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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 laser technology,{2., 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 laser technology,{2. university of science and technology,wuhan 430074,china 2.Department of Physics,{2. university of science and technology,wuhan 430074,china 1. State Key Laboratory of laser technology Huazhong University of Science and Technology 430074 Wuhan China 2. Department of Physics Huazhong University of Science and Technology 430074 Wuhan 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.

Structure and Magnetic Properties of Ni-doped ZnO Powder

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Journal of wuhan university of {2.(Materials science) 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

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,{2., 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

Structure and Properties of BaFe_(12.O_(19) Coated Fly Ash Cenospheres by Sol-Gel Process

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Journal of wuhan university of {2.(Materials science) 2006年第3期21卷 129-131页

作者：曾爱香 Department of Materials science and technology Changsha University of Science and TechnologyChangsha 410076ChinaState Kay Laboratry of Die and Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

Thin films of barium hexaferrite were prepared on fly ash cenosphere particles by the sol-gel method using Fe（ NO3 ）3 ·9H2., Ba（ NO3 ）2.and citric acid as raw materials. The prepared films were characterized by differential thermal and thermogravimetric analysis （DTA-TG）, X-ray diffraction analysis （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDX）, X-ray photoelectron spectroscopy （XPS）, and vibrating sample magnetometry . The magnetic and structural properties of barium hexaferrite coated cenosphere particles were also studied. The experimental results show that even and continual barium hexaferrite coatings were prepared on fly ash cenospheres , and the magnetic conductivity was imparted to these non-conducting oxide ceramic particles. The low density barium hexaferrite coated cenosphere particles may be atilized for manufacturing microwave absorbing materials.

关键词： barium hexaferrite coating fly ash cenosphere particles sol-gel

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,{2. 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

Convergence analysis for general linear methods applied to stiff delay differential equations

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Progress in Natural science:Materials International 2002年第6期12卷 16-22页

作者： ZHANG Chengjian(Department of Mathematics, huazhong university of science and technology, wuhan 430074,{2.) huazhong Univ Sci & Technol Dept Math Wuhan 430074 Peoples R China

For Runge-Kutta methods applied to stiff delay differential equations (DDEs), the concept of D-convergence was proposed, which is an extension to that of B-convergence in ordinary differential equations (ODEs) . In this paper, D-convergence of general linear methods is discussed and the previous related results are improved. Some order results to determine D-convergence of the methods are obtained.

关键词： D-convergence general linear methods stiff delay differential equations.

PEGylated PLGA Nanoparticles as Tumor Ecrosis Factor-α Receptor Blocking Peptide Carriers:Preparation,Characterization and Release in vitro

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Journal of wuhan university of {2.(Materials science) 2007年第1期22卷 112-116页

作者：刘卫杨祥良 College of Life science and technology Huazhong University of Science and Technology

To assess the merits of PEGylated poly （lactic-co-glycolic acid）（PEG-PLGA） nanoparticles as drug carriers for tumor necrosis factor-α receptor blocking peptide （TNFR-BP）, PEG-PLGA copolymer, which could be used to prepare the stealth nanoparticles, was synthesized with methoxypolyethyleneglycol, DL-lactide and glycolide. The structure of PEG-PLGA was confirmed with ^1H-NMR and FT-IR spectroscopy, and the molecular weight （MW） was determined by gel permeation chromatography. Fluorescent FITC-TNFR- BP was chosen as model protein and encapsulated within PEG-PLGA nanoparticles using the double emulsion method. Atomic force microscopy and photon correlation spectroscopy were employed to characterize the stealth nanoparticles fabricated for morphology, size with polydispersity index and zeta potential. Encapsulation efficiency （EE） and the release of FITC-TNFR-BP in nanopartieles in vitro were measured by the fluorescence measurement. The stealth nanoparticles were found to have the mean diameter less than 2.0 nm and zeta potential less than -2. mV. In all nanoparticle formulations, more than 45% of EE were obtained. FITC-TNFR-BP release from the PEG-PLGA nanoparticles exhibited a biphasic pattern, initial burst release and consequently sustained release. The experimental results show that PEG-PLGA nanoparticles possess the potential to develop as drug carriers for controlled release applications of TNFR-BP.

关键词： tumor necrosis factor-α receptor blocking peptide PEG-PLGA stealth nanoparticles ring-opening polymerization controlled and sustained drug release

A novel DNA computing model based on RecA-mediated triple-stranded DNA structure

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Progress in Natural science:Materials International 2007年第6期17卷 708-711页

作者： Fang Gang1, Zhang Shemin2. Dong Yafei1 and Xu Jin1(1. The Key Laboratory of Image Processing and Intelligent Control, Department of Control science & Engineering, huazhong university of science and technology,{2., china 2. Shaanxi university of technology, Hanzhong 72.000, china) [a]The Key Laboratory of Image Processing and Intelligent Control Department of Control Science & Engineering Huazhong University of Science and Technology Wuhan China [b]Shaanxi university of technology Hanzhong China

The field of DNA computing emerged in 1994 after Adleman’s paper was published. Henceforth,a few scholars solved some noted NP-complete problems in this way. And all these methods of DNA computing are based on conventional Watson-Crick hydrogen bond of doublehelical DNA molecule. In this paper, we show that the triple-stranded DNA structure mediated by RecA protein can be used for solving computational problems. Sequence-specific recognition of double-stranded DNA by oligonucleotide-directed triple helix (triplex) formation is used to carry out the algorithm. We present procedure for the 3-vertex-colorability problems. In our proposed procedure, it is suggested that it is possible to solve more complicated problems with more variables by this model.

关键词： DNA computing 3-vertex-colorability problem.