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

Chemistry Commons™

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

Physical Chemistry

PDF

2001

Articles 31 - 60 of 91

Full-Text Articles in Chemistry

The Influence Of Membrane Resistance On The Electrochemical Behavior Of Gold Electrode Modified By Self-Assembled Monolayer, Xiao-Li Cui, Zhi-Yu Jiang Aug 2001

The Influence Of Membrane Resistance On The Electrochemical Behavior Of Gold Electrode Modified By Self-Assembled Monolayer, Xiao-Li Cui, Zhi-Yu Jiang

Journal of Electrochemistry

The electrochemical behavior of gold electrode modified by hexadecanethiol self_assembled monolayer (SAM) in the solution of Fe(CN) 6 3- /Fe(CN) 6 4- was investigated by cyclic voltammetry and ac impedance spectroscopy. The pinhole_free SAM_modified gold electrode has excellent blocking properties to the interfacial electron transfer from redox couple in solution to the substrate. The current increased exponentially with the overpotential at the high potential region. A good linear relationship between ln( I/η ) and η 1/2 was observed. A model system Au/SAM/Hg was constructed and its I～V curve was measured. Similar phenomena were observed. There was also a linear relationship …

Go to article

Studies On The Electrochemical Properties Of Phosphate Derivatives Of C_(60), Ying Liu, Li Ding, Lou-Zhen Fan, Fu-Yong Cheng, Zhong-Da Wu Aug 2001

Studies On The Electrochemical Properties Of Phosphate Derivatives Of C_(60), Ying Liu, Li Ding, Lou-Zhen Fan, Fu-Yong Cheng, Zhong-Da Wu

Journal of Electrochemistry

The phosphorus chemistry of fullerene was investigated for the first time. We have synthesised three novel phosphate derivatives of C 60 .Their electrochemical properties were detected by cyclic voltammetry (CV).The influence of different substituents on the electron_accepting ability of methanofullerenes was also observed by the comparative study on the electrochemical properties of different C 60 derivertives.

Go to article

Determination Of Hydrogen Diffusion Coefficient In Metal Hydride Electrode With Electrochemical Impedance Spectroscopy, Xian Xia Yuan, Nai Xin Xu Aug 2001

Determination Of Hydrogen Diffusion Coefficient In Metal Hydride Electrode With Electrochemical Impedance Spectroscopy, Xian Xia Yuan, Nai Xin Xu

Journal of Electrochemistry

Electrochemical impedance spectroscopy was employed to determine the hydrogen diffusion coefficient in MlNi 3.75 Co 0.65 Mn 0.4 Al 0.2 metal hydride electrode with various states of charge(SOC) at room temperature and with 50% SOC at various temperatures. It was found that hydrogen diffusion coefficient in this electrode decreases with the increase in SOC at ambient temperature, and for the electrode with 50%SOC, hydrogen diffusion coefficient increases with the increase of temperature and the activation energy for hydrogen diffusion in it is 35 kJ/mol.

Go to article

Study Of Cathodic Protection For Underground Structures At Gas Station, Jiunn Shyong Luo, Yin Chieh Chang, Jun Chou Oung, Wen Chih Yang Aug 2001

Study Of Cathodic Protection For Underground Structures At Gas Station, Jiunn Shyong Luo, Yin Chieh Chang, Jun Chou Oung, Wen Chih Yang

Journal of Electrochemistry

Underground structures in gas station include storage tanks, transportation pipelines, and rebar inconcrete. If rebar contacted with tanks or pipelines, effects of cathodic protection will be interfered. Present study was focused upon the effectiveness of impressed current cathodic protection for underground structures at gas station as rebar contacted with/or without tanks and pipelines. It was founded that the -850 mV criterion could not be applied to evaluate effectiveness of cathodic protection systems in gas station. Quantity of polarization of protected structures should be calculated and evaluated.

Go to article

Immobilization Of Long-Strand Dna Onto Gold Surface And Electrochemical Labeling Of Hybridization Of Dna, Jian Zhang Zhou, Ling Ling Wu, Li Qin Dong, Zhong-Yu Lin, Jia Wei Yan, Ping Dong, Yue Bao, Zhong Hua Lin Aug 2001

Immobilization Of Long-Strand Dna Onto Gold Surface And Electrochemical Labeling Of Hybridization Of Dna, Jian Zhang Zhou, Ling Ling Wu, Li Qin Dong, Zhong-Yu Lin, Jia Wei Yan, Ping Dong, Yue Bao, Zhong Hua Lin

Journal of Electrochemistry

Poly(diallyldimethylammonium chloride)(PDDA) was used to facilitate long strand DNA immobilization onto gold surface using self assembly method. Characterization of the PDDA self assembled film and subsequently immobilized DNA were carried out by Diffuse Reflectance Infrared, XPS, STM and electrochemical measurements. Hybridization of DNA was labeled by electrochemical method.

Go to article

Charge/Discharge Characteristics And Structural Changing Of Spherical Β-Ni(Oh)_2 Prepared From Different Nickel Salt, Shu-Ting Yang, Yan-Hong Yin, Hong-Jun Chen, Jun-Hua Jia, Ming-Chum Zhang, Li Ding Aug 2001

Charge/Discharge Characteristics And Structural Changing Of Spherical Β-Ni(Oh)_2 Prepared From Different Nickel Salt, Shu-Ting Yang, Yan-Hong Yin, Hong-Jun Chen, Jun-Hua Jia, Ming-Chum Zhang, Li Ding

Journal of Electrochemistry

Spherical β Ni(OH) 2 was prepared from different nickel salt by homogeneous complexing precipitation method. Its charge/discharge and cyclic voltammetry properties were studied. The authors found that there are many differences in the electrochemical properties of the prepared Ni(OH) 2.The specific capacity, cycling life and the discharging plateau of the material prepared from NiSO 4 were superior to those of the material prepared from Ni(NO 3) 2.The reasons of the differences were analyzed by XRD and FTIR measurements, which will become abasis for the selection of raw materials.

Go to article

Codeposition And Corrosion Resistance Of Nickel-Cerium-Phosphorus Amorphous Alloys, Jiang Liu, Xiong Jiang, Lin-Cai Jiang, Ze-Shan Zhu Aug 2001

Codeposition And Corrosion Resistance Of Nickel-Cerium-Phosphorus Amorphous Alloys, Jiang Liu, Xiong Jiang, Lin-Cai Jiang, Ze-Shan Zhu

Journal of Electrochemistry

The possibility of electrodeposition of rare earth alloys from aqueous bath was investigated using varous techniques such as linear potential sweeping, cyclic voltammetry, electrodepositon at constant potential etc. The Ni Ce P alloys with different cerium content were electrodeposited from a weakly acidic solution containing CeCl 3, NaH 2PO 2 and so on the crystal structure and component were characterized by XPS, AES, XRD and SEM observation. The codeposits were found to be more highly corrosion resistent than that of Ni P amorphous alloys by measuring polarization resistance and corrosion potential. The effects of codeposition conditions on the corrosion resistance …

Go to article

The Activation Mechanism Of Al Alloys With Tin And Gallium In Alkaline Electrolytes, Zhen Ya Li, Ling Yi, Zhi Hui Liu, Lin Yang, Jing Xin Su, Yan Ying Chen Aug 2001

The Activation Mechanism Of Al Alloys With Tin And Gallium In Alkaline Electrolytes, Zhen Ya Li, Ling Yi, Zhi Hui Liu, Lin Yang, Jing Xin Su, Yan Ying Chen

Journal of Electrochemistry

The major reason for Al_anode's activation is that Ga and Sn deposit on the aluminum surface and form activated points. The Al_Sn and Al_Ga binary alloys can't be activated in alkaline medium. During the dissolution of the Al_Sn_Ga ternary anode, Sn and Ga dissolve into the solution and transform into ions. After the Sn ions deposit on the surface of Al_anode, the Ga ions will deposit on Sn. The higher activation of the polynary alloy anode is caused by much more new activated points composed of Ga_Sn alloy being continually formed. Ga_Sn alloy with low melting point deposited on the …

Go to article

Relativistic Effects On Interchannel Coupling In Atomic Photoionization: The Photoelectron Angular Distribution Of Xe, Oliver Hemmers, S. T. Manson, M. M. Sant'anna, P. Focke, H. Wang, I. A. Sellin, Dennis W. Lindle Jul 2001

Relativistic Effects On Interchannel Coupling In Atomic Photoionization: The Photoelectron Angular Distribution Of Xe, Oliver Hemmers, S. T. Manson, M. M. Sant'anna, P. Focke, H. Wang, I. A. Sellin, Dennis W. Lindle

Environmental Studies Faculty Publications

Measurements of the photoelectron angular-distribution asymmetry parameter β for Xe 5s photoionization have been performed in the 80–200 eV photon-energy region. The results show a substantial deviation from the nonrelativistic value of β=2 and provide a clear signature of significant relativistic effects in interchannel coupling.

Go to article

Shape Imprinting Due To Variable Disulfide Bonds In Polyacrylamide Gels, Andrew B. Greytak, Alexander Y. Grosberg, Toyoichi Tanaka Jun 2001

Shape Imprinting Due To Variable Disulfide Bonds In Polyacrylamide Gels, Andrew B. Greytak, Alexander Y. Grosberg, Toyoichi Tanaka

Faculty Publications

Through the use of variable disulfide crosslinkers, we have created polyacrylamide gels whose shape can be altered after polymerization. N,N'-bisacryloylcystamine is incorporated as a crosslinker, along with a smaller amount of a permanent crosslinker. After polymerization, the disulfide bonds are cleaved into thiols through reduction. By reoxidizing the thiols with the gel held in a new macroscopic shape, a new set of disulfide bonds is formed, and the gel is forced to adopt the new shape. Retension of the new shape improves with greater distortion from the original shape, as well as with increased concentration of variable …

Go to article

The Effect Of Preparation Condition On The Photoelectrochemical Performance Of Both The Pani Film And Tio_2-Pani Composite Film On Au, Huai-Guo Huang, Hong-Ping Zhang, Zhi-Xin Zheng, Yan-Yan Xi, Ling-Ling Wu, Zhong-Hua Lin May 2001

The Effect Of Preparation Condition On The Photoelectrochemical Performance Of Both The Pani Film And Tio_2-Pani Composite Film On Au, Huai-Guo Huang, Hong-Ping Zhang, Zhi-Xin Zheng, Yan-Yan Xi, Ling-Ling Wu, Zhong-Hua Lin

Journal of Electrochemistry

Both the PANI(polyaniline) film and TiO 2_PANI composite film on the PATP(p_aminothiophenol)/Au substrate were obtained under different preparation condition by electrochemical methods, and their photoelectrochemical performances were also studied.The results showed that the photoelectrochemical performances of the films depend deeply on the comditions of preparation.The self_assembling of PATP favors the adhesion of PANI.The partially_oxidized PANI has a greater photoelectrochemical response than that of the reduced PANI and oxidized PANI.There is an optimum of film thickness for the photoelectrochemical performance of PANI film.Heat treating is in favor of the photoelectrochemical performance of TiO 2,but decreases the photocurrent response of PANI film.There …

Go to article

Electrochemical Studies On The Intermetallic Interaction In Binuclear Ruthenium(Ⅱ) Complexes, Hong Li, Hui Chao, Liang-Nian Ji, Xiong Jiang May 2001

Electrochemical Studies On The Intermetallic Interaction In Binuclear Ruthenium(Ⅱ) Complexes, Hong Li, Hui Chao, Liang-Nian Ji, Xiong Jiang

Journal of Electrochemistry

The electrochemical characteristics and intermetallic interaction of symmetrical binuclear ruthenium(Ⅱ) complexes [Ru2:(bpy) 2Ru(DIPB)Ru(bpy) 2(ClO 4) 4 and Ru2_2H:(bpy) 2Ru(DIPB-2H)Ru(bpy) 2(ClO 4) 2 ]containing dinuclear ligand 2,2_bipyridine(bpy) and bridging ligand 1,4_di[2_imidazo[4,5_f][1,10] phenanthroine]benzene(DIPB) or 1,4_di[2_dehydrogen_imidazo[4,5_f][1,10] phenanthroine]benzene(DIPB_2H) on a platinum electrode have been investigated using cyclic voltammetry,cyclic ac voltammetry and differential capacitance techniques,etc.In acetonitrile solutions with a concentration of 0.1 mol/L TBAP,the central ruthenium ions in Ru2 and Ru2_2H complexes have shown a single 2e reversible oxidation_reduction wave on the cyclic voltammograms with basically the same formal potentials of Ru2_2H and Ru2 and a slightly larger apparent diffusion coefficient of the Ru2_2H complex …

Go to article

New Progress In Studies Of Lithium Nickel Oxide As Positive Electrode Materials Of Lithium Ion Batteris, Han-San Liu, Yong Yang, Zhong-Ru Zhang, Zu-Geng Lin May 2001

New Progress In Studies Of Lithium Nickel Oxide As Positive Electrode Materials Of Lithium Ion Batteris, Han-San Liu, Yong Yang, Zhong-Ru Zhang, Zu-Geng Lin

Journal of Electrochemistry

Lithium nickel oxide as the positive electrode of lithium ion batteries has aroused more and more interests.This paper reviews the recent reserches on synthesis and element_substitution of LiNiO 2 cathode material,and summarizes the intrinsical relationship between properties and sturcture of the material.The developments of new synthesis methods and mutil_substitution of the material are expecting to be studied in the future research.

Go to article

Electrochemistry Characteristic Of Carbon Steel Under Biofilm And Sulfide Film, Ze-Hua Dong, Xing-Peng Guo, Jia-Shen Zheng, Li-Ming Xu May 2001

Electrochemistry Characteristic Of Carbon Steel Under Biofilm And Sulfide Film, Ze-Hua Dong, Xing-Peng Guo, Jia-Shen Zheng, Li-Ming Xu

Journal of Electrochemistry

Wire Beam Electrode (WBE) made of Q235 carbon steel was applied to study the heterogeneous corrosion beneath biofilm formed by Sulfate Reducing Bacteria (SRB) in culture and sulfide film in solution with 1% NaCl and 300 mg/L S 2- . The potential,galvanic density mapping,as well as polarization curve and Electrochemical Impedance Spectrum (EIS) were measured to predict the localized corrosion under biofilm and sulfide film.As a result,the mapping showed the potential fluctuation on the WBE surface decreased over time due to the conductivity of the biofilm and sulfide film.Therefore,the potential mapping could not be a criterion of localized corrosion under …

Go to article

Corrosion Behavior Of Titanium In Fgd System, C Lin J, L Chang T, T Dung C, L Lee S, D Chyou S, S D Guo May 2001

Corrosion Behavior Of Titanium In Fgd System, C Lin J, L Chang T, T Dung C, L Lee S, D Chyou S, S D Guo

Journal of Electrochemistry

In situ corrosion test of titanium in flue gas desulfurization(FGD)system has been studied.Specimens of commercial Ti alloy have been put in four different locations(i.e,cooler,prescruber,absorber and heater) of the FGD system for 271 days.The corrosion rate is very low(i.e.

Go to article

Electrochemical Behavior Of Tinicu Shape Memry Alloy In Simulated Body Fluid, Cheng-Hao Liang, Hong-Yan Sui May 2001

Electrochemical Behavior Of Tinicu Shape Memry Alloy In Simulated Body Fluid, Cheng-Hao Liang, Hong-Yan Sui

Journal of Electrochemistry

The study of TiNiCu shape memory alloys(SMA) in Hank's simulated body fluid was carried out.The results showed that narrow passive range was found in acid environment and active anodic dissolution was discovered at 100～150 mV vs SCE on anodic polarization cure of TiNiCu SMA.Temperature had little effect on anodic polarization.With the decrease of pH and the increase of Cl - concentration,pitting corrosion potential ( E b) shifted negatively.The electrochemical capability of TiNiCu SMA was inferior to that of TiNi SMA.Observations by means of XRD and SEM indicate that TiNiCu SMA is not in single crystal structure,which caused irregular electrochemical behavior …

Go to article

Comparison In Surface Enhanced Raman Scattering On Salicylideneamine Between Silver And Gold Colloid And Silver Mirror Substrate, Zhao Bing, Yukihiro Ozaki May 2001

Comparison In Surface Enhanced Raman Scattering On Salicylideneamine Between Silver And Gold Colloid And Silver Mirror Substrate, Zhao Bing, Yukihiro Ozaki

Journal of Electrochemistry

In recent years, the study of photochromic and thermochromic materials has grown because of their possible applications in the optical processing of information, in addition to the scientific interest. Salicylidineaniles is one of the prospective choices owing to their photochromism caused by intramolecular hydrogen transfer [1～3] (Fig.1). It is generally agreed that, in the salicylideneamine system, photoexcitation is followed by a rapid barrierless proton transfer and subsequent rearrangement to form a colored photoproduct [4] . The photochemistry of the system in fluid solution is different from that of the solid, even in fluid solution, the photo? and thermo?chromic behavior is …

Go to article

Performance Of Proton Exchange Membrane Fuel Cell With Co/H_2 Fuel, Hong-Mei Yu, Zhong-Jun Hou, Bao-Lian Yi, Ke-Wan Bi, Jing-Xin Zhang, Zhi-Yin Lin, Ming Han May 2001

Performance Of Proton Exchange Membrane Fuel Cell With Co/H_2 Fuel, Hong-Mei Yu, Zhong-Jun Hou, Bao-Lian Yi, Ke-Wan Bi, Jing-Xin Zhang, Zhi-Yin Lin, Ming Han

Journal of Electrochemistry

Fuel of proton exchange membrane fuel cell(PEMFC) mostly comes from reformate contains CO which will poison the fuel cell electrocatalyst.The effect of CO on the performance of PEMFC was studied in this paper.The results of the experiment show that when CO is fed in PEMFC,the cell voltage will be decreased violently,then it will become steady with some vibration.The poison will become more serious with higher CO content and weaker at higher temperature.The adsorption of CO on the electrocatalyst is reversible. The PtRu electrocatalyst is more suitable for the electrocatalysis of CO/H 2 than Pt electrocatalyst.

Go to article

Atmospheric Corrosion Of Steels In China, Cai-Feng Liang May 2001

Atmospheric Corrosion Of Steels In China, Cai-Feng Liang

Journal of Electrochemistry

Data of eight year atmospheric exposures of 17 steels at 7 sites in China were analyzed.The result showed that the most detrimental pollution is sulfur dioxide and chloride ion for corrosion of carbon steels and low alloy weathering steels.This is in accordance with the common knowledge.The effect of sulfur dioxide is serious in the first few years and becomes weak obviously in the later years.The environment factor of humid hot is much more important in long run than the ordinarily acknowledged humidity,pollution for non weathering steels,although it is not obvious in the beginning.If pollution were existed,a severe corrosion may resulted.As …

Go to article

Galvanic Corrosion Of Tin-W Electro-Couple During Tungsten Chemical Mechanical Polishing, Xuan Cheng, Chang-Jian Lin May 2001

Galvanic Corrosion Of Tin-W Electro-Couple During Tungsten Chemical Mechanical Polishing, Xuan Cheng, Chang-Jian Lin

Journal of Electrochemistry

Chemical_mechanical polishing (CMP) is a process whereby mechanical and chemical forces are combined to remove material from a wafer and polish it to a flat surface. Tungsten CMP is an important process to gain the global planarity of silicon wafers with tungsten (W) plugs. Tungsten is actually deposited on a thin adhesive layer of titanium nitride (TiN) on silicon. When close to the final stage of polishing, TiN and W will be simultaneously exposed to the polishing chemistry, forming a galvanic couple. The corrosion of TiN and W couple will result in different polish rate. This work studied the potential …

Go to article

Preparation Of Ti-Based Nanocrystalline Tio_2 Film Electrode With High Activity, Dao-Bao Chu, Guang-Xia Shen, Xing-Fu Zhou, Chang-Jian Lin, Hua-Shui Lin May 2001

Preparation Of Ti-Based Nanocrystalline Tio_2 Film Electrode With High Activity, Dao-Bao Chu, Guang-Xia Shen, Xing-Fu Zhou, Chang-Jian Lin, Hua-Shui Lin

Journal of Electrochemistry

The potentiostatic electrosynthesis of Ti(EtO) 4 was studied by anodic dissolution of metal titanium(TA1) in solution of 0.005 mol·L -1 (EtO) 4NBr in the ethanol (AR) in the presence negligible CH 3COCH 2COCH 3.The Ti_based nanocrystalline TiO 2 Film electrode (Ti/nano_TiO 2) was prepared by sol_gel method.By TEM,SEM and XRD,it has been shown that the anatase particle of TiO 2 was 10～35 nm in diameter and the film was 0.5 μm in thickness.The nanocrystalline film was composed of a three_diminsional network of interconnected particles.Reodx behavior and electrocatalytic activities of the Ti/nano_TiO 2 electrode were investigated by cyclic voltammetry (CV) from …

Go to article

Properties Of Metallized Poly-O-Toluidide Membrane Modified Electrode, Li-Zong Dai, Yi-Ting Xu, Hui-Huang Wu May 2001

Properties Of Metallized Poly-O-Toluidide Membrane Modified Electrode, Li-Zong Dai, Yi-Ting Xu, Hui-Huang Wu

Journal of Electrochemistry

The platinum particles were electrodeposited on poly(o_toluidide),POT,modified electrode,and the surface configuration and crystal orientation of Pt particles were investigated by SEM and XRD.At the same time the oxidation of isopropanol on platinized POT modified electrode was studied.The results indicate that Pt particles deposite towards preferred_orientation;moreover the increase in polymer electroactivity due to proton doping affects the dimension and graininess of deposited Pt particles.At the metallized polymer electrode the oxidation of isopropanol can occur in POT electroactive potential region,however at the more positive than 0.70 V (SCE) potential where POT loses redox activity the electro_oxidation mainly occurrs on Pt particles.It follows …

Go to article

Performance Of A Direct Methanol Fuel Cell, Zhao-Bin Wei, Jian-Guo Liu, Ya-Guang Jiao, Wei-Jiang Zhou, Wen-Zhen Li, Li-Kang Chen, Qin Xin, Bao-Lian Yi May 2001

Performance Of A Direct Methanol Fuel Cell, Zhao-Bin Wei, Jian-Guo Liu, Ya-Guang Jiao, Wei-Jiang Zhou, Wen-Zhen Li, Li-Kang Chen, Qin Xin, Bao-Lian Yi

Journal of Electrochemistry

A direct methanol fuel cell with 9cm 2 active area consists of Pt_Ru/C anode,Pt/C cathode and Nafion 115 membrane.The effect of operating conditions:methanol solution concentration,oxygen pressure and cell temperature on the cell performances was investigated.The results show that performance of single cell was enhanced by increasing oxygen pressure and cell temperature,and a maximum power density 75 mW/cm 2 was obtained in the range of 250_300 mA/cm 2 current density,0.2 MPa oxygen pressure,1.0 mol/L methanol concentration and 75 ℃ cell temperature.When cell operating at room temperature,a relatively low,but a stable performance of cell was also observed.

Go to article

Preparation And Properties Of Separator For Lithium-Ion Battery, Xu-Mei Ren, Feng Wu, Chuan Wu, Han-Jun Li, Xue-Jie Huang May 2001

Preparation And Properties Of Separator For Lithium-Ion Battery, Xu-Mei Ren, Feng Wu, Chuan Wu, Han-Jun Li, Xue-Jie Huang

Journal of Electrochemistry

Lithium_ion batteries are well adapted to the new multimedia applications. PP/PE based microporous film is commonly used as separator in commercial lithium ion batteries. Here we report a microporous film which is superior to the commercial available separator. The microporous PVDF polymer separators were prepared by the phase inversion process. The pore size of the separator is  7 μm, and it's porosity is 75%. The membrane in LiPF 6 EC/DEC showed high ionic conductivity (above 10 -3 S/cm at room temperature), and good mechanical properties (10 3 kg/cm 2). The half_cells consisted of Li/PVDF separator/MCMB showed excellent cycling characteristics …

Go to article

The Effect Of Calcium On The Properties Of Molybdenum Nitride Electrode, Yun-Gui Zhu, Xue-Liang Li, Dao-Rong Lu, Jian-Bo He, Ji-Huai Xia May 2001

The Effect Of Calcium On The Properties Of Molybdenum Nitride Electrode, Yun-Gui Zhu, Xue-Liang Li, Dao-Rong Lu, Jian-Bo He, Ji-Huai Xia

Journal of Electrochemistry

The effect of calcium on the properties of molybdenum nitride film electrode was studied by using XRD, SEM and cyclic voltammetry. The results show that the specific electric capacity and the voltage operating range of electrode vary with the concentration of additive in the dipping solution. At the optimum concentration of additive in the dipping solution, the specific electric capacity of the electrode is 2.1 times as large as that of the electrode prepared in the dipping solution without additive, and the voltage operating range of electrode is increased by 0.11 V. The active mechanism of calcium on the properties …

Go to article

Study Of The Oxidation Dynamics Of Ti-Zro_2 Metal-Ceramics, Wen-Chao Li, Li-Dong Teng May 2001

Study Of The Oxidation Dynamics Of Ti-Zro_2 Metal-Ceramics, Wen-Chao Li, Li-Dong Teng

Journal of Electrochemistry

The oxidation dynamics of hot pressed Ti ZrO 2 metal_ceramics with the composition of 50 vol.% Ti and 50 vol.% ZrO 2 has been studied. Thermodynamic analysis shows that Ti could react with O 2 but not with N 2 in the oxidizing process of Ti ZrO 2 composites at 0.1 MPa air. The oxidation dynamic behavior of Ti ZrO 2 composites is analogous to that of pure Ti. The activation energy for the oxygen diffusion in Ti ZrO 2 composites is higher than that in Ti solutions, for the presence of ZrO 2 restrains the oxygen diffusion in Ti …

Go to article

The Dependence Of Relative Enhancement Of Sers Bands On Temperature, Ling Huang, Jian Shen, Tsing Yu, Qing-Jin Meng May 2001

The Dependence Of Relative Enhancement Of Sers Bands On Temperature, Ling Huang, Jian Shen, Tsing Yu, Qing-Jin Meng

Journal of Electrochemistry

The adsorption and binding behavior of 2,5_dimercapto_1,3,4_thiadizole(DMTD) on silver surface was studied by near_infrared Fourier Transfer surface enhanced Raman scattering(NIR FT-SERS) technique. It was found that the relative intensities of the SERS bands change regularly with the increasing of temperature, which suggests the transformation of the tautomers or the re_orientation of DMTD molecules in the surface layer.

Go to article

Study On Corrosion Resistance Of Electroless Nickel Composite Coatings, Tsong-Jen Yang, Meng-Feng Jou May 2001

Study On Corrosion Resistance Of Electroless Nickel Composite Coatings, Tsong-Jen Yang, Meng-Feng Jou

Journal of Electrochemistry

The eletroless nickel composite coating was prepared by uniform dispersion of diamond (or PTFE) particles throughout electroless nickel deposition. Corrosion resistance of composite coating in 3.5% NaCl aqueous solution was investigated by electrochemical analysis, dipping test and salt spray test. The results showed that the corrosion resistance of composite coating was inferior to that of electroless nickel coating if small amount of particles was added to the composite coating. Microsturctural analysis by SEM,AES,XRD,and EPMA indicated that the distribution of phosphorus is not homogeneous in the composite coating. The phosphorus_rich region acts as microcathode, however, the phosphorus_lean region acts as microanode.The …

Go to article

Anionic Photofragmentation Of Co: A Selective Probe Of Core-Level Resonances, Wayne C. Stolte, D. L. Hansen, Maria Novella Piancastelli, I. Dominguez-Lopez, A. Rizvi, Oliver Hemmers, H. Wang, Alfred S. Schlachter, M. S. Lubell, Dennis W. Lindle May 2001

Anionic Photofragmentation Of Co: A Selective Probe Of Core-Level Resonances, Wayne C. Stolte, D. L. Hansen, Maria Novella Piancastelli, I. Dominguez-Lopez, A. Rizvi, Oliver Hemmers, H. Wang, Alfred S. Schlachter, M. S. Lubell, Dennis W. Lindle

Environmental Studies Faculty Publications

Anion-yield spectroscopy using x rays is shown to be a selective probe of molecular core-level processes, providing unique experimental verification of shape resonances. For CO, partial anion and cation yields are presented for photon energies near the C K edge. The O- yield exhibits features above threshold related only to doubly excited states, in contrast to cation yields which also exhibit pronounced structure due to the well-known σ* shape resonance. Because the shape resonance is completely suppressed for O-, anion spectroscopy thus constitutes a highly selective probe, yielding information unobtainable with absorption or electron spectroscopy.

Go to article

Interchannel Coupling In The Photoionization Of The M-Shell Of Kr Well Above Threshold: Experiment And Theory, H. S. Chakraborty, D. L. Hansen, Oliver Hemmers, P. C. Deshmukh, P. Focke, I. A. Sellin, Clemens Heske, Dennis W. Lindle, S. T. Manson Apr 2001

Interchannel Coupling In The Photoionization Of The M-Shell Of Kr Well Above Threshold: Experiment And Theory, H. S. Chakraborty, D. L. Hansen, Oliver Hemmers, P. C. Deshmukh, P. Focke, I. A. Sellin, Clemens Heske, Dennis W. Lindle, S. T. Manson

Environmental Studies Faculty Publications

Photoionization cross sections and asymmetry (β) parameters for Kr 3s, 3p, and 3d subshells have been measured and calculated in the 300–1300-eV photon energy range. Good agreement between experiment and theory is found for both cross-section branching ratios and β parameters. Interchannel coupling among the channels arising from 3s, 3p, and 3d subshells is found to be necessary for quantitative accuracy of the theory. This shows that the interchannel coupling phenomenology far above threshold, found previously for outer shells of Ne and Ar, is also operative for inner atomic shells.

Go to article

First Prev Next Last