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Materials Science and Engineering

1997

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Articles 1 - 30 of 59

Full-Text Articles in Physical Sciences and Mathematics

Study On Perchlorate Produced By Electrolysis With Oxygen Cathode, Zhigang Shao, Baolian Yi, Naichao Li, Ming Han Nov 1997

Study On Perchlorate Produced By Electrolysis With Oxygen Cathode, Zhigang Shao, Baolian Yi, Naichao Li, Ming Han

Journal of Electrochemistry

A new method of measuring the flow capacity of cell gas in the perchlorate cell process equipped with an oxygen cathode is applided to investigate the influence of changes in the concentration of solution (chloride, chlorate, perchlorate and metal ion) and changes in the operation parameters (current density, temperature and pH) on perchlorate current efficiency. The main abstacle that the oxygen cathode is used in the perchlorate cell process is put forward and a method is provided to resolve it.


Photoluminescence Of Photoelectrochemically Etched N+-Si, Guozheng Li, Chengqian Zhang, Xiumei Yang Nov 1997

Photoluminescence Of Photoelectrochemically Etched N+-Si, Guozheng Li, Chengqian Zhang, Xiumei Yang

Journal of Electrochemistry

PS layer on n+Si with (111) orientation prepered by means of photoelectrochemically etched has photoluminescent (PL) ability like PS layer on usual nSi. The data of PL spectra and quenching are given.


Study On The Oxygen Electrodes Of Alkaline Fuel Cells Effect Of Dopant On The Activity Of Ag/C Catalyst, Jiawei Teng Nov 1997

Study On The Oxygen Electrodes Of Alkaline Fuel Cells Effect Of Dopant On The Activity Of Ag/C Catalyst, Jiawei Teng

Journal of Electrochemistry

A new kind of nonnoble catalyst for the oxygen electrodes of Alkaline Fuel Cells was investigated. The AgNiBiHg/C catalyst, which was prepared by chemical reduction, was active for the cathodic reduction of oxygen in alkaline fuel cells. It was found that the catalytic activity was improved by adding Ni, Bi, Hg to Ag/C catalyst, and the maximum activity was observed at Ag50%Ni2%Bi3%Hg3%C42%(wt%). XRD inconjunction with SEM indicated that the crystalline silver turned into amorphous in the presence of doping agents and the grain size of silver was reduced. No dramatic deactivation of the catalyst occured after 5200 hours of service.


Development Of A New Type Ni-S Evolution Hydrogen Electrode For Water Electrolysis, Xiaoyou Yuan Nov 1997

Development Of A New Type Ni-S Evolution Hydrogen Electrode For Water Electrolysis, Xiaoyou Yuan

Journal of Electrochemistry

A new type evolution hydrogen electrode NiS(N) has been made from nickel plating electrode in NiSO4CS(NH2)2 bath by electrodeposition. It is analyzed by SEM and Xray energy spectrum. The NiS(N) electrode is different from the NiS(O) electrode (which is used in plant at present time) in surface metallograph configuration and surfer content. The results of measurement polarization curves and water electrolysis 480 hours at 5 000 A·m-2 show that the evolution hydrogen overpotential of NiS(N) electrode is decreased at least 160 mV relative to NiS(O) electrode and the stablisum of NiS(N) electrode is better than that of NiS(O) electrode.


Molten Carbonate Fuel Cell Materials And Technology, Naichao Li, Baolian Yi Nov 1997

Molten Carbonate Fuel Cell Materials And Technology, Naichao Li, Baolian Yi

Journal of Electrochemistry

Molten Carbonate Fuel Cell materials are reviewed, and the technology of Molten Carbonate Fuel Cell are discussed.


Mechanism Of Electrodeposition Of Cu/Co Multilayer Thin Films, Jiangyun Xue, Jixun Wu, Dejun Yang Nov 1997

Mechanism Of Electrodeposition Of Cu/Co Multilayer Thin Films, Jiangyun Xue, Jixun Wu, Dejun Yang

Journal of Electrochemistry

The mechanism of electrodeposition of Cu/Co multilayer thin films has been studied by means of potentodynamic sweep, cyclic voltammetry sweep and AC impendance. The results indicated that the copper deposition is mass transfer controlled process and the cobalt deposition is related to the absorbed intermediate species such as Co(OH)ads. The cobalt ions first form Co(OH)ads, then was deoxygenated to cobalt on the electrode surface.


The Activity Of Alloy CuNi Electrode In Electroreduction Of Aromatic NitroCompounds, Chunan Ma, Shaoping Tong, Xiaojun Cheng, Hui Wang Nov 1997

The Activity Of Alloy CuNi Electrode In Electroreduction Of Aromatic NitroCompounds, Chunan Ma, Shaoping Tong, Xiaojun Cheng, Hui Wang

Journal of Electrochemistry

CuNi alloy on the basis of copper at different ratio Cu/Ni are prepared by codepostion. The cathode activtiy of film are studied by steadystate polarization for electroreduction nitrobenzene (NB) and 1,5dinitroanthraquinone (1,5DNA) to paminophenol and 1,5diamino4,8dihydroanthraquinone respectly. The results show that the alloy cathodes at different ratio Cu/Ni have different exchange current density (io) and apparent activition energy (EA). The alloy (CN30) has maximal io  and minimal EA by codeposition at the following conditions: electrolyte: 0.05 mol/L CuSO4·5H2O+0.6 mol/L NiSO4·6H2O+0.25 mol/L Na3Cit·2H2O; current density: 0.6 A/dm2 , pH=6, temperature at 50 ℃. Compared with the common cathodes such as …


Preparation Of High Rate Discharge Foamed Nicd Battery, Yuming Wang Nov 1997

Preparation Of High Rate Discharge Foamed Nicd Battery, Yuming Wang

Journal of Electrochemistry

A novel device of SC type foamed NiCd battery is presented, in which, the innerresistance of battery is appeared to be reduced, and the electrode performance is gained to very improved, and so, this battery can be suited to using of the powerdrive pistol drill.


Advances In Solid Polymer Electrolytes, Liming Ding, Shaojun Dong, Erkang Wang Nov 1997

Advances In Solid Polymer Electrolytes, Liming Ding, Shaojun Dong, Erkang Wang

Journal of Electrochemistry

The formation, classification, applications and iontransport mechanism studies of solid polymer electrolytes were reviewed. While the recent SPE reports on the preparation of novel materials, the full structure determinations of PEO/salt complexes, the exploration of iontransport mechanism and the applications in electrochemical devices being introduced, some prospects on the future SPE research were suggested. 84 references were quoted.


The Effect Of Bismuth On Microstructure Of The Cathodic Copper Deposition Of Copper Electrorefining, Daorong Lu, Jianxing Lin Nov 1997

The Effect Of Bismuth On Microstructure Of The Cathodic Copper Deposition Of Copper Electrorefining, Daorong Lu, Jianxing Lin

Journal of Electrochemistry

The electrocrystal formation, crystal orientation and the chemical composition of the cathodic copper deposition in the presence of Bi3+ in the electrolyte of acidified CuSO4 are studies by scanning electron microscopy, Xray diffraction, atomic absorption and EDAM. The results indicate that the Bi could′t deposit on cathode when copper electrolysed at common current density i=200 A·mol/L-2 and t=60 ℃. Bi3+ scarcely effected on the crystal orientation (220) of copper deposition. High concentration Bi3+ in the electrolyte promoted (220) growth and inhibited the other crystal orientation growth. Bi3+ effected on electrocrystal formation and the cell dimension of copper deposition.


The Effect Of Solution Composition On The Corrosion Behavior Of Electrodeposited Zinc Powder, Qingwen Li, Qin Yang, Xi Xia Nov 1997

The Effect Of Solution Composition On The Corrosion Behavior Of Electrodeposited Zinc Powder, Qingwen Li, Qin Yang, Xi Xia

Journal of Electrochemistry

Zinc powder as a widely anode material can be electrowon from ZnCl2 or ZnO+KOH media. The properties of zinc powder are likely to be modified with electrolytic conditions such as the composition of bath solution, electrolysis manner, current density and additives etc.. In this paper, we have discussed the effect of the compositions of bath solution on the microstructure and corrosion resistance of zinc powder.


Optically Transparent Composite Material And Process For Preparing Same, D. E. Day, James O. Stoffer, John M. Barr Sep 1997

Optically Transparent Composite Material And Process For Preparing Same, D. E. Day, James O. Stoffer, John M. Barr

Materials Science and Engineering Faculty Research & Creative Works

Glass ribbon-reinforced transparent polymer composites which provide excellent optical transparency and a low distortion level over a wide temperature range while exhibiting superior mechanical properties as compared to non- reinforced polymer counterparts, and equivalent properties as compared to glass fiber-reinforced counterparts.


Ocena Oddziaływania Na Środowisko Na Przykładzie Zabudowy Pieca Indukcyjnego W "Krakodlew" S.A., Marian Mazur, Marek Bogacki, Robert Oleniacz Sep 1997

Ocena Oddziaływania Na Środowisko Na Przykładzie Zabudowy Pieca Indukcyjnego W "Krakodlew" S.A., Marian Mazur, Marek Bogacki, Robert Oleniacz

Robert Oleniacz

The paper presents the procedure and the results of the environmental impact assessment for the induction furnace installed in the company "Krakodlew" S.A. in Krakow (Poland). This furnace will allow heating and keeping the liquid feed (pig iron) and adjust the chemical composition, which will allow for the production of high-quality heavy castings. The need to perform an environmental impact assessment for objects of this type results from the binding legal regulations in Poland. The analysis included all the main components of the environment: air, soil, vegetation, soil and water environment, land surface and acoustic climate. It was found that …


Segregation Of Bismuth To Triple Junctions In Copper, K.-M. Yin, Alexander H. King, T.E. Hsieh, F.-R. Chen, J.J. Kai, L. Chang Sep 1997

Segregation Of Bismuth To Triple Junctions In Copper, K.-M. Yin, Alexander H. King, T.E. Hsieh, F.-R. Chen, J.J. Kai, L. Chang

Alexander H. King

Bismuth segregation in copper has been studied using energy-dispersive X-ray spectrometry (EDX) in a JEOL 2010F transmission electron microscope. In addition to the expected solute enrichment at grain boundaries, we have observed extremely high concentrations of bismuth at certain triple junctions, with significantly greater enrichment factors than in the adjacent grain boundaries. It is shown here that the triple junction segregation is a function of the parameters of the grain boundaries at the triple line, and existence of this type of segregation implies that the affected triple junctions embody excess free energy. At least one of the observed triple junctions …


Vibrational Spectra In Ordered And Disordered Ni3al, Jeffrey D. Althoff, Dane Morgan, Didier De Fontaine, Mark Asta, S. M. Foiles, Duane D. Johnson Sep 1997

Vibrational Spectra In Ordered And Disordered Ni3al, Jeffrey D. Althoff, Dane Morgan, Didier De Fontaine, Mark Asta, S. M. Foiles, Duane D. Johnson

Duane D. Johnson

We calculate the vibrational density of states (DOS) and corresponding thermodynamic properties of L12 ordered and disordered Ni3Al in the quasiharmonic approximation using the embedded-atom method. Vibrational and thermodynamic properties, including vibrational entropy differences between ordered and disordered states, are found to be in good agreement with experiment. The DOS of the configurationally disordered alloy resembles a broadened version of the DOS of the L12 phase, not a one-atom per cell fcc DOS, and is shifted downward in frequency because the disordered state has a larger volume than the ordered phase. Calculations of the projected DOS indicate that high-frequency modes …


Study On The Diffusion Of Electroactive Molecules In Polymer Electrolyte By Microelectrode Voltammetry, Liming Ding, Shaojun Dong, Erkang Wang Aug 1997

Study On The Diffusion Of Electroactive Molecules In Polymer Electrolyte By Microelectrode Voltammetry, Liming Ding, Shaojun Dong, Erkang Wang

Journal of Electrochemistry

The ten years study on the diffusion of electroactive molecules in polymer electrolyte by microelectrode voltammetry was reviewed by considering the development background of polymer electrolyte materials. The classification, fabrication, applications and electrochemical measurements of microelectrode were introduced concisely. The several important factors influencing the diffusion of electroactive molecules were stressed. In the final part of this paper, some new reports on the diffusion of labeled molecules were introduced. 52 references were quoted.


Electrocatalytic Oxidation Of Methanol On The Stearate Nickel L B Film, Benzeng Hua, Wenyan Hu, Yanzhen Chen Aug 1997

Electrocatalytic Oxidation Of Methanol On The Stearate Nickel L B Film, Benzeng Hua, Wenyan Hu, Yanzhen Chen

Journal of Electrochemistry

The stearate nickel L B films is good electroacatlyst for the oxidation of methanol MeOH in alkaline. The electrochemical behaviors of stearate nickel L B films is affected by the concentration of KOH. The rate of quantity of mickel ion and stearic acid in L B films is 1∶1, which means that the nickel ion may exist in -COONi(OH) form. The electrocatalytic process is influenced by the concentration of OH - , it involves the penetration of MeOH into the films. The oxidative currents of MeOH are linearly dependent on the bulk concentration.


Behavior Of Copper In Hydrogen Storage Alloy Microencapsulated By Copper, Dawei Zhang, Huatang Yuan, Huabin Yang, Zuoxiang Zhou, Yunshi Zhang Aug 1997

Behavior Of Copper In Hydrogen Storage Alloy Microencapsulated By Copper, Dawei Zhang, Huatang Yuan, Huabin Yang, Zuoxiang Zhou, Yunshi Zhang

Journal of Electrochemistry

Negative electrode made from Cu microencapsulated hydrogen storage alloy was studied by using cyclic voltammetry method. The results showed that copper as a coating material was of a certain stability in 5 mol/L KOH solution within the range of charge and discharge voltage. But when expanding the sweep voltage, the CV curve showed a pair of distinct oxidation reduction current peaks of Cu 2O formation at E =-0.3 V and Cu 2O reduction at E =-0.6 V. With charging discharging cycles, copper is liable to be oxidized to Cu 2O and further oxidized into CuO 2- 2. When charged again, …


Corrosion Behaviour Of Copper Covered With Ion Selective Phenolic Coatings By Eis, Zhoucheng Wang, Yingzhou Zhang, Shaomin Zhou Aug 1997

Corrosion Behaviour Of Copper Covered With Ion Selective Phenolic Coatings By Eis, Zhoucheng Wang, Yingzhou Zhang, Shaomin Zhou

Journal of Electrochemistry

Electrochemical impedance spectroscopy(EIS) technique was employed to study the corrosion behaviour of copper painted with the anion selective、 cation selective and bipolar phenolic coatings in 3% NaCl solution. From the impedance spectrum characteristics, the models of equivalent circuit for these different coating systems were established,and the methods for the analysis of experimental impedance diagrams in terms of coating and interface properties were discussed. The research results show that the composition and structure of ion selective coatings have significant influence on corrosion behaviour of copper. The bipolar coating consisting of an anion selective inner layer and a cation selective outer layer …


Surface Modifications Of Carbon Materials Used As Anode Of Lithium Ion Battery Ⅲ. Improvement Of Artificially Imposed Solid Electrolyte Film On Cell Performance, Shuhua Ma, Xiabin Jing, Fosong Wang Aug 1997

Surface Modifications Of Carbon Materials Used As Anode Of Lithium Ion Battery Ⅲ. Improvement Of Artificially Imposed Solid Electrolyte Film On Cell Performance, Shuhua Ma, Xiabin Jing, Fosong Wang

Journal of Electrochemistry

The improving effect of solid electrolyte film artificially imposed on carbon electrode was investigated. The result showed that both the charge/discharge capacity and first charge/discharge efficiency, to a certain extent, were enhanced, and the result also suggested the effectiveness of the substitution of the artificially imposed solid electrolyte film for the inherent passivating film which was formed on the surface of the carbon electrode while inserted in the electrolyte during charging or discharging. The Scanning Electron Microscope result displayed the compact and well defined morphology of the artificially imposed crystalline film.


Investigation On Electro Reduction Behaviour Of Copper Anodic Products In Concentrated Naoh Solutions Ⅱ. Electro Reduction Of Cu(Ⅱ) Products, Jianbo He, Hanhe Chen, Jianxin Lin Aug 1997

Investigation On Electro Reduction Behaviour Of Copper Anodic Products In Concentrated Naoh Solutions Ⅱ. Electro Reduction Of Cu(Ⅱ) Products, Jianbo He, Hanhe Chen, Jianxin Lin

Journal of Electrochemistry

Potentiostatic oxidation potentiodynamic or galvanostatic reduction methods have been used to study the cathodic reduction behaviour of various products anodically formed on the second stage of copper oxidation in concentrated NaOH solutions. Seven cathodic current peaks and the corresponding cathodic potential plateaus are observed on the potentiodynamic E/i curves and the galvanostatic E/t curves, respectively. In the negative potential scan, there are three couples of voltammetric peaks which have been attributed to the formation and reduction of CuO, Cu(OH) 2 and Cu(Ⅱ) ion, respectively. The complicated mechanism for the electro formation of the three Cu(Ⅱ) species are discussed.


Studies On The Failure Modes Of Stationary Vrla Batteries, Yibo Tong, Xiangming Qiu Aug 1997

Studies On The Failure Modes Of Stationary Vrla Batteries, Yibo Tong, Xiangming Qiu

Journal of Electrochemistry

In order to improve the reliability and the quality of stationary valve regulated lead acid (VRLA) batteries, the failure modes of the stationary VRLA batteries which caused by the water loss and the thermal runaway are studied. The water loss may be solved by increasing the Oxygen recombination efficiency, choosing the suitable grid material and the additives of megative paste, decreasing the corrosion of the positive plates. The thermal runaway may be solved by decreasing the inner ohmic resistance of VRLA batteries, improving the outside condition of batteries such as putting into the absorbing heat material between the abtteries etc..


Preparation And Examination Of Planar Type Solid Oxide Fuel Cells, Yi Jiang, Jingwang Yan, Shizhong Wang, Chunying Yu, Wenzhao Li Aug 1997

Preparation And Examination Of Planar Type Solid Oxide Fuel Cells, Yi Jiang, Jingwang Yan, Shizhong Wang, Chunying Yu, Wenzhao Li

Journal of Electrochemistry

The solid oxide fuel cells of planar type(SOFC) have been developed after successfully preparing La 0.8 Sr 0.2 MnO 3 cathodes and Ni YSZ ceramic anodes on YSZ plates and solving the high temperature sealing technical problem. Examination of the single cells fabricated showed that the maximum power output at 950 ℃ for H 2 as fuel and air as oxidant reached 0.12 W/cm 2. It was found that the large polarization overpotential of the Ni YSZ anode and the Ohmic losses of the cells were two main factors responsible for the relative low output power density.


The Electrochemical Behavior And Deposited Mechanism Of Zn Ni Alloy Codeposition, Jixun Wu, Yongqin Liu, Huimin Meng Aug 1997

The Electrochemical Behavior And Deposited Mechanism Of Zn Ni Alloy Codeposition, Jixun Wu, Yongqin Liu, Huimin Meng

Journal of Electrochemistry

The electrochemical behavior of Zn Ni alloy codeposition and concomitant hydrogen evolution have been studied in the chloride ammonia solution through the d c electroplating method. Under the condition of the applied cathodic current density of 2A/dm 2 , the AC impedance spectra have been measured. An equivalent circuit has been presented for the impedance study on the alloy codeposition.


Preparation Of Pbo 2/Ti Plate Electrode, Zhigang Shao, Baolian Yi, Xinge Zhang, Enjun Zhang Aug 1997

Preparation Of Pbo 2/Ti Plate Electrode, Zhigang Shao, Baolian Yi, Xinge Zhang, Enjun Zhang

Journal of Electrochemistry

The perchlorate was made up of a lead dioxide plate elcetrode and an oxygen cathode. By measuring the flow capacity of cell gas in the cell, and by means of CV、SEM、XRD, the performances of the lead dioxide plate electrodes are evaluated. The influence of changes in the concentrations of electroplating solutions (F 、HNO 3、Bi 3+ 、Ni 2+ 、Fe 3+ and surface active agent) is investigated. The results show that the concentrations of Fe 3+ in the solutions must be lower 0.01 g/l, and the concentrations of HNO 3 in the solutions are about 20 g/l, in order to get better …


Electrorheological Characters Of Polyaniline Suspensions, Guangyao Su, Deshu Gao, Changqing Zhang Aug 1997

Electrorheological Characters Of Polyaniline Suspensions, Guangyao Su, Deshu Gao, Changqing Zhang

Journal of Electrochemistry

Polyaniline (PAn) as the dispersive particles and insulating oil as the dispersive medium, the electrorheological fluid (ERF) is constituted. Relations between the factors of electric field strength ( E ), temperature ( T ) and the static yield stress ( τ S ), current density ( i ) of ERF are investigated. The results show that the changes of τ S and i with electric field intensity have emerged in the exponential relation, i.e, τ S∝E 0.7 , i∝E 2.18 . Otherwise, when exert a constant voltage on ERF, owing to the polarization, the absorption of medium of ERF have …


The Electrode Process Of Some Organic Dyes Studied By Spectroelec Tro Chemical Technique In Situ, Yinxuan Tang, Hangsheng Yang, Baoen Shen Aug 1997

The Electrode Process Of Some Organic Dyes Studied By Spectroelec Tro Chemical Technique In Situ, Yinxuan Tang, Hangsheng Yang, Baoen Shen

Journal of Electrochemistry

Spectroelectrochemistry especially with in situ measurement in a cell provides a very useful mthodology for measuring the parameters of electrode process. In this paper, we report the determination of formal potentials, the number of electron transfer, the diffusion coefficient, the heterogeneous electron transfer rate constant and the transfer coefficient of some organic dyes (Methyelene blue, Neutral red, Indigo carmine) using spectroelectro chemical technique in situ.


39th Rocky Mountain Conference On Analytical Chemistry Aug 1997

39th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Preliminary program and registration information for the 39th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 3-7, 1997.


Experimental Investigation Of Nonlinear Dynamics In Single Mode Semiconductor Laser Diodes With Phase Conjugate Feedback, Gordon T. Hengst Aug 1997

Experimental Investigation Of Nonlinear Dynamics In Single Mode Semiconductor Laser Diodes With Phase Conjugate Feedback, Gordon T. Hengst

Theses and Dissertations

The semiconductor laser diode offers a unique system to investigate nonlinear dynamics when optical feedback is applied. Although there is extensive research of laser diodes with optical feedback from normal dielectric mirrors, very little has been done experimentally to analyze the effects of degenerate phase conjugate feedback from a BaTiO3 crystal. This research experimentally investigated the dynamics of a single-mode laser diode with weak phase conjugate feedback using both the self-pumped and double phase conjugate geometries. The experimental results validated a mathematical model which numerically evaluates the Lang-Kobayahsi coupled differential equations. The model simulated the nonlinear behavior of a …


Studies On Electrodeposition Of Rare Earth Metals And Their Alloys In Molten Salts, Qiqin Yand May 1997

Studies On Electrodeposition Of Rare Earth Metals And Their Alloys In Molten Salts, Qiqin Yand

Journal of Electrochemistry

The cyclic voltammetry, convolution voltammetry, potentiostatic electrolysis and open circuit potential time curve after electrolysis, current time curve at potential step, potential time curve at current step, X ray diffraction, EDAX, electron probe microanalysis were used to investigate the electrode processes of the reduction of rare earth ions on inert electrodes and alloying electrodes in molten chlorides and fluorides. The free energies of formation for the intermetallic compounds, the diffusion coefficients of rare earth ions in the melt, the diffusion coefficients of rare earth atoms in the alloy phases were determined. The alloys of rare earth with iron, cobalt, nickel, …