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Numerical simulations and experimental investigations on transverse effects of two-wave mixing in a photovoltaic photorefractive crystal

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science china(Physics,Mechanics & Astronomy) 2010年第5期53卷 856-863页

作者： CAI Xin1,2,LIU JinSong1 & WANG ShengLie1 1 wuhan National Laboratory for Optoelectronics,school of Optoelectronic science and Engineering,Huazhong university of science and technology,wuhan 430074,china 2.school of science,wuhan university of technology,wuhan 430070,china 1. wuhan National Laboratory for Optoelectronics School of Optoelectronic Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China2. School of Science Wuhan University of Technology Wuhan 430070 China

The transverse effects of two Gauss waves mixing in a photovoltaic photorefractive crystal,i.e.,the dynamical evolutions of signal beam with different parameters,are traced numerically and *** the one-dimensional numerical simulations and two-dimensional experimental investigations show that the self-focusing effect of signal beam becomes more obvious as the intensity of pump beam and the angle between the signal and pump beams *** accordance with these results,the state of two Gaussian waves mixing is controllable.

关键词： numerical simulation experimental investigation two-wave mixing transverse effects Gaussian distribution

Early Age Compressive Strength of Pastes by Electrical Resistivity Method and Maturity Method

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Journal of wuhan university of technology(Materials science) 2011年第5期26卷 983-989页

作者：肖莲珍 school of Materials science and Engineering Wuhan Institute of Technology

The compressive strength development of Portland cement pastes was investigated by the electrical resistivity method and the maturity *** experiments were carried out on the cement pastes with different water-cement ratios at different curing *** results show that the application of the maturity method has limitation to obtain the *** is found that both of the compressive strength and the electrical resistivity follow hyperbolic trend for all the *** hyperbolic equation of each mix is obtained to estimate the ultimate resistivity value which can probably be *** relationship between electrical resistivity and compressive strength of the cement pastes is established based on the test results and interpreted by the empirical Archie equation and a strength-porosity *** relationship between the electrical resistivity after temperature correction and the compressive strength was linear and independent of curing temperature and water-cement ratio.

关键词： electrical resistivity cement hydration compressive strength maturity method

Quasi-physical global optimization method for solving the equal circle packing problem

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science china(Information sciences) 2011年第7期54卷 1333-1339页

作者： HUANG WenQi & YE Tao school of computer science and technology,Huazhong university of science and technology,wuhan 430074,china 1. school of computer science and technology Huazhong University of Science and Technology Wuhan 430074 China

The equal circle packing problem is a well-known challenge in *** is also a natural,clear and fair test system for global *** paper presents a quasi-physical global optimization algorithm for solving the equal circle packing *** algorithm simulates two kinds of movements of N elastic disks: smooth movement driven by elastic pressures and violent movement driven by strong repulsive forces and attractive *** smooth movement makes the disks reach a locally optimal configuration,while the violent movement makes them jump out of the local optimum trap and reach a more promising *** algorithm is tested on the widely studied instances of N = 1,2,...,*** find better packings than the reported best-known ones on 37 instances and reproduce the best-known results on the remaining 113 instances.

关键词： equal circle packing global optimization quasi-physical method heuristic

Multispectral image fusion method based on intensity-hue-saturation and nonsubsampled three-channels non-separable wavelets

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Chinese Optics Letters 2010年第4期8卷 384-387页

作者：刘斌刘维杰彭嘉雄 school of Mathematics and computer science Hubei university computer school Wuhan University Institute of Image Recognition and Artificial Intelligence Huazhong University of Science and Technology

A new multispectral image fusion method based on intensity-hue-saturation（IHS） transform and threechannel non-separable wavelets whose dilation matrix is[2,1;1,1]is *** multi-resolution decompositions of the intensity of multispectral image and panchromatic image are performed in nonsubsampled mode using the three-channel non-separable wavelet filter *** approximation images and the detail images of the multi-resolution pyramids are *** experimental results show that this method has good visual *** performance outperforms the IHS fusion *** discrete wavelet transform （DWT） fusion method,and the IHS-DWT fusion method in preserving spectral quality and high spatial resolution information.

关键词： Decomposition Discrete wavelet transforms Filter banks Visual communication

A quasi-human algorithm for solving the three-dimensional rectangular packing problem

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science china(Information sciences) 2010年第12期53卷 2389-2398页

作者： HE Kun & HUANG WenQi school of computer science and technology, Huazhong university of science and technology, wuhan 430074, china 1. school of computer science and technology Huazhong University of Science and Technology Wuhan 430074 China

Based on the concept of maximal rectangular space that can be filled at current time and the siege warfare tactics, we make several critical improvements on the quasi-human caving-degree approach to get a stronger algorithm ICDA for a classical NP hard problem: the three-dimensional rectangular packing problem. Within similar computing time, the new algorithm gained an average volume utilization of 90.92% on the natural and difficult 100 benchmarks, called BR15, where items to be packed are almost different in size. Compared with current best record just reported in the literature in 2010, our result makes an improvement by 0.54%.

关键词： NP hard three-dimensional packing quasi-human action space caving degree

A New Clustering Algorithm for Categorical Attributes

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 318-322页

作者： Songfeng Lu, Zhengding Lu (College of computer science and technology, Huazhong university of science and technology, wuhan 430074, china) College of computer science and technology Huazhong University of Science and Technology Wuhan 430074 China

In traditional data clustering, similarity of a cluster of objects is measured by distance between objects. Such measures are not appropriate for categorical data. A new clustering criterion to determine the similarity between points with categorical attributes is pre- sented. Furthermore, a new clustering algorithm for categorical attributes is addressed. A single scan of the dataset yields a good clus- tering, and more additional passes can be used to improve the quality further.

关键词： data mining clustering similarity Information

Sol-gel Preparation Copper-cadmium Halide DopedPhotochromic Glass Coating on Plate Glass

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International Journal of Minerals,Metallurgy and Materials 2000年第1期14卷 34-37页

作者： ShiyongLuo Jiayun Zhang Jixiang Liu Metallurgy school, university of science and technology Beijing, Beijing 100083, china wuhan university of technology, wuhan 430070, china Univ Sci & Technol Beijing Met Sch Beijing 100083 Peoples R China wuhan Univ Technol Wuhan 430070 Peoples R China

Copper-cadmium halide doped photochromic glass coating on plate glass has been prepared by a sol-gel process. The sample shows reversible photochromic effect. The results of X-ray diffraction (XRD) and infrared (IR) spectrum investigations indicate that the photochromic phase of tile coating is CuBr_xCl_(1-x), solid solution, and that the structure network of the coating is connected with the bonds of Si-O-Si, Si-O-B and Si-O-Al.

关键词： photochromic glass coating sol-gel photochromic phase, structure network

Ferroelectric properties of Bi_(3.4)Ho_(0.6)Ti_3O_(12) thin films prepared by sol-gel method

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science china(Technological sciences) 2008年第9期51卷 1439-1444页

作者： FU ChengJu1, HUANG ZhiXiong1, LI Jie2 & GUO DongYun3 1 school of Materials science and technology, wuhan university of technology, wuhan 430070, china 2.school of Mechanical Engineering, Chongqing university of science and technology, Chongqing 400050, china 3 Department of Physics, wuhan university, wuhan 43.072, china school of Materials science and technology Wuhan University of Technology Wuhan 430070 China school of Mechanical Engineering Chongqing University of Science and Technology Chongqing 400050 China Department of Physics Wuhan University Wuhan 430072 China

We have prepared the Ho-substituted bismuth titanate (Bi3.4Ho0.6Ti3O12, BHT) thin films on Pt/Ti/SiO2/Si substrates using sol-gel method. The crystal structure and morphology of the films were characterized using X-ray diffraction and atomic force microscopy. The BHT film shows a single phase of Bi-layered Aurivillius structure and dense microstructure. The 2Pr and 2Ec of the 600-nm-thick BHT film were 38.4 μC/cm2 and 376.1 kV/cm, respectively at applied electric field 500 kV/cm. The dielectric constant and dielectric loss are about 310 and 0.015 at a frequency of 1 MHz, respectively. The Pr value decreased to 93% of its pre-fatigue values after 4.46×109 switching cycles at 1 MHz frenquency, and the BHT film shows good in-sulating behavior according to the test of leakage current.

关键词： Bi3.4Ho0.6Ti3O12 thin film sol-gel method ferroelectric property fatigue dielectric constant

Blank design optimization for stepped-section profile ring rolling

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science china(Technological sciences) 2010年第6期53卷 1612-1619页

作者： QIAN DongSheng & HUA Lin school of Materials science and Engineering,wuhan university of technology,wuhan 430070,china 1. school of Materials science and Engineering Wuhan University of Technology Wuhan 430070 China

A stepped-section ring consists of two rectangular section rings,a big ring and a small ring,joined *** kind of ring is difficult to process by the ring rolling technique because of its complex cross-sectional *** a reasonable blank design is *** this paper,four blank designs,one is a rectangular cross-section and the other three are stepped-sections with different step volumes,are proposed and compared with each other using theoretical analysis,FE simulation and *** is shown that three of the designs can lead to volume flow from small ring into big ring during rolling,which is disadvantageous for shape formation and dimensional precision;however,the other design may result in good ring shape and high dimensional ***,the optimal blank design is determined to be the one in which the volumes of the big and small rings of the initial blank are equal to those of the final rings,respectively.

关键词： ring rolling stepped-section ring optimization design FE simulation