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Full-Text Articles in Nanoscience and Nanotechnology

Drect Electro_Oxidation Synthesis Of D Arabinose On Spectroscopic Graphite Electrode, Hei Wei, Huang Ying Nov 1998

Drect Electro_Oxidation Synthesis Of D Arabinose On Spectroscopic Graphite Electrode, Hei Wei, Huang Ying

Journal of Electrochemistry

D Arabinose synthesized by direct electro_oxidative decarboxylation of D gluconate on graphite electrode from aqueous solutions. The effects of D gluconate concentration, electrolysis potential, temperature and electrolyte composition on the current efficiency and product yield of electrosynthsis are discussed. The laboratory scale electrosynthesis was achieved with flow through cell.The optimum technology conditions for electrosynthesis were obtained with orthogonal design method.Both galvanostatic and potentionstatic conditions have been exploited, the later was found to be more effective.


Studies Of Surface Alloy As High Efficient Electrocatalyst For Glyoxylic Acid Synthesis, Shengpei Chen, Shengqing Xia, Shigang Sun May 1998

Studies Of Surface Alloy As High Efficient Electrocatalyst For Glyoxylic Acid Synthesis, Shengpei Chen, Shengqing Xia, Shigang Sun

Journal of Electrochemistry

No abstract provided.


InSitu Raman Spectroscopic Study Of The Oxidation And Reduction Of Ag Electrode In Na_2so_4 Solution, Chen Y X, Huang K Q, Tian Z Q May 1998

InSitu Raman Spectroscopic Study Of The Oxidation And Reduction Of Ag Electrode In Na_2so_4 Solution, Chen Y X, Huang K Q, Tian Z Q

Journal of Electrochemistry

Insitu Raman spectroscopy combined with cyclic voltammogram measurements was used to investigate formation of oxygen species at Ag electrode surfaces during the oxidation and reduction process in 0.1 mol/L Na_2SO_4 solution. The time dependent Raman spectra show that at potentials positive of 0.2 V, adsorption of oxygen atom occurs, while at the potentials positive of 0.4 V, some oxygen atoms migrate into subsurface of the Ag electrode and the other form strongly bound oxygen on the surface through chemical bond. At the same potentials, part of the silver atoms are oxidized and form Ag_2SO_4. During the negative potential ex cursion, …


Progresses In Surface Electrochemistry And Electrocatalysis ——A Review On The 1997 Joint International Meeting Of Electrochemistry And 97′ International Meeting Of Surface Electrochemistry, Shigang Sun Feb 1998

Progresses In Surface Electrochemistry And Electrocatalysis ——A Review On The 1997 Joint International Meeting Of Electrochemistry And 97′ International Meeting Of Surface Electrochemistry, Shigang Sun

Journal of Electrochemistry

The progresses in surface electrochemistry and electrocatalsis reported in the 1997 joint international meeting of electrochemistry and in the 97′ international meeting of surface electrochemistry were reviewed. The main trends described in this paper consisted of 7 aspects: 1) the studies employing single crystal electrodes, 2) the development of in situ methods of diverse spectroscpoy, 3) the innovation of new research techniques, 4) the preparaton of electrocatalyst of high performances, 5) the quantitative studies on kinetics of electrocatalytic reactions, 6) the investigation on the dynamic processes of surface by timeresolved methods, and 7) the theoretical modeling and simulation of surface …


Studies Of Surface Electrochemistry And Electrocatalysis At Atomic And Molecule Level, Shigang Sun Feb 1998

Studies Of Surface Electrochemistry And Electrocatalysis At Atomic And Molecule Level, Shigang Sun

Journal of Electrochemistry

The main progresses achieved during last few years in our research group concerning studies of surface electrochemistry and electrocatalysis were reviewed in this present paper. Four topics were described: 1) the surface electrochemistry and model electrocatalysis of metal single crystal planes, 2) the electrocatalytic reaction mechanism and the control of reaction pathways at molecule level, 3) the reaction kinetics of electrooxidation of small organic molecules, and 4) the relationship between the properties and the surface chemical states of electrocatalyst. This review lays in emphasis on the demonstration of the results as well as the research direction of surface electrochemistry and …


The Investigations Of Surface Treatment Methods And Characterization Of Oxide Films On Ab_5Based Metal Hydride Electrodes Ⅰ. New NiRich Treatment Methods And Photoelectrochemical Characterization Of Oxide Films, Junmin Nan, Yong Yang, Jun Li, Zugeng Lin Feb 1998

The Investigations Of Surface Treatment Methods And Characterization Of Oxide Films On Ab_5Based Metal Hydride Electrodes Ⅰ. New NiRich Treatment Methods And Photoelectrochemical Characterization Of Oxide Films, Junmin Nan, Yong Yang, Jun Li, Zugeng Lin

Journal of Electrochemistry

Two simple and efficient surface treatment methods for AB_5type hydrogen storage alloys were developed. The results of X-ray photoelectron spectroscopy (XPS) and cyclic voltammetric (CV) experiments showed that the hydrogen storage alloys treated by two different methods had Nirich surface layer so that the performances of the electrodes were improved after treatment. The characterization of the oxide films which formed on the surface of electrodes through potentiodynamic oxidation with the help of photoelectrochemical microscopy (PEM) were done. The anodic photocurrent and the cathodic photocurrent related to the oxidation of hydrogen and the reduction of oxygen on the surface layer were …


Characterisation Of Non-Condensable Sulphur Containing Gases From Kraft Pulp Mills, João F. Gomes Jan 1998

Characterisation Of Non-Condensable Sulphur Containing Gases From Kraft Pulp Mills, João F. Gomes

João F Gomes

This paper describes work performed on the sampling and analysis of non-condensable gases (NCG) emitted from diffuse sources of a Portuguese kraft pulp mill, which is the background information for a NCG collection, treatment and disposal system. The variability found in the composition of the gaseous compounds showed the existence of gaseous streams other than typical total reduced sulphur (TRS) compounds as usually described.


A Simple Way To Measure Particle Size, João F. Gomes Jan 1998

A Simple Way To Measure Particle Size, João F. Gomes

João F Gomes

The size range of particles is an important parameter for subsequent dispersion estimates and sometimes is quite useful for analysing the performance of combustion equipment as well as dedusting equipment efficiency. So far, no standard method has been developed but several laboratories use laser-beam techniques which are usually quite expensive ones. In this paper a method is presented where the particles are collected isokinetically in a filter from gases circulating in a stack as described in USEPA method 5. Afterwards particles are observed at an optical microscope and measured. In spite of some limitations this appears to be an inexpensive …


Assessment Of Opacimeter Calibration On Kraft Pulp Mills, João F. Gomes Dec 1997

Assessment Of Opacimeter Calibration On Kraft Pulp Mills, João F. Gomes

João F Gomes

This paper describes the methodology and specific techniques for calibrating automatic on-line industrial emission analysers, specifically equipments that measure total suspended dust installed in pulp mills within the scope of Portuguese Regulation Nº 286/93 on air quality. The calibration of opacimeters is a multi-parameter relationship instead of the bi-dimensional calibration which is used in industrial practice. For a stationary source from a pulp mill such as the recovery boiler stack, which is subjected to significant variations, the effects of parameters such as the humidity and gas temperature, deviations on isokinetism, size range of particles and characteristic transmitance of equipment are …