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Synthesis and Characterization of Ibuprofen-Rectorite Composites by Solution Intercalation Method

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Journal of wuhan university of Technology(Materials Science) 2009年第4期24卷 654-657页

作者：王慧燕 Hospital Wuhan University of Teehnology

The ibuprofen-rectorite composites were prepared by the solution intercalation method using ibuprofen and rectorite as raw materials, and were characterized by X-ray diffraction （XRD） analysis, Fourier transform infrared analysis and scanning electron microscopy （SEM）. The experimental results show that the ibuprofen is intercalated into the interlayer spaces of rectorite. The values of the （001） peaks of the ibuprofen-rectorite composite are larger than that of Na-rectorite and reach the largest when the reaction time and ibuprofen amount is 2.h and 0.36 g, respectively. The layered structure of Na-rectorite is destroyed to some extent with the intercalation of ibuprofen into the interlayer space in the structure of Na-rectorite. A part of ibuprofen in the ibuprofen Na-rectorite covers on the surface of Na-rectorite besides some ibuprofen enters into the interlayer space.

关键词： ibuprofen rectorite solution intercalation composites clay

Numerical study of the auroral particle transport in the polar upper atmosphere

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Science china(Technological Sciences) 2008年第10期51卷 1759-1771页

作者： CAI HongTao1,2. MA ShuYing1,2.& PU ZuYin3 1 {2. of Electronic Information, wuhan university,{2., china 2.Key Laboratory of Geospace Environment and Geodesy, Ministry of Education of PRC,{2., china 3 {2. of Earth and Space Sciences, Peking university, Beijing 100871, china school of Electronic Information Wuhan University Wuhan China Key Laboratory of Geospace Environment and Geodesy Ministry of Education of PRC Wuhan China school of Earth and Space Sciences Peking University Beijing China

Starting from the Boltzmann equation and with some reasonable assumptions, a one-dimensional transport equation of charged energetic particles is derived by taking account of major interactions with neutral species in the upper atmosphere, including the processes of elastic scattering, the excitation, the ionization and the secondary electron production. The transport equation is numerically solved, for a simplified atmosphere consisting only of nitrogen molecules (N2., to obtain the variations of incident electron fluxes as a function of altitude, energy and pitch angle. The model results can describe fairly the transport characteristics of pre-cipitating auroral electron spectra in the polar upper atmosphere; meanwhile the N2.ionization rates calculated from the modeled differential flux spectra also exhibit good agreements with existing empirical models in terms of several key parameters. Taking the energy flux spectra of precipitating electrons observed by FAST satellite flying over EISCAT site on May 15, 1997 as model inputs, the model-calculated ionization rate profile of neutral atmosphere consists reasonably with that recon-structed from electron density measurements by the radar.

关键词： aurora particle precipitation polar upper atmosphere electron transport equation numerical simulation

Energy Efficient Beacon Discovering Scheme for Node Localization in Wireless Sensor Networks

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wuhan university Journal of Natural Sciences 2010年第4期15卷 303-307页

作者： LIU Xinxin1,2. ZHAO Erdun3, CHEN Kun2.1. {2. of {2.,{2., wuhan 430072. Hubei, china 2. wuhan Digital Engineering Research Institute, wuhan 430074, Hubei, china 3. Department of {2. Science, Huazhong Normal university, wuhan 430079, Hubei, china school of computer Wuhan University Wuhan Hubei China wuhan Digital Engineering Research Institute Wuhan Hubei China Department of computer Science Huazhong Normal University Wuhan Hubei China

Efficient sensor node localization is a crucial part of many location-dependent applications that utilize wireless sensor networks (WSNs). To cope with the problem of insufficient bea-con node for localization,we design a beacon discovery protocol in this paper that helps the blind node to find beacons nearby and present an energy efficient scheme for the beacon that receives the request from a blind node to adjust its radio range. We obtain the relationship between the mean energy consumption with adjust-ment number by the mathematical analysis. Numerical results show that great energy saving is achieved when the optimal ad-justment number is adopted.

关键词： localization wireless sensor networks energy- efficient radio range adjustment

Fractal Analysis of Gas Diffusion Layer in PEM Fuel Cells

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Journal of wuhan university of Technology(Materials Science) 2006年第1期21卷 22-25页

作者：石英肖金生 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070ChinaSchool of Automation Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070ChinaSchool of Automotive EngineeringWuhan University of Technology Wuhan 430070China

The aim of this study is to show how fractal analysis can be effectively used to characterize the texture of porous solids. The materials under study were carbon papers, the backing material of the gas diffusion layer （GDL） in Proton Exchange Membrane Fuel Cell （PEMFC）. The fractal dimensions were calculated by analyzing data from mercury porosimetry. The polytotrafluoroethylene （PTFE） treated carbon paper shows a significantly high fractal dimension value than pare sample, and the high fractal dimension signifies that the physical complexity of the pore surface is enhanced. The fractal dimension can be used as a valid parameter to monitor the textural evolution of the samples as the treatment progresses, as this behaves in a similar way to other textural parameters. The use of fractal analysis in conjunction with the results of classical characterization methods leads to a better understanding of textural modificatious in the processing of materials.

关键词： PEMFC gas diffusion layer fractal dimension mewury porosimetry

Preparation of PLL-PEG-PLL and its application to DNA encapsulation

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Science china Chemistry 2006年第4期49卷 357-362页

作者： YANG Zigang1, ZHOU Fen1, YUAN Jianjun1, MA Lixin2. ZHAI Chao2.& CHENG Shiyuan1 1. {2. of Chemistry and Materials Science, Hubei university,{2. 430062. china 2. {2. of Life Science, Hubei university,{2. 430062. china school of Chemistry and Materials Science Hubei University Wuhan China school of Life Science Hubei University Wuhan China

PLL-PEG-PLL was synthesized by deprotection of the amino group of PLL(Z)-PEG-PLL(Z). The properties of the polyion complex (PIC) micelles comprising of PLL-PEG-PLL and DNA were investigated. The results showed that the core of PIC was formed by PLL and DNA through electrostatic interactions, and PEG was shell of PIC, so PIC micelles in aque- ous medium were homogenous with no precipitation even under the neutral condition, and PIC had the characteristic of stability, which were very important in gene therapy. At the same time, the results showed PLL-PEG-PLL could condense DNA, longer PLL blocks were generally more effective at condensation, and the nuclease resistance of DNA was increased remarkably. PIC was spherical with diameter of 10―35 nm, which could be easily taken up by cells. Transfection experiments in vitro showed that the DNA encapsulated could be expressed in the cell line SF9.

关键词： poly(L-Lysine), poly(ethylene glycol), block copolymer, DNA, polyion complex micelles (PIC).

Locating the Polar Cap Boundary of Postnoon Sector from Observations of 630.0 nm Auroral Emission at Zhongshan Station

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wuhan university Journal of Natural Sciences 2002年第1期7卷 59-64页

作者： Liu Li-gang 1, Ai Yong 1, Liu Rui-yuan 2. Yang Hui-gen 2.1. {2. of Electronic Information,{2.,{2. 430072. Hubei, china 2. Polar Research Institute of china, Shanghai 2.012., china school of Electronic Information Wuhan University Wuhan Hubei China Polar Research Institute of china Shanghai China

We studied the ground observations of 630.0 nm auroral emission at Zhongshan Station to determine the polar cap boundary with the latitudinal profile of emission intensity. The open-closed field time boundary is assumed to lie at the boundary between polar rain and plasma sheet precipitation. We assume that nonprecipitation-dependent sources of 630.0 nm emission cause a spatially uniform luminosity in the polar cap and that auroral zone luminosity is also spatially uniform. Therefore we determine the location of the polar cap boundary of postnoon sector from the auroral emission data each time by finding the best fit of the observations to a step function in latitude and we produce a time series of the location of the polar cap boundary. The average error of the practice in the paper is less than 0.8 degree.

关键词： polar cap boundary aurora Zhongshan Station

Indoor imitation experimental study on driving factors of rainfall-runoff process

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Science china Earth Sciences 2005年第3期48卷 417-428页

作者： zhang Shifeng1, LIU Changming 1, XIA Jun1, TAN Ge 1, LI Lin1, LIU Caitang1, ZHOU Changqing 1 & GUO Lei2.1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101,{{2. {2. College of Water Resources and Hydropower Engineering,{2., wuhan 43007{2.{{2. Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China College of Water Resources and Hydropower Engineering Wuhan University Wuhan China

The driving actions of rainfall-runoff process can be attributed to two aspects. The first is the influence of precipitation process, and the second is that of the ground pad. The re- search results of 179 indoor experiments conducted to imitate rainfall-runoff process indicate that both precipitation duration and intensity play important roles in affecting confluence lag time, which is obviously inconsistent with the traditional hypotheses. The nonlinear relationship is of great significance to the confluence curve especially when the precipitation duration is less than the total confluence time or the precipitation intensity is small. Therefore it can be concluded that the unit hydrograph (UH) can be applied to rainfall-runoff process imitation in the humid areas in the south china region. However, the UH application should be strictly modified in accordance with precipitation conditions in the arid and semiarid region of north china where the precipitation duration is short and the intensity is unstable. It will be hard to get ideal imitation results if the UH is applied blindly without considering specific conditions in the north china region. This also explains the unsatisfactory imitation results caused by using various hydrological models in the north china region. When the precipitation duration is short, and the watershed has not reached total watershed concentration, the characteristics of confluence change greatly, which reflects the actual situation in the north china region. Therefore necessary nonlinear corrections should be made when UH is applied. If the duration is longer than the total confluence time and the balance between pondage and discharge is stricken, the imitation research results will be applicable to both rainfall-runoff relation with longer duration in the south china region and the basic theoreti- cal research on runoff generation and concentration. On conditions of adequate rainfall, peak discharge is in linear relationship with inten

关键词： rainfall-runoff, driving factors, indoor imitation, experiment.

Fabrication and Characterization of Nano Silver Powder Prepared by Spray Pyrolysis

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Journal of wuhan university of Technology(Materials Science) 2009年第6期24卷 871-874页

作者：章桥新 school of Mechanical and Electronic Engineering Wuhan University of Technology State Key Laboratory of Advanced Technology for Materials Synthesis & Processing Wuhan University of Technology

Silver powder was fabricated by spray pyrolysis, using 2.-2.% AgNO3 solution, 336-500 mL/h flux of AgNO3 solution, 0.2.-0.32.MPa flux of carrier gas and in the 62.-82. ℃ temperature range. The effects of furnace set temperature, concentration of AgNO3 aqueous solution, flux of AgNO3 aqueous solution as well as carrier gas on the morphology and particle size distribution of silver powder, were investigated. The experimental results showed that with the high concentration of AgNO3 aqueous solution, the average grain size of silver decreased with the increasing of furnace set temperature. But the gain size distribution was not homogenous, the discontinuous grain growth occurred. With the low concentration of AgNO3 aqueous solution, the higher furnace set temperature made the nano sliver grains sintered together to grow. Nano silver powder about 100 nm was fabricated by spray pyrolysis, using 2.t% AgNO3 solutions, 336 mL/h flux of AgNO3 aqueous solution, 0.32.MPa flux of carrier gas at 72. ℃ furnace set temperature.

关键词： nano silver powder fabrication characterization spray pyrolysis

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,{2. of Optoelectronic Science and Engineering,Huazhong{2. of Science and Technology,wuhan 430074,china 2.{2. of Science,wuhan{2. of Technology,wuhan 430070,china wuhan National Laboratory for Optoelectronics School of Optoelectronic Science and Engineering Huazhong University of Science and Technology Wuhan China school of Science Wuhan University of Technology Wuhan 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