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Semi-solid Casting of High Speed Steel Ingots Using Inclined Slope Pre-crystallization Method

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Journal of Wuhan University of Technology(Materials Science) 2009年第5期24卷 750-752页

作者：和优锋 State Key Laboratory for Fabrication and Process of Nonferrous Metals General Research Institute for Nonferrous Metals

Semi-solid casting of M2.high speed steel ingots was investigated by inclined slope pre-crystallization method. Effects of casting temperature and slope length on the microstructure of M2.HSS ingots were investigated. M2.cast ingots of non-dendritic primary austenite and fine eutectic ledeburite network carbide structure were obtained, with the casting temperature, slope length and angle of 1480 ℃, 500 mm and 60° respectively. Meanwhile, the microstructure of cast samples was quantitatively assessed by Image tool software. Results show that optimum mean equivalent diameter of primary austenite crystal grain is 50.8 μm, shape factor is 0.83, and mean thickness of network carbide is 5.2. μm.

关键词： M2.high speed steel semi-solid pre-crystallization inclined slope

A three-dimensional k-ε-k_p model in curvilinear coordinates for sediment movement and bed evolution

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Science China(Technological Sciences) 2009年第4期52卷 1090-1100页

作者： SHEN YongMing1 & LIU Cheng2.1 State Key Laboratory of Coastal and Offshore engineering, Dalian University of Technology, Dalian 11602., China 2.Pearl River Hydraulic research {2., Guangzhou 510611, China State Key Laboratory of Coastal and Offshore engineering Dalian University of Technology Dalian 116023 China Pearl River Hydraulic research institute Guangzhou 510611 China

To aim at the substitution of the magnitude and direction of water flow movement near bed for those of bed load transport in solid-liquid two-phase one-fluid model, and to simulate the effect of secondary flow on transverse bed load transport in channel bends and the effect of bed slope on bed load trans- port in a better way, a three-dimensional k-ε-kp solid-liquid two-phase two-fluid model in curvilinear coordinates is solved numerically with a finite-volume method on an adaptive grid for studying wa- ter-sediment movements and bed evolution in a 12.° channel bend. Numerical results show that the trajectories of solid-phase deviate from those of liquid-phase in the channel bend, and the deviation increases with the increase of the particle diameters. The calculated bed deformation by the k-ε-kp model is in better agreement with measured bed deformation than those by one-fluid model. It is proved that the k-ε-kp model can simulate the effect of secondary flow on lateral bed load transport with the higher accuracy than the one-fluid model.

关键词： curvilinear coordinates three-dimensional k-ε-kp model two-fluid model solid-liquid flows channel bend bed load bed evolution tra- jectory

Dragload and Downdrag Performances of Inclined Pile Group Embedded in Consolidating Soil

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Transactions of Tianjin University 2011年第3期17卷 175-180页

作者：孔纲强杨庆 Key Laboratory for Geomechanics and Embankment engineering of Ministry of Education Geotechnical Research Institute Hohai University State Key Laboratory of Coastal and Offshore engineering Dalian University of Technology

The performance of inclined pile group embedded in consolidating soil under surcharge load was investigated by experiment in comparison with vertical pile group and single pile under the same conditions; dragload, downdrag, and layered soil settlement were measured. A three-dimensional numerical model was built via FLAC3D software, and verified by the experimental results. Influence factors, such as consolidation time, pile spacing, and pile tilt angle were analyzed. The results show that dragload of inclined pile group increases with the increase of consolidation time and pile spacing or the decrease of pile tilt angle. Downdrag of inclined pile group increases with the increase of consolidation time, pile spacing and pile tilt angle.

关键词： pile group negative skin friction consolidating soil downdrag dragload neutral plane

Preparation and characterization of nitrogen-doped titanium dioxides

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Science China Chemistry 2007年第2期50卷 212-216页

作者： ZHU GuoPing1 & ZHOU KangGen2.1 Environmental Science research & Design institute of Zhejiang Province,Hangzhou 310007,China 2.Department of Environmental {2.,School of Metallurgical Science and {2.,Central South University,Changsha 410083,China 1. Environmental Science research & Design institute of Zhejiang Province Hangzhou 310007 China 2. Department of Environmental engineering School of Metallurgical Science and Engineering Central South University Changsha 410083 China

A type of high visible-light active titanium oxinitride(TiO2.xNx) powder was prepared by a simple proc-ess:the calcination of the hydrated titanium dioxide at the atmosphere of ammonia-argon using a tu-bular electric furnace at high temperatures. The hydrated titanium dioxide was synthesized as the precursor of TiO2.xNx using titanic acid as raw material,which came from sulfate technique of produc-ing titanium white. The effects of temperature and reaction time on the nitrogen content,grain size and crystal structure were studied. The visible-light activity and photocatalysis capability of the powder were also investigated.

关键词： nitrogen-doped titanium dioxides visible-light activity photocatalysis titanium oxinitride

Properties of Leakage Corrosion of Concrete and Its Durability

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Journal of Wuhan University of Technology(Materials Science) 2008年第6期23卷 946-949页

作者：戈雪良 Department of Materials and Structural engineering Nanjing Hydraulic Research Institute

The properties and mechanism of concrete under water leakage corrosion were studied in terms of the dissolution of calcium oxide and silicon oxide from concrete and the variation of pH value of permeate *** experimental results show that the amount of calcium oxide and silicon oxide dissolved from per cubic meter of concrete gradually decrease with penetration time and ultimately stabilize at a certain *** pH value of permeate water descend along with penetration *** durability of concrete under leakage corrosion was analyzed by a formula fitted on the dissolved amount of calcium oxide.

关键词： concrete leakage corrosion properties durability

Study of control effects of vortex generators on a supercritical wing

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Science China(Technological Sciences) 2010年第8期53卷 2038-2048页

作者： HUANG JingBo 1 ,XIAO ZhiXiang 1 ,FU Song 1 &ZHANG Miao 2.1 School of Aerospace engineering,Tsinghua University,Beijing 100084,China 2.Shanghai Aircraft Design and research {2. of COMAC,Shanghai 2.02.2.China 1. School of Aerospace engineering Tsinghua University Beijing 100084 China2. Shanghai Aircraft Design and Research Institute of COMAC Shanghai 200232 China

Flows around vortex generators(VGs),which serve as one of the important flow control methods,are investigated by solving Reynolds-averaged Navier-Stokes(RANS)*** influences on the main flow of VGs are intended to ***, the flow around a single VG on a flat plane is computed to validate the schemes and to acquire basic knowledge of this kind of ***,transonic flow past a standard model,named by ONERA-M6 wing,is predicted to investigate the flow features of shockwave/boundary-layer interactions(SWBLI).Thirdly,the effects of a row of VGs mounted about 2.%local chord on a supercritical wing are analyzed in transonic condition with strong ***,VGs are mounted more upwind(about 3.5%local chord)to explore the effects at low speed and high incidence *** numerical results show that seven VGs can effectively suppress the separations behind the strong SWBLI and decrease spanwise flow and wing-tip vortex in transonic *** also can decrease the large scope of separation over the wing at low speed with high angle of attack.

关键词： supercritical wing vortex generator(VG) shockwave/boundary-layer interactions(SWBLI)

Computer Simulation of the Indentation Creep Tests on Particle-Reinforced Composites

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Journal of Materials Science & Technology 2002年第4期18卷 335-340页

作者： Zhufeng YUE1,2.1)Department of engineering Mechanics, Northwestern Polytechnical University, Xi’an 710072. China2.institute of Materials, Ruhr University, 44780 Bochum, Germany Department of engineering Mechanics Northwestern Polytechnical University Xi'an 710072 China institute of Materials Ruhr University 44780 Bochum Germany

A systematical simulation has been carried out on the indentation creep test on particle-reinforced composites. The deformation, failure mechanisms and life are analyzed by three reasonable models. The following five factors have been considered simultaneously: creep property of the particle, creep property of the matrix, the shape of the particle, the volume fraction of the particle and the size (relative size to the particle) of the indentation indenter. For all the cases, the power law respecting to the applied stress can be used to model the steady indentation creep depth rate of the indenter, and the detail expressions have been presented. The computer simulation precision is analyzed by the two-phase model and the three-phase model. Two places of the stress concentration are found in the composites. One is ahead of the indentation indenter, where the high stress state is deduced by the edge of the indenter and will decrease rapidly near to a steady value with the creep time. The other one is at the interface, where the high stress state is deduced by the misfit of material properties between the particles and matrix. It has been found that the creep dissipation energy density other than a stress parameter can be used to be the criterion to model the debonding of the interfaces. With the criterion of the critical creep dissipation energy density, a power law to the applied stress with negative exponent can be used to model the failure life deduced by the debonding of interfaces. The influences of the shape of the particles and the matching of creep properties of particle and matrix can be discussed for the failure. With a crack model, the further growth of interface crack is analyzed, and some important experimental phenomena can be predicted. The failure mechanism which the particle will be punched into matrix has been also discussed. The critical differences between the creep properties of the particles and matrix have been calculated, after a parameter has b

关键词： Indentation creep test Particle-reinforced composites Computer simulation Deformation Failure

Final Temperature Prediction Model of Molten Steel in RH-TOP Refining Process for IF Steel Production

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Journal of Iron and Steel research International 2012年第3期19卷 1-5页

作者： WANG Yu-nan1, BAO Yan-ping1, CUI Heng2. CHEN Bin3, JI Chen-xi3 (1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China 2. engineering research {2., University of Science and Technology Beijing, Beijing 100083, China 3. Shougang research {2. of Technology, Beijing 100041, China) [a] State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing Beijing 100083 China [b] engineering research {2. University of Science and Technology Beijing Beijing 100083 China [c] Shougang research institute of Technology Beijing 100041 China

In order to precisely control the final temperature of molten steel in RH （Ruhrstahl Heraeus）-TOP blowing refining, the final temperature prediction models of molten steel in RH-TOP blowing refining process for Interstitial Free （IF） steel production were established under the condition of oxygen blowing and non-oxygen blowing respec- tively. The results show that the beginning molten steel temperature of refining and the amount of added scrap were influential factors, the baking temperature in vacuum chamber was a factor that had small influence. When the model was operated, the hitting probability was above 95%（under the condition of both oxygen blowing and non-oxygen blo- wing） of prediction deviation ±10℃. The accuracy is analyzed.

关键词： RH-TOP molten steel temperature prediction model

Earthquake Disaster Management and Insurance

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地球科学进展 2004年第S1期19卷 1-8页

作者： TANG Ai-ping~1, WEN Ai-hua~2.1. School of Civil engineering, Harbin institute of Technology, Harbin 150090, China 2. School of Science, Harbin institute of Technology, Harbin 150090, China)

As one of the most powerful tools to reduce the earthquake loss, the Earthquake Disaster Management [EDM] and Insurance [EI] have been highlighted and have had a great progress in many countries in recent years. Earthquake disaster management includes a series of contents, such as earthquake hazard and risk analysis, vulnerability analysis of building and infrastructure, earthquake aware training, and building the emergency response system. EI, which has been included in EDM after this practice has been...

关键词： Earthquake risk analysis Disaster management Earthquake insurance GIS.