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Articles 26011 - 26040 of 27331

Full-Text Articles in Engineering

The Preparation Of Heteropoly Compound Polypyrrole Film Modified Electrode And Its Electrochemical Properties, Weiqing Wang, Xiumei Zhang, Long Cheng, Baifeng Liu, Shaojun Dong Nov 1996

The Preparation Of Heteropoly Compound Polypyrrole Film Modified Electrode And Its Electrochemical Properties, Weiqing Wang, Xiumei Zhang, Long Cheng, Baifeng Liu, Shaojun Dong

Journal of Electrochemistry

Electronically conducting polypyrrole doped with heteropolyanions K10H3[Nd(SiMo7W4)2]·xH2O(denoted as [Nd(SiMo7W4)2]13-) was synthesized by electrochemical polymerization. This modified electrode maintains the electrochemical and electrocatalytic properties of heteropolyanion, with having good stability and electrocatalytic activity on the reduction of nitric oxide in acidic aqueous solution.


Surface Modifications Of Carbon Materials Used As Anode Of Lithium Ion Battery Ⅰ. Influences Of Oxidation And Reduction Pretreatment On Anode Performance, Shuhua Ma, Hanju Guo, Ji Li, Hongze Liang, Xiabin Jing, Fosong Wang Nov 1996

Surface Modifications Of Carbon Materials Used As Anode Of Lithium Ion Battery Ⅰ. Influences Of Oxidation And Reduction Pretreatment On Anode Performance, Shuhua Ma, Hanju Guo, Ji Li, Hongze Liang, Xiabin Jing, Fosong Wang

Journal of Electrochemistry

The influences of the trace oxygen containing functional groups on surface of carbon material on cell performance of carbon anode for lithium ion batteries were studied by means of the pretreament in various oxidant/reductant systems. The results showed that the rich oxygen containing functional groups impaired the cell performance of carbon material anode, and the reduction of these groups in quantity and oxidation degree can increase charge/discharge capacity and improve first charge/discharge efficiency. The reason was also discussed in the light of effects of surface organic groups on decomposition reactivity of electrolyte and formation process of surface passivating film.


The Current Distribution On The Anode Surface Of The Seale Oval Tubular Lead Acid Battery, Renao Gu, Jianlin Yao, Zhengfa Deng, Ru Sun, Liren Wu, Zhongsi Jiang, Wangen Miao Nov 1996

The Current Distribution On The Anode Surface Of The Seale Oval Tubular Lead Acid Battery, Renao Gu, Jianlin Yao, Zhengfa Deng, Ru Sun, Liren Wu, Zhongsi Jiang, Wangen Miao

Journal of Electrochemistry

The current distribution on anode surface of sealed lead acid batter under different discharge current and degree was studied by chemical analytical method for the first time. We can conclude that the current distribution is not even. The current density on the edge of the electrode surface and the electrode terminal are bigger than other areas, that is, there are edge effect and terminal effect, and these effect are more obvious when the discharge current is 100 A and degree is 100%.


Comparison Of The Charge/Discharge Charasteristics Between Ni-Cd And Ni-Mh Battery And Its Improvement Of Manufacture Technique, Yumimg Wang, Jinsheng Chen Nov 1996

Comparison Of The Charge/Discharge Charasteristics Between Ni-Cd And Ni-Mh Battery And Its Improvement Of Manufacture Technique, Yumimg Wang, Jinsheng Chen

Journal of Electrochemistry

Based on the difference of charge discharge charasteristies between Ni-Cd and Ni-MH battery, some appropriate manufacture technoque to improve the battery performances or to extend its service life are adopted.


Ole Miss Engineer 1996 Oct 1996

Ole Miss Engineer 1996

Ole Miss Engineer

No abstract provided.


Bs News Oct 1996

Bs News

Building Services Engineering

No abstract provided.


Review Of: Ike Jeanes, Forecast And Solution - A Trilogy For Everyone Grappling With The Nuclear (Pocahontas Press 1996), Drew Schaefer Sep 1996

Review Of: Ike Jeanes, Forecast And Solution - A Trilogy For Everyone Grappling With The Nuclear (Pocahontas Press 1996), Drew Schaefer

RISK: Health, Safety & Environment (1990-2002)

Review of the book: Ike Jeanes, Forecast and Solution - A Trilogy for Everyone Grappling with the Nuclear (Pocahontas Press 1996). Addenda, appendix, figures, front matter, notes, references, tables. ISBN 0-936015-62-4 [800 pp. Cloth $32.00; paper $25.00. P.O. Drawer F, Blacksburg VA 24063-1020.]


Risk Criteria For Approving Or Rejecting Field Tests Of High-Performance Weapons, Shaul Feller, Michael Maharik Sep 1996

Risk Criteria For Approving Or Rejecting Field Tests Of High-Performance Weapons, Shaul Feller, Michael Maharik

RISK: Health, Safety & Environment (1990-2002)

Because details are classified and participation by affected populations is limited, military test ranges impose difficult challenges on those responsible for their safety. Here, the authors catalog some of those challenges and suggest ways to address them.


Review Of: Science Advice To The President (William T. Golden, Ed. Aaas Press 2d Ed. 1993)., Timothy Van Dyke Sep 1996

Review Of: Science Advice To The President (William T. Golden, Ed. Aaas Press 2d Ed. 1993)., Timothy Van Dyke

RISK: Health, Safety & Environment (1990-2002)

Review of: Science Advice to the President (William T. Golden, ed. AAAS Press 2d Ed. 1993). Acknowledgments, index of names, introductions, notes, tables. ISBN 0-87168-509-4 [340 pp. $29.95 paper. American Association for the Advancement of Science, 1333 H St. NW, Washington DC 20701.]


Bs News Sep 1996

Bs News

Building Services Engineering

No abstract provided.


Studies On The Charge And Discharge Reaction Of Li/Lini0.3Co0.7O2 Battery, Fupjng Zhang Aug 1996

Studies On The Charge And Discharge Reaction Of Li/Lini0.3Co0.7O2 Battery, Fupjng Zhang

Journal of Electrochemistry

The charge and discharge reaction of Li/LiNi0.3Co0.7O2 battery have been studied by using CV,CT,XRD and GCP. It is shown that the discharge capacity of the cell reaches 120-140 mA·h·g-1 in the 4.30-3.00 V in 1 mol/L LiClO4/PC electrolyte system. The discharge mechanism involve a two-step Li+ intercalation reaction. The thermodynamic data such as ΔG,ΔS, ΔH, of the reaction are given. Furthermore, the changes of the D or σi of Li+ with its composition have been discussed.


An Esr Study Of Free Radicals In Electroreduction Process Of Allyl Alcohol, Jindong Zhang, Yafei Kuang, Shukun Huang, Naixian Xie, Fengzhen Wang, Dewen Chen Aug 1996

An Esr Study Of Free Radicals In Electroreduction Process Of Allyl Alcohol, Jindong Zhang, Yafei Kuang, Shukun Huang, Naixian Xie, Fengzhen Wang, Dewen Chen

Journal of Electrochemistry

Electrochemical-ESR technique with spin trap phenyl-t-butyl nitrone(PBN)was used to study the intermediates of electroreduction of allyl alcohol at platinized platinum electrode in acidic alcohol-aqua solution. Hydrogen and allyl group and(or)propyl group radicals were identified by a hyperfine spectrum of the radical adducts, and that provided a direct evidence for the presence of these radicals in the electroreduction of allyl alcohol.


A Study On Solid Polymer Electrolyte Fuel Cell, Hongfeng Xu, Ming Han, Baolian Yi, Xinge Zhang, Shanhai Ge Aug 1996

A Study On Solid Polymer Electrolyte Fuel Cell, Hongfeng Xu, Ming Han, Baolian Yi, Xinge Zhang, Shanhai Ge

Journal of Electrochemistry

Solid polymer electrolyte fuel cell (SPEFC) show promise of a high level of performance in the present fuel cell. In this paper, we report the method of SPEFC electrode preparation,and the effects of temperature, pressure and gas flow rate on the performance.


Improvement Of The Anti-Interference Characteristics Of God Electrode By Using The Powder Microelectrode Technique, Chen Jian, Chuansin Cha Aug 1996

Improvement Of The Anti-Interference Characteristics Of God Electrode By Using The Powder Microelectrode Technique, Chen Jian, Chuansin Cha

Journal of Electrochemistry

The electrochemical behavior of ascorbic acid(AA), uric acid(UA), L-cystein(L-Cys) and acetaminophen (APAP), i.e. The main interference to the GOD electrode, were studied at the Pt,GC and powder microelectrode. Experimental results indicated that, due to the electrochemical activity of these interference, it is difficult to eliminate their interference effects by manipulation of electrode materials or working potential of the GOD electrode. However, it was found that the limiting curtents at the KB electrode are mainly controlled by mass transfer in liquid phase, so it is only related to the geometer size of the electrode, not its real surface area. Therefore, it …


The Effect Of Co On The Proton Diffusion Coefficient For The Ni(Oh)2 Electrodes, Xiaoyan Cao, Zuoxiang Zhou, Huatang Yuan, Yunshi Zhang Aug 1996

The Effect Of Co On The Proton Diffusion Coefficient For The Ni(Oh)2 Electrodes, Xiaoyan Cao, Zuoxiang Zhou, Huatang Yuan, Yunshi Zhang

Journal of Electrochemistry

The diffusion coefficients of protons moving in the Ni(OH)2 electrodes have being investigated by constant current, cyclic voltammetry and potential step technineques. The electrodes were prepared by cathodic deposition and their active material contained 0~53% cobalt. It was found that the diffusion coefficients are about 10-9~10-10 cm2/s during charging and about 10-11 cm2/s during discharging. Moreover the value increases with the increacing content of Co in the electrodes. During the calculation, the relevant fomulars were modified especially the wrong fomular for constant current methode.


Electrochemical Study Of The Corrosion Behavior Of Coalesced Copper And Sw-206 Stainless Steel In The Acetic-Acid Solution, Rongzong Hu, Changjian Lin, Jianguang Tan, Zhanmei Sun, Xueqin Wu, Biao Wang Aug 1996

Electrochemical Study Of The Corrosion Behavior Of Coalesced Copper And Sw-206 Stainless Steel In The Acetic-Acid Solution, Rongzong Hu, Changjian Lin, Jianguang Tan, Zhanmei Sun, Xueqin Wu, Biao Wang

Journal of Electrochemistry

In order to provide a theoretic and experimental consideration for the material selection and anit-corrosion in the petrochemical industries the corrosion behavior of coalesced copper and sw-206 stainless steel in the acetic acid solution was studied by electrochemical impedance spectroscopy and polarization techniques. The effects of the temperature, acetic acid concentration and solubilized oxygen in the acetic acid solution on the corrosion process of this two metals were analyzed. It was found that these effects obviously accelerate corrosion process for the coalesced copper, but no apparent influnce for the sw-206 stainless steel.In the the acetic acid solution, containing water and …


A Study On Electrochemical Oxidation Of Reduced Nicotinamide Coenzyme Nadh In Organic Media, Fangzu Yang, Huihuang Wu, Shukai Xu, Shaomin Zhou Aug 1996

A Study On Electrochemical Oxidation Of Reduced Nicotinamide Coenzyme Nadh In Organic Media, Fangzu Yang, Huihuang Wu, Shukai Xu, Shaomin Zhou

Journal of Electrochemistry

The behaviour of electrochemical oxidation of the reduced nicotinamide coenzyme NADH on glassy carbon was studied and some kinetic parameters were measured by means of voltammometry in the N-dimethylformamide (DMF) and 1,4-dioxane media respectively. The eletrochemical oxidation of NADH shows completely irriversable both in the two solvents,and the diagnostic experiments support that the process involves a fast chemical step.The oxidation rate and the diffusion coefficient of NADH in DMP are smaller than those in 1,4-dioxane, but the response current is more stable in DMF. The experimental results are discussed by solvent effects.


A Preliminary Study Of Electrochemically Amplified Measurement Of Gold Electrodeposition, Bingwei Mao, Caihui Shi, Xiaoqin Li, Lihua Xiong Aug 1996

A Preliminary Study Of Electrochemically Amplified Measurement Of Gold Electrodeposition, Bingwei Mao, Caihui Shi, Xiaoqin Li, Lihua Xiong

Journal of Electrochemistry

Gold electrodeposition onto a glassy carbon microelectrode is studied using an electrochemical amplification method. Taking the advantage that the electrochemical reduction of K2Cr2O7 has significantly higher reaction activity on gold electrode than carbon electrode, it is tentatively used to amplify the gold electrodeposition current. The results show that there is a marked increase in current of gold electrodeposition in presence of K2Cr2O7 in comparison with that absent of K2Cr2O7.The electrochemical amplification method can be applied to study the electrodeposition of very in intial stage …


A Review Of Differential Electrochemical Mass Spectroscopy Techniqueⅰ. The Principle And Development Of Dems, Fujikawa Keikichi, Li Feng Aug 1996

A Review Of Differential Electrochemical Mass Spectroscopy Techniqueⅰ. The Principle And Development Of Dems, Fujikawa Keikichi, Li Feng

Journal of Electrochemistry

No abstract provided.


Time-Resolved Electron Spin Resonance Spectroscopy For In-Situ Studies Of Electrochemical Systems, Lin Zhuang, Juntao Lu Aug 1996

Time-Resolved Electron Spin Resonance Spectroscopy For In-Situ Studies Of Electrochemical Systems, Lin Zhuang, Juntao Lu

Journal of Electrochemistry

No abstract provided.


Surface Raman Spectra Obtained From Various Electrodeposited Transidon Metals, Jingsong Gao, Bin Ren, Qunjian Huang, Zhongqun Tian Aug 1996

Surface Raman Spectra Obtained From Various Electrodeposited Transidon Metals, Jingsong Gao, Bin Ren, Qunjian Huang, Zhongqun Tian

Journal of Electrochemistry

Good quality potential-dependent surface Raman spectra of pyridine were obtained for the first time from a series of transition metals, e. g., Fe, Co, Ni, Ru, Rh, Pd and Pt, which were electrodeposited on non-SERS-active substrates. The influences of the applied potential and the nature of metal on the adsorption behaviors were discussed briefly. This result illustrates that Raman spectroscopy is becoming a more general and powerful tool to study various electrochemical interfaces.


Electrodeposition Of Cu-Co Multilayer Thin Films, Jiangyun Xue, Jixun Wu, Dejun Yang Aug 1996

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

Journal of Electrochemistry

A method has been developed to produce Cu-Co Multilayer from a single electrolyte by electrodeposition. The effects of the concentration of copper ions, current density and the speed of rotation were investigated, and the Cu-Co electrodeposition films were analysed by TEM, AES and X-ray diffraction. The results indicated that the film was alternating pure copper and coppercobalt alloy layers. If the content of copper in cobalt layer is to be small, the concentration of its ions in solution must be small and the rotation speed must be low.


Study On The Ionic Conductivity Of Comb Polymer Electrolytes, Liming Ding Aug 1996

Study On The Ionic Conductivity Of Comb Polymer Electrolytes, Liming Ding

Journal of Electrochemistry

A comb polymer (CP350) with oligo-oxyethylene side chains was prepared from methyl vinyl ether/maleic anhydride copolymer.The ionic conductivity of CP350/LiAsF6 and CP350/LiAsF6 complexes was studied as a function of temperature and [Li]/[EO] ratios. A equivalent circuit was given to interpret complex impedance spectra. At 25 ℃, the ionic conductivity maxima of the two systems are 1.38×10-4, 8.32×10-5 S/cm respectively. The appearance of the conductivity maxima has been interpreted as being due to the effect of microviscosity on ion transport. lonic conduction displays non-Arrhenius behaviour. The temperature dependence of ionic conductivity was attributed mainly to the …


Electrochemical Studies On Chemical Polishing Of Copper, Keping Han, Jingli Fang Aug 1996

Electrochemical Studies On Chemical Polishing Of Copper, Keping Han, Jingli Fang

Journal of Electrochemistry

Changes in specular reflectivity,weight loss,surface topograph and potential with time and current-potential curves during chemical polishing were determined. The results showed that chemical polishing was composed of the etching, polishing and pitting stage. The passivating film theory also applied to the chemical polishing.


Study On The Growth Process Of Lead Dioxide On Lead-Antimony Electrodes By Impedance Tracing Method, Guolin Wei, Hongxin Yang, Jiarong Wang Aug 1996

Study On The Growth Process Of Lead Dioxide On Lead-Antimony Electrodes By Impedance Tracing Method, Guolin Wei, Hongxin Yang, Jiarong Wang

Journal of Electrochemistry

The growth process of PbO2 formed by the oxidation of PbSO4 in the anodic film on lead-(1,3,5,7)wt% antimony electrodes was investigated with impedance tracing method of single frequency and the current-time transient method. The influence of antimony on this process was studied.The simulation curves obtained for capacity-time transients fit the experimental results very well. It has been shown that the mentioned growth process is a two-dimentional instantaneous nucleation and growth process. Antimony will inhibit the growth of PbO2 nucleus but enhance its nucleation.


The Relationship Between Ionic Conductivity And The Structure Of The New Polymer Electrolytes, Hongze Liang, Yongxiang Song, Liming Ding, Yuchen Qi, Lixia Li, Xiabin Jing, Fusong Wang Aug 1996

The Relationship Between Ionic Conductivity And The Structure Of The New Polymer Electrolytes, Hongze Liang, Yongxiang Song, Liming Ding, Yuchen Qi, Lixia Li, Xiabin Jing, Fusong Wang

Journal of Electrochemistry

Ionic conductivity of polymer-eutectic composed of lithium perchlorate and lithium nitrate has been studied. The effects of eutectic and polymers upon the conductivities have been discussed.The lonic conductivity depends on the eutectic properties as well as the treatment method of samples.


38th Rocky Mountain Conference On Analytical Chemistry Jul 1996

38th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 38th 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, July 21-26, 1996.


Bs News Jul 1996

Bs News

Building Services Engineering

No abstract provided.


Spherical Surface Vibration Identification By Spherical Holography And Acoustic Intensity, Jen-Chieh Lee Jun 1996

Spherical Surface Vibration Identification By Spherical Holography And Acoustic Intensity, Jen-Chieh Lee

Journal of Marine Science and Technology–Taiwan

This study presents the capabilities of spherical surface vibration identification by using spherical acoustical holography and acoustic intensity measurement. The spherical holographic technique reconstructs the surface particle velocity from the acoustic pressure on the hologram. The acoustic pressure can be calculated from acoustic intensity measurement. The results of computer simulation show that, based on one direction acoustic intensity measurement only, spherical surface vibration can be identified from spherical holographic techniques.


A Modularized Software Package For Adaptive Beamforming, Shun-Hsyung Chang, Shao-Wei Leu, Hsing-Wang Liang Jun 1996

A Modularized Software Package For Adaptive Beamforming, Shun-Hsyung Chang, Shao-Wei Leu, Hsing-Wang Liang

Journal of Marine Science and Technology–Taiwan

This paper presents a modularized simulation software package for adaptive beamforming. In recent years, the theory and technology of adaptive beamforming have been applied extensively in many different areas such as radar, sonar, communication systems, and geophysical exploration. As many new beamforming architectures and related algorithms are being introduced, researchers find themselves repeating the laborious process of writing similar software routines in order to conduct simulations. This is largely due to the lack of well-defined and modularized supporting software. Therefore, we have implemented a collection of representative algorithms available for adaptive beamforming and constructed a simulator with menu-driven user interface. …