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Preparation and corrosion resistance of the micro-arc oxidation coating on Al_2O_3f/ZL109 composites

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Rare Metals 2013年第3期32卷 290-293页

作者： ming-Chao yu Wei Liang School of Materials Science and Engineering Taiyuan University of Technology

A ceramic layer was prepared on the surface of Al2O3f/ZL109 composites by means of micro-arc oxidation （MAO） technique. The surface morphology and phase constituent of the ceramic layer were analyzed using scanning electron microscope and X-ray diffraction. The polarization curves of the composites before and after MAO treatment were measured and analyzed. The results showed that after Al2O3f/ZL109 composites were treated using MAO technique in silicate solution, the ceramic layer formed, and it was composed of Al, Si, and mullite phase. Al and Si came from Al alloy matrix of the composites, and the mullite phase formed in process of MAO. Al2O3 fiber in the composites affects the electric conductivity of the composites, the MAO reaction is promoted, and the cera- mic layer forming on the composite material side is slightly thicker than that on the Al alloy side. After Al2O3f/ZL109 composites were treated using MAO technique, the corro- sion resistance of the composites is significantly improved.

关键词： Micro-arc oxidation Al alloy composites Ceramic layer Corrosion resistance

Error model identification of inertial navigation platform based on errors-in-variables model

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journal of Systems Engineering and Electronics 2009年第2期20卷 388-393页

作者： Liu ming Liu yu Su Baoku Space Control and Inertial Technology Research Center Harbin Inst. of Technology Harbin 150001 P. R. China

Because the real input acceleration cannot be obtained during the error model identification of inertial navigation platform, both the input and output data contain noises. In this case, the conventional regression model and the least squares （LS） method will result in bias. Based on the models of inertial navigation platform error and observation error, the errors-in-variables （EV） model and the total least squares （TLS） method axe proposed to identify the error model of the inertial navigation platform. The estimation precision is improved and the result is better than the conventional regression model based LS method. The simulation results illustrate the effectiveness of the proposed method.

关键词： errors-in-variables model total least squares method inertial navigation platform error model identification

Quantum Chemistry Calculation of Quercetin-silver Complex

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Chinese journal of Structural Chemistry 2005年第11期24卷 1340-1346页

作者： jIANG Liu-yun LIU yu-ming Analytical and Testing Center of Sichuan University Chengdu 610064 China

Three possible molecular structures of quercetin-silver complexes obtained from the reaction of quercetin and Ag^＋ in equivalent molar ratio were designed and optimized by using Gaussian 98 program at the B3LYP/LanL2DZ basis set. Through theoretical analysis, one of the three designed structures is discovered to have the most stable coordination position. Then its geometry structure, natural bond orbital analyses, vibrational frequency and biological activity were performed. The results show that it has good stability and relatively stronger antioxidative activity because it is favorably attacked by O2^-. Therefore theoretical foundation is provided for the development of new quercetin metal complexes with higher activity antioxidants.

关键词： quercetin,silver-complex quantum chemistry

Non-Fourier heat conduction in a thin gold film heated by an ultra-fast-laser

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Science China(Technological Sciences) 2015年第4期58卷 638-649页

作者： MAO yu Dong XU ming Tian Department of Engineering Mechanics School of Civil Engineering Shandong University School of Energy and Power Engineering Shandong University

Based on the dual-phase-lagging(DPL)heat conduction model,the Cattaneo-Vernotte(CV)model and the improved CV model we investigate the one-dimensional heat conduction in gold films with nano-scale thickness exposed to an ultra-fast laser *** influence of system parameters on the temperature field is *** find that for all the non-Fourier heat conduction models considered in this work,a larger Knudsen number normally leads to a higher *** the DPL model,the large ratio of the phase lag of temperature gradient to the phase lag of heat flux reduces the maximum temperature and shortens the time for the system to reach its steady *** CV model and the improved CV model lead to the similar thermal wave behavior of the temperature field,but the thermal wave speeds for these two models are different,especially for large Knudsen *** the phase lag of temperature gradient is smaller,the difference between the DPL model and the improved CV model is not significant,but for the large phase lag of temperature gradient the difference becomes quite significant,especially for the large Knudsen *** addition,the effect of the surface accommodation coefficient,which is a parameter in the slip boundary condition,on the temperature field of the gold film heated by ultra-fast laser pulses is investigated based on the DPL model.

关键词： Nano-scale heat conduction ultrafast laser heating thin film Knudsen number

Safe semi-supervised learning: a brief introduction

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Frontiers of Computer Science 2019年第4期13卷 669-676页

作者： yu-Feng LI De-ming LIANG National Key Laboratory for Novel Software Technology Nanjing University Nanjing 210023 China Collaborative Innovation Center of Novel Software Technology and Industrialization Nanjing 210023 China

Semi-supervised learning constructs the predictive model by learning from a few labeled training examples and a large pool of unlabeled ones. It has a wide range of application scenarios and has attracted much attention in the past decades. However, it is noteworthy that although the learning performance is expected to be improved by exploiting unlabeled data, some empirical studies show that there are situations where the use of unlabeled data may degenerate the performance. Thus, it is advisable to be able to exploit unlabeled data safely. This article reviews some research progress of safe semi-supervised learning, focusing on three types of safeness issue: data quality, where the training data is risky or of low?quality;model uncertainty, where the learning algorithm fails to handle the uncertainty during training;measure diversity, where the safe performance could be adapted to diverse measures.

关键词： machine learning semi-supervised learning safe

On redundancy-modified NAND multiplexing

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journal of Systems Engineering and Electronics 2018年第4期29卷 864-872页

作者： DIAO ming yu Lianhua CHEN Xiaobo College of Information and Communication Engineering Harbin Engineering University College of Automation Harbin Engineering University

In order to make systems that are based on unreliable components reliable, the design of fault tolerant architectures will be necessary. Inspired by von Neumann＇s negative AND（NAND）multiplexing and William＇s interwoven redundant logic, this paper presents a fault tolerant technique based on redundancy-modified NAND gates for future nanocomputers. Bifurcation theory is used to analyze fault tolerant ability of the system and the simulation results show that the new system has a much higher fault tolerant ability than the conventional multiplexing based on NAND *** to the evaluation, the proposed architecture can tolerate a device error rate of up to 10-1, with multiple redundant components. This fault tolerant technique is potentially useful for future nanoelectronics.

关键词： fault tolerant multiplexing redundancy-modified neg-ative AND (NAND) gate

ESTIMATION OF WATER TABLE ELEVATION BY UNIVERSAL COKRIGING

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journal of Hydrodynamics 2005年第2期17卷 154-163页

作者： CHENjia-jun TIANKai-ming GUOQiao-yu StateKeyjointLaboratoryofEnvironmentalSimulationandPollutionControl InstituteofEnvironmentalSciencesBeijingNormalUniversityBeijing100875China ChinaUniversityofGeosciences Beijing100083China StateKeyjointLaboratoryofEnvironmentalSimulationandPollutionControl.InstituteofEnvironmentalSciences BeijingNormalUniversityBeijing100875China

When water resource or quality problems associated with phreatic water in geological settings are studied, information about water table elevations is often crucial. In those cases where the water table is a subdued replica of the ground surface, universal cokriging can be used to estimate water table elevations at un-sampled locations on the basis of water table and ground surface elevation measurements obtained at well locations. In this paper, universal cokriging, with ground surface elevation considered as a co-variate, was used to estimate water table elevations. Universal cokriging equations were derived, an iterative method for obtaining experimental variograms was established, and a case study of an initial groundwater flow simulation in the Xiuwu County, Henan Province, China, was presented. In the case study, the initial groundwater flow regime was represented both by universal cokriging with the ground surface elevation serving as a covariate and by universal kriging without the inclusion of ground surface elevation as a covariate. A comparison of the results from these two approaches shows that groundwater levels of phreatic water at locations without measurements in regions with unconsolidated porous media can be estimated more accurately by universal cokriging.

关键词： water table estimation universal cokriging covariate ground surface elevation variogram

Hydrothermal Synthesis and Structure Analysis of Indium Vanadate (InVO_4)

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Chinese journal of Structural Chemistry 2005年第11期24卷 1242-1248页

作者： HUANG Qing-ming yu jian-Chang Instrumentation Analysis and Research Center Fuzhou University Fuzhou Fujian 350002 China Material science and engineering department Fuzhou University Fuzhou Fujian 350002 China

In this article, hydrothermal process is applied to synthesize nanometer InVO4. Influences of different experimental conditions （including mixing ratio of raw materials, reaction temperature, reaction time and so on） upon the synthetic products＇ purity and crystallite size are discussed to determine the best synthetic condition. The structure of nanometer InVO4 is analyzed, which helps to further understand the structure characteristics of InVO4 synthesized by applying hydrothermal process and lays foundation for further research.

关键词： hydrothermal process InVO4 experimental conditions structure

Modeling and inferring 2.1D sketch with mixed Markov random field

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journal of Systems Engineering and Electronics 2017年第2期28卷 361-373页

作者： Anlong ming yu Zhou Tianfu Wu School of Computer Beijing University of Posts & Telecommunications Beijing 100876 China Institute of Sensing Technology and Business (Wuxi) Beijing University of Posts & Telecommunications Beijing 100876 China Department of Statistics University of California Los Angeles 90095 USA

This paper presents a method of computing a 2.1D sketch (i.e., layered image representation) from a single image with mixed Markov random field (MRF) under the Bayesian framework. Our model consists of three layers: the input image layer, the graphical representation layer of the computed 2D atomic regions and 3-degree junctions (such as T or arrow junctions), and the 2.1D sketch layer. There are two types of vertices in the graphical representation of the 2D entities: (i) regions, which act as the vertices found in traditional MRF, and (ii) address variables assigned to the terminators decomposed from the 3-degree junctions, which are a new type of vertices for the mixed MRF. We formulate the inference problem as computing the 2.1D sketch from the 2D graphical representation under the Bayesian framework, which consists of two components: (i) region layering/coloring based on the Swendsen-Wang cuts algorithm, which infers partial occluding order of regions, and (ii) address variable assignments based on Gibbs sampling, which completes the open bonds of the terminators of the 3-degree junctions. The proposed method is tested on the D-Order dataset, the Berkeley segmentation dataset and the Stanford 3D dataset. The experimental results show the efficiency and robustness of our approach. © 2017 Beijing Institute of Aerospace Information.

关键词： Graphic methods Image segmentation Inference engines Markov processes Structural frames