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Synthesis, Characterization and Flame-retardant Properties of Epoxy Resins and AACHH Composites

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Journal of wuhan university of {2.(Materials {3.) 2009年第5期24卷 763-767页

作者：秦麟卿 State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of Technology

Flame retardant epoxy resins were prepared by a simple mixed method using ammonium aluminum carbonate hydroxy hydrate （AACHH） as a halogen-free flame retardant. The prepared samples were characterized by X-ray diffraction, thermogravimetric and differential scanning calorimetry, scanning electron microscope and limiting oxygen index（LOI） experiments. Effects of AACHH content on LOI of epoxy resins/AACHH composite and flame retardant mechanism were investigated and discussed. Results show that AACHH exhibites excellent flame-retardant properties in epoxy resin（EP）. When the content of AACHH was 47.4%, the LOI of EP reached 3.0}2.. Moreover, the initial and terminal decomposition temperature of EP increased by 48 ℃ and 40 ℃, respectively. The flame retarded mechanism of AACHH is due to the synergic flame retardant effects of diluting, cooling, decomposition resisting and obstructing.

关键词： epoxy resin(EP) flame retardant ammonium aluminum carbonate hydroxy hydrate (AACHH) composite

3.D Lightning Location Solution and Precision Analysis of Cloud Flash

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wuhan university Journal of Natural {2.s 2009年第3期14卷 241-244页

作者： ZHANG Ping1,2. ZHAO Wenguang2.3., HU Zhixiang2.3. WEN Yinping2.3.1. school of Architecture and Urban Planning, Huazhong university of {2. and {3., wuhan 43.074, Hubei, China 2. school of Civil Engineering and Mechanics, Huazhong university of {2. and {3., wuhan 43.074, Hubei, China 3. Hubei Key Laboratory of Control Structure, Huazhong university of {2. and {3., wuhan 43.074, Hubei, China school of Architecture and Urban Planning Huazhong University of Science and Technology Wuhan 430074 Hubei China school of Civil Engineering and Mechanics Huazhong University of Science and Technology Wuhan 430074 Hubei China Hubei Key Laboratory of Control Structure Huazhong University of Science and Technology Wuhan 430074 Hubei China

Using the spatial coordinates of detection stations and the time of arrival of lightning wave, the observation equations can be expressed. For the large lightning detection network, the least square method is used to process the adjustment of observation data to find the most probable value of lightning position, and the result is assessed by the mean error and dilution of precision. Lightning location precision is affected by figure factor. The conclusion can be used in the design of location network, data processing, and data analysis.

关键词： 3.D lightning location cloud flash detection solution model dilution of precision figure factor

Polarity for a Class of Levy Processes

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wuhan university Journal of Natural {2.s 2002年第4期7卷 394-398页

作者： Wu Chuan ju 1,2., Liu Lu qin 1 1. school of Mathematics and Statistics, wuhan {2., wuhan 43.072. Hubei, China 2. College of Urban Construction, wuhan {2. of science and technology, wuhan 43.070, Hubei, China wuhan university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) wuhan university of {2. and {3. College of Urban Construction Wuhan Hubei China (GRID:grid.412787.f) (ISNI:***) wuhan university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

Polar set of Markov processes is an important concept in probabilistic potential theory, but it is not easy to judge the polarity of the sets. In this paper, we give some results which can be easily used to examine the polarity of the sets whenX t belongs to a special class of Levy processes. We also give a result about polar functions of symmetric stable processes.

关键词： Levy process subordinator (essentially) polar set polar function

Structure and Magnetic Properties of Ni-doped ZnO Powder

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Journal of wuhan university of {2.(Materials {3.) 2010年第5期25卷 770-773页

作者：高放赵俊 Department of Electronic science and technology Huazhong University of Science and Technology

Ni-doped ZnO nanopowder （Zn0.98Ni0.2.） was synthesized by improved coprecipitation method. The average particle size of the powder was estimated to be 50 nm. The powder was then processed by thermal treatment. Samples were annealed at 1 073. 1 2.3. and 1 473.K, respectively. The solubility of NiO in ZnO and the lattice parameters of ZnO both increased with the temperature. The magnetic property of the doped samples was examined, and hysteresis loops were got. The results showed all the samples were ferromagnetic, while powder processed at 1 2.3.K for 4 h got a highest saturation magnetization （Ms） of 0.0457 emu/g. Also, magnetic properties were related to the grain size of the powder.

关键词： ferromagnetism diluted magnetic semiconductor Ni-doped ZnO coprecipitation solid state reaction

Effect of Tin on the Reaction Synthesis of Ternary Carbide Ti_3.lC_2

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Journal of wuhan university of {2.(Materials {3.) 2009年第2期24卷 283-286页

作者：周卫兵 school of Materials science and Engineering Wuhan University of Technology

The effect of tin on synthesis of Ti3.lC2.by spark plasma sintering （SPS） from TiC/Ti/Al powders was investigated. X-ray diffraction （XRD） and scanning electron microscopy （SEM） were used for phase identification and microstructure evaluation. The experimental results show that addition of tin can considerably accelerate the synthesis reaction of Ti3.lC2.and fully dense, essentially single-phase polycrystalline Ti3.lC2.could be successfully obtained by sintering 2.iC/1Ti/1Al/0.2.n powders at 12.0-12.0 ℃ under a pressure of 3. MPa. SEM images show that Ti3.lC2.samples in about 2.5 μm thick and 10-2.μm long platelets can be obtained. The fracture toughness and flexural strength of Ti3.lC2.were 6.5±0.2.MPa·m^1/2.and 560±10 MPa, respectively.

关键词： titanium aluminum carbide spark sintering technique synthesis

Segregation of Molten Salt on Chromizing in Thermal Diffusion Process

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Journal of wuhan university of {2.(Materials {3.) 2011年第6期26卷 1189-1192页

作者：王洪福 school of Mechanical Engineering and automation North University of China

The segregation of thermal diffusion salt bath chromizing process was analyzed. The experimental chromizing ingredients were prepared by the four groups A, B, C, and D. In order to study the segregation status of this case, the cooling molten salt in the crucible was removed by drilling from the heart core of molten salt. The core of molten salt was analyzed by X-ray fluorescence spectroscopy and XRD. Through the analysis, we can conclude that the Cr element deposited in the bottom was 4.51 times than the top. Chloride added to the molten salt will reduce segregation. Meantime we proposed some measures to overcome the segregation problem.

关键词： segregation thermal diffusion process chromizing

A Note on Abelian Extensions

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wuhan university Journal of Natural {2.s 2008年第1期13卷 6-8页

作者： YU Chuxiong1,2. FAN Yun3.1. school of Mathematics and Statistics, wuhan {2., wuhan 43.072. Hubei, China 2. school of Mathematics and Computer science, Jianghan {2., wuhan 43.056, Hubei, China 3. school of Mathematics and Statistics, Huazhong Normal {2., wuhan 43.079, Hubei, China school of Mathematics and Statistics Wuhan University Wuhan 430072 Hubei China

Let K/Q be any abelian extension where Q is the field of rational numbers. By Galois theory and the Frobenius formula for induced characters, we prove that there exists a metabelian group G and an irreducible characte... 详细信息

关键词： abelian extensions metabelian groups induced characters Galois groups

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 {2.,Huazhong {3. of science and {2.,wuhan 43.074,China 1. school of Computer science and {2. 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 3. instances and reproduce the best-known results on the remaining 113.instances.

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

Multi-spectral image fusion method based on two channels non-separable wavelets

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science in China(Series F) 2008年第12期51卷 2022-2032页

作者： LIU Bin1,2.& PENG JiaXiong3.1 school of Mathematics and Computer science, Hubei {2., {3. 43.062. China 2.Key Laboratory of Applied Mathematics of Hubei Province, {3. 43.062. China 3.Institute of Image Recognition and Artificial Intelligence, Huazhong {2. of science and technology, {3. 43.074, China 1. school of Mathematics and Computer science Hubei University Wuhan 430062 China 2. Key Laboratory of Applied Mathematics of Hubei Province Wuhan 430062 China 3. Institute of Image Recognition and Artificial Intelligence Huazhong University of Science and Technology Wuhan 430074 China

A construction method of two channels non-separable wavelets filter bank which dilation matrix is [1, 1; 1,-1] and its application in the fusion of multi-spectral image are presented. Many 4×4 filter banks are designed. The multi-spectral image fusion algorithm based on this kind of wavelet is proposed. Using this filter bank, multi-resolution wavelet decomposition of the intensity of multi-spectral image and panchromatic image is performed, and the two low-frequency components of the intensity and the panchromatic image are merged by using a tradeoff parameter. The experiment results show that this method is good in the preservation of spectral quality and high spatial resolution information. Its performance in preserving spectral quality and high spatial information is better than the fusion method based on DWFT and IHS. When the parameter t is closed to 1, the fused image can obtain rich spectral information from the original MS image. The amount of computation reduced to only half of the fusion method based on four channels wavelet transform.

关键词： image fusion non-separable wavelets multi-spectral image panchromatic image