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Electrochemical behavior of Ce(III) in LiF-BaF_2 melts

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Journal of Rare Earths 2012年第2期30卷 151-154页

作者：林如山叶国安何辉唐洪彬欧阳应根 Department of Radiochemistry China Institute of Atomic Energy

The electrochemical behavior of Ce（III） was investigated in the molten LiF-BaF2 （81 mol.%-19 mol.%） on a molybdenum elec-trode in the temperature range of 1098-1188 K using cyclic voltammetry and chronopotentiometry. It was observed that CeF3 could be re-duced into cerium metal in a reversible one-step process exchanging three electrons （Ce（III）＋3e-→Ce（0）） at the operating temperatures on a molybdenum cathode. The electrochemical reduction process was controlled by the diffusion of Ce（III） in the solution. The Ce（III） diffusion coefficients were calculated at different temperatures and the values obeyed the Arrhenius law with an activation energy of 87.5 kJ/mol.

关键词： molten salt fluoride electrochemistry cerium LiF-BaF2 rare earths

Vibration Suppression Analysis for Supporter with Constrained Layer Damping

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Journal of Harbin Institute of Technology(New Series) 2004年第2期11卷 231-236页

作者：杜华军邹振祝黄文虎 School of Astronautics Harbin Institute of Technology Harbin 150001 China School of Astronautics Harbin Institute of Technology Harbin 150001 Chinay analyzing the correlation between modal calculations and modal experiments of a typical supporter an effective finite element analysis(FEA)model of the actual aerospace supporter is created. According to the analysis of constrained viscoelastic damping the strategies of PVC have been worked out and the correlation between modal calculations and modal experiments of the supporter has also been computed and then an experiment has been designed based on the calculation results. The results of experiments verify that the PVC strategy can effectively suppress vibration.

By analyzing the correlation between modal calculations and modal experiments of a typical supporter, an effective finite element analysis( FEA)model of the actual aerospace supporter is created. According to the analysis of constrained viscoelastic damping, the strategies of PVC have been worked out, and the correlation between modal calculations and modal experiments of the supporter has also been computed, and then, an experiment has been designed based on the calculation results. The results of experiments verify that the PVC strategy can effectively suppress vibration.

关键词： passive vibration control constrained damping structural optimization

INFLUENCES OF ACID POST-TREATMENT ON THE MORPHOLOGY OF SOAP-FREE P(MMA-EA-MAA)PARTICLES PREPARED BY SEEDED EMULSION POLYMERIZATION

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Chinese Journal of Polymer Science 2005年第5期23卷 479-485页

作者： Kai Kang Cheng-you Kan Yi Du De-shan Liu Department of Chemical Engineering,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China Department of Chemical Engineering School of Materials Science and Engineering Tsinghua University Beijing 100084 China

Soap-free poly（methyl methacrylate-ethyl acrylate-methacrylic acid） latex particles with narrow size distribution were synthesized by seeded emulsion polymerization, and the porous particles were created by a stepwise alkali/acid treatment method. Effects of acid treatment conditions on the particle morphology were investigated. Results show that one to three pores were formed inside most of particles after post-treatment. At pH 7.0, when the treatment temperature was lower than 70℃, the size of particles and the volume of pores remained almost unchanged, and these two values increased significantly when the temperature was higher than 70℃. Both the particle size and the pore volume decreased with the increase of initial pH value and treatment time in the acid treatment. As the pH was below 4.0 and the treatment time was longer than 180 min, the particles shrunk in size.

关键词： Soap-free emulsion polymerization Particle morphology Porous structure Acid treatment Methyl methacrylate based copolymer.

A new algorithm for microwave radiometer remote sensing of sea surface salinity and temperature

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Science China Earth Sciences 2006年第11期49卷 1204-1211页

作者： YIN Xiaobin1, LIU Yuguang1, WANG Zhenzhan2 & XIU Peng1 1. Physical Oceanography Laboratory, Ocean University of China, Qingdao 266003, China 2. Center for Space and Applied Research, Chinese Academy of Sciences, Beijing 100080, China Physical Oceanography Laboratory Ocean University of China Qingdao China Center for Space and Applied Research Chinese Academy of Sciences Beijing China

The microwave radiation of the sea surface, which is denoted by the sea surface brightness temperature, is not only related with sea surface salinity (SSS) and temperature (SST), but also influenced by sea surface wind. The errors of wind detected by satellite sensor have significant influences on the accuracy of SSS and SST retrieval. The effects of sea surface wind on sea surface brightness temperature, i.e. △Th,v, and the relations among △Th,v, wind speed, sea surface tempera- ture, sea surface salinity and incidence angle of observation are investigated. Based on the investi- gations, a new algorithm depending on the design of a single radiometer with double polarizations and multi-incidence angles is proposed. The algorithm excludes the influence of sea surface wind on SSS and SST retrieval, and provides a new method for remote sensing of SSS and SST.

关键词： microwave radiometer, sea surface temperature, sea surface salinity, wind, brightness temperature.

Polynomial algorithm of limited propositional deduction

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Science China(Technological Sciences) 1999年第4期42卷 418-424页

作者：史忠植廖乐健 Institute of Computing Technology Chinese Academy of Sciences Beijing China

For the problem of propositional satisfiability a polynomial algorithm of limited propositional deduction is proposed which can be viewed as a sort of boolean constraint propagation mechanism. It can be embodied in a backtracking search program for propositional satisfiability problems to make search efficient. The efficiency is gained in two ways:One is to use the algorithm to derive literals so as to overcome the ambiguities in search. The other is to exploit the consequence sets of unbound atoms generated during limited deduction as a heuristic measure for possible choices. The experiments have shown remarkable improvement in reducing search space.

关键词： limited propositional deduction polynomial algorithm problem of propositional satisfiability constraint satisfaction problem

The wavelet analysis of satellite sea surface temperature in the South China Sea and the Pacific Ocean

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Chinese Science Bulletin 2000年第23期45卷 2187-2192页

作者： WEI Enbo The Physical Oceanography Laboratory Ocean University of QingdaoQingdao 266003China

Using wavelet transform, the sea surface temperature (SST) during the period of 1982-1999 of the South China Sea and the equatorial Pacific, from datasets of NOAA/AVHRR, was analyzed. It is shown that there are 4- and 8-year interannual oscillations in the eastern equatorial Pacific and 8-year interannual oscillation in the western equatorial Pacific. In terms of attractive time-frequency localization and multi-scale properties of wavelet transform, as shown by the Morlet wavelet, it is found that an in-phase coupling oscillation occurs between the SCS and the equatorial Pacific. The SST changes of SCS will have echoed every event of El Nino (abnormally warm) and La Nina (abnormally cold) in the equatorial Pacific. There is a positive correlation between the SCS and the western equatorial Pacific in the 8-year time-scale. Evidence is presented that the SST anomalies of the equatorial Pacific influence the SST of the SCS.

关键词： SST the South China Sea the Pacific El Nino wavelet transform remote sensing

APPROACH TO IMPROVEMENT OF ROBOT TRAJECTORY ACCURACY BY DYNAMIC COMPENSATION

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Chinese Journal of Mechanical Engineering 2004年第3期17卷 446-449页

作者： WangGang RenGuoli YanXiang＇an WangGuodong DepartmentofMechanicalEngineenng TianjinUniversityTianjin300072China

Some dynamic factors, such as inertial forces and friction, may affect therobot trajectory accuracy. But these effects are not taken into account in robot motion controlschemes. Dynamic control methods, on the other hand, require the dynamic model of robot and theimplementation of new type controller. A method to improve robot trajectory accuracy by dynamiccompensation in robot motion control system is proposed. The dynamic compensation is applied as anadditional velocity feedforward and a multilayer neural network is employed to realize the robotinverse dynamics. The complicated dynamic parameter identification problem becomes a learningprocess of neural network connecting weights under supervision. The finite Fourier series is used toactivate each actuator of robot joints for obtaining training samples. Robot control system,consisting of an industrial computer and a digital motion controller, is implemented. The system isof open architecture with velocity feedforward function. The proposed method is not model-based andcombines the advantages of close-loop position control and computed torque control. Experimentalresults have shown that the method is validatities to improve the robot trajectory accuracy.

关键词： Robot Dynamic compensation Trajectory accuracy Identification

Crystallization in Pb-Zr-Ti-Si-O gel glass

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Chinese Science Bulletin 1996年第21期41卷 1835-1838页

作者：赵青春姚奎张良莹姚熹 Electronic Materials Research Laboratory Xi'an Jiaotong University Xi'an 710049 China

Materials in the lead zirconotitanate system possess useful and interesting electroopticaland piezoelectric *** the sol-gel method possesses a number of desirableadvantages compared with conventional methods, it has been developed as an importantand potential process enabling the preparation of oxide glasses which are difficult or impos-sible to make by conventional ***,ZrO2-TiO2 and ZrO2TiO2-SiO2 with ahigh content of ZrO2,and PbO-TiO2 with PbO were prepared by sol-gel process.

关键词： sol-gel process gel glass perovskite.

Synthesis of Ti-Ce-Si Binary and Ternary Nanocomposite Photocatalyst by Supercritical Fluid Drying Technology

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Journal of Rare Earths 2006年第2期24卷 182-187页

作者：张敬畅高玲玲曹维良 Institute of Modern Catalysis Key Laboratory of Science and Technology of Controllable Chemical Reactions of the Ministry of Education Beijing University of Chemical Technology Beijing 100029 China Institute

Ti-Ce, Ti-Si binary and Ti-Ce-Si ternary novel nanocomposite oxide photocatalysts were prepared with cheap inorganic salts TiCI4, Na2SiO3·9H2O and Ce（NO3）3·6H2O as precursors by supercritical fluid drying （SCFD） technology. The catalysts were characterized by means of XRD and TEM. The particle size of nanocomposite oxide photocatalysts synthesized by SCFD method is about 6 - 11 nm, which is smaller than those obtained by common drying method （CD）. The phase transformation from anatase to rutile was inhibited by SCFD technology. The peaks of SiO2 and CeO2 in XRD patterns indicate that a SiO2 amorphorous phase exists in all the samples and CeO2 is well dispersed on the surface of TiO2. The orthogonal test was designed to optimize the preparing conditions. It is found that ceria dop;.ng enhances the photocatalyric activity markedly, and the optimum doping of CeO2 is 0.1%. The thermal stability of photocatalyst can be improved ; the growth of particle-size and the decrease of surface area can be prohibited by doping of SlOe. Heat-treatment is a necessary factor to induce chemistry change of Ti-Si surface. The optimum heat-treating temperature is 600℃. A novel and efficient Ti-Ce-Si ternary nanocomposite was prepared by SCFI） method with strong thermal stability and high photoactivity in the photodegratation of phenol.

关键词： titania silica ceria nanocomposite photocatalysts supercritical fluid dried rare earths