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Articles 14611 - 14640 of 16695

Full-Text Articles in Engineering

Mössbauer Effect Determination Of Relative Recoilless Fractions For Iron Oxides, Sei J. Oh, Desmond C. Cook Jan 1999

Mössbauer Effect Determination Of Relative Recoilless Fractions For Iron Oxides, Sei J. Oh, Desmond C. Cook

Physics Faculty Publications

The relative recoilless fraction (F-value) of each of six iron oxides, defined as the ratio of the recoil-free fractions of two different materials, was experimentally determined relative to hematite at 300 K and 77 K by Mössbauer spectroscopy. Using the relative recoil-free fractions compared to that of hematite, the relative recoilless fractions between all pairs of the seven iron oxides were determined. The F-values can allow conversion of Mössbauer subspectral areas to the relative atomic, molecular, or weight fractions of each iron oxide present in a mixed oxide phase sample.

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An Analysis Of Texture Resulting From Thermomechanical Processing Of Ti-6al-V, David J. Brock Dec 1998

An Analysis Of Texture Resulting From Thermomechanical Processing Of Ti-6al-V, David J. Brock

Masters Theses

An investigation of texture and microstructure formation in Ti-6Al-4V after thermomechanical processing and heat treating was performed. X-ray diffraction was used to measure prismatic and pyramidal pole figures. These pole figures were used to calculate basal pole figures, which showed significant changes in texture from heavy rolling and near or above β-transus heat treatments. Primary texture components were found to be strengthened by near β-transus heat treatments. For heavily rolled material, above β-transus heat treatments were found to reverse the primary texture components order of dominants. Heavy rolling was found to reduce the RD component and strengthen the TD.

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The Effect Of Suspended Particles On The Corrosion Resistance Of Electrodeposited Zinc Powders, Qing-Wen Li, Qing Yang, Xi Xia Nov 1998

The Effect Of Suspended Particles On The Corrosion Resistance Of Electrodeposited Zinc Powders, Qing-Wen Li, Qing Yang, Xi Xia

Journal of Electrochemistry

Zinc powders were electrodeposited from ZnCl2 baths with containing suspension of unsoluble particles such as graphite, PbO2, SnO2, TiO2, SiO2 etc.. The structure, morphology and corrosion behavior of zinc powder were analyzed. SEM results showed that the dendritic growth of zinc can be inhibited by applying the suspension method. Suspension of PbO2, SnO2, TiO2, SiO2 and In2O3 could greatly improve the corrosion protection of zinc powder in 5 mol/L KOH. In addition, fractal theory is employed to further explain the results

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Oxygen Evolution Behavour On Ni Electrode In Koh Solution, Xiao-Yan Cao, Hua-Tang Yuan, Zuo-Xiang Zhou, Yun-Shi Zhang Nov 1998

Oxygen Evolution Behavour On Ni Electrode In Koh Solution, Xiao-Yan Cao, Hua-Tang Yuan, Zuo-Xiang Zhou, Yun-Shi Zhang

Journal of Electrochemistry

The steady-state polarization curves of oxygen evolution were measured at temperatures between 22～70 ℃ on Ni electrode in 30 wt.% KOH solution by galvanostat methode. The exchange current densities, Tafel slopes and transfer coefficients were studied. It was found that 40 ℃ is a special temperature, near which the kinetic parameters change abrupdy. The Tafel slopes for oxygen evolution reactions at higher overpotentials change from more than 120 mV to about 70 mV when the temperature raises to 40～70 ℃ from 22～35 ℃. Simultaneously, the heat of activation is changes from 79.88 kJ/mol to 55.32 kJ/mol. Moreover, the -(η/Τ) i …

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Study On Ni-Co-S-Mo Alloys New Cathode Material For Aquous Electrolysis, Yuan-Shou Xie, Quan-Feng Liu Nov 1998

Study On Ni-Co-S-Mo Alloys New Cathode Material For Aquous Electrolysis, Yuan-Shou Xie, Quan-Feng Liu

Journal of Electrochemistry

The parameters of electrodeposion of Ni-Co-S-Mo alloy were studied. The experimental results indicate that the electrodeposition alloy shows high catalytic activity for hydrogen evolution reaction, as well as better mechanical strength and higher chemical stability. The mechanism of catalytic hydrogen evolution reaction on this type of alloy electrode was also investigated by means of polarization curve and cyclic voltametry.

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The Latest World Wide Progress In Solid Oxide Fuel Cell, Yi Jiang Nov 1998

The Latest World Wide Progress In Solid Oxide Fuel Cell, Yi Jiang

Journal of Electrochemistry

Solid oxide fuel cell (SOFC) is a novel, green electricity generation technology, which has been showing rapid development since 1980's. In light of its high efficiency, environmental friendly, fuel adaptability and long term stability, the Research, Development and Demonstration (RD&D) of this hype of full cell have been emphasized in a large number of developed countries. Based on the information communicated at the latest symposium on SOFC held last year in Aachen (Germany) and the knowledge gained through years of research in this field, a comprehensive review on the latest development of the tubular, this planar SOFC as well as …

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A Preliminary Study Of The Synthesis Of Tin-Based Amorphous Material And Its Behavior On Lithium Intercalation, Li Liu, Han-Xi Yang, Ju-Tang Sun, Xing-Ping Ai Nov 1998

A Preliminary Study Of The Synthesis Of Tin-Based Amorphous Material And Its Behavior On Lithium Intercalation, Li Liu, Han-Xi Yang, Ju-Tang Sun, Xing-Ping Ai

Journal of Electrochemistry

An amorphous lithium inserting anode material based on Tin oxide glass was synthesized by salification in solution and its properties on lithium intercalation was investigated by X ray diffraction (XRD), microelectrode voltammetry and charge discharge measurements. The results have shown that this kind of material has considerable electrochemical reversibility toward lithium intercalation deintercalation. The available discharge capacity of the material reaches 430 mAh/g with charge-discharge efficiency over 90%, showing a great potential for practical use.

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Studies Of Spinal Li(1+X)Mn(2-X)O4 Rechargeable Lithium Ion Battery, Xiao-Mei Wu, Qing-He Yang, Zhong-Kao Jin, Hao-Qing Wu, Xiang-Fu Zong Nov 1998

Studies Of Spinal Li(1+X)Mn(2-X)O4 Rechargeable Lithium Ion Battery, Xiao-Mei Wu, Qing-He Yang, Zhong-Kao Jin, Hao-Qing Wu, Xiang-Fu Zong

Journal of Electrochemistry

The spinel Li intercalation compound Li1+xMn2-xO4 (0< x <1) was prepared by using techniques of cyclic voltammetry. The electrochemical parameters of Li1+xMn2-xO4 electrode vary as either the starting materials or the synthesis temperature changes. It was found that the initial capacity and reversible behaviors of the Li1+xMn2-xO4 electrode depends on the amount of the excess Li, represented as x in Li1+xMn2-xO4. The reversible of Li intercalation process for Li1+xMn2-xO4 electrode was demonstrate by cyclic voltammograms.

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Corrosion Characteristics Of Electrodeposited Ni-Mo-P Alloy Immersed In Nacl Solution, Yue Zeng, Hong-Xin Huang, Xiao-Ming Xiao, Shi-Xun Lian, Su-Wei Yao, He-Tong Guo Nov 1998

Corrosion Characteristics Of Electrodeposited Ni-Mo-P Alloy Immersed In Nacl Solution, Yue Zeng, Hong-Xin Huang, Xiao-Ming Xiao, Shi-Xun Lian, Su-Wei Yao, He-Tong Guo

Journal of Electrochemistry

The corrosion characteristics of electrodeposited Ni-Mo-P alloy immersed in 5wt.% NaCl solution were investigated using immersion, anodic polarization curves, XPS and AES analysis. The corrosion rates of amorphous Ni Mo P alloys are lower than that of crystalline Ni-Mo-P alloys. Anodic polarization curve experiments show that for the electrodeposited Ni-Mo-P alloys, the nickel mol fraction of which has in between 0.719 and 0.868, the corrosion potential moves to positive with the increase of P content, and the peak current value of active region increase with the increase of Mo content in alloys, though the effects of P content on the …

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Direct Electro-Oxidation Synthesis Of D-Arabinose On Spectroscopic Graphite Electrode, Hei Wei, Huang Ying Nov 1998

Direct Electro-Oxidation Synthesis Of D-Arabinose On Spectroscopic Graphite Electrode, Hei Wei, Huang Ying

Journal of Electrochemistry

D Arabinose synthesized by direct electro-oxidative decarboxylation of D gluconate on graphite electrode from aqueous solutions. The effects of D gluconate concentration, electrolysis potential, temperature and electrolyte composition on the current efficiency and product yield of electrosynthsis are discussed. The laboratory scale electrosynthesis was achieved with flow through cell. The optimum technology conditions for electrosynthesis were obtained with orthogonal design method. Both galvanostatic and potentionstatic conditions have been exploited, the later was found to be more effective.

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Study On Electrosynthesis Of Butyl Butyrate At Conducting Oxide Anode Support On Titanium, Jun-Xiang He, Jin-Cheng Zhou, Kang-Ning Chen Nov 1998

Study On Electrosynthesis Of Butyl Butyrate At Conducting Oxide Anode Support On Titanium, Jun-Xiang He, Jin-Cheng Zhou, Kang-Ning Chen

Journal of Electrochemistry

Synthesis of butyl butyrate by direct electroxidation of n butyl alcohol and the electrochemical behaviors of several selected conducting oxide electrodes (Pb/PbO2, Ti/PbO2, i/SnO2+Sb2O3/PbO2 and Ti/SnO2+Sb2O3+PdOx/PbO2) have been investigated. The results demonstrated that the intermediate layers of SnO2, Sb2O3 and PdOx could significantly decrease the interfacial resistance of the electrodes, and that the Ti/SnO2+Sb2O3+PdOx/PbO2 electrode possessed better electrocatelytic performance than others.

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The Study On The Performance Of Mcfc Matrix Prepared By Flow Cast, Hua-Xin Lin, Bao-Lian Yi, Nai-Chao Li, Tian-Xi Qu, En-Jun Zhang, Lian-Yin Kong, Ying-Cai Chen Nov 1998

The Study On The Performance Of Mcfc Matrix Prepared By Flow Cast, Hua-Xin Lin, Bao-Lian Yi, Nai-Chao Li, Tian-Xi Qu, En-Jun Zhang, Lian-Yin Kong, Ying-Cai Chen

Journal of Electrochemistry

The matrix for MCFC were prepared by flow cast technique which gives reproducible and reliable results. Its mean pore radius is about 0.18 μm, and the porosity is about 65%. The performance of MCFC stacked with this type of matrix is 0.854 V at 200 mA/cm2.

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Primary Research Of Reversible Proton Exchange Membrane Regenerative Fuel Cells, Zhi-Gang Shao, Bao-Lian Yi, Ming Han Nov 1998

Primary Research Of Reversible Proton Exchange Membrane Regenerative Fuel Cells, Zhi-Gang Shao, Bao-Lian Yi, Ming Han

Journal of Electrochemistry

In this paper, we report the results of our studies on regenerative proton exchange membrane fuel cell (RPEMRFC) catalysts, electrode preparation and their performances. The Pt catalyst for the oxygen electrode was replaced by 60 w%Pt + 40 w%IrO2 which reduces polarization by 0.2 V in a polymer protone exchange membrane fuel cell. The cycle performance of RPEMRFC was found to be manly effected by the stability of the diffiusion layer of bifunctional oxygen electrode.

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The Study Of Poly [N-(3-Ferrocene Acetamino Propyl- Pyrrole] Film Modified Glucose Electrode, Cheng-Yun Tian, Jing Chen, Li Zhang Nov 1998

The Study Of Poly [N-(3-Ferrocene Acetamino Propyl- Pyrrole] Film Modified Glucose Electrode, Cheng-Yun Tian, Jing Chen, Li Zhang

Journal of Electrochemistry

A poly [N-(3-ferrocene-acetamino-propyl-pyrrole)] film modified electrode was fabricated and studied by cyclic voltammetric method. The result shows that the modified electrode can give stable redox peaks of ferrocene, and an obvious catalytic peak due to glucose. This modified electrode was used to tabricate a glucose sensor which operates at +0.2 V, so that the ascorbic acid or uric acid doesn't affect the accuracy detection of glucose concentration. The sensor has a linear range of 0.1～10 mmol/L glucose, which the period of long term stability and response time of the sensor are about ten days and 2 min.

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Vacancy Clustering In Quenched Al-Li Solid Solution Alloys Studied By Doppler Broadening Spectroscopy, Hollis P. Leighly, P. G. Coleman Nov 1998

Vacancy Clustering In Quenched Al-Li Solid Solution Alloys Studied By Doppler Broadening Spectroscopy, Hollis P. Leighly, P. G. Coleman

Materials Science and Engineering Faculty Research & Creative Works

The clustering of vacancies in severely quenched Al-Li solid solution alloys, with Li content between 230 and 2760 ppm, has been studied using Doppler broadening spectroscopy. The alloy samples were initially annealed at 873 K in dry air or dry, pure nitrogen. The onset temperature for vacancy clustering in samples initially annealed in air was found to be 150 ± 10 K, 40 ± 15 K lower than for the nitrogen-annealed samples. This result is consistent with the migration of divacancies, formed as a result of the significant increase in vacancy concentration caused by Li migration to, and oxidation at, …

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Specific Heat And Transport “Anomalies” In Mixed Alkali Glasses, Peter F. Green, Richard K. Brow, James J. Hudgens Nov 1998

Specific Heat And Transport “Anomalies” In Mixed Alkali Glasses, Peter F. Green, Richard K. Brow, James J. Hudgens

Materials Science and Engineering Faculty Research & Creative Works

We show that changes in the relative mole fractions of Li2O and Na2O in alkali metaphosphate glasses lead to “anomalies” in the specific heat and structural relaxations. The heat capacity change between the liquid and glassy states, Δcp(Tg), at the calorimetric glass transition temperature, Tg, exhibits a minimum when the mole fractions of Li2O and Na2O are comparable. Moreover, systematic changes in the temperature dependence of the viscosity, η, i.e., changes in the “fragility” of the system, accompany these changes in mole fraction. This observed dependence …

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Microstructures And Mechanical Properties Of Two-Phase Alloys Based On Nbcr2, Katherine C. Chen, Paul G . Kotula, Carl M. Cady, Michael E. Mauro, Dan J. Thoma Oct 1998

Microstructures And Mechanical Properties Of Two-Phase Alloys Based On Nbcr2, Katherine C. Chen, Paul G . Kotula, Carl M. Cady, Michael E. Mauro, Dan J. Thoma

Materials Engineering

A two-phase, NbCrTi alloy (bcc + C15 Laves phase) has been developed using several alloy design methodologies. In efforts to understand processing-microstructure-property relationships, different processing routes were employed. The resulting microstructures and mechanical properties are discussed and compared. Plasma arc melted (PAM) samples served to establish baseline, as-cast properties. In addition, a novel processing technique, involving decomposition of a supersaturated and metastable precursor phase during hot isostatic pressing (HIP), was used to produce a refined, equilibrium two-phase microstructure. Quasi-static compression tests as a function of temperature were performed on both alloy types. Different deformation mechanisms were encountered based upon temperature …

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Neuron Scattering Studies Of The Magnetic Fluctuations In Yba2cu3o7−Δ, Herbert A. Mook, Pengcheng Dai, Rodney Dale Hunt, Fatih Dogan Oct 1998

Neuron Scattering Studies Of The Magnetic Fluctuations In Yba2cu3o7−Δ, Herbert A. Mook, Pengcheng Dai, Rodney Dale Hunt, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Neutron scattering measurements were made on the spin fluctuations in YBa2Cu3O7−δ for different oxygen doping levels. Incommensurability is clearly observed for oxygen concentrations of 6.6 and 6.7 and is suggested for the 6.93. Measurements of the resonance for the O6.6 concentration show that it exists in a broadened and less intense form at temperatures much higher than Tc.

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Synthesis And Characterization Of Silicon Dioxide Films Using Diethyl Silane And Oxygen, Kiran Kumar Aug 1998

Synthesis And Characterization Of Silicon Dioxide Films Using Diethyl Silane And Oxygen, Kiran Kumar

Theses

This study focuses on producing thin and thick silicon dioxide films towards the fabrication of integrated optical sensor capable of monitoring and determining in-situ, the concentration of numerous analyze species simultaneously. In this study, diethylsilane (DES) has been used as a precursor to produce silicon dioxide films by low pressure chemical vapor deposition. The films were synthesized with two different flow ratios of oxygen to DES in the temperature range of 550°C to 800°C at a constant pressure of 200mTorr. The films deposited with lower oxygen to DES flow ratio have very high growth rate but suffer from high tensile …

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Direct Electrochemical Reaction Of Cytochrome C At The Poly (Ethylene Oxide) Film Modified Gold Electrodes, Xiao-Gang Qu, Gong-Quan Sun, Hui Yang, Tian-Hong Lu Aug 1998

Direct Electrochemical Reaction Of Cytochrome C At The Poly (Ethylene Oxide) Film Modified Gold Electrodes, Xiao-Gang Qu, Gong-Quan Sun, Hui Yang, Tian-Hong Lu

Journal of Electrochemistry

In this paper, the direct electrochemical reaction of cytochrome c was sudied at the poly (ethylene oxide) film modified gold electrodes. It was found the PEO is a good promoter for the electrochemical reaction of cytochrome c, and the reversibility of reaction of cytochrome c was found to depend on the molecular weight of PEO and the morphology of the PEO films.

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Ac Impedance Study Of The La0.8Sr0.2Mno3/Ysz Electrode, Shi-Zhong Wang, Yi Jiang, Ya-Hong Zhang, Jing-Wang Yan, Wen-Zhao Li Aug 1998

Ac Impedance Study Of The La0.8Sr0.2Mno3/Ysz Electrode, Shi-Zhong Wang, Yi Jiang, Ya-Hong Zhang, Jing-Wang Yan, Wen-Zhao Li

Journal of Electrochemistry

Electrochemical reaction of oxygen on the La0.8Sr0.2MnO3/YSZ electrode has been investigated in detail with AC impedance. The results demonstrated that the rate determining step(rds) of the reaction varies with the temperature, oxygen partial pressure and overpotential applied. At open circuit potential, the rds is the dissociative adsorption of oxygen on the LSM surface. A large number of electron holes are generated at high anodic overpotentials, while oxygen vacancies are formed at high cathodic overpotentials. The formation of the electron holes results in the electronic conduction of the YSZ electrolyte and the extension of the …

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The Hydrogen Evolution Reaction On The Hydrogen Storage Alloy Electrode, Shi-Gang Lu, Qun Li, Qing-Guo Liu, Chun Lu, Bing Dang, Han-Xi Yang Aug 1998

The Hydrogen Evolution Reaction On The Hydrogen Storage Alloy Electrode, Shi-Gang Lu, Qun Li, Qing-Guo Liu, Chun Lu, Bing Dang, Han-Xi Yang

Journal of Electrochemistry

The hydrogen evolution reaction was studied in 1 mol/L KOH solution on the hydrogen storage alloy Mm(NiCoMnAl)5 electrode using open circuit potential decay and ac impedance technique. The reaction was found to proceed by the Volmer(discharge)-Tafel(recombination)mechanism. The measured overpotential η can be subdivided into two components η 1 and η 2 corresponding to the elementary Volmer and Tafel reaction. The Faradaic impedance was analyzed and characterized by the Volmer reaction. Then the exchange current density was evaluated . It was founded that the activity of hydrogen storage alloy electrode for the hydrogen evolution reaction was similar to that of …

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Modification Of Carbon Anode Materials Of Lithium-Ion Secondary Battery, Yuping Wu, Chun-Rong Wan, Chang-Yin Jiang, Jiang-Iun Li Aug 1998

Modification Of Carbon Anode Materials Of Lithium-Ion Secondary Battery, Yuping Wu, Chun-Rong Wan, Chang-Yin Jiang, Jiang-Iun Li

Journal of Electrochemistry

In this paper, the latest research work on modification of carbon anode materials of lithium ion secondary battery is reviewed. Modification methods include: incorporation of nonmetal elements such as boron, silicon, nitrogen, phosphorus and sulfur, metal elements such as potassium, aluminum, gallium and transitional metal elements such as vanadium, nickel, cobalt, copper and iron and surface treatment such as oxidation and formation of surface layer. Since these methods can affect the carbon materials' electronics state, crystal structure and surface structure, the electrochemical properties of the carbon materials could probably be improved. Besides, mechanisms for lithium storage in carbonaceous materials are …

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Formation And Effect Of Tribo Cell For Fe Cr Alloy, Dong-Bai Sun, Tao Li, Hong-Ying Yu, De-Ji Yang Aug 1998

Formation And Effect Of Tribo Cell For Fe Cr Alloy, Dong-Bai Sun, Tao Li, Hong-Ying Yu, De-Ji Yang

Journal of Electrochemistry

The micro galvanic corrosion of 1Cr18 alloy and its effects on the triboelectrochemical behavior were investigated and analyzed in this article. It is shown that the micro galvanic corroson is due to the electrochemical inhomogenity on the surface of the alloy during the friction process. Like galvanic corrosion,the micro galvanic corrosion behaviors are greatly affected by the area ratio of unrubbed to rubbed surface.The load effects on electrochemical behavior of 1Cr18 alloy are also attributed to existence of electrochemical inhomogenity on the surface of materal.

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Lithiun Insertion In Carbon Nanotubes, Guo-Tao Wu, Chun-Sheng Wang, Zhong-Fu Qi, Wenz-Hu Li Aug 1998

Lithiun Insertion In Carbon Nanotubes, Guo-Tao Wu, Chun-Sheng Wang, Zhong-Fu Qi, Wenz-Hu Li

Journal of Electrochemistry

Carbon nanotubes were produced by chemical vapour deposition(CVD) of acetylene under hydrogen gas.The reversible specific capacity of carbon nanotubes is up to 700 mAh/g, much higher than the theoretical specific capacity of graphite(372 mAh/g).After twenty charge/discharge cycles,the discharge capacity of carbon nanotube anode still maintains 65.3% of its original discharge capacity . Besides, the charge/discharge efficiency of carbon nanotube in the first charge/discharge cycle was found to improve from 42.6% up to 55.9% by coating carbon nanotubes with copper.

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External Transducing Measurement Of The Internal Pressure In Sealed Battery By Resistance Strain Gauge, Han-Xi Yang, Rong-Hui Hu, Xin-Ping Ai, Cong-Zhi Yang, Sheng-Xian Li Aug 1998

External Transducing Measurement Of The Internal Pressure In Sealed Battery By Resistance Strain Gauge, Han-Xi Yang, Rong-Hui Hu, Xin-Ping Ai, Cong-Zhi Yang, Sheng-Xian Li

Journal of Electrochemistry

A novel method to monitor dynamically the internal pressure of sealed battery with no damage of the battery by using of resistance strain measurement technique is presented. This technique employs the resistence strain gauges in touch of the battery case and to detect the minimal change in the battery deformation due to the increasing internal pressure, electrode expantion or intrenal temperature rise. Application of the technique for the study of the effects of the battery processing factors on the battery performance is described taking Ni MH battery as example.

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Photoelectrochemical Studies On Nanoporous Tio2/Pan Film Electrode, Min-Sheng Liu, Yan-Zhong Hao, Xue-Bin Qiao, Mai-Zhi Yang, Sheng-Min Cai Aug 1998

Photoelectrochemical Studies On Nanoporous Tio2/Pan Film Electrode, Min-Sheng Liu, Yan-Zhong Hao, Xue-Bin Qiao, Mai-Zhi Yang, Sheng-Min Cai

Journal of Electrochemistry

The photon to electricity conversion process of nanoporous TiO2/PAn film electrode was studied in electrolytes with and without redox couple by using the photocurrent action spectra and potential dependence of photocurrent. It is concluded that the nanoporous TiO2/PAn film electrode has a structure of duplex n type semiconductor layers. The band gap of PAn film is 2.88eV.The TiO2 nanoporous film electrode modified by PAn can extend the range of optical absorption into visible and infrared region and effectively increase the photocurrent in the visible and infrared region. The photocurrent threshold shifts to>600nm and conversion …

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Studies On The Electrode Kinetics Of Electrooxidation Of Mn2+, Wan-Li Hu, Tong Su, Wei Guo, Ding Zhou Aug 1998

Studies On The Electrode Kinetics Of Electrooxidation Of Mn2+, Wan-Li Hu, Tong Su, Wei Guo, Ding Zhou

Journal of Electrochemistry

The mechanism of electrooxidation of MnSO4 on Pb Sb As alloy anode was investigated by using rotating disc electrode technique. The results shown that the conditional standard potential of Mn(Ⅲ)/Mn(Ⅱ)in 40% H2SO4 is 0.886 4 V.The rate controlling step of electrode process is mixed controlled by charge transfer and diffusion.

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Electrochemical Behavior Of Chemically Prepared Ring-Substituted Polyanilines, Li-Zong Dai, Hui-Huang Wu Aug 1998

Electrochemical Behavior Of Chemically Prepared Ring-Substituted Polyanilines, Li-Zong Dai, Hui-Huang Wu

Journal of Electrochemistry

Polyaniline (PAn) has been known as a promising conducting polymer for technological applications. In research work elecrochemically synthesized PAn has been frequently used since electropolymerization is convenient to prepare the polymer film with controllable thickness or dopingon electrodes. However , the processibility of elecrosynthesized PAn is too poor to produce largearea devices because of its insolubility and infusibility. Recently, therefore, chemical polymerization has attracted a considerable attentionfl-3],  especially suitably derivatized ring substituted (e.g. alkyl or alkoxy) polyanilines have been synthesized, and their appreciable solubility in commonorganic solvents enable the preparation of film on industrial scale by casting. Moreover, emulsionpolymerization reduces …

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Studies On The Preparation Of Nanophase Electrode Materials And Its Electrochemical Properties(Ⅲ)—Performance Of Nm-Γ-Mno2 Obtained By Microemulsion Method, Ling Liu, Xi Xia Aug 1998

Studies On The Preparation Of Nanophase Electrode Materials And Its Electrochemical Properties(Ⅲ)—Performance Of Nm-Γ-Mno2 Obtained By Microemulsion Method, Ling Liu, Xi Xia

Journal of Electrochemistry

A nanophase MnO2 was synthesized using w/o microemulsion as reation media, The most favorable experiment conditions for the preparation of nm MnO2 were researched. XRD,TEM,AC impedance, cyclic voltammetry etc. examinations were used to characterize the sample comparison with the classical MnO2 (I.C.No.1EMD,electrolytic manganese dioxide). Sample shows that the crystal styucture of the synthesized samples are mainly γ-MnO2, with average particle size in the nanometer as shown by TEM. It was found that the discharge capacity of nm MnO2 obtained is significantly higher than that of the I.C.No.1 EMD.

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