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Evolution of Bright Screening-photovoltaic Spatial Optical Solitons

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Chinese Journal of lasers 2001年第5期10卷 28-33页

作者： LIU Jinsong (state key Laboratory of {2. Technology, {3. university of science and Technology, wuhan 430074, china) 华中科技大学激光技术国家重点实验室湖北武汉

A numerical analysis of the dynamical evolution of bright screening photovoltaic (SP) spatial solitons in biased photovoltaic photorefractive materials in the case of neglecting the material loss and the diffusion is presented. When an incident optical beam is a bright SP soliton, the beam propagates along a linear path with its shape kept unchanged. When the incident optical beam is slightly different from a bright SP soliton, the beam reshapes itself and tries to evolve into a bright SP soliton after a short distance. However, when the incident optical beam is significantly different from a SP bright soliton, the beam cannot evolve into a stable bright SP soliton, and tends to experience periodic compression and expansion. For a low intensity input beam, the wave experiences a periodic process of compression first and then expansion during the initial part of the cycle. For a high intensity input beam, however, the wave will initially diffract and then experiences compression during the cycle.

关键词： nonlinear optics spatial optical solitons photorefractive effects

Exact eigenstates for a class of models describing multiphoton processes in the presence of seven bosonic modes

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science china(Physics,Mechanics & Astronomy) 2004年第6期47卷 649-657页

作者： ZHAN Zhiming1,LI Weibin2.YOU Jun2.XIE Xiaotao2.& YANG Wenxing2.1.state key Laboratory of {2. Technology,{3. university of science and Technology,wuhan 430074,china 2.Department of Physics,{3. university of science and Technology,wuhan 430074,china state key Laboratory of {2. Technology Huazhong University of Science and Technology Wuhan 430074 China Department of Physics Huazhong University of Science and Technology Wuhan 430074 China

We present the analytical expressions of eigenstates and eigenenergies by using a parameter λ without the assumption of Bethe anzatz for three kinds of seven-bosonic-mode mixing models. The parameter is shown to be determined by the roots of a simple polynomial. We also demonstrate the exact analytical expressions of eigenstates and energies without any unknown parameter.

关键词： spectra, eigenstate, eigenvalue.

Spectral anomalies and spectral switches of partially coherent and polychromatic light diffracted at an aperture

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science china(Physics,Mechanics & Astronomy) 2004年第1期47卷 24-35页

作者： Lü Baida1, 3.& PAN Liuzhan1, 2.1. Institute of laser Physics and Chemistry, Sichuan {2., Chengdu 610064, china 2. Department of Physics, Luoyang Normal College, Luoyang 47102., china 3. state key Laboratory of laser Technology, huazhong {2. of science and Technology,{12., china Correspondence should be addressed to L Baida (email: badalu@***) Received July 10, 2.03 Institute of laser Physics and Chemistry Sichuan University Chengdu China state key Laboratory of {2. Technology Huazhong University of Science and Technology Wuhan China Department of Physics Luoyang Normal College Luoyang China

Based on the propagation theory of partially coherent light in the space-frequency domain, the anomalous spectral behavior and spectral switches in the far field of partially coherent and polychromatic light diffracted at an aperture are studied. It is shown that, as compared with spatially fully coherent and polychromatic light whose spectral anomalies are induced only by aperture diffraction, the spectral anomalies and spectral switches of partially coherent and polychromatic light depend on the aperture diffraction, spatial correlationβ and bandwidth of the original spectrum. Detailed numerical calculations are made to illustrate the behavior of spectral switches of partially coherent and polychromatic light, and the results for spatially fully coherent and polychromatic light are treated as a special case ofβ=1 and included in our theory.

关键词： spectral anomaly spectral switch partially coherent and polychromatic light far field aperture diffraction

Effect of Powder Particle Size on the Properties and Microstructure of Ti(C,N)-Based Cermet

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Rare Metals 2001年第1期20卷 47-51页

作者： Yong Zheng, Weihao Xiong (key state Laboratory of Die Technology, {2. {3. of science and Technology, wuhan 430074, china) 华中科技大学材料成形与模具技术国家重点实验室湖北武汉 430074

The influence of raw powder particle size on the properties and microstructures of Ti (C, N)-based cermets has been studied. The conclusions are as follows: The microstructures of cermets were composed of two kinds of grains, the one with black cores surrounded by obvious rim structures, and the other whose cores were white with unconspicuous rim structures and adhesive phase. In the cermet made from fine powders, the amount of grains with white cores was much more than that in cermet made from coarse powders. In addition, their properties were also much better.

关键词： Ti(C, N)-based cermet powder particle size property microstructure

Removal of elemental mercury by iodine-modified rice husk ash sorbents

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Journal of Environmental sciences 2010年第10期22卷 1629-1636页

作者： Pengfei Zhao,Xin Guoff,Chuguang Zheng state key Laboratory of Coal Combustion,{2. {3. of science and Technology,wuhan 430074,china state key Laboratory of Coal Combustion Huazhong University of Science and Technology

Iodine-modified calcium-based rice husk ash sorbents （I2.CaO/RHA） were synthesized and characterized by X-ray diffraction, X-ray fluorescence, and N2.isotherm adsorption/desorption. Adsorption experiments of vapor-phase elemental mercury （Hg^0） were performed in a laboratory-scale fixed-bed reactor. I2.CaO/RHA performances on Hg^0 adsorption were compared with those of modified Cabased fly ash sorbents （I2.CaO/FA） and modified fly ash sorbents （I2.FA）. Effects of oxidant loading, supports, pore size distribution, iodine impregnation modes, and temperature were investigated as well to understand the mechanism in capturing Hg^0. The modified sorbents exhibited reasonable efficiency for Hg^0 removal under simulated flue gas. The surface area, pore size distribution, and iodine impregnation modes of the sorbents did not produce a strong effect on Hg^0 capture efficiency, while fair correlation was observed between Hg^0 uptake capacity and iodine concentration. Therefore, the content of 12.impregnated on the sorbents was identified as the most important factor influencing the capacity of these sorbents for Hg^0 uptake. Increasing temperature in the range of 80-140℃ caused a rise in Hg^0 removal. A reaction mechanism that may explain the experimental results was presumed based on the characterizations and adsorption study.

关键词： mercury sorbents fly ash rice husk ash iodine impregnation

HCWCI/Carbon Steel Bimetal Liner by Liquid-Liquid Compound Lost Foam Casting

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Journal of Iron and Steel Research International 2012年第10期19卷 13-19页

作者： XIAO Xiao-feng1,2. YE Sheng-ping2. YIN Wei-xin3. XUE Qiong4 (1. School of Mechanical Engineering and Automation, wuhan Textile {2., wuhan 43.073. Hubei,{3. 2. state key Laboratory of Material Processing and Die and Mould Technology, huazhong {2. of science and Technology,{12., Hubei,{3. 3. wuhan Zhike Abrasive-Resistant Material science and Technology Development Co Ltd, wuhan 43.073. Hubei,{3. 4. College of science, wuhan {2. of Technology, wuhan 43.079, Hubei,{3.) School of Mechanical Engineering and Automation Wuhan Textile University Wuhan Hubei China state key Laboratory of Material Processing and Die and Mould Technology Huazhong University of Science and Technology Wuhan Hubei China wuhan Zhike Abrasive-Resistant Material science and Technology Development Co Ltd Wuhan Hubei China College of science Wuhan University of Technology Wuhan Hubei China

Impact, friction and corrosion from the grinding balls and the grinding medium during the mineral processing result in liner breakage. Liner, made from Hadfield steel or alloyed steel, could not have served in wet grinding environment for more than ten months. Composite liner, made from HCWCI (high Cr white cast iron) and carbon steel, has been developed successfully with liquid-liquid composing process based on LFC (lost foam casting). The microstructure of composite was analyzed with optical microscope, SEM (scanning electron microscope)/EDX energy-dispersive X-ray and XRD (X-ray diffraction). According to micrograph, the combination region of two metals was staggered like dogtooth, no mixtures occurred between two liquid metals, and its interface presented excellent metallurgical bonding state. The results of mechanical property test show that, the hardness of HRC, the fracture toughness, and the bending strength are more than 61, 16.5 J/cm2.and 1 600 MPa, respectively. Comparison between liners made from bimetal composite and alloyed steel has also been investigated in industrial hematite ball mill. The results of eight months test in wet grinding environment prove that the service life of bimetal composite liner is three times as long as that of one made from alloyed steel.

关键词： composite liner bimetal liquid-liquid compound composite interface lost foam casting high Cr white cast iron

Numerical simulation of the transient multiphase field during plasma deposition manufacturing composite materials

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science china(Physics,Mechanics & Astronomy) 2009年第4期52卷 508-517页

作者： KONG FanRong1,2.ZHANG HaiOu1 & WANG GuiLan3.1 state {2. Laboratory of Digital Manufacturing Equipment and Technology,huazhong {3. of science and Technology,wuhan 430074,china 2.Research Center for Advanced Manufacturing,Southern Methodist {3.,3.01 Dyer Street,Dallas,Texas 752.5,USA 3.College of Material science and Engineering,huazhong {3. of science and Technology,wuhan 430074,china state key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology Wuhan China Research Center for Advanced Manufacturing Southern Methodist University Dallas USA College of Material science and Engineering Huazhong University of Science and Technology Wuhan China

A solid/liquid/gas unified model has been developed to investigate the gradient composition formation during the plasma deposition manufacturing(PDM) composite materials process. In this model,an enthalpy porosity model was applied to deal with the melting and solidification of the deposited layer,and a level-set approach was introduced to track the evolution of the free surface of the molten pool and the deposited layer. Moreover,complicated physical phenomena occurring at the liquid/gas interface,including forced convection heat loss,heat emission and plasma heat source,have been incorporated into the governing equations by source terms. In this study,the numerical experiment of nickel base alloy powder deposited on the medium steel substrate by PDM technique was implemented based on the staggered grid and SIMPLEC algorithm. Concentration gradient distribution of the solute material at the composite material interface,fluid flow and temperature distribution in the molten pool and the deposited layer have been investigated in detail.

关键词： plasma deposition manufacturing composite material solid/liquid/gas unified model level-set approach

Modeling and simulation of heat transfer for glass bulb mold

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Progress in Natural science:Materials International 2005年第7期15卷 650-655页

作者： ZHOU Huamin and LI Dequn (state key Laboratory of Mold & Die Technology, {2. {3. of science and Technology, wuhan 430074, china) state key Laboratory of Mold & Die Technology Huazhong University of Science and Technology Wuhan 430074 China

Cooling system design in glass bulb pressing operation can greatly affect the productivity and the quality of the final product. The concept of cyclic-averaged steady temperature field is proposed in modeling. Heat transfer in the mold region is considered to be a cyclic-steady, three-dimensional conduction; heat transfer within the glass melt region is treated as a transient, one-dimensional conduction; heat exchange between the cooling system surface and coolant is treated as a steady heat convection. A hybrid model consisting of a three-dimensional boundary element method for the mold region and a finite-difference method with a variable mesh for the melt region is used for numerical simulation. Compared with the experimental data, the numerical model developed here is computationally efficient and sufficiently accurate.

关键词： glass bulb mold numerical simulation boundary element method cyclic-averaged steady temperature field.

Preparation of Oriented Barium Titanate Thin Films by Combination of Electrophoretic Deposition with Hydrothermal Treatment

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Journal of Materials science & Technology 2010年第11期26卷 996-1000页

作者： Lihong Xue and Youwei Yan state key Laboratory of Materials Processing and Die and Mould Technology,{2. {3. of science and Technology,wuhan 430074,china state key Laboratory of Materials Processing and Die and Mould Technology Huazhong University of Science and Technology Wuhan 430074 China

Highly oriented barium titanate （BaTiO 3. thin films on Pt substrate were fabricated by combination of electrophoretic deposition with hydrothermal *** structure and morphology of thin films were characterized by X-ray diffraction and field-emission scanning electron *** is found that the titania precursor film,Ba（OH）2.concentration and hydrothermal temperature play crucial roles in the film morphology and *** BaTiO3.thin films with highly （110） preferred orientation can be formed on polycrystalline Pt substrate by appropriate adjustment of the reaction *** orientation parameter f of highly oriented BaTiO3.films was up to *** films exhibited a smooth and crack-free surface and remained in the layered *** situ topotactic transformation and dissolution-crystallization mechanisms were proposed to explain the morphology and orientation of BaTiO3.films during hydrothermal treatment.

关键词： Barium titanate Preferred orientation Electrophoretic deposition Hydrothermal treatment