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Articles 3691 - 3720 of 4488

Full-Text Articles in Chemistry

Research Progress On Proton Exchange Membranes Of Fuel Cells, Jing-Rong Yu, Dan-Min Xing, Fu-Qiang Liu, Jian-Guo Liu, Bao-Lian Yi Nov 2001

Research Progress On Proton Exchange Membranes Of Fuel Cells, Jing-Rong Yu, Dan-Min Xing, Fu-Qiang Liu, Jian-Guo Liu, Bao-Lian Yi

Journal of Electrochemistry

The proton exchange membrane fuel cells (PEMFC) use proton exchange membranes(PEM) as their electrolytes. The performance of the PEMFC is strongly dependent on the characteristics of the PEM. In this paper, the requirements of the PEM utilized in the PEMFC were analyzed. The per-fluorinated, partially fluorinated and non-fluorinated PEM were introduced respectively. The structures, preparation, properties of the various types of PEM and their applications in the PEMFC were also discussed in detail.

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The Influence Of Synthesis Conditions On The Electrochemical Properties Of Spinel Limn2O4, Jun-Feng Xu, Zhi-Yu Jiang Nov 2001

The Influence Of Synthesis Conditions On The Electrochemical Properties Of Spinel Limn2O4, Jun-Feng Xu, Zhi-Yu Jiang

Journal of Electrochemistry

The electrochemical properties of spine LiMn2O4 synthesized via a solid state reaction were investigated. Electrolysis MnO2(EMD), Li2CO3 ,LiOH and LiNO3 were used as the initial materials. It was found that the electrochemical properties of LiMn2O4 were strongly influenced by the synthesis conditions. The LiMn2O4 sample sprepared via the reactionof EMD and LiNO3 showed the best properties for a lithiumion intercalation reaction. The procedure includes two steps:pretreatment at 280 ℃ for 6 hours to initiate the permeation of melting LiNO3 into the microporesof EMD …

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Adsorption And Oxidation Of Methanol On Pt And Sb, S Modified Pt Electrodes Using Cyclic Voltammetry And Eqcm, Guo-Liang Chen, Sheng-Pei Chen, Heng Lin, Xing-Hong Zheng, Shi-Gang Sun Nov 2001

Adsorption And Oxidation Of Methanol On Pt And Sb, S Modified Pt Electrodes Using Cyclic Voltammetry And Eqcm, Guo-Liang Chen, Sheng-Pei Chen, Heng Lin, Xing-Hong Zheng, Shi-Gang Sun

Journal of Electrochemistry

The processes of adsorption and oxidation of methanol on Pt, Pt/Sb ad and Pt/S ad electrodes were studied by using cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The results demonstrated that the oxidation of methanol depends strongly on oxidation states of electrode surface. Sb adatoms on Pt surface can adsorb oxygen at relatively low potentials, and exhibit catalytic effects for methanol oxidation. In contrast to Pt electrodes, the oxidation peak potential of methanol in this case negatively shifted to about 130 mV. In a contrary, the oxidation of Sad atoms consumes oxygen species of Pt electrode surface. As …

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Study On Electrochemical Behavior Of Copper In Nh3 ·H2O Solution Medium Including K3[Fe(Cn)6] During Cmp, Yue-Hua Hu, Han-Wei He, Ke-Long Huang Nov 2001

Study On Electrochemical Behavior Of Copper In Nh3 ·H2O Solution Medium Including K3[Fe(Cn)6] During Cmp, Yue-Hua Hu, Han-Wei He, Ke-Long Huang

Journal of Electrochemistry

Influence of medium pH value and passivator concentrations on the copper passivation and CMP process were studied by electrochemical measurement technologies, relations of the film thickness and tightness with polishing process and polishing rates were investigated. Electrochemical variables influencing polishing process and rates were found out. Electochemical mechanism of polishing processes were explained by corrosion potential and corrosion current density. A recipe of K3[Fe(CN)6] as passivator and nano sized γ-Al2O3 as abrasives in medium of NH3·H2O solution was confirmed reasonable. It is shown that the conditions of polishing process …

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Study On The Anticorrosion Of Ld-2 Compound Inhibitor On Reinforcing Steel In Seawater, Rong-Gui Du, Zhou-Cheng Wang, Ruo-Shuang Huang, Rong-Gang Hu, Bing Zhao, Jian-Guang Tan, Chang-Jian Lin Nov 2001

Study On The Anticorrosion Of Ld-2 Compound Inhibitor On Reinforcing Steel In Seawater, Rong-Gui Du, Zhou-Cheng Wang, Ruo-Shuang Huang, Rong-Gang Hu, Bing Zhao, Jian-Guang Tan, Chang-Jian Lin

Journal of Electrochemistry

The effect of LD-2 compound inhibitor developed in our laboratory on its anticorrosion action on the reinforcing steel in concrete immersed in seawater was shown in this paper. The corrosion behavior of the reinforcing steel in seawater was studied using electrochemical techniquesand immersion tests. The polarization curve of the reinforcing steel immersed in seawater showedthe free corrosion potential of the steel increased by 0. 220 V (vs. SCE), and the corrosion current decreased by two orders of magnitude by adding 25 g⋅L-1 compound inhibitor to the seawater. The potentiodynamic anodic polarization curve of reinforcing steel in the seawater with …

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Collision-Induced Electronic Energy Transfer From V=0 Of The E(0g+) Ion-Pair State In I2: Collisions With I2(X), Christopher J. Fecko , '98, Miriam Arak Freedman , '00, Thomas Alex Stephenson Sep 2001

Collision-Induced Electronic Energy Transfer From V=0 Of The E(0g+) Ion-Pair State In I2: Collisions With I2(X), Christopher J. Fecko , '98, Miriam Arak Freedman , '00, Thomas Alex Stephenson

Chemistry & Biochemistry Faculty Works

The collision-induced electronic energy transfer that occurs when I-2 in the E(0(g)(+)) ion-pair electronic state collides with ground electronic state I-2 has been investigated. We prepare I-2 in single rotational levels in v = 0 of the E state using two-color double resonance laser excitation. The resulting emission spectrum shows that the nearby (DeltaT(e) = -385 cm(-1)) D(0(u)(+)) electronic state is populated. The cross section for collision-induced E -->D energy transfer is found to be IS - 3 Angstrom (2). A range of D state vibrational levels are populated, consistent with a model in which overlap between the initial …

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Dynamical Relativistic Effects In Photoionization: Spin-Orbit-Resolved Angular Distributions Of Xenon 4d Photoelectrons Near The Cooper Minimum, H. Wang, G. Snell, Oliver Hemmers, M. M. Sant'anna, I. A. Sellin, N. Berrah, Dennis W. Lindle, P. C. Deshmukh, N. Haque, S. T. Manson Sep 2001

Dynamical Relativistic Effects In Photoionization: Spin-Orbit-Resolved Angular Distributions Of Xenon 4d Photoelectrons Near The Cooper Minimum, H. Wang, G. Snell, Oliver Hemmers, M. M. Sant'anna, I. A. Sellin, N. Berrah, Dennis W. Lindle, P. C. Deshmukh, N. Haque, S. T. Manson

Environmental Studies Faculty Publications

Two decades ago, it was predicted [Y. S. Kim et al., Phys. Rev. Lett. 46, 1326 (1981)] that relativistic effects should alter the dynamics of the photoionization process in the vicinity of Cooper minima. The present experimental and theoretical study of the angular distributions of Xe 4d3/2 and 4d5/2 photoelectrons demonstrates this effect for the first time. The results clearly imply that relativistic effects are likely to be important for intermediate- Z atoms at most energies.

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Characterization And Electrochemical Investigation Of Boron-Doped Mesocarbon Microbeads Anode Materials For Lithium-Ion Battery, Mao-Hui Chen, Guo-Tao Wu, Guang-Ming Zhu, Jin-Kua You, Zu-Geng Lin Aug 2001

Characterization And Electrochemical Investigation Of Boron-Doped Mesocarbon Microbeads Anode Materials For Lithium-Ion Battery, Mao-Hui Chen, Guo-Tao Wu, Guang-Ming Zhu, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

The anodic performances of boron doped and undoped mesocarbon microbeads(MCMBs) were comparatively studied and the structures were characterized by XPS, SEM, XRD and electrochemical measurements. It was found that boron doping samples greatly increased the degree of graphitization and the crystallite size, leading to quite different morphology. Electrochemical discharge/charge cycle tests indicate that lithium intercalation occurred at a little higher potential for the boron doped MCMBs, being attended by greater irreversible capacity loss.

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Microstructure And Electrochemical Properties Of The Melt-Spinning Zr0.9Ti0.1(Ni, Co, Mn, V)2.1 Alloy, Ming-Fen Wen, Yu-Chun Zhai, Lian Chen, Min Tong, Hua Zhen, Rong-Jun Ma Aug 2001

Microstructure And Electrochemical Properties Of The Melt-Spinning Zr0.9Ti0.1(Ni, Co, Mn, V)2.1 Alloy, Ming-Fen Wen, Yu-Chun Zhai, Lian Chen, Min Tong, Hua Zhen, Rong-Jun Ma

Journal of Electrochemistry

The microstructure and electrochemical properties of Zr0.9Ti0.1(Ni,Co,Mn,V)2.1 alloys prepared by both the melt-spinning method and the conventional induction melting were investigated. XRD studies show that Zr0.9Ti 0.1(Ni,Co,Mn,V)2.1 alloys at as-cast, melt-spinning and annealing are all face center cubic structure with C15 laves phase, the higher the melt-spinning rate, the more the amorphous content. The electrochemical measurements show that melt-spinning alloys have better active behavior, low discharge capacity (< 280 mAh/g); but after annealed, the alloys are activated completely with 30 cycles, the capacities about 340 mAh/g are higher than those of as-cast and melt-spinning alloys; the annealec alloys have a better cycle stability than that of as-cast alloy, and the higher the melt-spinning rate is, the more stable the alloy becomes; at 300 mAh/g current density, the capacity of annealed 40 m/s alloy is up to 85% of the maximum capacity after 800 cycles, the capacity decay rate is about 6.9%.

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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 NiSO4 were superior to those of the material prepared from Ni(NO3)2. The reasons of the differences were analyzed by XRD and FTIR measurements, which will become abasis for the selection of raw materials.

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Uneven Anodic Dissolution Of Iron Induced By Magnetic Field, Zhan-Peng Lv, De-Lun Huang, Wu Yang Aug 2001

Uneven Anodic Dissolution Of Iron Induced By Magnetic Field, Zhan-Peng Lv, De-Lun Huang, Wu Yang

Journal of Electrochemistry

The effects of magnetic field on anodic dissolution of iron in sulfuric acid were studied by potentiostatic polarization measurements and scanning electron microscopy observation. Magnetic field would reduce the surface film coverage fraction on electrode by enhancing the film dissolution process, thus made the electrode prone to active dissolution state. With increasing the applied potentials, magnetic field would accelerate the anodic dissolution, change the oscillation state or passive state to active dissolution state, or maintain the passive state, respectively. Potential for onset of passivation moved in the noble direction when magnetic field was imposed. At specific anodic potentials, denting occurred …

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Simultaneous Determination Of Gold(Ⅲ) And Copper(Ⅱ) With Two-Way Stripping Voltammetry, Rong-Zong Hu, Dong-Ping Wei, Guang Wei, Yue-Ying Liu Aug 2001

Simultaneous Determination Of Gold(Ⅲ) And Copper(Ⅱ) With Two-Way Stripping Voltammetry, Rong-Zong Hu, Dong-Ping Wei, Guang Wei, Yue-Ying Liu

Journal of Electrochemistry

A novel Two-way Stripping Voltammetry method for simultaneous determination of Au3+ and Cu2+ was reported in this paper. Because of the strongly electrostatic attraction of carbon paste electrode towards Au(Ⅲ) ion at positive potential and the biochemical contribution of Gram-positive bacteria strain DO1, the ion can be determined by cathodic stripping voltammetry. At the same time, Cu(Ⅱ) is reduced readily under the catalysis of ultra-fine gold particles, thereafter it can be determined by anode stripping voltammetry. There is no interference between the determination of Au3+ and Cu2+ . A perfect liner relationship between the concentrations of …

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The Dissolution Of Perfluorinated Proton Exchange Membrane And The Analysis On The Performance Of The Recast Membrane, Hong-Feng Xu, Xi-Qiang Yan, Xuan Li, Li Wan Aug 2001

The Dissolution Of Perfluorinated Proton Exchange Membrane And The Analysis On The Performance Of The Recast Membrane, Hong-Feng Xu, Xi-Qiang Yan, Xuan Li, Li Wan

Journal of Electrochemistry

Perfluorinated resin solution is useful in proton exchange membrane fuel cell. At 270～280 ℃ and protected with N2, the proton exchange membrane(Nafion 115) was dissolved in the dimethyl sulfoxide, and two kinds of membrane solutions were obtained. With those solutions, a recast membrane was prepared. The exchange capacity, rate of water content and conductivity of the recast membrane were measured. The results show that the properties of the recast membrane are lower than those of its mother membrane. This may be caused by that some sulfonic acid groups were destroyed in the dissolving process.

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In Situ Ftir Reflection Spectroscopy Of Bioelectrode, Sa-Ying Dong, Guang-Yu Zhao, Yuzhu Gao, Guang-Zhang Chen, Ming-Xiang Lv Aug 2001

In Situ Ftir Reflection Spectroscopy Of Bioelectrode, Sa-Ying Dong, Guang-Yu Zhao, Yuzhu Gao, Guang-Zhang Chen, Ming-Xiang Lv

Journal of Electrochemistry

In situ FTIR reflection spectroscopy was used to study mediated enzyme electrode and immunoelectrode. We determined and analyzed IR characteristic spectra of GOD and glucose by the use of potential difference spectra and single beam subtractive spectra. At last, we explored the IR absorption characters of enzyme-immunoelectrode.

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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)63-/Fe(CN)64- 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 η1/2 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 between ln(I/V) …

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Studies On The Electrochemical Properties Of Phosphate Derivatives Of C60, Ying Liu, Li Ding, Lou-Zhen Fan, Fu-Yong Cheng, Zhong-Da Wu Aug 2001

Studies On The Electrochemical Properties Of Phosphate Derivatives Of C60, 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 C60. 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 C60 derivertives.

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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 CeCl3, NaH2PO2 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 were …

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Current Oscillations In The System Of Carbon Steel/Phosphoric Acid/Platinum, Shao-Yuan Shi, Jin-Ping Wu, Jing Liu, An Lin Aug 2001

Current Oscillations In The System Of Carbon Steel/Phosphoric Acid/Platinum, Shao-Yuan Shi, Jin-Ping Wu, Jing Liu, An Lin

Journal of Electrochemistry

The periodic,aperiodic, chaotic and mixed-mode oscillations can occur in the process of the anodic electrodissolution of carbon steel in the solution of dilute phosphoric acid. More plentiful dynamic behaviors can be found in this system compared with the system of Fe/H3PO4/Pt.

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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 …

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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 3.75Co 0.65 Mn0.4Al0.2 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.

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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.

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Electrochemical Impedance Spectroscopy Study On A3 Steel In Anti-Corrosive Pigment Extract Solution, Zhi-Jun Gu, Yong-Gui Liao, Zhi-Gang Zhang, Qi-Long Guo, Fang-Teng Su, Wen-Yun Hu, Yan-Zhen Chen Aug 2001

Electrochemical Impedance Spectroscopy Study On A3 Steel In Anti-Corrosive Pigment Extract Solution, Zhi-Jun Gu, Yong-Gui Liao, Zhi-Gang Zhang, Qi-Long Guo, Fang-Teng Su, Wen-Yun Hu, Yan-Zhen Chen

Journal of Electrochemistry

The corrosion behaviors of A3 steel in different pH, 3.5%NaCl, modified zinc phosphate and aluminum triphosphate extract solutions have been studied by EIS. Results show:(a) The resistance increases with the increase of pH value under the same circumstances, but the capacity is the reverse. (b) Zinc phosphate, because of its low solubility, shows no inhibitive performance for A3 steel in 3.5% NaCl extract solutions. (c) Aluminum triphosphate has good inhibitive performance for A3 steel in 3.5% NaCl extract solutions at a pH of 6, probably because the triphosphate ion can complex with the corrosion-product, such as ferric …

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A New Method For Impregnating Nafion Solution Into The Electrode Of Pemfc, Qian Tang, Ming Han, Bao-Lian Yi, Zhi-Yin Lin Aug 2001

A New Method For Impregnating Nafion Solution Into The Electrode Of Pemfc, Qian Tang, Ming Han, Bao-Lian Yi, Zhi-Yin Lin

Journal of Electrochemistry

We have developed a new method for impregnating Nafion solution into the catalyst layer of homemade hydrophobic electrode using capillary process. Those electrodes show better performance and higher utilization of catalyst (detected by CV and TEM) than traditional spray method in PEMFC. According to the results of SEM photograph and linear-analysis of sulfur and platinum for the electrode cross-section, we can conclude that the resin is uniform in the catalyst layer and has almost same depth as catalyst in the impregnated electrode. While in traditional method resin is not uniform in the catalyst layer and penetrates into the diffusion layer, …

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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.

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The Coulostatic Method For Evaluating Corrosion In Reinforced Concrete, Yong-Tao Zhao, Jian-Hua Wu, Chang-Jiu Zhao Aug 2001

The Coulostatic Method For Evaluating Corrosion In Reinforced Concrete, Yong-Tao Zhao, Jian-Hua Wu, Chang-Jiu Zhao

Journal of Electrochemistry

In the present paper, the application of the coulostatic method to the corrosion of steel in concrete was reviewed. By comparing with other electrochemical techniques, the results obtained in the previous work reveal that the coulostatic method is an interesting alternative to the usual procedures for estimation of corrosion rate, and is better than them in some respects. The main advantages are as follows. The signal to be used can be instantaneous and as small as desired, so the electrode is minimally perturted during the measuring process. In addition, it is as rapid and quantitative, and at least as reliable …

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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.

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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 …

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Performance Of Proton Exchange Membranefuel Cell With Co/H2 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 Membranefuel Cell With Co/H2 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 reformatecontains 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 inPEMFC ,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 moresuitable for the electrocatalysis of CO/H2 than Pt electrocatalyst.

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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 …

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Properties Of Metallized Polyo-Toluididemembrane Modified Electrode, Li-Zong Dai, Yi-Ting Xu, Hui-Huang Wu May 2001

Properties Of Metallized Polyo-Toluididemembrane 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 …

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