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research on stability of the accumulated rock-soil body of reservoir bank under rainfall condition

Science China(Technological Sciences) 2009年第9期52卷 2528-2535页

作者： GU ChongShi1,2.WU HaiZhen1,2.& SU HuaiZhi1,2.1 College of Water Resources and Hydropower engineering,Hohai university,Nanjing 2.0098,China 2.{2. engineering research center of Water Resources Efficient Utilization and engineering Safety,Hohai university,Nanjing 2.0098,China 3 Jiangxi Water Conservancy research Institute,Nanchang 33002.,China College of Water Resources and Hydropower engineering Hohai University Nanjing China national engineering {2. center of Water Resources Efficient Utilization and engineering Safety Hohai University Nanjing China Jiangxi Water Conservancy research Institute Nanchang China

The shear strength parameters property of rock-soil aggregates in embankment slope of reservoir,that is,the relationship between cohesion and gravel content,between friction angle and gravel content,and the relationship between cohesion and water content,between friction angle and water content,is studied based on the direct shear test results,the shear strength change law of the rock-soil aggregates is given,and the unsaturated shear strength formulation of rock-soil aggregates that could consider suction and saturation degree influence is put forward in this paper,through which the sliding or failure physical mechanism of this type of slope under the condition of rainfall infiltration is studied. Also the 3D unsteady saturated-unsaturated seepage field and its FEM resolving mode are established based on the analysis of the slope rainfall infiltration process. Case study with this method indicates that the minimum safety factor of the accumulated rock-soil aggregates dose not arrive at the moment of rainfall cessation,but appears several hours after the rainfall cessation,this phenomenon is in accordance with the practical slope engineering's failure process and could explain appropriately the slope failure caused by rainfall infiltration. research results in this paper have an important reference value for the research on stability of the accumulated rock-soil aggregates in embankment slope of reservoir,and can enrich the stability analysis method and relevant theory of reservoir embankment slope.

关键词： reservoir bank slope rock-soil aggregates rainfall infiltration saturated/unsaturated seepage

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Synthesis and Luminescence Properties of Pr^(3+) Doped Ca_xBa_(1-x)TiO_3 (0.3≤x<1) Fine Particles

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Journal of Wuhan university of Technology(Materials Science) 2009年第5期24卷 689-693页

作者：何声太 College of Materials Science and engineering Tianjin Polytechnic University

CaxBa1-xTiO3 （CBT） fine particles doped with red luminescence center of Pr3＋ ions （Pr： CBT） were successfully synthesized by salt assisted spray pyrolysis （SASP） process. Scanning electronic microscope （SEM） and laser scattering analysis demonstrate that salt can be removed from the surface of particles by washing with Milli-Q water and the particles can be further separated by ball-milling to get well-dispersed Pr^3＋ ions doped CBT fine particles. The luminescence properties, such as photoluminescence （PL） and mechanoluminescence （ML）, of as-synthesized Pr： CBT particles were investigated. For Pr： CBT fine particles with different Ca molar ratios, all the samples show one emission at 612.nm, with increasing Ca molar ratio, PL intensity of Pr： CBT fine particles become stronger and stronger. When pressure was loaded on the Pr： CBT pellet, mechanoluminescence（ML） emission was measured. The results show that the ML intensity is proportional to the applied pressure.

关键词： synthesis luminescence mechanoluminescence photoluminescence Pr^3+ doped CaxBa1-xTiO3 fine particles

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Multivariate analysis in dam monitoring data with PCA

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Science China(Technological Sciences) 2010年第4期53卷 1088-1097页

作者： YU Hong1,2.WU ZhongRu1,2.BAO TengFei1,2.& ZHANG Lan1,2.1 State Key Laboratory of Hydrology-Water Resources and Hydraulic engineering,Hohai university,Nanjing 2.0098,China 2.{2. engineering research center of Water Resources Efficient Utilization and engineering Safety,Hohai university,Nanjing 2.0098,China State Key Laboratory of Hydrology-Water Resources and Hydraulic engineering Hohai University Nanjing China national engineering {2. center of Water Resources Efficient Utilization and engineering Safety Hohai University Nanjing China

Given the limitation of traditional univariate analysis method in processing the multicollinearity of dam monitoring data,this paper reconstructs the multivariate response variables by introducing principal component analysis(PCA) method,explores the ways of determining principal components(PCs),and extracts a few PCs that have major influence on data *** steady observation series,a control field for the whole observation values has been established based upon PCA;for unsteady observation series that have significant tendency,a control field for the future observation values has been constructed according to PC statistical predication *** methods have already been applied to an actual project and the results showed that data interpretation method with PCA can not only realize data reduction,lower data redundancy,and reduce noise and false alarm rate,but also be effective to data analysis,having a broad application prospect.

关键词： dam safety monitoring multivariate response variables principal component analysis data reduction

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Effects of scandium addition on microstructure and mechanical properties of ZK60 alloy

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Progress in Natural Science:Materials International 2011年第1期21卷 59-65页

作者： Fu-sheng PAN~(1,2.,Ting-ting LIU~(1,2.,Xi-yan ZHANG~(1,2.,Ai-tao TANG~(1,2.,Wei-qing WANG~(1,2. 1.national engineering {2. center for Magnesium Alloys,Chongqing university,Chongqing 400045,China 2.College of Materials Science and engineering,Chongqing university,Chongqing 400045,China national engineering {2. center for Magnesium Alloys Chongqing University Chongqing 400045 China College of Materials Science and engineering Chongqing University Chongqing 400045 China

The effects of Sc addition on the microstructure and mechanical properties of the ZK60 wrought magnesium alloy were investigated by using optical microscope,scanning electron microscopy,X-ray diffraction and tensile *** experimental results show that a minor Sc addition to ZK60 alloy has an obvious effect on the refinement of the microstructure of the ZK60 alloy. During hot extrusion,incomplete dynamic recrystallization occurs in all the alloys,and the recrystallized grains become much finer with increasing Sc *** tensile strengths of ZK60 evidently increase with the addition of Sc,but the elongations decrease. The ZK60 alloy with 0.6%(mass fraction) Sc addition is found to have the tensile strength of about 350 MPa and the yield strength of about 2.0 *** T6 heat treatment,the tensile strength of the alloy containing 0.6%Sc remains almost ***, the yield strength of the alloy increases up to 352.MPa,and the ratio of the tensile strength to the yield strength is close to 1.

关键词： wrought magnesium alloy scandium microstructure mechanical properties

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Theoretical study of aging effects on LaNi_(5) tritium storage

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Science China(Physics,Mechanics & Astronomy) 2005年第6期48卷 676-686页

作者： PING Feilin1,2. JIANG Gang1, ZHANG Lin2.& ZHU Zhenghe1 1. Institute of Atomic and Molecular Physics, Sichuan university, Chengdu 610065, China 2. research {2. of Laser Fusion, Mianyang 62.900, China Institute of Atomic and Molecular Physics Sichuan University Chengdu China research center of Laser Fusion Miangyang China

The electronic structure and energy of La2.i10H12.and La2.i10H11He (He is at tetrahedral, octahedral or twelve-face polyhedral interstitials) double cells have been calculated using the density functional theory. Their equilibrium structure, energy bands, electronic density of states (DOS) and X-ray diffraction are presented and discussed. The results indicate the helium-3 produced due to the decay of tritium is most possibly sited at twelve-face polyhedral and octahedral interstices and changes the thermodynamic properties of LaNi5 tritide system. The changes due to aging such as the reduction in the isotherm plateau pressure, increase of the isotherm plateau slope, and appearance of deeply trapped hydrogen are caused not only by the lattice expansion, but also by modification of the electronic structure due to the presence of He.

关键词： LaNi5 alloy, density functional theory, electronic structure, aging.

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Detection of subcritical crack propagation for concrete dams

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Science China(Technological Sciences) 2009年第12期52卷 3654-3660页

作者： BAO TengFei1 ,2.YU Hong 1,2.1College of Water Conservancy&Hydropower engineering,Hohai university,Nanjing 2.0098,China 2.2. engineering research center of Water Resources Efficient Utilization and engineering Safety,Nanjing 2.0098,China College of Water Conservancy & Hydropower engineering Hohai University Nanjing China national engineering {2. center of Water Resources Efficient Utilization and engineering Safety Nanjing China

Subcritical propagation of cracks is a warning sign of *** such propagation is detected at an early stage,timely maintenance measures can be taken to prevent the failure of *** detect the subcritical propagation of a crack,the crack needs to be monitored continuously in a long term, which is not realistic under certain ***,cracks in concrete dams can be monitored continuously by dam monitoring to offer possible detection for subcritical *** this paper, with measured crack openings from dam monitoring,a state equation for characterizing crack development is established based on the grey system *** relation between the stability of the equation and the subcritical crack propagation is investigated,then a criterion is proposed for detecting subcritical *** example demonstrates the validity of the criterion and its potential for practical application.

关键词： crack subcritical propagation criterion concrete

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Assessment model of dam operation risk based on monitoring data

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Science China(Technological Sciences) 2007年第Z1期50卷 144-152页

作者： WU ZhongRu1,2., SU HuaiZhi1,2.& GUO HaiQing1 1 College of Water Conservancy and Hydropower engineering, Hohai university, Nanjing 2.0098, China 2.{2. engineering research center of Water Resources Efficient Utilization and engineering Safety, Nanjing 2.0098, China College of Water Conservancy and Hydropower engineering Hohai University Nanjing China national engineering {2. center of Water Resources Efficient Utilization and engineering Safety Nanjing China

Although the dams produce remarkable social and economic benefits, the threat made by unsafe dams to the life and property of people who live in the lower river area is un-negligible. Based on the monitoring data which reflect the safety condition of dams, the risk degree concept is proposed and the analysis system and model for evaluating risk degree (rate) are established in this paper by combining the reliability theory and field monitoring data. The analysis method for risk degree is presented based on Bayesian approach. A five-grade risk degree system for dam operation risk and corresponding risk degree is put forward according to the safety condition of dams. The operation risks of four cascade dams on some river are analyzed by the model and approach presented here and the result is adopted by the owner.

关键词： dam monitoring data operation risk degree analysis model

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Mechanical Property and Microstructural Characterization of C-Mn-Al-Si Hot Dip Galvanizing TRIP Steel

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Journal of Iron and Steel research International 2012年第8期19卷 29-36页

作者： JIANG Hai-tao1, DING Wei1,2. TANG Di1, HUANG Wei1 (1. national engineering {2. center for Advanced Rolling Technology, university of Science and Technology Beijing, Beijing 100083, China 2. School of Material and Metallurgy, Inner Mongolia university of Science and Technology, Baotou 014010, Inner Mongolia, China) national engineering {2. center for Advanced Rolling Technology University of Science and Technology Beijing Beijing China School of Material and Metallurgy Inner Mongolia University of Science and Technology Baotou Inner Mongolia China

Mechanical properties and microstructure in high strength hot dip galvanizing TRIP steel were investigated by optical microscope (OM), transmission electron microscope (TEM), X-ray diffraction (XRD), dilatometry and mechanical testing. On the heat treatment process of different intercritical annealing (IA) temperatures, isothermal bainitic transformation (IBT) temperatures and IBT time, this steel shows excellent mechanical properties with tensile strength over 780 MPa and elongation more than 2.%. IBT time is a crucial factor in determining the mechanical properties as it confirms the bainite transformation process, as well as the microstructure of the steel. The microstructure of the hot dip galvanizing TRIP steel consisted of ferrite, bainite, retained austenite and martensite during the short IBT time. The contents of ferrite, bainite, retained austenite and martensite with different IBT time were calculated. The results showed that when IBT time increased from 2. to 60 s, the volume of bainite increased from 14.31% to 16.95% and the volume of retained austenite increased from 13.64% to 16.2.%; meanwhile, the volume of martensite decreased from 7.18% to 1.89%. Both the transformation induced plasticity of retained austenite and the hardening of martensite are effective, especially, the latter plays a dominant role in the steel containing 7.18% martensite which shows similar strength characteristics as dual-phase steel, but a better elongation. When martensite volume decreases to 1.89%, the steel shows typical mechanical properties of TRIP, as so small amount of martensite has no obvious effect on the mechanical properties.

关键词： TRIP steel isothermal bainitic transformation martensite mechanical property

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Review on hidden trouble detection and health diagnosis of hydraulic concrete structures

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Science China(Technological Sciences) 2007年第Z1期50卷 34-50页

作者： WU ZhongRu1,2., LI Ji1, GU ChongShi1,2.& SU HuaiZhi1,2.1 College of Water Conservancy and Hydropower engineering, Hohai university, Nanjing 2.0098, China 2.{2. engineering research center of Water Resources Efficient Utilization and engineering Safety, Nanjing 2.0098, China College of Water Conservancy and Hydropower engineering Hohai University Nanjing China national engineering {2. center of Water Resources Efficient Utilization and engineering Safety Nanjing China

A large number of hydraulic concrete structures have hidden defects such as cracks, erosion, freeze and thaw, thermal fatigue, carbonization. These hidden defects seriously affect the strength, stability and durability of structures. These problems are studied mainly by single monitoring or diagnosis methods at present. The integration of multiple monitoring and diagnosis methods is not applied widely. Besides, the analysis theory on these problems is not developed very well. The systemic study on the aging mechanism of hydraulic concrete structures, time- variation model and health diagnosis is still not enough. The support for engineering practice is limited. Aimed at these major scientific and technological problems and combined with specific projects, study on detection of hidden defects and health diagnosis of hydraulic concrete structure has been carried out. This study includes the following content: field non-destructive examination of hidden defects of hydraulic concrete structures, seepage detection, the construction of in-situ sensing system, the combination of field detection and in-situ monitoring, the mechanism of crack, freeze and thaw, erosion and carbonization of hydraulic concrete structure, mechanism of combination aging; time-variation model of hydraulic concrete structure, theories and methods for health diagnosis of hydraulic concrete structures.

关键词： hydraulic concrete structure hidden trouble detection health diagnosis

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Effect of surface nanocrystallization on the corrosion behavior of Zircaloy-4

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Science China(Technological Sciences) 2009年第8期52卷 2227-2231页

作者： ZHU YuTao1,2.& ZHANG XiYan1,2.3 1 College of Materials Science and engineering, Chongqing university, Chongqing 400045, China 2.{2. engineering research center for Magnesium Alloys, Chongqing university, Chongqing 400044, China 3 School of Physical Science and engineering Technology, Guangxi university, Nanning 530004, China College of Materials Science and engineering Chongqing University Chongqing China national engineering {2. center for Magnesium Alloys Chongqing University Chongqing China School of Physical Science and engineering Technology Guangxi University Nanning China

The contrastive corrosion experiments between surface nanocrystallined Zircaloy-4 and coarse-grained Zircaloy-4 under the condition of 673 K/10.3 MPa in pure water are carried out, and the microstructure of oxide films has been studied. The results indicate that the growth rate of oxide films formed on the nanocrystalline Zircaloy-4 is lower than that of oxide films formed on the coarse-grained Zircaloy-4. Simultaneously, the oxide/metal interface of the former is more regular and glossy than that of the latter. For nanocrystalline Zircaloy-4, the low oxygen diffusion rate through the oxide/metal interface can hinder the reaction of oxygen ion with metal ion. Furthermore, more tetragonal ZrO2.are observed in the oxide films, which can delay the martensite phase transition from tetragonal to monoclinic phase in oxide films.

关键词： nanocrystalline Zircaloy oxide film microstructure

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