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Journal of Magnesium and Alloys 2023年第4期11卷 1422-1439页

作者： Guowei Wang Dan Song Yanxin Qiao Jiangbo Cheng Huan Liu Jinghua Jiang Aibin Ma Xiaolong Ma College of Mechanics and Materials Hohai UniversityNanjing 211100China Suqian Research Institute Hohai UniversitySuqian 223800China Jiangsu university of science and Technology Zhenjiang 212003China Department of Materials science and Engineering North Carolina State UniversityRaleighNC 27695United States

Formation of super-hydrophobic and corrosion-resistant coatings can provide significant corrosion protection to magnesium ***,it remains a grand challenge to produce such coatings for magnesium-lithium alloys due to their high chemical ***,a one-step hydrothermal processing was developed using a stearic-acid-based precursor medium,which enables the hydrothermal conversion and the formation of low surface energy materials concurrently to produce the super-hydrophobic and corrosion-resistant *** multiscale microstructures with nanoscale stacks and microscale spheres on the surface,as well as the through-thickness stearates,lead to the super-hydrophobicity and excellent corrosion resistance of the obtained coating.

关键词： Magnesium-lithium alloy Super-hydrophobic coating One-step hydrothermal process Corrosion resistance Multiscale microstructure

Linear goal programming approach to obtaining the weights of intuitionistic fuzzy ordered weighted averaging operator

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Journal of Systems Engineering and Electronics 2010年第6期21卷 990-994页

作者： Yejun Xu Chao Huang Qingli Da Xinwang Liu Business School Hohai University Nanjing 210098 E R. China School of Economics and Management Nanjing University of Information Science and Technology Nanjing 210044 E R. China School of Economics and Management Southeast University Nanjing 210096 E R. China

The multiple attribute decision making problems are studied, in which the information about attribute weights is partly known and the attribute values take the form of intuitionistic fuzzy numbers. The operational laws of intuitionistic fuzzy numbers are introduced, and the score function and accuracy function are presented to compare the intuitionistic fuzzy numbers. The intuitionistic fuzzy ordered weighted averaging （IFOWA） operator which is an extension of the well-known ordered weighted averaging （OWA） operator is investigated to aggregate the intuitionistic fuzzy information. In order to determine the weights of intuitionistic fuzzy ordered weighted averaging operator, a linear goal programming procedure is proposed for learning the weights from data. Finally, an example is illustrated to verify the effectiveness and practicability of the developed method.

关键词： intuitionistic fuzzy set intuitionistic fuzzy ordered weighted averaging(IFOWA) operator linear goal programming weights multiple attribute decision making(MADM).

Certificateless Strong Key-Insulated Signature Without Random Oracles

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Journal of Shanghai Jiaotong university(science) 2011年第5期16卷 571-576页

作者：万中美孟祥芹洪璇 College of science Hohai University Department of Computer science Shanghai Normal University

It is important to ensure the private key secure in cryptosystem. To reduce the underlying danger caused by the private key leakage, Dodis et al. (2003) introduced the notion of key-insulated security. To handle the private key leakage problems in certificateless signature schemes, we propose a new certificateless strong key-insulated signature scheme. Our scheme has two desirable properties. First, its security can be proved without utilizing the random oracle model. Second, it solves the key escrow problems in identity-based key-insulated signatures (IBKISs).

关键词： key-insulated key leakage certificateless bilinear pairings

A NEW IMPLICIT SCHEME FOR SOLVING 3-D SHALLOW WATER FLOWS

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Journal of Hydrodynamics 2009年第6期21卷 790-798页

作者： ZHANG Zhuo SONG Zhi-yao LV Guo-nian State Key Laboratory of Hydrology Water Resources and Hydraulic Engineering Ocean College Hohai University Nanjing 210098 China Key Laboratory of Virtual Geographic Environment Ministry of Education Nanjing Normal University Nanjing 210097 China

Based on the improved ADI method, this article proposes an improved implicit finite difference scheme for solving 3-D shallow water flows. The main objective is to design a numerical relation between the horizontal velocity on each layer and the depth-averaged velocity for employing the improved ADI method. With the free surface elevation and the depth-averaged velocity obtained by using essentially 2-D depth-averaged mode, the velocity profiles can be obtained easily and simultaneously. The wind-induced flows, the open channel flows due to the pressure gradient and the tidal flows in coastal waters are simulated, and the results are consistent well with the analytical solution and the field data, which shows that the present implicit scheme is stable and effective, and the established model is practical. Moreover, when only one vertical layer is specified, the present 3-D numerical model is reducea to the 2-D depth-averaged model.

关键词： shallow water equation ADI method wind-induced flow gravity-drived flow tidal flow

Characteristics of Fe-based WC Composite Coatings Prepared by Double-pass Plasma Cladding Process

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稀有金属材料与工程 2012年第S1期41卷 195-198页

作者： Jiang Shaoqun Ren Qingwen Ying, Ding Gang, Wang Yu, Yi Wang Zehua Zhou Zehua hohai Univ Coll Mech & Mat Nanjing 210098 Jiangsu Peoples R China

The Fe-based WC composite coatings were clad on Q235 steel by double-pass plasma cladding method,in which the WC-Co(WC covered with cobalt:78wt%WC,12wt%Co)doping was about 10wt%,20wt%and 40wt%,*** microstructure and wear performance of the composite coatings were investigated by X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and ball-disc wear *** results show that the clad coatings contain mainly?-Fe,WC and carbides(Cr23C6,Fe3W3C-Fe4W2C)phases and the precipitation of carbides increases with the increase of WC-Co doping *** WC-Co doping content has an obvious effect on the microstructure of the clad *** the clad coatings with low WC-Co doping,the microstructure gradually transforms from planar crystal at the interface of substrate/coating to cell/dendritic crystal at the middle and the upper portion of the *** there are a number of fishbone-like structure at the middle and the upper portion of clad coating with 40wt%WC-Co *** microstructure at the top is smaller than that at the bottom for all the *** maximum of hardness of the clad coatings is 72.3HRC which is about 6.9 as much as the hardness of Q235 steel *** composite coatings have good wear resistance due to the reinforcement of carbide particles and the strong bonding between carbide particles and *** suitable increase of WC-Co doping content can improve the wear resistance of the composite coatings.

关键词： plasma cladding Fe-based WC wear resistance metal matrix composite

An experimental study on embankment failure induced by prolonged immersion in floodwater

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Water science and Engineering 2016年第1期9卷 81-86页

作者： Yu-long Luo Cheng Zhang Min Nie Mei-li Zhan Jin-chang Sheng College of Water Conservancy and Hydropower Engineering Hohai University

Prolonged immersion in floodwater is one of the main causes of embankment failure or dam breaks, although failure mechanisms have not been extensively studied. In this study, an embankment model was constructed to investigate the influence of prolonged immersion in floodwater on the failure of an embankment. The results indicate that：（1） the phreatic surface gradually rises and negative pore pressures gradually dissipate with the time of prolonged immersion in floodwater, and, finally, a stable and fully saturated state is reached; （2） observable cracks and a heave phenomenon are found near the downstream toe and in the top stratum of the foundation, which are attributed to the large uplift pressure on the interface between the top stratum and the pervious substratum, the tremendous impact effect induced by the rapid rise in water level, and the reduction of shear strength of heavy silt loam. The present study enhances our in-depth knowledge of the mechanisms of embankment failure induced by floodwater, and provides experimental data for validation of mathematical models of the embankment seepage failure.

关键词： Embankment Floodwater Seepage failure Prolonged immersion Heave phenomenon

Experimental research and numerical simulation of RC beams strengthened with bonded steel plates

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science China(Technological sciences) 2012年第12期55卷 3270-3277页

作者： LEI Dong CHEN GuangYuan CHEN YuQuan REN QingWen State Key Laboratory of Hydrology-Water Rexources and Hydraulic Engineering Hohai UniversityNanjing 210098China College of Mechanics and Materials Hohai UniversityNanjing 210098China

It is a common method to strengthen the damaged RC structures with bonded steel plates. At present the ultimate bearing ca- pacity of RC structures strengthened with bonded steel plates is calculated mostly using the theory based on the test. Four beams, including one reference beam, two strengthened concrete beams in primary force and secondary force respectively, and one strengthened concrete beam which was not anchored enough, were tested under four-point bending (4PB) in order to get the data of strain of longitudinal bars, bonded bottom steel plate in tension and deflection of beams in the middle span. The experimental program was supported by a three-dimensioned finite analysis using ABAQUS. At the end of experiments and finite analysis, it is concluded that the investing strengthening technique can significantly improve the load-carrying capacity and the phenomenon of stress concentration at the end of interface, as well as the damage at interface, can be well simulated with cohesive element provided by ABAQUS.

关键词： RC beams, strengthened with bonded steel plates secondary force, finite element analysis, damage of interface

A Method for the Damage Detection of Pile foundation in High-Pile Wharf Based on A Curvature Mode Deletion Model

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China Ocean Engineering 2020年第6期34卷 871-880页

作者： WANG Qi-ming ZHU Rui-hu ZHENG Jin-hai WANG Ning LUO Meng-yan CHE Yu-fei College of science Hohai UniversityNanjing 210098China College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210098China

As the top of the pile foundation in high-pile wharf is connected to the superstructure and most of the pile bodies are located below the water surface, traditional damage detection methods are greatly limited in their application to pile foundation in service. In the present study, a new method for pile foundation damage detection is developed based on the curve shape of the curvature mode difference(CMD) before and after damage. In the method, the influence at each node on the overall CMD curve shape is analyzed through a data deletion model, statistical characteristic indexes are established to reflect the difference between damaged and undamaged units, and structural damage is accurately detected. The effectiveness and robustness of the method are verified by a finite element model(FEM) of high-pile wharf under different damage conditions and different intensities of Gaussian white noise. The applicability of the method is then experimentally validated by a physical model of high-pile wharf. Both the FEM and the experimental results show that the method is capable of detecting pile foundation damage in noisy curvature mode and has strong application potential.

关键词： high-pile wharf pile foundation curvature mode data deletion model damage detection

Numerical simulation of the transport and diffusion of dissolved pollutants in the Changjiang (Yangtze) River estuary

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Chinese Journal of Oceanology and Limnology 2010年第3期28卷 649-657页

作者：吴德安严以新 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University College of Harbor Coastal and Offshore Engineering Hohai University

Based on a coupled hydrodynamic–ecological model for regional and shelf seas (COHERENS), a three-dimensional baroclinic model for the Changjiang (Yangtze) River estuary and the adjacent sea area was established using the sigma-coordinate in the vertical direction and spherical coordinate in the horizontal direction. In the study, changing-grid technology and the "dry-wet" method were designed to deal with the moving boundary. The minimum water depth limit condition was introduced for numerical simulation stability and to avoid producing negative depths in the shallow water areas. Using the Eulerian transport approaches included in COHERENS for the advection and dispersion of dissolved pollutants, numerical simulation of dissolved pollutant transport and diffusion in the Changjiang River estuary were carried out. The mass centre track of dissolved pollutants released from outlets in the south branch of the Changjiang River estuary water course has the characteristic of reverse current motion in the inner water course and clockwise motion offshore. In the transition area, water transport is a combination of the two types of motion. In a sewage-discharge numerical experiment, it is found that there are mainly two kinds of pollution distribution forms: one is a single nuclear structure and the other is a double nuclear (dinuclear) structure in the turbid zone of the Changjiang River estuary. The rate of expansion of the dissolved pollutant distribution decreased gradually. The results of the numerical experiment indicate that the maximum turbid zone of the Changjiang River estuary is also the zone enriched with pollutants. Backward pollutant flow occurs in the north branch of the estuary, which is similar to the backward salt water flow, and the backward flow of pollutants released upstream is more obvious.

关键词： COHERENS model Changjiang (Yangtze) River estuary discharge outlet dissolved pollutants Euler transport distribution

Self-propagating High-temperature Synthesis of Al_2O_3-TiB_2 Coatings by Aluminothermic Reactions

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稀有金属材料与工程 2012年第S1期41卷 215-218页

作者： Wang Gang,Jiang Shaoqun,Wang Zehua,Cai Dong,Yi Yu,Zhou Zehua hohai university,Nanjing 210098,China$$$$ hohai Univ Coll Mech & Mat Nanjing 210098 Jiangsu Peoples R China

The Al2O3-TiB2 coatings were fabricated on Q235 steel by self-propagating high-temperature synthesis(SHS)process using aluminothermic reactions with aluminum,titania,boron oxide and ferric oxide *** effect of the content of excessive aluminum in the reactants on Al2O3-TiB2 coatings was studied when only Al-TiO2-B2O3 system was used for preparation of the *** results indicate that the combustion reaction cannot occur when excessive aluminum is over 40wt%and the coating has good quality when excessive aluminum is 20wt%.In order to improve the bonding of the coating and substrate and optimize the ratio of Al2O3/TiB2,composite reaction systems Al-TiO2-B2O3 and Al-Fe2O3 were used for the preparation of Al2O3-TiB2 *** XRD result shows that the coatings contain FeAl intermetallic compound which can improve efficiently the interface bonding of the coating and *** percentage of Al-Fe2O3 system in reactants has only a small effect on the hardness of Al2O3-TiB2 coating,which is about 22000 MPa(Hv),but has an obvious effect on the morphology and interface bonding of the coatings.

关键词： Al2O3-TiB2 coating SHS aluminothermic reaction