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MICRO-EXPERIMENTAL STUDY OF LARGE PLASTIC DEFORMATION FOR HIGH-PURITY POLYCRYSTALLINE ALUMINUM

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Acta Mechanica Sinica 1991年第4期7卷 360-368页

作者：仲政杨卫黄克智 Currently in the Department of Engineering Mechanics Tongji University. Tsinghua University Beijing 100084China

This paper aims at revealing various micro- deformation characteristics, such as crystalline slip and grain boundary slide, which are recorded under scanning electronic microscope for high-purity aluminum tensile specimen at room temperature. These experimental data provide us direct evidence for shear localization near the grain boundary network via multi- directional grain boundary slide. The nonuniform deformation induced in the grain interiors would have decisive effect on the plastic flow and failure of polycrystalline materials.

关键词： polycrystals large plastic deformation grain boundary sliding micromechanics grid method

Comprehensive Evidence of Octupole Vibration in ^(158)Gd

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Chinese Physics Letters 1999年第12期16卷 870-872页

作者： LONG Gui-lu JI Hua-ying ZHAO En-guang Department of Physics Tsinghua UniversityBeijing 100084 Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100080 Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion AcceleratorChinese Academy of SciencesLanzhou 730000

Comprehensive evidence of the SU(3) octupole vibration limit in the spdf interacting boson model is found in the spectrum, E2 and El transition rates, and relative intensities in 158Gd. This is a good example of a rot... 详细信息

关键词： rare Vibration limit

Numerical Simulation of Viscous Flow Around a Rolling Cylinder with Ship-Like Section

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china Ocean Engineering 1995年第1期10卷 9-18页

作者： Chung, Huaixin Miao, Guoping Liu, yingzhong

Two-dimensional unsteady incompressible viscous flow around a rolling cylinder with ship-like section is numerically simulated by employing the computational scheme previously developed by the authors, in which the continuity and momentum equations are satisfied simultaneously at each time step for oscillating flow. The numerical results show that the motion of vortices around a rolling ship hull is cyclical. It is found that the location of the vortices is very similar to the existing experimental result. Using these simulation results, we can calculate the roll damping of ships including viscous effects.

关键词： viscous flow numerical simulation two-dimensional cylinder rolling motion

Transferability of Charpy Absorbed Energy to Fracture Toughness Based on Weibull Stress Criterion

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Journal of Materials Science & Technology 2005年第1期21卷 1-4页

作者： HongyangJING LianyongXU LixingHUO FumiyoshiMinami SchoolofMaterialsScienceandEngineering TianjinUniversityTianjin300072China OsakaUniversity OsakaJapan

The relationship between Charpy absorbed energy and the fracture toughness by means of the (crack tip opening displacement (CTOD)) method was analyzed based on the Weibull stress criterion. The Charpy absorbed energy and the fracture toughness were measured for the SN490B steel under the ductile-brittle transition temperature region. For the instrumented Charpy impact test, the curves between the loading point displacement and the load against time were recorded. The critical Weibull stress was taken as a fracture controlled parameter, and it could not be affected by the specimen configuration and the loading pattern based on the local approach. The parameters controlled brittle fracture are obtained from the Charpy absorbed energy results, then the fracture toughness for the compact tension (CT) specimen is predicted. It is found that the results predicted are in good agreement with the experimental. The fracture toughness could be evaluated by the Charpy absorbed energy, because the local approach gives a good description for the brittle fracture even though the Charpy impact specimen or the CT specimen is used for the given material.

关键词： Local approach Weibull stress Fracture toughness Charpy absorbed energy

Topological properties of one-dimensional hardcore Bose-Fermi mixture

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Chinese Physics B 2013年第9期22卷 258-262页

作者：贾永飞郭怀明秦吉红陈子瑜冯世平 Department of Physics Beihang University Department of Physics University of Science and Technology Beijing Department of Physics Beijing Normal University

We study the topological properties of a one-dimensional （1D） hardcore Bose-Fermi mixture using the exact diagonalization method. We firstly add a hardcore boson to a fermionic system and by examining the edge states we find that the quasi-particle manifests the topological properties of the system. Then we study a mixture with 7 fermions and 1 boson. We find that the mixture also exhibits topological properties and its behaviors are similar to that of the corresponding fermionic system. We present a qualitative explanation to understand such behaviors using the mapping between a hardcore boson and a spinless fermion. These results show the existence of topological properties in a 1D hardcore Bose-Fermi mixture and may be realized using cold atoms trapped in optical lattices experimentally.

关键词： Bose-Fermi mixture topological insulators

Generation of Three-Dimensional Entangled States for Two Atoms Trapped in Different Cavities

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Chinese Physics Letters 2005年第12期22卷 3064-3066页

作者：郑仕标 Department of Electronic Science and Applied Physics Fuzhou University Fuzhou 350002

We propose a scheme for generating three-dimensional entangled states for two atoms trapped in two separate cavities. The scheme is based on the detection of photons leaking from the cavities after the atom-cavity int... 详细信息

关键词： Atoms

ON THE p-SOLVABILITY OF THE FINITE GROUPS WITH A T.I. SYLOW p-SUBGROUP

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Chinese Science Bulletin 1989年第3期34卷 177-179页

作者：张继平 Mathematics Department Peking University

W. Feit has ever beautifully proved the following theorem by the abstract group theoretic *** 1. Let G be an arbitrary finite group with a cyclic Sylow p-subgroup. If there exists a normal subgroup N of G such that P|... 详细信息

关键词： group solvability T.I. set representation.

Catalytic Asymmetric Cross-Dehydrogenative Coupling of 2H-Chromenes and Aldehydes

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Chinese Journal of Chemistry 2018年第12期36卷 1187-1190页

作者： Xinhui Pan Xigong Liu Shutao Sun Zhilin Meng Lei Liu School of Pharmaceutical Sciences Shandong UniversityJinanShandong 250012China School of Chemistry and Chemical Engineering Shandong UniversityJinanShandong 250100China Key Laboratory of Xinjiang Phytomedicine Resource and Utilization Ministry of EducationSchool of Pharmaceutical SciencesShihezi UniversityShiheziXinjiang 832002China

The first catalytic asymmetric cross‐dehydrogenative coupling of 2H‐chromenes with aldehydes using o‐chloranil (3,4,5,6‐tetrachloro‐1,2‐ benzoquinone) as an oxidant has been described. The organocatalytic process is tolerated with a broad range of structurally and electronically varied 2H‐chromenes and aldehydes with good yield and high enantiocontrol.

关键词： asymmetric catalysis C—H functionalization 2H‐chromene aldehyde oxidation synthetic method

C-Glycoside Synthesis Enabled by Nickel Catalysis

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Chinese Journal of Chemistry 2023年第17期41卷 2217-2236页

作者： Weidong Shang Rong Shi Dawen Niu Targeted Tracer Research and Development Laboratory Institute of Respiratory HealthState Key Laboratory of Biotherapy and Cancer Center West China Hospital and Schoolof Chemical EngineeringSichuan UniversityChengduSichuan 610041China State Key Laboratory of Biotherapy and Cancer Center West China Hospital and Department of Chemical EngineeringSichuan UniversityChengduSichuan 610041China

Comprehensive Summary,C-Glycosides are critical,naturally occurring products and medicinal candidates,and extensive efforts have been made to explore efficient approaches for creating C-glycosidic ***-metal-catalysis,particularly nickel-catalyzed C-glycosylation reactions constitute a promising ***,achieving a stereoselective synthesis ofα-andβ-C-glycosides has been a long-standing *** address this problem,a variety of nickel-mediated strategies have been *** review highlights recent developments in the nickel-catalyzed diastereoselective C-glycosylation reactions and briefly summarizes the mechanistic understandings of these methods.

关键词： C-Glycosides Nickel Glycosylation Glycosyl radical Carbohydrates