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Study Of The Action Mechanism Of A New Type Additive Sd-1 On The Electrodepositional Process Of Zinc, Huaqiang Wu, Yiqin Yan, Guangming Ni

Journal of Electrochemistry

The action mechanism of a new type additive SD-1 on the electrodepositionalprocess of zinc is reported.The results showed that the additive SD-1 is not electrochemistry activesubstane in the range of adsorption potential at rotating disk electrode surface. The action of additive SD-1 on the electrodepositional process of zinc is considerated to be fitting in with the diffusion controlmechanism.

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 normal electrochemical measurements, the behavior and structure of PPY films in neutral or basic solutions were studied. The oxidized PPY loses protons on the N atoms of pyrrole rings and is deprotonated in these solutions, resulting the formation of the quinoid structure. It makes the C=C stretching vibration bonds of PPY split. Because this quinoid structure can′t be further oxidized, the PPY becomes more difficult to be oxidized and less reversible with the increasing of pH value of solutions and the degree of deprotonation of PPY. In the strong basic solution …

Catalytic Oxidation Of Methanol On Pt/C-Spe And Ptru/C-Spe Electodes, Aihua Su, Changzhi Li, Gongquan Sun, Ying Zhang, Tianhong Lu

Journal of Electrochemistry

Anode catalysts of methanol oxidation for direct methanol fuel cell, Pt/C and PtRu/C, ere prepared by chemical reduction in this work. The results indicated that the PtRu/C showed higher electrocatalytic activity than that of Pt/C. It was explained by XRD and XPS analyses that the existence of Ru enhanced the catalytic activity for electrochemical oxidation of methanol.

Influence Of O-Phenylenediamine On The Catalysis At Hrp Enzyme Electrode In 1,4-Dioxane, Hong Chen, Hui-Huang Wu

Journal of Electrochemistry

Horseradish peroxidase (HRP) was immobilized by crosslinkage on the glassycarbon electrode to prepare the enzyme electrode, where the reduction of H₂O₂ was studied in 1,4-dioxane media. It was shown that HRP electrode can catalyze the reduction of H₂O₂ without anymedintor, however, as an activator, o-phenylenediamine can promote the bio-catalysis. In thepresence of the activator, the parallel reactions occurred on the enzyme electrode. The workingcondition of the HRP electrode was investigated as the sensors for H₂O₂ and o-phenylenediamine, also the influence of water content in organic phase was discussed on the performance …

Synthesis And Characterization Of Silicon Dioxide Thin Films By Plasma Enhances Chemical Vapor Deposition From Diethylsilane And Nitrous Oxide, Lan Chen

Theses

This study is focused on the synthesis and characterization of silicon dioxide thin films deposited on silicon wafers by plasma enhanced chemical vapor deposition(PECVD), using diethylsilane (DES) as a precursor and nitrous oxide (N₂O) as the oxidant. The process parameters, such as temperature, pressure and reactant gas composition have been systematically varied and their effects on the film growth rate and properties were investigated. The growth rate was found to be inversely proportional to the temperature in the examined range of 100-300°C. It increased with increasing N₂O/DES flow rate ratio as the total flow rate increased …

Factors Effecting Calcification Of Bioprosthetic Heart Valves, Sumei Yu

Theses

Calcification is the most frequent cause of clinical dysfunction of glutaraldehyde treated bioprosthetic heart valves. In this study, we compared calcification of bioprostheses of the No-ReactTM and the conventional glutaraldehyde treated pericardium by both in-vivo and in-vitro methods, and to further delineate the role of the host's inflammatory response in implant degeneration.

In the in-vitro study, the two types of pericardial samples were placed in individual polystyrene tubes containing physiological concentrations of calcium and phosphate and incubated for 21 days at 37°C. In the in-vivo study, the two types of pericardial samples were implanted subcutaneously in rats and subsequently retrieved …

Three-Phase Intersection Points In Monolayers, John P. Hagen, Harden M. Mcconnell

Chemistry and Biochemistry

Some phospholipid/dihydrocholesterol Langmuir monolayers form coexisting liquid phases. Gas domains form at the interface between the phospholipid-rich and dihydrocholesterol-rich liquid phases when these monolayers undergo expansion to low surface pressure. Analysis of the domain shapes thus formed yields the relative line tensions of the gas/phospholipid, gas/dihydrocholesterol, and phospholipid/dihydrocholesterol phase interfaces.

Vr Projects, P.D. Quick

SWITCH

A description of three three projects having to do with virtual reality. The first is the Nanomanipulator, developed at the University of North Carolina Chapel Hill Department of Computer Science in conjunction with the UCLA Department of Chemistry in 1991. It is a machine that allows the user to interact with microscopic particles previously only visible in 2D from an electron microscope. The second project, The Augmented Reality Project, also developed at the Chapel Hill Department of Computer Science. This device used ultrasound images to be placed over a body allowing the user to see inside of it. The final …

Development Of High Active Aluminum Alloy Sacrificail Anode, Zhaobo Wei, Jianhua Wu, Guangzhang Chen, Songrao Jiang, Zenya Li

Journal of Electrochemistry

A high active aluminum alloy sacrificial anode with the operating potential-1.40 v (SCE), and the the current capacity more than 2175 A·h/kg and dissolution fair issuccessfully developed by adding zinc, indium, gallium, bismuth and heat treatment. The aluminumalloy sacrificial anode with super electrochemical properties can throughly replace the magnesium alloyanode when applied to seawater and freshening seawater, which is obviously advantageous to thetechnology and economy.

Self-Assembled Monolayers: Preparation,Properties And Application, Xiandui Dong, Juntao Lu, Chuansin Cha

Journal of Electrochemistry

Self-assembling technique is a versatile approach to the preparation of monolayersof well-defined composition, structure, thickness and physicochemical properties. Different aspects, such as wettability, adhesion, corrosion, tribology, electrontransfer, protein adsorption, molecular recognition, and applications of SAMs are widely studied. The developments in the last decade arereviewed, with special attention to the electrochemical studies related to electrodes modified with thiol-derivative-based SAMs.

Problems On The Study Of Anodic Films On Pb In Sulfuric Acid Solution (Ⅰ), Wenbin Cai, Houtian Liu, Weifang Zhou

Journal of Electrochemistry

The identification of the phase composition of the anodic film on Pb formed in H₂SO₄ solution in PbO potential region has long been argued, together with the explanation of thecathodic peak at about -0.9V (Hg/HgSO₄) in the linear sweep voltammogram for a Pb-H₂SO₄ system. In this article, a review of our recent investigations was presented on the above problems.

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.

Studies Of Cl- On The Electrochemical Oscillation Behaviour Of Electrodeposited Silver Indium Selenide Thin Films By Using Dynamic Impedance And The Condensance Method, Shaoai Xie, Xunnan Deng, Jinkua You

Journal of Electrochemistry

The electrochemical oscillation behaviour of hydrogen peroxide cathodic reductionprocess on the electro deposited silver indium selenide electrode has been studied by using in-situ dynamic impedance and the condensance measurement technique in different supporting electrolytes solutions. The surface composition of AglnSe₂ electrodes (before and after oscillating) were also givenby AES. According to the experimental results, the influence of Cl^- on the mechanism of this electrochemical oscillaton process has been discussed in detail.

The Photoelectrochemical Studies Of Passive Films On Rebar Electrodes In Simulated Cement Pore Solution, Wei Chu, Yuanxiang Shi, Baoming Wei, Yong Yang, Xuguang Chen, Zugeng Lin

Journal of Electrochemistry

The electronic properties of the passive film on REBAR electrodes in simulatedcement pore solution (pH=9.0～13.8) have been investigated using in-situ photoelectrochemical methods. The results show that the passive film is composed of mixed oxides of ferrum, and it is an amorphous, n-type semiconductive film. Variations of pH values, ions in the solution and film-formation potentials can affect the composition of the films. There are two main stages in the growthof the film, with two rate functions characterized by linear relation between the film thickness and thelogarithm of time. The addition of inhibitor NaNO₂ changes the composition, structure and growth …

Properties Of Zr-Based Laves Phase Hydrogen Storage Electrode, Xueping Gao, Huabin Yang, Deying Song, Yunshi Zhang, Zuoxiang Zhou, Wei Zhang, Panwen Shen

Journal of Electrochemistry

After treated by HF solution,the surface of Zr(V_0.2Mn_0.2Ni_0.54Mo_0.06)_2.4 alloy was transformed from Zr-rich and Mn-rich layer to Ni-rich layer. In this way, the nickel on thesurface could be believed to be the Raney-type nickel, which could obviously shorten the activation cycles, improve electrocatalytic activity and hydrogen adsorption ability. In this paper, the reaction mechanism on the alloy surface (i.e. the mechanism of nickel-catalysis, hydrogen-adsorption and hydrogen-transference) had been investigated. And the impedance spectra were fitted to an equivalentcircuit using a non-linear, least-squares (NLLS) fitting program.

Coadsorption Of Para-Toluene Sulfamide And 1.4-Butynediol At Mercury Electrode, Shukun Huang, Naixian Xie, De Gao, Qiang Liu

Journal of Electrochemistry

The coadsorption characteristics of para-toluene sulfamide and 1,4-butynediol atmercury electrode have been studied by means of electrocapillary curve, differential capacity curve, Stuart model and the SCFMO method (CNDO/2). The coadsorption is a physical adsorption occuringnaturally. Lateral and flat orientations in the two adsorbates close to their maximum adsorptionpotential were considered respectively. Unlike attractive interactions of their own, there was arepulsive interaction at their coadsorption layer. A preferred adsorption of 1,4-butynediol occurred when they were at the same volume concentration.

A Relativistic Density-Functional Investigation Of Vibrational Frequencies Of Cn- On Cu And Ag Electrodes, Mengsheng Liao, Xin Lv, Qianer Zhang

Journal of Electrochemistry

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Studies On The Structure Of Licoo2 Synthesized With Tartaric Acid And The Behaviorof Its Rechargeable Lithium Battery, Fuping Zhang

Journal of Electrochemistry

The structure of LiCoO₂ synthesized with tartaric acid and the behavior of itsrechargeable Lithium battery have been studied by XRD, XPS, CV, CT. It has been shown that LiCoO₂ has a space group R3m with hexagonal parameters a=0.2810 nm, c=1.4088 nm. Low-spin state Co³⁺ configuration in LiCoO₂ has been suggested. Also, Li₂O, was identified onits surface. Furthermore, the capacity and the middle working voltage of its Lithium battery are about 120 mA·h·g^-1 and 3.8 V, respectively. The EMF of the cell changes with the Lithium composition of itscathode following E=4.318-0.450 X^2/3 in …

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 cathode made 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. The results show that the active film, which a thickness of 20～25nm can be obtained under SAC densityof about 7 A·dm^-2 ,so that the adherent iron deposit can be achieved on the active film. The effect of SAC on cathode surface is discussed in detail.

The Oxidation Of Hydrogen Absotbing Alloys And Its Inhibition, Suqin Wang, Baojia Xia, Geping Yin, Pengfei Shi

Journal of Electrochemistry

This paper introduces the method to judge: 1)the possibility of oxidation of themetal hydride electrode in an anode process by cyclic voltammetric curves, 2)the oxidation pattern ofmetal hydride electrode in oxygen atmosphere in various charged states, and 3)the inhibition ofoxidation of hydrogen absorbing alloys by certain surface treatment.

Photoelectric Property For Zinc Phthalocyanine Of Doping C60 On Inp Electrode, Mengxiong Zhan, Rongqing Yu, Biaolian Zhen, Dadian Cheng, Lansun Zheng

Journal of Electrochemistry

The curves of spectral and photovoltaic responses to zinc phthalocyanine of doping C₆₀ were determinted. The photovoltaic property for zinc phthalocyanine of doping C₆₀ wereinvestigated on the InP single crystal in the photoelectrochemical cell.The results have shown that: 1)The photovoltaic effect and the in tensities of the spectral response and of the photovoltaic responsefor ZnPc of doping C₆₀ were greater than those of ZnPc; 2)had better redox couple in the cells.

Theory Of Cyclic Voltammetry At Microdisk Electrode For Reversible Systems, Qiankun Zhuang, Hongyuan Chen

Journal of Electrochemistry

By means of a new approach, the current equations of cyclic voltammetry which describes two cases of quasi-steady-state and fast linear scan at microdisk electrode for reversiblesystem were presented and verified experimentally. It has been shown that the features of this currentessentially depend on the ration of, which is described in detail. ln extreme cases, the equationsare the same as those listed in literatures for large plane and spherical electrodes. Using the quasi-steady-state equation, the causes and conditions for forming steady state, quasi-steady state andhysteresis current for linear sweep voltammetry are all explained and discussed. The width of the ″hysteresis …

Progress In R&D Of Lithium Rechargeable Batteries In China, Jiqiang Wang

Journal of Electrochemistry

No abstract provided.

Electrodeposition Of Cobalt And Rare Earth-Cobalt In Urea-Nabr-Kbr Melt, Qiqin Yang, Kairong Qiu, Derong Zhu, Lichang Sa

Journal of Electrochemistry

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Studies On The Bright Zinc-Nickel Alloy Palting In Alkaline Baths, Jiale Cai, Shaomin Zhou

Journal of Electrochemistry

The electrochemical properties of the Zn-Ni plating baths and the structure andperformance of the obtained deposits were investigated. The results show that the nickel content of theobtained deposits is incereased with decreasing of Zn²⁺/Ni²⁺ ratio in the baths and with increasing of cathodic current density; The cathode current efficiency is increased with increasing of Zn[Ⅱ] content in the bath and with decreasing of cathodic current density. The ZN-11 additive used is thereaction product of heterocyclic compound and polyamines with epichlorohydrin, it has a higheradsorptivity on Hg-electrode at potential between -0.16～-1.68 V (vs. Hg/HgO, 1 mol·L^-1 KOH). …

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 Er³⁺ 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.

37th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 37th 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 23-27, 1995.

Environments Of The Four Tryptophans In The Extracellular Domain Of Human Tissue Factor: Comparison Of Results From Absorption And Fluorescence Difference Spectra Of Tryptophan Replacement Mutants With The Crystal Structure Of The Wild-Type Protein, C. A. Hasselbacher, E. Rusinova, R. Rusinova, R. A. Kohanski, W. Lam, A. Guha, J. Du, T. C. Lin, I. Polikarpov, C. W. G. Boys, Y. Nemerson, W. H. Konigsberg, J. B. A. Ross

Chemistry and Biochemistry Faculty Publications

The local environments of the four tryptophan residues of the extracellular domain of human tissue factor (sTF) were assessed from difference absorption and fluorescence spectra. The difference spectra were derived by subtracting spectra from single Trp-to-Phe or Trp-to-Tyr replacement mutants from the corresponding spectrum of the wild-type protein. Each of the mutants was capable of enhancing the proteolytic activity of factor Vila showing that the mutations did not introduce major structural changes, although the mutants were more susceptible to denaturation by guanidinium chloride. The difference spectra indicate that the Trp residues are buried to different extents within the protein matrix. …

Electrochcmical Reaction Of Redox Proteins Speeded Up By The Dye Modified Electrodes, Ting Chen, Shaojun Dong, Yuanwu Xie

Journal of Electrochemistry

The electron transfer reaction of redox proteins faciliated by dye medifiedelectrode was reviewed in this paper. The medification metheds and the properties of dye modifiedelectrode were discussed. Several different studying metheds,such as voltammetry, flow analysis and spectroelectrochemical method, were reviewed. Areversible electrocatalytic reaction mechanism was proposed and verified by comparing the digital calculation results with the experimental results.

Laser Scanning In-Situ Photoelectrochemical Microscopictechnique And Its Applications, Zugeng Lin, Jinkua You, Xiangdong Zhuo, Chun Zhang, Yong Yang

Journal of Electrochemistry

The main factors of the laser scanning in-situ photoelectrochemical microscopic measurement system which is set up in our lab have been discusaed in this paper. Some applications of this technique for in-situ study of modification and processing of semiconductor electrodes, monitoring of electro deposition process of semiconducting material and redox reaction occurring at metal oxide electrodes have also been presented. The results have shown that the technique is very powerful that for studing local photoelectrochemical properties of semiconductors and metal oxide electrodes. These provide important information on the micro structural and electronic properties in the solid/electrolyte interface.