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Modification and Anticorrosion Property of Carbon Steel with TiO_2 Film

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Journal of Iron and Steel Research International 2005年第6期12卷 37-41页

作者： song Lai-zhou ZHAO Jing WANG xiu-li Yanshan University Qinhuangdao 066004 China

A new TiO2 modified film on carbon steel was prepared by electroless plating and sol gel composite process. An artificial neural net was used to optimize the preparing condition of the film. The optimized condition of the TiO2-modified film on carbon steel is as follows： plating time of NiP is 50 min, number of dip coating is 4, heat treatment time is 2 h, and the molar ratio of complexing reagent to Ti（OC4 H9）4 is 1.5 ： 1. Corrosion behavior of carbon steel with coating was investigated by polarization resistance measurement, anode polarization, EIS and ESEM measurement. XPS was used to characterize the element valence of the modified film. Results show that carbon steel with TiO2 modified film has good corrosion resistance in 0.5 mol/L of H2SO4 solution and 0.5 mol/L of NaCl solution. It is also found that the preparing condition of forming TiO2-modified film can be obtained easily by the artificial neural net.

关键词： electroless plating sol-gel composite process artificial neural net TiO2-modified film corrosion resistance

Receptivity of hypersonic boundary layer due to fast-slow acoustics interaction

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Acta Mechanica Sinica 2015年第6期31卷 899-909页

作者： Jun Gao Ji-sheng Luo Xue-song Wu Department of Mechanics Tianjin University Department of Mathematics Imperial College London

The objective of receptivity is to investigate the mechanisms by which external disturbances generate unsta- ble waves. In hypersonic boundary layers, a new receptivity process is revealed, which is that fast and slow acoustics through nonlinear interaction can excite the second mode near the lower-branch of the second mode. They can generate a sum-frequency disturbance though nonlinear interaction, which can excite the second mode. This receptivity process is generated by the nonlinear interaction and the nonparal- lel nature of the boundary layer. The receptivity coefficient is sensitive to the wavenumber difference between the sumfrequency disturbance and the lower-branch second mode. When the wavenumber difference is zero, the receptivity coefficient is maximum. The receptivity coefficient decreases with the increase of the wavenumber difference. It is also found that the evolution of the sum-frequency disturbance grows linearly in the beginning. It indicates that the forced term generated by the sum-frequency disturbance resonates with the second mode.

关键词： Hypersonic boundary layer · Receptivity·Nonlinear interaction · Acoustic

Mathematical model of the direct reduction of dust composite pellets containing zinc and iron

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International Journal of Minerals,Metallurgy and Materials 2013年第7期20卷 627-635页

作者： xiu-wei An Jing-song Wang Xue-feng She Qing-guo Xue State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing School of Metallurgical and Ecological Engineering University of Science and Technology Beijing School of Mechanical Engineering University of Science and Technology Beijing

Direct reduction of dust composite pellets containing zinc and iron was examined by simulating the conditions of actual production process of a rotary hearth furnace （RHF） in laboratory. A mathematical model was constructed to study the reduction kinetics of iron oxides and ZnO in the dust composite pellets. It was validated by comparing the calculated values with experimental results. The effects of furnace temperature, pellet radius, and pellet porosity on the reduction were investigated by the model. It is shown that furnace temperature has obvious influence on both of the reduction of iron oxides and ZnO, but the influence of pellet radius and porosity is much smaller. Model calculations suggest that both of the reduction of iron oxides and ZnO are under mixed control with interface reactions and Boudouard reaction in the early stage, but only with interface reactions in the later stage.

关键词： rotary hearth furnaces dust zinc ore pellets direct reduction process mathematical models kinetics

Adaptive service configuration approach for quality of service management in ubiquitous computing environments

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第7期10卷 964-975页

作者： Yong ZHANG Shen-sheng ZHANG song-qiao HAN Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China

Mobility and resource-limitedness pose challenging issues to service configuration for quality of service (QoS) management in ubiquitous computing environments. Previous configuration approaches, such as static resource reservation, dynamic resource allocation and single service composition are not valid in the environments. In this study, we present an adaptive service configuration approach. Firstly, we reduce the dynamic configuration process to a control model which aims to achieve the variation of critical QoS on minimal level with less resource cost. Secondly, to deal with different QoS variations, we design two configuration strategies—service chain reconfiguration and QoS parameter adjustment—and implement them based on fuzzy logic control theory. Finally, a configuration algorithm is developed to flexibly employ the two configuration strategies in tune with the error of critical QoS in configuration process. The results of simulation experiments suggest that our approach outper- forms existing configuration approaches in both QoS improvement and resource utilization.

关键词： Service configuration Ubiquitous computing (UbiComp) Quality of service (QoS) Fuzzy logic control

Microstructure and Properties of M40 Carbon Fibre Reinforced Mg-Re-Zr Alloy Composites

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Journal of Materials Science & Technology 2009年第3期25卷 423-426页

作者： Gaohui Wu Meihui song Ziyang xiu Ning Wang Wenshu Yang School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

M40 carbon fibre reinforced rare earth magnesium alloy ZM6 composites with fibre volume fraction about 60% were fabricated by pressure infiltration method. The microstructure, interracial morphology, and precipitation were studied by scanning electron microscopy, transmission electron microscopy, and energy dispersive X- ray spectrometer. It was shown that the interfaces between Mg alloy and fibres were well bonded and free from cracks. The Mg12Nd phase was preferentially precipitated at the fibre/matrix interfaces, leading to the segregation of Nd at the interfaces and the dramatic decrease of Mg12Nd precipitation in the matrix far from interfaces. Crystal defects such as high-density dislocations and twins were observed in the matrix near the fibre/matrix interface. A high bending strength （1393 MPa） and elastic modulus （190 GPa） were achieved in M40/ZM6 composite.

关键词： Magnesium matrix composites Microstructure Dislocations Twin

Resilient tightly coupled INS/UWB integration method for indoor UAV navigation under challenging scenarios

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Defence Technology（防务技术） 2023年第4期22卷 185-196页

作者： Qian Meng Yang song sheng-ying Li Yuan Zhuang Key Laboratory of Micro-Inertial Instrument and Advanced Navigation Technology Southeast UniversityNanjing210096China Department of Mechanical Engineering Hong Kong Polytechnic UniversityHong KongChina State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanChina

Based on the high positioning accuracy,low cost and low-power consumption,the ultra-wide-band(UWB)is an ideal solution for indoor unmanned aerial vehicle(UAV)localization and ***,the UWB signals are easy to be blocked or reflected by obstacles such as walls and furniture.A resilient tightly-coupled inertial navigation system(INS)/UWB integration is proposed and implemented for indoor UAV navigation in this paper.A factor graph optimization(FGO)method enhanced by resilient stochastic model is established to cope with the indoor challenging *** deal with the impact of UWB non-line-of-sight(NLOS)signals and noise uncertainty,the conventional neural net-works(CNNs)are introduced into the stochastic modelling to improve the resilience and reliability of the *** on the status that the UWB features are limited,a‘two-phase'CNNs structure was designed and implemented:one for signal classification and the other one for measurement noise *** proposed resilient FGO method is tested on flighting UAV platform under actual indoor challenging *** to classical FGO method,the overall positioning errors can be decreased from about 0.60 m to centimeter-level under signal block and reflection *** superiority of resilient FGO which effectively verified in constrained environment is pretty important for positioning accuracy and integrity for indoor navigation task.

关键词： Unmanned aerial vehicle(UAV) Resilient navigation Indoor positioning Factor graph optimization Ultra-wide band(UWB)

Hot cracking behavior of large size GH4742 superalloy vacuum induction melting ingot

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Journal of Iron and Steel Research International 2022年第9期29卷 1505-1512页

作者： Liang Zhang Lei Wang Yang Liu xiu song Teng Yu Ran Duan Key Laboratory for Anisotropy and Texture of Materials Ministry of EducationSchool of Materials Science and EngineeringNortheasternUniversityShenyang 110819LiaoningChina High Temperature Materials Division Fushun Special Steel Co.Ltd.Fushun 113001LiaoningChina Gaona Aero Material Co. Ltd.Beijing 100081China

The developing of large size superalloy vacuum induction melting(VIM)ingots is limited owing to hot cracking,The hot cracking behavior of the large size GH4742 superalloy VIM ingot was investigated via experiment and *** microstructure was examined by optical microscopy,and element segregation was investigated by electron probe *** solidification temperature range and yield strength at high temperature(YSHT)were calculated by JMatPro *** results show that the variations of microstructure and element segregation in different locations are caused by different cooling ***,the larger secondary dendrite arm spacing and serious element segregation of Nb accelerate hot cracking of the VIM *** addition,the solidification temperature range is wider,and YSHT is lower in center than at edge of the ***,the hot cracking susceptibility is the highest in the center of the GH4742 superalloy VIM *** critical criterion of element segregation for hot cracking is that the partition coeffcient of Nb should be larger than 0.5.

关键词： Hot cracking Large size-Superlloy Vacuum induction melting ingot Element segregation

Supporting structure failure caused by the squeezing tunnel creep and its reinforcement measure

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Journal of Mountain Science 2023年第6期20卷 1774-1789页

作者： ZHAO Jin-peng TAN Zhong-sheng LI Lei WANG xiu-ying Key Laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China

Tunnels deeply buried have high crustal stress and are prone to large deformation disasters when encountering soft *** large deformation phenomenon during the construction process of the Maoxian Tunnel on the Chengdu-Lanzhou Railway is particularly *** article focuses on the large deformation problem of the No.1 inclined shaft of the Maoxian Tunnel,and uses on-site monitoring methods to explore the reasons for tunnel structure failure,and analyzes the mechanical behavior of the tunnel *** using numerical simulation methods,the effectiveness of the second-layer support in resisting creep loads in tunnels was studied,and the influence of the construction time of the secondlayer support on the mechanical properties of the tunnel was *** results indicate that the first-layer support in the tunnel is a structural failure caused by asymmetric deformation caused by creep,while the second-layer support has a good effect on resisting creep *** research results can provide a technical reference for deformation control of squeezing tunnels.

关键词： Squeezing tunnel Mechanical responses Long-term creep Second-layer support On-site monitoring

Stress-corrosion behavior and characteristics of the friction stir welding of an AA2198-T34 alloy

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International Journal of Minerals,Metallurgy and Materials 2020年第6期27卷 774-782页

作者： Quan-qing Zeng song-sheng Zeng Dong-yao Wang Research Institute of Light Alloy Central South UniversityChangsha 410083China Key Laboratory of the Ministry of Education of Nonferrous Metals Central South UniversityChangsha 410083China Technology Center Valin ArcelorMittal Automotive Steel Co.Ltd.Loudi 417009China

To better understand the stress-corrosion behavior of friction stir welding(FSW),the effects of the microstructure on the stress-corrosion behavior of the FSW in a 2198-T34 aluminum alloy were *** experimental results show that the low-angle grain boundary(LABs)of the stir zone(SZ)of FSW is significantly less than that of heated affected zone(HAZ),thermo-mechanically affected zone(TMAZ),and parent materials(PM),but the grain boundary precipitates(GBPs)T1(Al2CuLi)were less,which has a slight effect on the stress *** dislocation density in SZ was greater than that in other *** residual stress in SZ was+67 MPa,which is greater than that in the *** residual stress in the HAZ and PM is-8 MPa and-32 MPa,respectively,and both compressive *** corrosion potential in SZ is obviously less than that in other ***,micro-cracks were formed in the SZ at low strain rate,which indicates that the grain boundary characters and GBPs have no significant effect on the crack initiation in the stress-corrosion process of the ***,the residual tensile stress has significant effect on the crack initiation during the stress-corrosion process.

关键词： slow strain rate test residual stress grain boundary characteristic AA2198-T34 alloy friction stir welding