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1995

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Articles 1 - 15 of 15

Full-Text Articles in Nanoscience and Nanotechnology

Simultaneous Detection System Combining Studies Of Programmedpotential Step Technique And Time-Resolved Ftir Spectroscopy, Shigang Sun, Xiaoyu Chen, Guoqiang Lu, Wenfeng Lin, Nanhai Li, Shenpei Chen, Hongping Dai, Jiqian Mu Nov 1995

Simultaneous Detection System Combining Studies Of Programmedpotential Step Technique And Time-Resolved Ftir Spectroscopy, Shigang Sun, Xiaoyu Chen, Guoqiang Lu, Wenfeng Lin, Nanhai Li, Shenpei Chen, Hongping Dai, Jiqian Mu

Journal of Electrochemistry

No abstract provided.


Studies Of In-Situ Raman Spectroscopy On Deprotonation And Degeneration Of Ppy Films, Jinsong Gao, Jing Chen, Yanzhen Chen, Qi Xue, Zhongqun Tian Nov 1995

Studies Of In-Situ Raman Spectroscopy On Deprotonation And Degeneration Of Ppy Films, Jinsong Gao, Jing Chen, Yanzhen Chen, Qi Xue, Zhongqun Tian

Journal of Electrochemistry

By combining the in-situ Raman spectroscopic technique with the normalelectrochemical measurements ,the behavior and structure of PPY films in neutral or basic solutionswere studied.The oxidized PPY loses protons on the N atoms of pyrrole rings and is deprotonated inthese solutions ,resulting the formation of the quinoid structure. It makes the C=C stretching vibrationbonds of PPY split.Because this quinoid structure can′t be further oxidized ,the PPY becomes moredifficult to be oxidized and less reversible with the increasing of pH value of solutions and the degree ofdeprotonation of PPY. In the strong basic solution ( pH=13),the PPY film is degenerated in thepotential …


Process For The Formation Of Wear- And Scuff-Resistant Carbon Coatings, Gerard W. Malaczynski, Xiaohong Qiu, Joseph V. Mantese, Alaa A. Elmoursi, Aboud H. Hamdi, Blake P. Wood, Kevin C. Walter, Michael Nastasi Oct 1995

Process For The Formation Of Wear- And Scuff-Resistant Carbon Coatings, Gerard W. Malaczynski, Xiaohong Qiu, Joseph V. Mantese, Alaa A. Elmoursi, Aboud H. Hamdi, Blake P. Wood, Kevin C. Walter, Michael Nastasi

Department of Mechanical and Materials Engineering: Faculty Publications

A process for forming an adherent diamond-like carbon coating on a workpiece of suitable material such as an aluminum alloy is disclosed. The workpiece is successively immersed in different plasma atmospheres and subjected to short duration, high voltage, negative electrical potential pulses or constant negative electrical potentials or the like so as to clean the surface of oxygen atoms, implant carbon atoms into the surface of the alloy to form carbide com pounds while codepositing a carbonaceous layer on the surface, bombard and remove the carbonaceous layer, and to thereafter deposit a generally amorphous hydrogen-containing carbon layer on the surface …


Study On The Surface States Of Zinc Sulfide Thin Film Doped With Erbium And Their Effect On The Relaxation Luminance, Yujiang Wang, Zhaohong Liu, Zhenxiang Chen Aug 1995

Study On The Surface States Of Zinc Sulfide Thin Film Doped With Erbium And Their Effect On The Relaxation Luminance, Yujiang Wang, Zhaohong Liu, Zhenxiang Chen

Journal of Electrochemistry

X-ray photoelectron spectrum and characteristics of the capacity,versus thevoltage of the thin film devices are measured to study the surface states of the zinc sulfide thin film.The transient electroluminescence excited by pulses shows the relaxation luminance peaks during anon-exponential decay process of the characteristic transitions activated by Er ̄(3+) in the ZnS directcurrent thin film electroluminescence (DCTFEL) devices.The surface structures of ZnS:Cu,Cl,Erfilm with the absorption of oxygen,and the effect of the surface states on the relaxation luminance ofthe devices are discussed.


Effect Of Symmetric Alternating Current On Cathode Surface Before Iron Deposition, Xintan Hu Aug 1995

Effect Of Symmetric Alternating Current On Cathode Surface Before Iron Deposition, Xintan Hu

Journal of Electrochemistry

The composition and thickness of active film formed on the surface of cathodemade of low carbon steel after treated by symmetric alternating current(SAC)in ferris chloride bathis studied,and the interfacial morphology of the iron deposit and the substrate is also examined.Theresults show that the active film,which a thickness of 20~25nm can be obtained under SAC densityof about 7A dm ̄(-2) ,so that the adherent iron deposit can be achieved on the active film. The effect ofSAC on cathode surface is discussed in detail.


The Influnce Of Conjugated Π Bond In Promoter Molecule On The Direct Electrochemical Reaction Of Cytochrome C, Xiaogang Qu, Tianhong Lu, Shaojun Dong Aug 1995

The Influnce Of Conjugated Π Bond In Promoter Molecule On The Direct Electrochemical Reaction Of Cytochrome C, Xiaogang Qu, Tianhong Lu, Shaojun Dong

Journal of Electrochemistry

The promoter effect of thiophene with only one-functional group on the directelectrochemical reaction of cytochrome c was compared with that of tetrahydrothiophene in this report.It was found that thiophene is a good promoter.But tetrahydrothiophene could not facilitate the directelectrochemistry of cytochrome c although this compound is very similar to thiophene in str uctureexcept for conjugated π bond.This demonstrated that the conjugated π bond in thiophene plays animportant role for the acceleration of the direct electrochemistry of cytochrome c.


Method Of Making Quasicrystal Alloy Powder, Protectivecoatings And Articles, Jeffrey E. Shield, Alan I. Goldman, Iver E. Anderson, Timothy W. Ellis, R. William Mccallum, Daniel J. Sordelet Jul 1995

Method Of Making Quasicrystal Alloy Powder, Protectivecoatings And Articles, Jeffrey E. Shield, Alan I. Goldman, Iver E. Anderson, Timothy W. Ellis, R. William Mccallum, Daniel J. Sordelet

Department of Mechanical and Materials Engineering: Faculty Publications

A method of making quasicrystalline alloy particulates wherein an alloy is superheated and the meltis atomized to form generally spherical alloy particulates free of mechanical fracture and exhibiting a predominantly quasicrystalline in the atomized condition structure. The particulates can be plasma sprayed to form a coating or consolidated to form an article of manufacture.


A Sutface-Enhanced Raman Spectroscopic Study On The Inhibition Mechanism Of Bmat On Stainless Steel In Hydrochloric Acid Solutions, Yinghua Zha, Baoming Wei May 1995

A Sutface-Enhanced Raman Spectroscopic Study On The Inhibition Mechanism Of Bmat On Stainless Steel In Hydrochloric Acid Solutions, Yinghua Zha, Baoming Wei

Journal of Electrochemistry

The absorbtion of some nitrogen and sulfur compounds such as BMAT on 18-8stainless steel(SS)in 0.5% HCl were investigated by surface enhanced Raman scattering(SERS)spectroscopy.The SERS spectra of BMAT adsorbed on SS were measured using a SS electredepositedwith discontin uous silvet micro-islands.The results show that the inhibitor,BMAT,is chemisorbed onthe SS surface through the N atom. Under the influence of π-electron interaction ,BMAT can beadsorbed on SS surface at an angle. The allyls in BMAT molecules play the role of steric hindrance inthe inbibition effect.


Incorporation Of Zn In Gaas During Organometallic Vapor Phase Epitaxy Growth Compared To Equilibrium, W. Reichert, C.Y. Chen, W.M. Li, Jeffrey E. Shield, R.M. Cohen, D.S. Simons, P.H. Chi Mar 1995

Incorporation Of Zn In Gaas During Organometallic Vapor Phase Epitaxy Growth Compared To Equilibrium, W. Reichert, C.Y. Chen, W.M. Li, Jeffrey E. Shield, R.M. Cohen, D.S. Simons, P.H. Chi

Nebraska Center for Materials and Nanoscience: Faculty Publications

The zinc concentration measured after organometallic vapor phase epitaxy (GMVPE) growth on (100)-oriented GaAs at 700 °C has been compared to the zinc concentration measured after in-diffusion under near-equilibrium conditions. During diffusion, the concentration of Zn 20 nm below the surface was found to vary with PZn1/2, as expected for bulk solid-vapor equilibrium. During growth, the concentration of Zn varied linearly with PZn up to a maximum value which was found to correspond to the solubility limit set by second phase formation, e.g., growth of Zn3As2. Although large differences were observed between …


Atomic And Molecular-Perspectives In Electrochemical Interfaces, Zhaowu Tian Feb 1995

Atomic And Molecular-Perspectives In Electrochemical Interfaces, Zhaowu Tian

Journal of Electrochemistry

The following recent studies on the atomic and molecular-perspectives atelectrochemical interfaces using Raman,IR,STM and quantum chemical methed by electrOchemistrygroup in Xiamen University are briefly reviewed. 1.Orientation,charge transfer and bonding of adsorbed molecules. 2.Adsorption effect,electrode potential effect and adatom effect on the electron populations and strength of intramolec ular bonds of the adsorbed molecules. 3.Detailed classification into various types(e. g.,competitive,chemically inductive, physical inductive etc.)of coadsorption on electrodes according to the above-mentioned effects. 4. Single crystal face structure effect and adatom effect on the kinetics and the mechanisms of electrocatalytic oxidation processes of small organic molecules. 5.Electrochemical scanning tunneling microscopy(ECSTM)specially designed for …


Transient Photocurrent Behavior Of Multiple Quantum Well Gaas/Al_Xga_(1-X)As Electrode, Liuyao Liuyao, Xurui Xiao, Liyuan Liyuan Feb 1995

Transient Photocurrent Behavior Of Multiple Quantum Well Gaas/Al_Xga_(1-X)As Electrode, Liuyao Liuyao, Xurui Xiao, Liyuan Liyuan

Journal of Electrochemistry

Transient photocurrents induced by short light pulses at lattice-matched multiplequantum well(MQW)GaAs/Al_(0.3)Ga_(0.7)As electredes were studied in the 1 ×10 ̄(-2)mol·dm ̄(-3)ferrocene([Fc ̄0]/[Fc) ̄+]=9/1)-0.1 mol·dm ̄(-3)tetrabutylammonium tetrafluoroborate acetonitrile solutionin order to examine the relaxation photoprocesses and to evaluate kinetic parameters of superlattice electrodes. GaAs/Al_(0.3)Ca_(0. 7)As MQW electrode consisting of 10 periods with each of GaAs well(5.3nm)and Al_(0. 3)Ga_(0. 7)As barrier(10nm)showed two pronounced and well-resolved peak structures located at 1.503 eV and 1.699 eV in the photocurrent spectrum,corresponding to the theoretical allowedexcitonic transitions(Δn=0) for heavy holes(H11,H22)in the quantum well respectively. Transient photocurrent spectra were measured by a monochromatic light pulse with 7 μs pulsewidth and 9 nJ·cm ̄(-2) of …


Self Assembly Via Layer By Layer Surface Reaction On Gold Electrodes And The Electrochcmical Characterization, Xiandui Dong, Juntao Lu, Chuanxin Cha Feb 1995

Self Assembly Via Layer By Layer Surface Reaction On Gold Electrodes And The Electrochcmical Characterization, Xiandui Dong, Juntao Lu, Chuanxin Cha

Journal of Electrochemistry

The self-assembled monolayers,which were built by spontaneous adsorption of ω-carboxylic acid thiols on gold surface,were used as substrate for further modification through later bylayer amide surface reactions.At each stage of modification,the gold surface was characterizedelectochemieally. The results demonstrated that the strategies of layer by layer self assembly is ofsignificant potential for fabrieating functionalized ultrathin layers.


The Electrode Process Of Y(Ⅲ)On Copper Electrode And Its Surface Metallizing, Chungen Zhou, Shuzhen Duan Feb 1995

The Electrode Process Of Y(Ⅲ)On Copper Electrode And Its Surface Metallizing, Chungen Zhou, Shuzhen Duan

Journal of Electrochemistry

The reduction of yttrium ion on copper electrode in NaCl-KCl-YCl_3 molten saltshas been investigated.The results indicate that the formation of intermetallic compounds is occuredbefore the metallic yttrium to be formed.The formation of intermetallic compounds is controlled bythe process of which yttrium atoms are diffusing into copper electrode.The kinetic characters todiffusion of yttrium atoms were also discussed.


Study Of Electrochemical Properties Of Ni(Oh)_2 /Niooh With Spectroscopic Ellipsometry, Shengtao Zhang, Zongqing Huang Feb 1995

Study Of Electrochemical Properties Of Ni(Oh)_2 /Niooh With Spectroscopic Ellipsometry, Shengtao Zhang, Zongqing Huang

Journal of Electrochemistry

Electrochemical reactions of Ni(OH)_2 /NiOOH system were studied by using in-situ spectroscopic ellipsometry and the conventional electrochemical metheds.By fitting data fromellipsometric measurements,a transformation medel of the surface film was obtained for cathedic andanodic processes. The results indicated that the transformation medel after cobalt implantation almostremained the same as that before cobalt implantation,but the electrochemical properties wereaffectedobviously by implantation of cobalt.


Characterization Of Piezoceramic Crosses With Large Range Scanning Capability And Applications For Low Temperature Scanning Tunneling Microscopy, J. A. Helfrich, Shireen Adenwalla, J. B. Ketterson, G. A. Zhitomirsky Jan 1995

Characterization Of Piezoceramic Crosses With Large Range Scanning Capability And Applications For Low Temperature Scanning Tunneling Microscopy, J. A. Helfrich, Shireen Adenwalla, J. B. Ketterson, G. A. Zhitomirsky

Shireen Adenwalla Papers

We have developed a large amplitude piezoceramic scanner which should have numerous applications. Scanning tunneling microscopy (STM) and other scanning probe microscopies predominantly use piezoceramics for the scanning elements. Similarly adaptive optics, high resolution lithography, and micromanipulators are other examples of research which regularly utilize piezoceramic scanners. We present a new geometry for a piezoceramic scanner which allows for both high resolution (~nanometers) and large amplitude (~400 µm) displacements. The cross-shaped geometry makes it possible to produce extremely long pieces with very high tolerances. We have shown its effectiveness by using it as the major component of a low temperature …