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Chemistry

Chinese Chemical Society | Xiamen University

1995

Articles 61 - 72 of 72

Full-Text Articles in Physical Sciences and Mathematics

Studies Of Elecctrochcmical Oscillation Of Au/Hcl In Presence Of ″Positive Feedback ″Of Substrate Electrodes, Bin Ren, Bingwei Mao, Xiongwei Cai, Tao Jiang, Jiqian Mu Feb 1995

Studies Of Elecctrochcmical Oscillation Of Au/Hcl In Presence Of ″Positive Feedback ″Of Substrate Electrodes, Bin Ren, Bingwei Mao, Xiongwei Cai, Tao Jiang, Jiqian Mu

Journal of Electrochemistry

No abstract provided.

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Transient Photocurrent Behavior Of Multiple Quantum Well Gaas/Al_Xga_(1-X)As Electrode, Liuyao Liuyao, Xurui Xiao, Liyuan Liyuan Feb 1995

Transient Photocurrent Behavior Of Multiple Quantum Well Gaas/Al_Xga_(1-X)As Electrode, Liuyao Liuyao, Xurui Xiao, Liyuan Liyuan

Journal of Electrochemistry

Transient photocurrents induced by short light pulses at lattice-matched multiplequantum well(MQW)GaAs/Al_(0.3)Ga_(0.7)As electredes were studied in the 1 ×10￣(-2)mol·dm￣(-3)ferrocene([Fc￣0]/[Fc)￣+]=9/1)-0.1 mol·dm￣(-3)tetrabutylammonium tetrafluoroborate acetonitrile solutionin order to examine the relaxation photoprocesses and to evaluate kinetic parameters of superlattice electrodes. GaAs/Al_(0.3)Ca_(0. 7)As MQW electrode consisting of 10 periods with each of GaAs well(5.3nm)and Al_(0. 3)Ga_(0. 7)As barrier(10nm)showed two pronounced and well-resolved peak structures located at 1.503 eV and 1.699 eV in the photocurrent spectrum,corresponding to the theoretical allowedexcitonic transitions(Δn=0) for heavy holes(H11,H22)in the quantum well respectively. Transient photocurrent spectra were measured by a monochromatic light pulse with 7 μs pulsewidth and 9 nJ·cm￣(-2) of …

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A Photoelectrochemical Investigation Of Zirconium Oxide Film, Maizhi Yang Feb 1995

A Photoelectrochemical Investigation Of Zirconium Oxide Film, Maizhi Yang

Journal of Electrochemistry

A photoelectrochemical investigation has been carried out on zirconium initialoxide film and its oxide film grownanodically at constant rate up to different thickness. Both anodicand cathedic photocurrents on the photocurrent spectrum depended on the potential,but had littlerelation with the forming anedic films or measuring solutions. Photocurrent spectrum and photocurrenttransients suggested that the oxide films on zirconium were duplex layers structure. The internal layerwas ZrO_2 and the external layer ZrO_2·(H_2O)_n. The photocurrent included photogenerated carrier ininternal and external oxide films,as well as internal photoinjection process for electrons from thesubstrate metal into the electrode/electolyte interface reacting with the redox couple. The analysis …

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Electroreduction Of Holmium Ion On Iron Electrde In Molten Cholorides, Qiqin Yang, Guankun Liu, Yuzhi Su Feb 1995

Electroreduction Of Holmium Ion On Iron Electrde In Molten Cholorides, Qiqin Yang, Guankun Liu, Yuzhi Su

Journal of Electrochemistry

The cyclic voltammetry,open circuit potential-time curve after poteritiostaticelectrolysis,current-time curve at potential step,x-ray diffraction and electron probe microanalysiswere used to investigate the electrode process of Ho(Ⅲ)reduced on iron electrode in molten chloridesand the phases of surface alloy layer.The Ho-Fe alloys are formed at first,and then the metallicholmium is deposited when Ho(Ⅲ)is reduced on iron electrede. The charge transfer is reversible. Thefree energies of formation for the four intermetallic compounds of Ho-Fe system,the diffusioncoefficients and diffusion activation energy of Ho in alloyed cathode are determined.

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Study Of Electrochemical Properties Of Ni(Oh)_2 /Niooh With Spectroscopic Ellipsometry, Shengtao Zhang, Zongqing Huang Feb 1995

Study Of Electrochemical Properties Of Ni(Oh)_2 /Niooh With Spectroscopic Ellipsometry, Shengtao Zhang, Zongqing Huang

Journal of Electrochemistry

Electrochemical reactions of Ni(OH)_2 /NiOOH system were studied by using in-situ spectroscopic ellipsometry and the conventional electrochemical metheds.By fitting data fromellipsometric measurements,a transformation medel of the surface film was obtained for cathedic andanodic processes. The results indicated that the transformation medel after cobalt implantation almostremained the same as that before cobalt implantation,but the electrochemical properties wereaffectedobviously by implantation of cobalt.

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Electrocatalytic Oxidation Of Formaidehyde And Formic Acid On A Pt/Sb_(Ad) Electrode, Hong Li, Lincai Jiang, Xiong Jiang Feb 1995

Electrocatalytic Oxidation Of Formaidehyde And Formic Acid On A Pt/Sb_(Ad) Electrode, Hong Li, Lincai Jiang, Xiong Jiang

Journal of Electrochemistry

The electrocatalytic activity for the oxidation of formaldehyde and formic acid ona Sb-modified platinum (Pt/Sb_(ad))was investigated.Results showed that the Pt/Sb_(ad) electrode waselectrocatalytically more active than a Pt electrode in the anodic oxidation of formaldehyde and formicacid.In the case of formaldehyde,an oxidation peak appeared at a potential of ca.0.7V.During theoxidation of formic acid,a 4-fold increase in the 1st peak current was observed.The Sb-modifiedplatinum electrode was found to be most electrocatalytically active at a coverage of 0.75±0.05.Theelectrocatalytic activity of the Pt/Sb_(ad) electrode can be best explained in terms of the geometrical effect,which may lead to the inhibition of the formation of the …

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Synthesis Of Li_Xcoo_2 And Its Behaviour In Rechargeable Lithium Battery, Mingfeng Guo, Ruimin Yang, Zebo Zhang, Jincao Ye Feb 1995

Synthesis Of Li_Xcoo_2 And Its Behaviour In Rechargeable Lithium Battery, Mingfeng Guo, Ruimin Yang, Zebo Zhang, Jincao Ye

Journal of Electrochemistry

The Variations of crystal lattice parameters of Li_xCoO_2 during charge anddischarge have been st ud ied by XRD and AAR spectroscopy.It was found that the Li_xCoO_2 crystalvolume expanded during charge and contracted during discharge.The crystal lattice structure wasbroken because of the formation of Co_3O_4 when deeply charge.The variation of lattice parameter C_0value in cycling process was similar to that in charge process.The variation of 006 peak was the mostsensitive in every case.In case of preheating for 20 hours at 700℃ before operating hightemperature,the 006 peak obtained an enhancement obviously.It has had the good rechargeability inmeasurement of the cyclic voltammograms,the CV …

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Application Of Inhibitor To Improve The Anticorrosion Performance Of Electrophoretic Coating, Changshou Cai, Fangteng Su, Bihuan Liu, Guomou Wen, Jingdong Guo Feb 1995

Application Of Inhibitor To Improve The Anticorrosion Performance Of Electrophoretic Coating, Changshou Cai, Fangteng Su, Bihuan Liu, Guomou Wen, Jingdong Guo

Journal of Electrochemistry

To improve the anti-corrosion performance of electrocoating,organic andinorganic inhibitors are applied in an anodic electrophoretic-coating.The results show that thedeposition of polymer with zinc phospate exhibits a high inbihition efficiency.The inhibitionmechanism of the inhibitor in electrocoating has been studied.

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The Device Of Wy-Ⅱ Type Cyanide Monitor And Its Applications, Xianmin Wang Feb 1995

The Device Of Wy-Ⅱ Type Cyanide Monitor And Its Applications, Xianmin Wang

Journal of Electrochemistry

A device of WY-Ⅱtype micro-computerized cyanide monitor is presented,inwhich the cyanide analvsis is carried out by means of microcoulomb-iodimetric with automaticfollowing system.This instrument can be successifully employed to analyze the cyanides in industrial waste-waterfor vavious departments of chemical industry.A serious of experimental tests showed that theanalytical sensitivity went up to 0.01 mg/L and the accuracy of determination was excellentlycoincided with that of National standard method and other methods.

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The Electrode Process Of Y(Ⅲ)On Copper Electrode And Its Surface Metallizing, Chungen Zhou, Shuzhen Duan Feb 1995

The Electrode Process Of Y(Ⅲ)On Copper Electrode And Its Surface Metallizing, Chungen Zhou, Shuzhen Duan

Journal of Electrochemistry

The reduction of yttrium ion on copper electrode in NaCl-KCl-YCl_3 molten saltshas been investigated.The results indicate that the formation of intermetallic compounds is occuredbefore the metallic yttrium to be formed.The formation of intermetallic compounds is controlled bythe process of which yttrium atoms are diffusing into copper electrode.The kinetic characters todiffusion of yttrium atoms were also discussed.

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The Catalytic Behavior For Ni-W Electrode Modified By Carbon Ion Beam Implantion, Jishuang Zhang, Yaojiao Lv, Qinglian Li Feb 1995

The Catalytic Behavior For Ni-W Electrode Modified By Carbon Ion Beam Implantion, Jishuang Zhang, Yaojiao Lv, Qinglian Li

Journal of Electrochemistry

The hydrogen evolution activity in acidic and basic mediums for Ni-W electrodemodified by carbon ion beam implantation was investigated.The experimental results show thiselectrode has superior catalytic activity for the hydrogen evolution reaction than that of the unmodifiedNi-electrode.Long period testing of electrolysis under high current density show that this electrode hasalonger useful life hence it is a practical electrode material.The temperature effect of electrocatalyticproperty was also inverstigated.The experimental regularities are explained on the basis of the formation of surface m uItialloys of Ni-W-WC.

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The Ehect Of Some Ions On Anodic Formation Process At Pt And Pbo_2 Electrodes, Shixiong Jin, Zhigang Zhou, Lan Wang Feb 1995

The Ehect Of Some Ions On Anodic Formation Process At Pt And Pbo_2 Electrodes, Shixiong Jin, Zhigang Zhou, Lan Wang

Journal of Electrochemistry

The influence of Ag_2SO_4,Li_2SO_4,Na_2SO_4,K_2SO_4,NH_4)_2SO_4,MgSO_4 and KF onthe evolution of O_2 and the formation of Cr_2O at Pt and PbO_2 anodes was investigated in mixedH_2SO_4-Cr_2(SO_2)_3 solutions.The kinetic data related respectively to Cr_2O formation and O_2 evolutionat Pt and PbO_2 anodes were measured by method of resolving the steady-state polarization curve.TheTafel slope of steady-state ～1g i relationships for Cr_2O formation reaction is close to 2×2. 303RT/βF,whereas for O_2 evolution it is close to 2.303 RT/βF(with β=0.5). The results indicate thatthe current efficiency for Cr_2O formation is increased by adding Ag￣+ ions to the anolyte and decreasedby adding Li￣+,Na￣+,K￣+,NH and Mg￣(2+) ions to …

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