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Articles 2971 - 3000 of 4489

Full-Text Articles in Chemistry

Electrochemical Performances Of Copper/Activated Carbon Composites, Lan-Ting Li, Qiang Xie, Wen Yan, Yan-Yan Wang, Wen-Wen Xing May 2008

Electrochemical Performances Of Copper/Activated Carbon Composites, Lan-Ting Li, Qiang Xie, Wen Yan, Yan-Yan Wang, Wen-Wen Xing

Journal of Electrochemistry

The development and improvement of electrode materials can result in the enhancement of the performances of electrochemical capacitor.In this paper various copper/activated carbon composites were prepared in the presence of different amounts(from 0% to 40%) of copper nitrate from bituminous coal.Then different electrodes were prepared from copper oxide,activated carbon and copper/activated carbon composites,respectively,and were characterized by cyclic voltammetry,alternative current(AC) impedance,charge-discharge at constant current and maintenance of the self-potential.The results showed that the proper amount of copper in copper/activated carbon composites positively influenced the electrochemical performances of electrodes,and the capacitance of copper/activated carbon composites was larger than that of the total …

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Preparation Of Zn-Ni Alloy Whisker By Electrochemical Method, Zhen-Hai Liang, Xi-Hua Xia May 2008

Preparation Of Zn-Ni Alloy Whisker By Electrochemical Method, Zhen-Hai Liang, Xi-Hua Xia

Journal of Electrochemistry

The Zn-Ni alloy whiskers were prepared by electrochemical method and were characterized by XRD, SEM and EDS methods. The results showed that Ni5Zn21 and Ni3Zn22 whiskers were obtained with the length of 2~4 μm and the diameter of 250 nm, thereby the rations of length/diameter fell between 8 and 16. The electrochemical behavior was investigated by cyclic voltammetry method simultaneously. A new method was provided on whisker preparation based on this work.

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Carbon Nanotube Array Electrodes Based Supercapacitors With 3.5v Working Voltage, Hao Zhang, Gao-Ping Cao, Yu-Sheng Yang, Zhen-Nan Gu, Bin Xu, Wen-Feng Zhang May 2008

Carbon Nanotube Array Electrodes Based Supercapacitors With 3.5v Working Voltage, Hao Zhang, Gao-Ping Cao, Yu-Sheng Yang, Zhen-Nan Gu, Bin Xu, Wen-Feng Zhang

Journal of Electrochemistry

The carbon nanotube arrays(CNTA) were grown directly on the substrates of Ta and stainless steel by chemical vapor deposition.The button-like supercapacitors were fabricated based the CNTA electrodes.The electrochemical performance of CNTA based supercapacitors presentsed high working voltage(3.5 V),long cycle life,and good rate capability.The power and energy densities are were 928 kW·kg-1 and 19 Wh·kg-1,respectively(based on the mass of CNTA).

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Direct Electrochemistry Of God On Glassy Carbon Electrode Modified With Mesoporous Carbon, Kun-Qi Wang, Lin Zhu, Wei Xing May 2008

Direct Electrochemistry Of God On Glassy Carbon Electrode Modified With Mesoporous Carbon, Kun-Qi Wang, Lin Zhu, Wei Xing

Journal of Electrochemistry

Glucose oxidase(GOD) is immobilized on glassy carbon electrode mesoporous carbon by simple method.Cyclic voltammetric results indicated that on GOD of the modified electrode a quasi-reversible redox reaction took place(GCE) surface modified at a formal potential of-0.4294 V in 0.1 mol/L phosphate buffer solution(PBS)(pH 7.1).The electrochemical reaction consisted of a two-electron transfer coupled with a two-proton transfer.The GOD can completely catalyze oxidation of glucose via electron transfer intermedia of ferrocene monocarboxylic acid(FMCA) in saturated solutions with N2.The bioactivity of GOD on the modified electrode with mesoporous carbon was obviously unattacked.

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Electrochemical Performance Of C-Lifepo4 By Polyaniline Doping, Wei Wang, Li-Fang Jiao, Hua-Tang Yuan May 2008

Electrochemical Performance Of C-Lifepo4 By Polyaniline Doping, Wei Wang, Li-Fang Jiao, Hua-Tang Yuan

Journal of Electrochemistry

The olivine LiFePO4 cathode materials were synthesized using the solid state method in an inert atmosphere by doping polyaniline into the C-LiFePO4.It was found that the electrochemical performance of polyaniline-doped C-LiFePO4 slightly improved.At a low discharging rate(0.1C), the capability of(C-LiFePO4)0.9(PANI)0.1 reached 164 mAh·g-1.When the charge-discharge rate is increased to 0.5C and 1.0C,the showed capacities of 121.6 mAh·g-1 and 110.1 mAh·g-1 were obtained,respectively.

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Electroless-Deposition Synthesis Of Highly Active Ptru/C And Ptrusn/C As Anode Catalysts For Defc, Jing Zhu, Yi Su, Hua Ma, Fang-Yi Cheng, Zhan-Liang Tao, Jing Liang, Jun Chen May 2008

Electroless-Deposition Synthesis Of Highly Active Ptru/C And Ptrusn/C As Anode Catalysts For Defc, Jing Zhu, Yi Su, Hua Ma, Fang-Yi Cheng, Zhan-Liang Tao, Jing Liang, Jun Chen

Journal of Electrochemistry

In this paper,the preparation,characterization,and ethanol electrocatalytic oxidation of Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C electrocatalysts were reported.The electroless-deposition with sensitization-activation pretreatment was applied to prepare Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C electrocatalysts. The XRD and TEM analyses showed that the as-prepared catalysts were composed of well-dispersed PtRu or PtRuSn nanoparticles with an average particle size of about 3 nm.The electrochemical measurements demonstrated that the as-prepared Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C catalysts exhibited much enhanced peak current density for …

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Electrocatalytic Performance Of Pt/C And Pt/Wo3/C Catalysts For Methanol Oxidation, Yuan-Yuan Chu, Bing Wu, Ya-Wen Tang, Tian-Hong Lu, Ying Gao May 2008

Electrocatalytic Performance Of Pt/C And Pt/Wo3/C Catalysts For Methanol Oxidation, Yuan-Yuan Chu, Bing Wu, Ya-Wen Tang, Tian-Hong Lu, Ying Gao

Journal of Electrochemistry

The catalysts of Carbon supported Pt(Pt/C) and carbon supported Pt/WO3(Pt/WO3/C) were prepared with liquid phase reduction method.It was found that the catalytic activity and stability of the Pt/WO3/C catalysts were increased with the addition of WO3.When the atomic ratio of Pt and W was 1∶1,the best electrocatalytic performance of the Pt/WO3/C catalyst for the methanol oxidation was obtained.This is attributed to the larger electrochemical surface area of Pt/WO3/C and the weeker adsorption of CO towards the catalyst.

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Preparation And Electrochemical Capacitance Of Spherical-Like Polypyrrole Doped With Heparin Sodium, Hong-Yu Mi, Xiao-Gang Zhang, Su-Dong Yang, Xiang-Guo Ye May 2008

Preparation And Electrochemical Capacitance Of Spherical-Like Polypyrrole Doped With Heparin Sodium, Hong-Yu Mi, Xiao-Gang Zhang, Su-Dong Yang, Xiang-Guo Ye

Journal of Electrochemistry

Spherical-like polypyrrole with an average diameter of 100 nm as the electrode material for supercapacitor was prepared by a self-assembly process with heparin sodium salt as the dopant at-10 ℃.The morphology and electrochemical properties were characterized by transmission electron microscopy(TEM),cyclic voltammetry(CV),galvanostatic charge/discharge and electrochemical impedance spectroscopy(EIS) measurements.The results showed that the polypyrrole doped with heparin sodium salt exhibited good capacitive behavior.The specific capacitance of single electrode was up to 338 F/g at 3 mA/cm2.

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Synthesis Of Agv3O8 As High-Capacity Of Cathode Materials For Lithium Secondary Batteries Via A Soft Chemistry Technique, Xiao-Yu Cao, Tao Li, Ling-Ling Xie, Xiang-Yang Yan, Chi-Wei Wang May 2008

Synthesis Of Agv3O8 As High-Capacity Of Cathode Materials For Lithium Secondary Batteries Via A Soft Chemistry Technique, Xiao-Yu Cao, Tao Li, Ling-Ling Xie, Xiang-Yang Yan, Chi-Wei Wang

Journal of Electrochemistry

The layered cathode material of AgV3O8 has been prepared for the lithium secondary batteries via the soft chemistry technique. The so-synthesized powders were characterized by XRD(powder X-ray diffraction), SEM(scanning electron microscope) and LPSA(laser particle size analysis). The electrochemical property was investigated by the galvanostatic discharge-charge technique. The results indicated that the particale sizes of AgV3O8 prepared were small in the distribution of narrow range, which leads to high discharge capacity. Among them, the material synthesized at 400 ℃ displayed the first discharge capacity of 760.5 mAh/g.

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Influence Of Assembly Force In A Pemfc Under A Lifetime Test, Fan Xu, Xuan Cheng, Ying Zhang, Qin-Bai Fan May 2008

Influence Of Assembly Force In A Pemfc Under A Lifetime Test, Fan Xu, Xuan Cheng, Ying Zhang, Qin-Bai Fan

Journal of Electrochemistry

The lifetime performance was investigated by assembling the single cell of PEMFC under a series of holding forces ranging from 0.45 to 11.3 MPa and reassembled under optimal holding force.The polarization and power density curves were obtained during different periods of operating time up to 2000 hours and the fuel cell catalyst activation regions in the polarization curves were analyzed to evaluate the electrochemical kinetic parameters.The results revealed that the holding forces affected not only the internal contact resistances,but also the kinetic parameters which might be caused by the change of the MEA microstructures.The apparent degradation observed at higher current …

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Passivation Behaviors Of Mo, W Electrodes In Mgcl2-Kcl-Nacl-Cacl2 Molten Salt For Electrolysis Of Magnesium, Ye Chen, Ke Ye May 2008

Passivation Behaviors Of Mo, W Electrodes In Mgcl2-Kcl-Nacl-Cacl2 Molten Salt For Electrolysis Of Magnesium, Ye Chen, Ke Ye

Journal of Electrochemistry

The discharge process and passivation behaviors of Mg(Ⅱ) on cathode(Mo, W) in MgCl2-KCl-NaCl-CaCl2 molten salt system had been investigated by means of cyclic voltammetry and chronoamperometry. The composition of molten salt was MgCl(10%) + CaCl(20%) + NaCl(60%) + KCl(10%)(by mass) and the temperature of electrolysis was 725 ℃. The deposition potential of Mo was 37 mV more negative than that of W, while the peak current was sharper than Mo according to the voltammograms at 0.05 V/s, indicating that the passivation on Mo cathode is easier than W. The formation of MgO impurities during the electrolysis could …

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Inhibition Of Amino Acids Against Steel In Hydrochloric Acid Solution, Ming-Yan Cheng, Wei-Ming Wu, He-Ming Liu, Hai-Yan Du May 2008

Inhibition Of Amino Acids Against Steel In Hydrochloric Acid Solution, Ming-Yan Cheng, Wei-Ming Wu, He-Ming Liu, Hai-Yan Du

Journal of Electrochemistry

The inhibition effect of glutamic acid towards the corrosion of X65 steel in hydrochloric acid solution(10%) was investigated using polarization techniques, electrochemical impedance spectroscopy (EIS) and SEM. The corrosion rate, corrosion potential (Ecoor), polarization resistance (Rp) and inhibition efficiency (η) were determined. The results revealed that the inhibitor is a mixed type inhibitor.It has promising corrosion inhibition efficiency at low concentrations. The inhibition efficiency (η) increased with increasing the concentration. The maximum inhibition efficiency appeared at 0.3 g·L-1.

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The Effect Of Annealed Temperature On Properties Of Ru-Ir-Sn Oxide Anode Coatings, Lei Ji, Jun-Tao Wang, Li-Kun Xu, Wen-Bin Liu, Gui-Lin Xue May 2008

The Effect Of Annealed Temperature On Properties Of Ru-Ir-Sn Oxide Anode Coatings, Lei Ji, Jun-Tao Wang, Li-Kun Xu, Wen-Bin Liu, Gui-Lin Xue

Journal of Electrochemistry

The anode coatings of Ru-Ir-Sn oxide were prepared by sol-gel method with different annealed temperatures.The influences of annealed temperature in properties of anode coatings were characterized by scanning electron microscope(SEM),energy dispersive X-ray detector(EDX),X-ray diffraction(XRD),potential of chlorine evolution,accelerated life,cyclic voltammetry and electrochemical impedance spectroscopy(EIS) tests.The results showed that the annealed temperature affected the morphology of coatings,while the electric quantities of cyclic voltammetry and double layer capacitances of anode coatings had a tendency to fall down and the potential of chlorine evolution and accelerated life had a tendency to increase as the annealed temperature increased.

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Preparation And Photoelectrochemical Properties Of Fe-Doped Tio2 Nanotube Arrays, Jing Li, Lan Sun, Hui-Fang Zhuang, Cheng-Lin Wang, Rong-Gui Du, Chang-Jian Lin May 2008

Preparation And Photoelectrochemical Properties Of Fe-Doped Tio2 Nanotube Arrays, Jing Li, Lan Sun, Hui-Fang Zhuang, Cheng-Lin Wang, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

The Fe-doped TiO2 nanotube arrays were fabricated in Fe(NO3)3-HF mixing solutions by electrochemical anodic oxidation method,and characterized by FESEM,Raman,XPS and DRS.The effect of Fe concentratiions on photoelectrochemical property of the arrays was also investigated.The diameters and lengths of Fe-doped TiO2 nanotube arrays were 50~90 nm and about 200 nm,respectively.Compared with the undoped TiO2 nanotube arrays,the absorption edge of Fe-doped TiO2 nanotube arrays appeared red shifting.The more Fe content,the larger red shifting,in addition,the photocurrent of Fe-doped TiO2 nanotube arrays increased obviously.

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Cyclic Voltammetry And In Situ Ftir Studies Of Cyanide Adsorption On Nanostructured Au Film Electrode In Alkaline Solutions, Chun-Hua Zhen, Chun-Jie Fan, Shi-Gang Sun May 2008

Cyclic Voltammetry And In Situ Ftir Studies Of Cyanide Adsorption On Nanostructured Au Film Electrode In Alkaline Solutions, Chun-Hua Zhen, Chun-Jie Fan, Shi-Gang Sun

Journal of Electrochemistry

The adsorption of cyanide(CN-) on electrodes of nanometer scale thin film of gold supported on glassy carbon(nm-Au/GC) in alkaline solutions were investigated using cyclic voltammetry and in situ FTIR spectroscopy.It has revealed that the electrodeposited nanostructured Au thin film exhibited AIREs(abnormal infrared effects) for CN-adsorption,which manifested 3 nonlinear IR spectral features: inversion of the direction of CN-band,enhancement of IR absorption of adsorbed CN-species(about 39.2 folds) and increase in the FWHM(full width at half maximum) of CN-band.

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Quick Tester With Usb Interface For The Corrosion Protection Properties Of Organic Coating, Xiang-Dong Zhuo, Chang-Jian Lin May 2008

Quick Tester With Usb Interface For The Corrosion Protection Properties Of Organic Coating, Xiang-Dong Zhuo, Chang-Jian Lin

Journal of Electrochemistry

According to the principle of multiple dynamic potential scaning polarization,a quick tester with USB interface for the fast study of corrosion resistance properties of organic coating/ metal system has been developed.This tester is portable,facile,practical,and has a strong function for data collection and data treatment.It is not only suitable for the accelerated test in laboratory,but also for the quick test and evaluation to the corrosion resistance of the organic coating/metal system in industrial spots.

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Theoretical And Experimental Studies Of Collision-Induced Electronic Energy Transfer From V=0-3 Of The E(0g+) Ion-Pair State Of Br2: Collisions With He And Ar, J. M. Hutchison, Robin R. O'Hern, Thomas Alex Stephenson, Y. V. Suleimanov, A. A. Buchachenko May 2008

Theoretical And Experimental Studies Of Collision-Induced Electronic Energy Transfer From V=0-3 Of The E(0g+) Ion-Pair State Of Br2: Collisions With He And Ar, J. M. Hutchison, Robin R. O'Hern, Thomas Alex Stephenson, Y. V. Suleimanov, A. A. Buchachenko

Chemistry & Biochemistry Faculty Works

Collisions of Br(2), prepared in the E(0(g)(+)) ion-pair (IP) electronic state, with He or Ar result in electronic energy transfer to the D, D('), and beta IP states. These events have been examined in experimental and theoretical investigations. Experimentally, analysis of the wavelength resolved emission spectra reveals the distribution of population in the vibrational levels of the final electronic states and the relative efficiencies of He and Ar collisions in promoting a specific electronic energy transfer channel. Theoretically, semiempirical rare gas-Br(2) potential energy surfaces and diabatic couplings are used in quantum scattering calculations of the state-to-state rate constants for electronic …

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Preparation Of Halogenated Derivatives Of Thiazolo[5,4-D]Thiazole Via Direct Electrophilic Aromatic Substitution, Vladimir Benin, Alan T. Yeates, Douglas Dudis May 2008

Preparation Of Halogenated Derivatives Of Thiazolo[5,4-D]Thiazole Via Direct Electrophilic Aromatic Substitution, Vladimir Benin, Alan T. Yeates, Douglas Dudis

Chemistry Faculty Publications

Chlorination and bromination reactions of thiazolo[5,4-d]thiazole led to the generation of its mono- and dihalogenated derivatives. These are the first instances of successful direct electrophilic aromatic substitution in the thiazolo[5,4-d]thiazole ring system. X-ray analysis demonstrates that both 2-bromothiazolo[5,4-d]-thiazole and 2,5-dibromothiazolo[5,4-d]thiazole are planar structures, with strongly manifested π-stacking in the solid state. Theoretical analysis of the pyridine-catalyzed halogenation (MP2/6-31+G(d) and B3LYP/6-31+G(d)calculations) reveals that introduction of one halogen actually leads to a slightly enhanced reactivity towards further halogenation. Several halogenation mechanisms have been investigated: 1) The direct C-halogenation with N-halopyridine as electrophile; …

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Structure And Dynamics Of Poly (Para-Phenyleneethynylene)S In Solutions And Thin Films, Yunfei Jiang May 2008

Structure And Dynamics Of Poly (Para-Phenyleneethynylene)S In Solutions And Thin Films, Yunfei Jiang

All Dissertations

This research focuses on the structure and dynamics of a family of rigid polymers, poly(para-phenyleneethynylene)s (PPEs) in solutions and thin films using small angle neutron scattering, neutron spin echo, nuclear magnetic resonance, X-ray scattering, atomic force microscopy and fluorescence spectroscopy. The effects of the solvent and the side chain on the molecular conformation and the association of PPEs have been investigated.
In dilute solutions, the phase diagram of dinonyl PPE in toluene and cyclohexane exhibits three distinct phases. At higher temperatures, PPEs form molecular solutions with extended conformations in toluene and worm-like chains in cyclohexane. With decreasing temperatures, PPEs associate …

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Real-Time Plasma Controlled Chemistry In A Two-Frequency, Confined Plasma Etcher, Vladimir Milosavljevic, Albert R. Ellingboe, Cezar Gaman, John V. Ringwood Apr 2008

Real-Time Plasma Controlled Chemistry In A Two-Frequency, Confined Plasma Etcher, Vladimir Milosavljevic, Albert R. Ellingboe, Cezar Gaman, John V. Ringwood

Articles

The physics issues of developing model-based control of plasma etching are presented. A novel methodology for incorporating real-time model-based control of plasma processing systems is developed. The methodology is developed for control of two dependent variables (ion flux and chemical densities) by two independent controls (27 MHz power and O2flow). A phenomenological physics model of the nonlinear coupling between the independent controls and the dependent variables of the plasma is presented. By using a design of experiment, the functional dependencies of the response surface are determined. In conjunction with the physical model, the dependencies are used to deconvolve the sensor …

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Stability And Equation Of State Of A Nanocrystalline Ga-Ge Mullite In A Vitroceramic Composite: A Synchrotron X-Ray Iffraction Study, Kristina E. Lipinska-Kalita, Patricia Kalita, Cedric Gobin, Oliver Hemmers, Thomas Hartmann, Gino Mariotto Apr 2008

Stability And Equation Of State Of A Nanocrystalline Ga-Ge Mullite In A Vitroceramic Composite: A Synchrotron X-Ray Iffraction Study, Kristina E. Lipinska-Kalita, Patricia Kalita, Cedric Gobin, Oliver Hemmers, Thomas Hartmann, Gino Mariotto

Environmental Studies Faculty Publications

Synchrotron x-ray diffraction and diamond anvil cell techniques were used to characterize the phase transformations and to evaluate the structural stability at elevated pressures of a developed nanocrystalline composite. The optically transparent material was built of a germanium oxide-based amorphous host matrix with homogeneously dispersed 13±3 nm Ga-Ge mullite-type nanocrystals, which had a structure similar to the conventional Al2O3-SiO2 mullite. The equation of state of the nanocrystals and the overall structural integrity of the nanocomposite were investigated in quasihydrostatic conditions on compression to 36 GPa and on the following decompression to ambient conditions. The overall …

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Spectroscopy Is Applied Quantum Mechanics. Part 3: Introduction To Quantum Mechanics, David W. Ball Apr 2008

Spectroscopy Is Applied Quantum Mechanics. Part 3: Introduction To Quantum Mechanics, David W. Ball

Chemistry Faculty Publications

The article discusses the pioneering work of Erwin Schrödinger on wave mechanics that forms the basis of modern understanding in subatomic behavior. Schrödinger introduced a second-order differential equation that had to be solved to explain the nature of the hydrogen atom. He also demonstrated that the matrix mechanics of Heisenberg and Born were mathematically equivalent and developed the concept of perturbation theory to explain the Stark effect.

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Equation Of State Of Gallium Oxide To 70 Gpa: Comparison Of Quasihydrostatic And Nonhydrostatic Compression, Kristina E. Lipinska-Kalita, Patricia Kalita, Oliver Hemmers, Thomas Hartmann Mar 2008

Equation Of State Of Gallium Oxide To 70 Gpa: Comparison Of Quasihydrostatic And Nonhydrostatic Compression, Kristina E. Lipinska-Kalita, Patricia Kalita, Oliver Hemmers, Thomas Hartmann

Environmental Studies Faculty Publications

Synchrotron x-ray diffraction and diamond-anvil cell techniques were used to characterize pressure induced structural modifications in gallium oxide. Gallium oxide was studied on compression up to 70 GPa and on the following decompression. The effect of the pressure-transmitting medium on the structural transformations was investigated in two sets of compression and decompression runs, one with nitrogen as a quasihydrostatic pressure-transmitting medium and the other in nonhydrostatic pressure conditions. The x-ray diffraction data showed gradual phase transition from a low-density, monoclinic β-Ga2O3 to a high-density, rhombohedral α-Ga2O3. With the use of nitrogen as a …

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Cu Doping Lifepo4 And Its Electrochemical Performance, Ming-Sen Zheng, Shan-Ke Liu, Shi-Gang Sun, Quan-Feng Dong Feb 2008

Cu Doping Lifepo4 And Its Electrochemical Performance, Ming-Sen Zheng, Shan-Ke Liu, Shi-Gang Sun, Quan-Feng Dong

Journal of Electrochemistry

LiFePO4 and LiFePO4 doped with Cu2+ ions were synthesized by solid-state reactions.The structure of LiFePO4 and the Fe valence were analyzed by the XRD(X-ray diffraction) and XPS(X-ray photoelectron spectroscopy) respectively.The Cu doping position in LiFePO4 is discussed.It has found that the volume of LiFePO4 by doping Cu2+ ions is reduced.The minim Cu2+ ions doping does not almost change the binding energy of Fe2p1/2 in LiFePO4.According to the experiment results,we conclude that most of the Cu2+ ions substitute the Fe2+ ions in LiFePO4 when a …

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In Situ Measurement Of Chloride Concentration And Ph Distribution In The Crevice During The Crevice Corrosion Of Copper Electronic Board, Min Zhang, Xiang-Dong Zhuo, Chang-Jian Lin Feb 2008

In Situ Measurement Of Chloride Concentration And Ph Distribution In The Crevice During The Crevice Corrosion Of Copper Electronic Board, Min Zhang, Xiang-Dong Zhuo, Chang-Jian Lin

Journal of Electrochemistry

Although the crevice corrosion of metals had been extensively studied in the past years,it remained lack of direct experimental information of the micro chemical environments and electrochemical conditions inside the corroding crevice.The distribution of chloride concentration and local pH in the occluded area are the most crucial factors in development of crevice corrosion.The array probes in one dimension of Ag/AgCl and IrO2 array were developed in this work to in situ follow the distribution of chloride concentration and local pH in the occluded area during the crevice corrosion propagation.Based on a designed simulated crevice corrosion system in 0.5mol/L NaCl …

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A Study On Supercapacitor Based On Aligned Carbon Nanotubes, Xiao-Yan Ye, Yan-Zhi Wang, Hai-Yan Song, Zhuo Sun, Pin-Gang He, Yu-Zhi Fang Feb 2008

A Study On Supercapacitor Based On Aligned Carbon Nanotubes, Xiao-Yan Ye, Yan-Zhi Wang, Hai-Yan Song, Zhuo Sun, Pin-Gang He, Yu-Zhi Fang

Journal of Electrochemistry

Large scale vertically aligned carbon nanotubes(ACNTs) with uniform length and diameter were prepared by the pyrolysis of iron(Ⅱ) phthalocyanine at low pressure.The ACNTs were activated by electrolyte-activation,acid-activation or electrochemical activation.The performance of the capacitor based on activated ACNTs was characterized by cyclic voltammograms which was of rectangular shape,impedence spectroscopy in which the phase is above 80° and the result specific capacitance was 16～32 F/g,which suggest that the ACNTs are the promising material for the supercapacitor.

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Preparation And Electrochemical Performance Of Ordered Mesoporous Titanium Phosphate As Cathode Material For Li-Ion Battery, Qiong Wang, Attia Adel, Zhi-Cong Shi, Yong Yang Feb 2008

Preparation And Electrochemical Performance Of Ordered Mesoporous Titanium Phosphate As Cathode Material For Li-Ion Battery, Qiong Wang, Attia Adel, Zhi-Cong Shi, Yong Yang

Journal of Electrochemistry

Ordered porous titanium phosphate materials were prepared by using the surfactant template combined with the sol-gel method. The samples were characterized by small angle X-ray diffraction(SA-XRD) method, N2 adsorption/desorption techniques,high resolution transmission electron microscopy(HRTEM) and element analysis. It is found that the calcination temperature is a big influence on the porous structure, and electrochemical performance of the titanium phosphate materials, and the mesoporous titanium phosphate showed good performance in the electrochemical test, the first discharge capacity is 94 mAh/g at the current density of 150 mA/g. On the other hand, the no porous material with a low capacity of …

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Synthesis Of Adipic Acid From Cyclohexanol By Electrochemical Oxidation Using Cr2O72-/Cr3+ As Indirect Oxidant, Zhen-Hai Liang, Yu-Qing Cui, Hong-Yan Sun Feb 2008

Synthesis Of Adipic Acid From Cyclohexanol By Electrochemical Oxidation Using Cr2O72-/Cr3+ As Indirect Oxidant, Zhen-Hai Liang, Yu-Qing Cui, Hong-Yan Sun

Journal of Electrochemistry

Adipic acid was synthesized by electro-oxidation of cyclohexanol taking Cr2O72-/Cr3+ as indirect oxidant.The best technological conditions were optimized by orthogonal experiment.The optimum condition are as follows: the temperature is 35 ℃,ratio of crude material is n(cyclohexanol)∶n(Cr2O72-)=0.4∶1 and concentration of H2SO4 is 4 mol·L-1.Under these conditions,the yield of adipic acid can reach 70.29%.Moreover,The effects of concentration of Ag2SO4,(NH4)2SO4,H2SO4and current density on the formation of Cr2O72-were also …

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Study Of Black Electromagnetic Shielding Fabric, Shao-Wen Lu, Wei Wang, Bin Sun Feb 2008

Study Of Black Electromagnetic Shielding Fabric, Shao-Wen Lu, Wei Wang, Bin Sun

Journal of Electrochemistry

A soft electromagnetic shielding fabric was successfully prepared by electroplating black nickel on the Cu-plated PET fabric,preliminary thechnigue conditions were carried out as NiSO4·6H2O 40 g·L-1,H3BO3 30 g·L-1,NiSO4·(NH4)SO4·6H2O 40 g·L-1,ZnSO4·7H2O 50 g·L-1,NH4CNS 20 g·L-1,pH=4,t=30 ℃.The expericments showed that the soft electromagnetic shielding fabric had good conductive and electromagnetic shielding effectiveness,great abrasion resistance and erosion resistance performance and excellent absorbency performance,all of these promote the fabric decoration,protection and absorbency property.

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Mechanism Of The Cathode Reduction Of Ti(Ⅳ) In Molten Na3Alf6-Alf3, Hai-Bin Sun, Xiu-Rong Zuo, Zhi-Guo Zhong, Xue-Hui Hu Feb 2008

Mechanism Of The Cathode Reduction Of Ti(Ⅳ) In Molten Na3Alf6-Alf3, Hai-Bin Sun, Xiu-Rong Zuo, Zhi-Guo Zhong, Xue-Hui Hu

Journal of Electrochemistry

The mechanism of TiO2 electrode process has been investigated by cyclic voltammetry and chronopotentiometry on the tungsten filament in molten Na3AlF6-AlF3 salts at 990 ℃.The experimental results showed that electrochemical reduction of Ti(Ⅳ) precede were two steps,firstly Ti(Ⅳ) was reduced to Ti(Ⅱ),then Ti(Ⅱ) was reduced to Ti,namely: Ti(Ⅳ)→Ti(Ⅱ)→Ti.

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