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1998

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Articles 1 - 17 of 17

Full-Text Articles in Nanoscience and Nanotechnology

Direct Electro-Oxidation Synthesis Of D-Arabinose On Spectroscopic Graphite Electrode, Hei Wei, Huang Ying Nov 1998

Direct 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.

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Study Of The Effect Of Rare Earth Ions On Dna Using Cyclic Voltammetry And Spectroscopy, Hei-Bai Shen, Yu-Zhuan Kang, Hai-Feng Yang, Lin Yu, Zong-Rang Zhang Nov 1998

Study Of The Effect Of Rare Earth Ions On Dna Using Cyclic Voltammetry And Spectroscopy, Hei-Bai Shen, Yu-Zhuan Kang, Hai-Feng Yang, Lin Yu, Zong-Rang Zhang

Journal of Electrochemistry

The interaction between rare earth ions(e.g. Eu3+ ,Ce3+, Er3+, Sm3+, Tb3+, La3+ and Nd3+) and DNA had been investigated by using Cyclic Voltammetry, Ultraviolet and Raman Spectroscopy. After the adding of Ce3+ ion to DNA solution, the cathodic peak current of Ce3+ ion reduction was found to decrease obviously, and the anodic peak current to decrease even more significantly. Differential UV spectra of Ce3+ ion depicted hyperchromic effect after the reaction of these two species and a new peak of 272 nm was found. Differential …

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Asymptotic Decay Of Radius Of A Weakly Conductive Viscous Jet, A.F. Spivak, Yuris A. Dzenis Nov 1998

Asymptotic Decay Of Radius Of A Weakly Conductive Viscous Jet, A.F. Spivak, Yuris A. Dzenis

Nebraska Center for Materials and Nanoscience: Faculty Publications

Motion of a weakly conductive viscous jet accelerated by an external electric field is considered. Nonlinear rheological constitutive equation applicable for polymer fluids (Oswald–deWaele law) is applied. A differential equation for the variation of jet radius with axial coordinate is derived. Asymptotic variation of the jet radius at large distances from the jet origin is analyzed. It is found that the well-known power-law asymptote for Newtonian fluids with the exponent 1/4 holds for more general class of fluids, i.e., pseudoplastic (shear thinning) and dilatant (shear thickening) fluids with the flow index between 0 and 2. Dilatant fluids with the flow …

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Processing Of Hydroxylapatite Coatings On Titanium Alloy Bone Prostheses, Michael A. Nastasi, Timothy E. Levine, James W. Mayer, Vincent B. Pizziconi Oct 1998

Processing Of Hydroxylapatite Coatings On Titanium Alloy Bone Prostheses, Michael A. Nastasi, Timothy E. Levine, James W. Mayer, Vincent B. Pizziconi

Department of Mechanical and Materials Engineering: Faculty Publications

Processing of hydroxylapatite Sol-gel films on titanium alloy bone prostheses. A method utilizing non-line-of-Sight ion beam implantation and/or rapid thermal processing to provide improved bonding of layers of hydroxylapatite to titanium alloy Substrates while encouraging bone ingrowth into the hydroxylapatite layers located away from the substrate, is described for the fabrication of prostheses. The first layer of hydroxylapatite is mixed into the Substrate by the ions or rapidly thermally annealed, while Subsequent layers are heat treated or densified using ion implantation to form layers of decreasing density and larger crystallization, with the outermost layers being Suitable for bone ingrowth.

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Lithiun Insertion In Carbon Nanotubes, Guo-Tao Wu, Chun-Sheng Wang, Zhong-Fu Qi, Wenz-Hu Li Aug 1998

Lithiun Insertion In Carbon Nanotubes, Guo-Tao Wu, Chun-Sheng Wang, Zhong-Fu Qi, Wenz-Hu Li

Journal of Electrochemistry

Carbon nanotubes were produced by chemical vapour deposition(CVD) of acetylene under hydrogen gas.The reversible specific capacity of carbon nanotubes is up to 700 mAh/g, much higher than the theoretical specific capacity of graphite(372 mAh/g).After twenty charge/discharge cycles,the discharge capacity of carbon nanotube anode still maintains 65.3% of its original discharge capacity . Besides, the charge/discharge efficiency of carbon nanotube in the first charge/discharge cycle was found to improve from 42.6% up to 55.9% by coating carbon nanotubes with copper.

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Photoelectrochemical Studies On Nanoporous Tio2/Pan Film Electrode, Min-Sheng Liu, Yan-Zhong Hao, Xue-Bin Qiao, Mai-Zhi Yang, Sheng-Min Cai Aug 1998

Photoelectrochemical Studies On Nanoporous Tio2/Pan Film Electrode, Min-Sheng Liu, Yan-Zhong Hao, Xue-Bin Qiao, Mai-Zhi Yang, Sheng-Min Cai

Journal of Electrochemistry

The photon to electricity conversion process of nanoporous TiO2/PAn film electrode was studied in electrolytes with and without redox couple by using the photocurrent action spectra and potential dependence of photocurrent. It is concluded that the nanoporous TiO2/PAn film electrode has a structure of duplex n type semiconductor layers. The band gap of PAn film is 2.88eV.The TiO2 nanoporous film electrode modified by PAn can extend the range of optical absorption into visible and infrared region and effectively increase the photocurrent in the visible and infrared region. The photocurrent threshold shifts to>600nm and conversion …

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Studies On The Preparation Of Nanophase Electrode Materials And Its Electrochemical Properties(Ⅲ)—Performance Of Nm-Γ-Mno2 Obtained By Microemulsion Method, Ling Liu, Xi Xia Aug 1998

Studies On The Preparation Of Nanophase Electrode Materials And Its Electrochemical Properties(Ⅲ)—Performance Of Nm-Γ-Mno2 Obtained By Microemulsion Method, Ling Liu, Xi Xia

Journal of Electrochemistry

A nanophase MnO2 was synthesized using w/o microemulsion as reation media, The most favorable experiment conditions for the preparation of nm MnO2 were researched. XRD,TEM,AC impedance, cyclic voltammetry etc. examinations were used to characterize the sample comparison with the classical MnO2 (I.C.No.1EMD,electrolytic manganese dioxide). Sample shows that the crystal styucture of the synthesized samples are mainly γ-MnO2, with average particle size in the nanometer as shown by TEM. It was found that the discharge capacity of nm MnO2 obtained is significantly higher than that of the I.C.No.1 EMD.

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In-Situ Raman Spectroscopic Study Of The Oxidation And Reduction Of Ag Electrode In Na2So4, Yan-Xia Chen, Kai-Qi Huang, Zhong-Qun Tian May 1998

In-Situ Raman Spectroscopic Study Of The Oxidation And Reduction Of Ag Electrode In Na2So4, Yan-Xia Chen, Kai-Qi Huang, Zhong-Qun Tian

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 Na2SO4 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 Ag2SO4 …

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Study Of Charged Property On The Interface Of Porous Membrane Of Anodized Aluminum, Ya-Fei Kuang, Ling Wang, Fei Hu May 1998

Study Of Charged Property On The Interface Of Porous Membrane Of Anodized Aluminum, Ya-Fei Kuang, Ling Wang, Fei Hu

Journal of Electrochemistry

Using electrodialytic method, the relation between the pH value of tested solution and the ζ potential of porous anodized aluminum membrane, which was separated by reverse electrolysis from aluminum substrate, has been investigated. The following results can be obtained in 1.0×10-2 mol/L KCl solution: The pHIEP (isoelectric potential) of the porous membrane is equal to 9.20. In the range of 2.00

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Studies Of Surface Alloy As High Efficient Electrocatalyst For Glyoxylic Acid Synthesis, Sheng-Pei Chen, Sheng-Qing Xia, Shi-Gang Sun May 1998

Studies Of Surface Alloy As High Efficient Electrocatalyst For Glyoxylic Acid Synthesis, Sheng-Pei Chen, Sheng-Qing Xia, Shi-Gang Sun

Journal of Electrochemistry

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The Effect Of Grain Size On Magnetic Properties In Sm2Fe17NX, Jeffrey E. Shield, D.J. Branagan, C.P. Li, R.W. Mccallum May 1998

The Effect Of Grain Size On Magnetic Properties In Sm2Fe17NX, Jeffrey E. Shield, D.J. Branagan, C.P. Li, R.W. Mccallum

Nebraska Center for Materials and Nanoscience: Faculty Publications

The microstructures of melt spun Sm11Fe89 and (Sm11Fe89)94Ti3C3 have been investigated under different solidification conditions. The magnetic properties of the nitrided materials have been related to the observed microstructures. Melt spinning of the Sm11Fe89 alloys resulted in grain sizes at or above the single domain limit. The addition of Ti and C resulted in an order of magnitude refinement in the microstructural scale. The magnetic properties of the samples with grain sizes below the single domain limit decreased with decreasing grain size due to increased intergranular exchange coupling.

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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 …

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The Investigations Of Surface Treatment Methods And Characterization Of Oxide Films On Ab5 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 Ab5 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 AB5 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 …

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Spectroscopic Investigation Of Ion Transport Mechanisms In Polyacrylonitrile Based Electrolytes, Zhaoxiang Wang, Biying Huang, Rongjian Xue, Xuejie Huang, Liquan Chen Feb 1998

Spectroscopic Investigation Of Ion Transport Mechanisms In Polyacrylonitrile Based Electrolytes, Zhaoxiang Wang, Biying Huang, Rongjian Xue, Xuejie Huang, Liquan Chen

Journal of Electrochemistry

Raman, IR, X-ray photoelectron (XPS), and NMR spectra of components in polyacrylonitrile based electrolytes have been studied. It is found that there are strong interactions among the components though different systems show different interaction characteristics. A concept of competition is proposed between the polymer matrix and the plasticizer on associating with the Li+ ions. By analyzing the important functions of the plasticizer, a possible mechanism of the ions transport in the polymer electrolyte is suggested.

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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 …

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Study On Nano Electrode Material Of Lithium Ion Batteries, Jinkua You, Yong Yang, Dong Shu, Shenghui Wu, Yingchun Zhang, Zugeng Lin Feb 1998

Study On Nano Electrode Material Of Lithium Ion Batteries, Jinkua You, Yong Yang, Dong Shu, Shenghui Wu, Yingchun Zhang, Zugeng Lin

Journal of Electrochemistry

In this paper, the structure and morphology of the nano phase electrode materials have been characterized with XRD and TEM. The performances of electrochemical intercalation and deintercalation of lithium ions have been studied by using cyclic voltammograms and galvanostatic charge discharge techniques. The results show that the nano materials posses advantage of micro structure and Li+ ions intercalation performances. The observed high capacity and large charge discharge current density of the nano phase materials seem to have resulted from three kinds of effects: 1) an increase in the space for Li+ ions intercalation; 2) a decrease in the …

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The Migration Of Samarium(Ⅲ) Across Oil/Water Interface, Jun-Wei Di, Xiao-Xing Xu, Ying Wu, Rui-Xi Fan Feb 1998

The Migration Of Samarium(Ⅲ) Across Oil/Water Interface, Jun-Wei Di, Xiao-Xing Xu, Ying Wu, Rui-Xi Fan

Journal of Electrochemistry

The migration of Samarium(Ⅲ) across water/nitrobenzene (w/nb) interface facilitated by diantipyrylmethane (DAM) and the electrochemical behaviour affected by emulsifier OP in the nb phase have been studied by normal and convolute cyclic voltammetry. It is concluded that the formation of the complex occurs at w/nb interface and the mechanism of the samarium(Ⅲ)transfer across w/nb interface facilitated by DAM is E mechanism.

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