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Symmetric or asymmetric glide resistance to twinning disconnection?

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npj Computational Materials 2022年第1期8卷 1615-1621页

作者： Mingyu Gong Houyu Ma Kunming Yang Yue Liu Jian-Feng Nie Jian Wang State Key Lab of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200240P.R.China Department of Materials Science and Engineering Monash UniversityClaytonVIC3800Australia Department of Mechanical&Materials Engineering University of Nebraska-LincolnLincolnNE68583USA

Successive gliding of twinning disconnections(TDs)creates three-dimensional twins in parent crystal and accommodates shear *** is generally recognized that TD is subject to the same Peierls stress as it glides forward or backward because of its dislocation character and the twofold rotation symmetry of the twin *** on atomistic simulations,we demonstrate that the glide of TDs may be subject to a symmetric or asymmetric resistance corresponding to step character,symmetric resistance for A/A type steps but asymmetric resistance for A/B type steps,where A and B represent crystallographic planes in twin and ***,we experimentally demonstrate that the asymmetric resistance results in asymmetric propagation and growth of twins in Mg alloys.

关键词： resistance deformation. steps

deformation.in the Three Gorges Reservoir after the first impoundment determined by GPS measurements

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Progress in Natural Science:Materials International 2005年第6期15卷 515-522页

作者： DU Ruilin 1,2 , QIAO Xuejun 1,2 *, WANG Qi 1,2 , XING Canfei 1,2 and YOU Xinzhao 1,3 (1. Institute of Seismology, CEA, Wuhan 430071, China 2. Laboratory of Crustal Movement and Earth Observation, Wuhan 430071, China 3. Center for Analysis and Prediction, CEA, Beijing 100036, China) Institute of Seismology CEA Wuhan 430071 China Laboratory of Crustal Movement and Earth Observation Wuhan 430071 China Center for Analysis and Prediction CEA Beijing 100036 China

A 6-year long GPS observation (1998—2003) indicates that crustal deformation.in the Three Gorges area is less active at a marginally measurable rate of 0—5 mm/a relative to stable South China block. However, the impounding water in June 2003 has induced transient displacement at the Three Gorges dam and the emerging reservoir. GPS measurements after the first stage of water filling of the reservoir demonstrate that vertical subsidence close by Yangtze River is about 10—40 mm, and the horizontal displacement is less than 5—10 mm. The maximum subsidence induced by the impoundment is located in the segment of the reservoir from Maoping to Xiangxi. The water loading-induced deformation.diminishes rapidly with the distance from banks of the reservoir. The overall pattern of transient deformation.is consistent with the simulation result of Farrell, and is attributed to the elastic response of upper lithosphere crust to overlying water reservoir.

关键词： Three Gorges GPS impoundment deformation.

Experimental study about nano-deformation.field near quasi-cleavage crack tip

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Science China Mathematics 2000年第9期43卷 963-968页

作者：邢永明戴福隆杨卫FML Department of Engineering Mechanics Tsinghua University Beijing 100084 China

Using the nano-moiré method, we measure the near tip nanoscopic deformation.on the [111] plane of single crystal silicon with a loaded quasi-cleavage crack running in the [110] direction. The measured strain distribution ahead of the crack tip agrees with the linear elastic fracture mechanics prediction up to 10 nm from the crack tip. Dislocations of Peierls type are detected and they extend from the crack tip over a length of hundreds of Burgers vectors.

关键词： nano-moiré method brittle materials crack tip Peierls dislocation deformation.

Tensile and compression properties of Zr-based bulk amorphous alloy at different temperatures

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Science China(Technological Sciences) 2005年第5期48卷 489-495页

作者： WANG Xu1,3, LOU Decheng1, GAO Zhanjun4, LIU Lei1, LIANG Hongmei1, WANG Qingfeng1, LI Qiang1,3 & MA Mingzhen1,2 1. Key Laboratory of Metastable Materials Science & Technology of Hebei, Yanshan University, Qinhuangdao 066004, China 2. National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001, China 3. College of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China 4. Chinese Academy of Engineering, Beijing 100038, China Key Laboratory of Metastable Materials Science & Technology of Hebei Yanshan University

Mechanical properties of the Zr41Ti14Cu12.5Ni10Be22.5 bulk amorphous alloy at different temperatures were investigated. The compression test was carried out on a Gleebe-3200 machine at 345 and 375°C, respectively, in the supercooled liquid region. It is shown that decreasing the compressive rate and increasing temperature have a similar influence trend on the compressive behavior of the bulk amorphous alloy. Room and low temperature tensile strengths were tested on the Instron materials testing system. At low temperature, the tensile strength decreased with decreasing of the testing temperature. Hardness measurement indicated that below the glass transition temperature, the hardness decreased with increasing of the annealing temperature and duration time. It, however, increased when the annealing treatment was performed above the glass transition temperature.

关键词： Zr41Ti14Cu12.5Ni10Be22.5 bulk amorphous alloy, mechanical properties, compressive deformation.

Research on deformation. Texture and Properties of IF Steel in Multiple Rolling Technology

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Journal of Materials Science & Technology 2003年第2期19卷 183-184页

作者： Jinxia LI, Xianghua LIU and Guodong WANGState Key Lab. of Rolling and Automation, Northeastern University, Shenyang 110004, China Lab. of Rolling and Automat. Northeastern Univ. Shenyang 110004 China

The relationships among the deformation. texture and deep drawing properties of IF steel were investigated. By adopting double cold rolling (DCR) technology, the deep drawing property has been developed evidently. With the aid of orientation distribution function (ODF) analysis, it was found that he main reason for good property is the counterbalance in intensity of the ideal texture component {111} and {111} .

关键词： Texture Double cold rolling r-value deformation.

Generalized Coupled-Mode Formulation for Sound Propagation in Range-Dependent Waveguides

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Chinese Physics Letters 2012年第1期29卷 168-171页

作者： LUO Wen-Yu YANG Chun-Mei ZHANG Ren-He State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190 Graduate University of Chinese Academy of Sciences Beijing 100049

An accurate and numerically stable method based on the coupled-mode theory is *** applying the direct global matrix approach to obtain the modal expansion coefficients,this method is numerically *** addition,appropriately normalized range solutions are introduced,which resolves the overflow problem ***,we put forward source conditions appropriate for the line-source problem in plane *** a result,this method is capable of dealing with the scenario where a line source is located inside the region of a ***-form expressions for coupling matrices are provided for ideal *** results indicate that the present method is accurate and numerically ***,this model can serve as a benchmark in range-dependent propagation modeling.

关键词： deformation. entirely dealing

Measurement of gear tooth dynamic deformation.using dynamic speckle photography

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Chinese Science Bulletin 1998年第6期43卷 514-518页

作者： Jianfeng Li Xing Ai Zhiren Tian Shandong Univ Technol Jinan 250061 Peoples R China

A new method of measuring gear tooth dynamic deformation.is proposed. Dynamic speckle photographs of the rotating gear tooth have been achieved by combining the pulsed ruby laser with the out-syn-signal. Double speckle patterns of the whole mesh period of gear tooth are obtained by accurate time delay of the ruby laser. Gear tooth dynamic deformation.of the whole mesh period is achieved using the automatic image processing. Testing results show that the trends of gear tooth deformation.coincides with the calculation by the finite element method. The success of this new trying provides a new technique for the measurement of gear tooth dynamic deformation.

关键词： pulsed ruby laser dynamic speckle photography image process gears deformation.

Response of an old landslide to reservoir filling: A case history

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Science China(Technological Sciences) 2005年第z1期48卷 27-32页

作者： L.G. Tham C.F. Lee Department of Civil Engineering University of Hong Kong Hong Kong China

Unfavorable hydrodynamic evolution is considered as the major cause leading to reservoir slope instability and is often modeled by numerical method. However, this simulation is seldom checked by systematic field instrumentation. Taking the opportunity of filling the Three Gorges Reservoir, a system was established in Xietan landslide to monitor reservoir water level, subground water level, seepage pressure, rainfall and deformation. etc. The monitored data during reservoir filling shows that: (1) The water level rise in the bank lags behind the reservoir filling and the lag time depends on the bank permeability; (2) rainfall-induced subground water rise and its lag time is closely correlated to hourly rainfall, indicating that it is not feasible or sufficient to use daily rainfall for analysis; (3) the effect of inverse seepage during reservoir filling on stability is ephemeral and reservoir filling is the major cause leading to bank instability.

关键词： reservoir filling, old landslide, monitoring system, water level, deformation.

Textural and chemical zoning in garnets related to mantle metasomatism and deformation.processes

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Chinese Science Bulletin 2000年第2期45卷 174-180页

作者： ZHANG Hongfu Menzies M.A. ZHOU Xinhua LU Fengxiang Laboratory of Lithosphere Tectonic Evolution Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China Depement of Geology Royal Holloway University of London EghamSurrey TW20 0EXUK China University of Geosciences Wuhan 430074China

A few texturally-zoned garnets were found in a polymict peridotite (JJG1414) from the Cretaceous kimberlite, Kimberley South Africa. The systematic analyses of electron and ion microprobe as well as laser fluorination technique reveal the existencal of marked elemental and oxygen isotopic zonation in these gamed. corresponding to the textural zonation. The rims are normally enriched in Ca, Ti, Cr, LREE. Sr, Nb, and depleted in Mg, Al and 18O. It is demonstrated that these gamats were infiltrated by melts/fiuids, probably representing the disequilibrated products of fluid-asssted mantle deformation.

关键词： South African kimberlite polymict xenolith garnet zoning mantle. metasomatism and deformation.