Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

1997

Chemistry

Institution
Keyword
Publication
Publication Type
File Type

Articles 31 - 60 of 365

Full-Text Articles in Entire DC Network

Li/Α-Sn(Hpo4)2 Cell And Its Reaction Mechanism, Yuan Lin, Runliang Cai, Haoqing Wu Nov 1997

Li/Α-Sn(Hpo4)2 Cell And Its Reaction Mechanism, Yuan Lin, Runliang Cai, Haoqing Wu

Journal of Electrochemistry

The discharge mechanism of Li/αSn(HPO4)2 cell has been investigated by means of Xray diffraction, XPS and cyclic voltammetry methodes. It has been shown that the electrochemical intercalation reation exists in the cathode material. There is a new phase after some degree of intercalation. With potential step and galvanostatic techniques, the chemical diffusion cofficients of Li+ in LixSn(HPO4)2 is estimated to be 10-12～10-13 cm2·s-1.

Go to article

Calculation Of The Sacrificial Anode Resistance Utilizing Boundary Element Method, Jianhua Wu, Mingxian Sun, Guangzhou Liu, Guangzhang Chen Nov 1997

Calculation Of The Sacrificial Anode Resistance Utilizing Boundary Element Method, Jianhua Wu, Mingxian Sun, Guangzhou Liu, Guangzhang Chen

Journal of Electrochemistry

According to a kind of mathematic model set up for the cathodic protection potential field, the boundary element method (BEM) was used to study the working state of plate sacrificial anodes which were galvanically coupled to mild steel. In situ experiment showed that the current output and resistance of sacrificial anodes could be calculated more accurately using BEM than loiyd formula. On the basis of the calculation, the cathodic protection design would be more accurate. It was also investigated that the effect of the lengthtobreadth ratio (L/B) on current output and resistance of plate zinc anodes. The results demonstrated that …

Go to article

Mechanism Of Electrodeposition Of Cu/Co Multilayer Thin Films, Jiangyun Xue, Jixun Wu, Dejun Yang Nov 1997

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

Journal of Electrochemistry

The mechanism of electrodeposition of Cu/Co multilayer thin films has been studied by means of potentodynamic sweep, cyclic voltammetry sweep and AC impendance. The results indicated that the copper deposition is mass transfer controlled process and the cobalt deposition is related to the absorbed intermediate species such as Co(OH)ads. The cobalt ions first form Co(OH)ads, then was deoxygenated to cobalt on the electrode surface.

Go to article

Study On The Electrochemical Behaviour Of Eu(Ⅲ) Tryptophane Imidazole Triple Complex, Huixia Wu, Zemin Wang, Xiaqin Wu, Haifeng Yang, Zongrang Zhand Nov 1997

Study On The Electrochemical Behaviour Of Eu(Ⅲ) Tryptophane Imidazole Triple Complex, Huixia Wu, Zemin Wang, Xiaqin Wu, Haifeng Yang, Zongrang Zhand

Journal of Electrochemistry

Eu(Ⅲ)TryptophaneImidazole binary and triple complexes were synthesized. IR spectra indicate that the carboxy group of tryptophane and the N atom of imidazole are coordinated with Eu(Ⅲ) ion. Cyclic voltammetry was used to study the electrochemical behaviour of Eu(Ⅲ) ion, the mixture of Eu(Ⅲ) with tryptophane and imidazole, and Eu(Ⅲ) binary or triple complexes. Among the scan range of -0.4～-1.0 V (vs. SCE), all of these three kinds of systems depicted pseudoreversible electron transfer. The kinetic parameters including D and Ks were also evaluated. 

Go to article

Study On Perchlorate Produced By Electrolysis With Oxygen Cathode, Zhigang Shao, Baolian Yi, Naichao Li, Ming Han Nov 1997

Study On Perchlorate Produced By Electrolysis With Oxygen Cathode, Zhigang Shao, Baolian Yi, Naichao Li, Ming Han

Journal of Electrochemistry

A new method of measuring the flow capacity of cell gas in the perchlorate cell process equipped with an oxygen cathode is applided to investigate the influence of changes in the concentration of solution (chloride, chlorate, perchlorate and metal ion) and changes in the operation parameters (current density, temperature and pH) on perchlorate current efficiency. The main abstacle that the oxygen cathode is used in the perchlorate cell process is put forward and a method is provided to resolve it.

Go to article

The Initial Process Of Amophous Electroless Nickel, Yi Chi, Lei Zhang, Yijan Wang, Maoyuan Ma Nov 1997

The Initial Process Of Amophous Electroless Nickel, Yi Chi, Lei Zhang, Yijan Wang, Maoyuan Ma

Journal of Electrochemistry

The initial process and mophology of electroless nickel played a domination role in adhesive strenghth of EN coating. The structure of initial deposits on certain matrixes was observed by TEM analysis. The deposition of a extremaly fine grain film depended on relative contrast between a coating and a matrix in crystal lattice parameters. When the coating and matrix had similar srystal lattice parameters. A extremely fine grain film was obtained. On the contrary, when the crystal lattice parameters were very different, a amorphous structure was observed.

Go to article

The Activity Of Alloy CuNi Electrode In Electroreduction Of Aromatic NitroCompounds, Chunan Ma, Shaoping Tong, Xiaojun Cheng, Hui Wang Nov 1997

The Activity Of Alloy CuNi Electrode In Electroreduction Of Aromatic NitroCompounds, Chunan Ma, Shaoping Tong, Xiaojun Cheng, Hui Wang

Journal of Electrochemistry

CuNi alloy on the basis of copper at different ratio Cu/Ni are prepared by codepostion. The cathode activtiy of film are studied by steadystate polarization for electroreduction nitrobenzene (NB) and 1,5dinitroanthraquinone (1,5DNA) to paminophenol and 1,5diamino4,8dihydroanthraquinone respectly. The results show that the alloy cathodes at different ratio Cu/Ni have different exchange current density (io) and apparent activition energy (EA). The alloy (CN30) has maximal io  and minimal EA by codeposition at the following conditions: electrolyte: 0.05 mol/L CuSO4·5H2O+0.6 mol/L NiSO4·6H2O+0.25 mol/L Na3Cit·2H2O; current density: 0.6 A/dm2 , pH=6, temperature at 50 ℃. Compared with the common cathodes such as …

Go to article

Photoluminescence Of Photoelectrochemically Etched N+-Si, Guozheng Li, Chengqian Zhang, Xiumei Yang Nov 1997

Photoluminescence Of Photoelectrochemically Etched N+-Si, Guozheng Li, Chengqian Zhang, Xiumei Yang

Journal of Electrochemistry

PS layer on n+Si with (111) orientation prepered by means of photoelectrochemically etched has photoluminescent (PL) ability like PS layer on usual nSi. The data of PL spectra and quenching are given.

Go to article

Study On The Oxygen Electrodes Of Alkaline Fuel Cells Effect Of Dopant On The Activity Of Ag/C Catalyst, Jiawei Teng Nov 1997

Study On The Oxygen Electrodes Of Alkaline Fuel Cells Effect Of Dopant On The Activity Of Ag/C Catalyst, Jiawei Teng

Journal of Electrochemistry

A new kind of nonnoble catalyst for the oxygen electrodes of Alkaline Fuel Cells was investigated. The AgNiBiHg/C catalyst, which was prepared by chemical reduction, was active for the cathodic reduction of oxygen in alkaline fuel cells. It was found that the catalytic activity was improved by adding Ni, Bi, Hg to Ag/C catalyst, and the maximum activity was observed at Ag50%Ni2%Bi3%Hg3%C42%(wt%). XRD inconjunction with SEM indicated that the crystalline silver turned into amorphous in the presence of doping agents and the grain size of silver was reduced. No dramatic deactivation of the catalyst occured after 5200 hours of service.

Go to article

Effect Of Addition Groups On The Redox Properties Of Fullerenes, Louzhen Fan, Yongfang Li, Dagui Li Yuliang Zheng, Daoben Zhu Nov 1997

Effect Of Addition Groups On The Redox Properties Of Fullerenes, Louzhen Fan, Yongfang Li, Dagui Li Yuliang Zheng, Daoben Zhu

Journal of Electrochemistry

Electrochemical properties of fullerene derivatives, including five C60 derivatives and four C70 derivatives, were studied systematically and comparatively by cyclic voltammetry and differential pulse wave voltammetry. The addition of the electrondonating groups on the fullerenes caused negative shift of the redox potentials of the fullerenes. The extent of the negative shift depends on the number and properties of the addition groups, and on the nature of the fullerenes. 0.08～0.20 V negative shift was observed for C60 and C70 monoadducts, 0.30～0.32 V for bisadduct and 0.53～0.58 V for triadduct of C60. Meanwhile, the oxidation waves of most of these derivatives appeared …

Go to article

The Effect Of Bismuth On Microstructure Of The Cathodic Copper Deposition Of Copper Electrorefining, Daorong Lu, Jianxing Lin Nov 1997

The Effect Of Bismuth On Microstructure Of The Cathodic Copper Deposition Of Copper Electrorefining, Daorong Lu, Jianxing Lin

Journal of Electrochemistry

The electrocrystal formation, crystal orientation and the chemical composition of the cathodic copper deposition in the presence of Bi3+ in the electrolyte of acidified CuSO4 are studies by scanning electron microscopy, Xray diffraction, atomic absorption and EDAM. The results indicate that the Bi could′t deposit on cathode when copper electrolysed at common current density i=200 A·mol/L-2 and t=60 ℃. Bi3+ scarcely effected on the crystal orientation (220) of copper deposition. High concentration Bi3+ in the electrolyte promoted (220) growth and inhibited the other crystal orientation growth. Bi3+ effected on electrocrystal formation and the cell dimension of copper deposition.

Go to article

35. Shigeharu Onogi, Otto Vogl, Masaoki Takahashi, Toshiro Masuda Nov 1997

35. Shigeharu Onogi, Otto Vogl, Masaoki Takahashi, Toshiro Masuda

Emeritus Faculty Author Gallery

No abstract provided.

Go to article

Japan-Us Seminar: Macromolecular Architecture And Engineering, Otto Vogl, Shin-Ichiro Shoda Nov 1997

Japan-Us Seminar: Macromolecular Architecture And Engineering, Otto Vogl, Shin-Ichiro Shoda

Emeritus Faculty Author Gallery

No abstract provided.

Go to article

Japan-Us Seminar: Macromolecular Architecture And Engineering, Otto Vogl, Shin-Ichiro Shoda Nov 1997

Japan-Us Seminar: Macromolecular Architecture And Engineering, Otto Vogl, Shin-Ichiro Shoda

Otto Vogl

No abstract provided.

Go to article

35. Shigeharu Onogi, Otto Vogl, Masaoki Takahashi, Toshiro Masuda Nov 1997

35. Shigeharu Onogi, Otto Vogl, Masaoki Takahashi, Toshiro Masuda

Otto Vogl

No abstract provided.

Go to article

Coordinate Regulation Of G- And C Strand Length During New Telomere Synthesis, Xinqing Fan, Carolyn Mary Price Nov 1997

Coordinate Regulation Of G- And C Strand Length During New Telomere Synthesis, Xinqing Fan, Carolyn Mary Price

Chemistry Department: Faculty Publications

We have used the ciliate Euplotes to study the role of DNA polymerase in telomeric C strand synthesis. Euplotes provides a unique opportunity to study C strand synthesis without the complication of simultaneous DNA replication because millions of new telomeres are made at a stage in the life cycle when no general DNA replication takes place. Previously we showed that the C-strands of newly synthesized telomeres have a precisely controlled length while the G-strands are more heterogeneous. This finding suggested that, although synthesis of the G-strand (by telomerase) is the first step in telomere addition, a major regulatory step occurs …

Go to article

Hybrid Quantum And Molecular Mechanics Embedded Cluster Models For Chemistry On Silicon And Silicon Carbide Surfaces, James R. Shoemaker Oct 1997

Hybrid Quantum And Molecular Mechanics Embedded Cluster Models For Chemistry On Silicon And Silicon Carbide Surfaces, James R. Shoemaker

Theses and Dissertations

Fabrication of silicon carbide SiC semiconductor devices are of interest for aerospace applications because of their high-temperature tolerance. Growth of an insulating SiO2 layer on SiC is a poorly understood process, and sometimes produces interface defects that degrade device performance. Accurate theoretical models of surface chemistry, using quantum mechanics QM, do not exist because of the huge computational cost of solving Schroedingers equation for a molecular cluster large enough to represent a surface. Molecular mechanics MM, which describes a molecule as a collection of atoms interacting through classical potentials, is a fast computational method, good at predicting molecular structure, …

Go to article

Hybrid Reflection-Transmission Surface Light-Scattering Instrument With Reduced Sensitivity To Surface Sloshing, William V. Meyer, James A. Lock, Michael Cheung, Thomas W. Taylor, Padetha Tin, J. Adin Mann Jr. Oct 1997

Hybrid Reflection-Transmission Surface Light-Scattering Instrument With Reduced Sensitivity To Surface Sloshing, William V. Meyer, James A. Lock, Michael Cheung, Thomas W. Taylor, Padetha Tin, J. Adin Mann Jr.

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

A hybrid reflection-transmission surface light-scattering instrumental design is presented, examined theoretically, and tested experimentally. The purpose of the design is to reduce the sensitivity of the instrument to vibration in general and surface sloshing in particular while sacrificing Little performance. Traditional optical arrangements and two new optical configurations with varying trade-offs between slosh resistance and instrumental simplicity and accuracy are examined by use of Fourier optics methods. The most promising design was constructed and tested with acetone, ethanol, and water as subject fluids. The test involved backcalculation of the wave number of the capillary wave examined with the known physical …

Go to article

Liquid-Liquid Immiscibility In Lipid Monolayers, John P. Hagen, Harden M. Mcconnell Oct 1997

Liquid-Liquid Immiscibility In Lipid Monolayers, John P. Hagen, Harden M. Mcconnell

Chemistry and Biochemistry

Some binary lipid mixtures form coexisting liquid phases when spread at the air/water interface. This work describes the pressure–composition phase diagrams of binary mixtures of four unsaturated phosphatidylcholines with dihydrocholesterol. These four binary mixtures have critical compositions of approximately fifty mole percent, and average critical exponents of 0.25±0.07. The data can also be approximated by a regular solution thermodynamic model, yielding parameters for the non-ideality of these mixtures.

Go to article

36. Qian Renyuan, Otto Vogl, Wu Meiyan Oct 1997

36. Qian Renyuan, Otto Vogl, Wu Meiyan

Emeritus Faculty Author Gallery

No abstract provided.

Go to article

36. Qian Renyuan, Otto Vogl, Wu Meiyan Oct 1997

36. Qian Renyuan, Otto Vogl, Wu Meiyan

Otto Vogl

No abstract provided.

Go to article

Assembly And Disassembly Of Dna Polymerase Holoenzyme, Daniel J. Sexton, Anthony J. Berdis, Stephen J. Benkovic Oct 1997

Assembly And Disassembly Of Dna Polymerase Holoenzyme, Daniel J. Sexton, Anthony J. Berdis, Stephen J. Benkovic

Chemistry Faculty Publications

The complex task of genomic replication requires a large collection of proteins properly assembled within the close confines of the replication fork. The mechanism and dynamics of holoenzyme assembly and disassembly have been investigated using steady state and pre-steady state methods as opposed to structural studies, primarily due to the intrinsic transient nature of these protein complexes during DNA replication. The key step in bacteriophage T4 holoenzyme assembly involves ATP hydrolysis, whereas disassembly is mediated by subunit dissociation of the clamp protein in an ATP-independent manner.

Go to article

Voltammetric Studies Of Metallofullerenes, Mark Anderson Sep 1997

Voltammetric Studies Of Metallofullerenes, Mark Anderson

Mark R. Anderson

No abstract is available at this time.

Go to article

Langmuir Monolayers As Disordered Solids: Strain-State Calculations Applied To Stearic Acid, David R. Swanson, Tadeusz Luty, Craig J. Eckhardt Sep 1997

Langmuir Monolayers As Disordered Solids: Strain-State Calculations Applied To Stearic Acid, David R. Swanson, Tadeusz Luty, Craig J. Eckhardt

Craig J. Eckhardt Publications

This paper presents a calculational procedure to determine the equilibrium phase for a given surface pressure π. The monolayer is treated as orientationally free tails grafted to a two-dimensional net formed by the head groups of the amphiphilic molecules. The head groups form a subsystem with translational degrees of freedom characterized by strain variables in the plane of the surface, and the tail groups compose a subsystem characterized by rotational degrees of freedom. The order in the monolayer derives indirectly from the crystalline head groups through translational–rotational coupling. A stress–strain relation is derived which shows the energetically most favorable path …

Go to article

Scanning Probe Nanolithography Of Conducting Metal Oxides, Chen-Jen Hung, Jianian Gui, Jay A. Switzer Sep 1997

Scanning Probe Nanolithography Of Conducting Metal Oxides, Chen-Jen Hung, Jianian Gui, Jay A. Switzer

Chemistry Faculty Research & Creative Works

The scanning tunneling microscope (STM) was used to form nanometer-size holes in thin conducting films of thallium (III) oxide. Hole formation was only observed when the process was performed in humid ambient conditions. The hole formation was attributed to localized electrochemical etching reactions beneath the STM tip. etching reactions consistent with the observed hole formation are a direct electrochemical reduction of thallium (III) oxide to soluble T1 (I) at negative sample bias, and local reduction of pH at positive sample bias. The fastest etching was observed at negative sample bias. Holes as small as 10 nm or as large as …

Go to article

Optically Transparent Composite Material And Process For Preparing Same, D. E. Day, James O. Stoffer, John M. Barr Sep 1997

Optically Transparent Composite Material And Process For Preparing Same, D. E. Day, James O. Stoffer, John M. Barr

Materials Science and Engineering Faculty Research & Creative Works

Glass ribbon-reinforced transparent polymer composites which provide excellent optical transparency and a low distortion level over a wide temperature range while exhibiting superior mechanical properties as compared to non- reinforced polymer counterparts, and equivalent properties as compared to glass fiber-reinforced counterparts.

Go to article

Serotonin 5-Ht4 Agonist Activity Of A Series Of Meso-Azanoradamantane Benzamides, Daniel Becker, Roger Nosal, Clara I. Villamil, Gary Gullikson Sep 1997

Serotonin 5-Ht4 Agonist Activity Of A Series Of Meso-Azanoradamantane Benzamides, Daniel Becker, Roger Nosal, Clara I. Villamil, Gary Gullikson

Chemistry: Faculty Publications and Other Works

A series of meso-amino(methyl)azanoradamantane benzamides has been prepared and evaluated for 5-HT4agonism activity in the rat tunica muscularis mucosae (TMM) assay. Compound 8i is the most potent 5-HT4agonist in the series, with an EC50 of 217 nM.

Go to article

Voltammetry And Spectroelectrochemistry Of Metallofullerenes, Mark Anderson, Harry Dorn, Paul Burbank, James Gibson Sep 1997

Voltammetry And Spectroelectrochemistry Of Metallofullerenes, Mark Anderson, Harry Dorn, Paul Burbank, James Gibson

Mark R. Anderson

No abstract is currently available.

Go to article

37. Masao Horio 1905-1996, Otto Vogl, Masahide Yamamoto Sep 1997

37. Masao Horio 1905-1996, Otto Vogl, Masahide Yamamoto

Emeritus Faculty Author Gallery

No abstract provided.

Go to article

Segregation Of Bismuth To Triple Junctions In Copper, K.-M. Yin, Alexander H. King, T.E. Hsieh, F.-R. Chen, J.J. Kai, L. Chang Sep 1997

Segregation Of Bismuth To Triple Junctions In Copper, K.-M. Yin, Alexander H. King, T.E. Hsieh, F.-R. Chen, J.J. Kai, L. Chang

Alexander H. King

Bismuth segregation in copper has been studied using energy-dispersive X-ray spectrometry (EDX) in a JEOL 2010F transmission electron microscope. In addition to the expected solute enrichment at grain boundaries, we have observed extremely high concentrations of bismuth at certain triple junctions, with significantly greater enrichment factors than in the adjacent grain boundaries. It is shown here that the triple junction segregation is a function of the parameters of the grain boundaries at the triple line, and existence of this type of segregation implies that the affected triple junctions embody excess free energy. At least one of the observed triple junctions …

Go to article

First Prev Next Last