页

作者： Wang, y Wu, DC li, RX SICHUAN UNION UNIV COLL TEXTCHENGDU 610065PEOPLES R CHINA

The effects of thermal treatment on microstructure of the Polyesters were studied. Annealing below Tc-n, physical diffusion PrOCesses dominate to yield an increasing crystallinity along with increased molecular weight transesterification reactions are limited to the end groups and the microstructure had not changed Annealing near Tc-n, chemical processes dominate and simultaneously make the microdomains ordered more perfectly. Analysis by 13C NMR Proved that interchain transesterification had occurred.

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HCV genotypes in hepatitis C patients and their clinical significances

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World Journal of Gastroenterology 1999年第6期5卷 547-549页

作者： Huang F Zhao GZ li y China Med Univ Affiliated Hosp 2 Dept Infect Dis Shenyang 110003 Liaoning Prov Peoples R China

INTRODUCTIONIt has been discovered that hepatitis C virus (HCV) presents considerable nucleotide variation and has many genotypes. At least twelve, 5 of which prevalent, i.e.: Ⅰ/1a, Ⅱ/1b, Ⅲ/2a, Ⅳ/2b, and Ⅴ/3a types. The different genotypes of HCV may possess some retationship with regional distribution, clinical manifestation, response to treatment and prognosis of HCV infection, thus to study the genotypes of HCV further in different areas is of practical value. We detected HCV genotypes in 94 patients with hepatitis C and in 6 patients with primary hepatocarcinoma by PCR assay with four kinds of type-specific primers with a view to study the distribution of HCV genotypes in hepatitis C in Sheny.ng area and their clinical significances.

关键词： hepatitis C hepatitis C virus genotyping

Dielectric Behavior of Middle Phase Microemulsion

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Chinese Chemical Letters 2000年第8期11卷 739-742页

作者： Lei, JP li, y Zhao, KS S China Normal Univ Dept Chem Guangzhou 510631 Peoples R China

Dielectric measurements were performed on middle phase microemulsions composed of sodium dodecylsulfate(SDS), cetyltrimethylammonium bromide(CTAB), n-butanol, n-heptane and brine. Distinct and unique dielectric behavior, with characteristic frequency dependence regularity on the salinity of the microemulsions, was observed in the low-frequency range from 10-10(3)Hz. It can be considered to be an interfacial polarization mechanism.

关键词： middle phase microemulsions dielectric spectroscopy relaxation time

Progresses and problems in nano-tribology

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Chinese Science Bulletin 1998年第5期43卷 369-378页

作者： LawrenceK.y.li PatrickL.Wong State Key Laboratory of Tribology Tsinghua University Beijing China City University of Hong Kong Kowloon Hong Kong

The recent development in the four areas of nano-tribology is analysed. They are micro- and nano-friction and wear, micro- and nano-tribological engineering. The research methods in nano-tribology and thin film lubrication in which five branches are included: equivalent viscusity and flowing characteristics of micro fluid, the transition between ordered molecular film and disordered one, the essence of matrix influence on thin film lubrication, the lubrication mechanism of high polymer lubricants and the problem of superlubricity. Meanwhile, more than 35 problems are proposed which should be solved in the future.

关键词： micro-nanotribology thin film lubrication nano-tribology measuring technique at nanometer scale.