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1.
Survila A. Mockus Z. Kanapeckaitė S. Jasulaitienė V. 《Russian Journal of Electrochemistry》2004,40(8):855-859
Voltammetry and x-ray photoelectron spectroscopy data show micromolar amounts of halides to noticeably affect co-deposition of copper and tin from acidic sulfate solutions containing polyether Laprol 2402C as the surface-active substance. The reduction of Cu(II) slows down and that of Sn(II) accelerates in the series Cl– < Br– < I–. Compounds on the surface of bronze coatings are oxides of Cu(I) and Sn(II) and halides of Cu(I). 相似文献
2.
A. Survila S. Kanapeckaité I. Valsiünas V. Yasulaitené 《Russian Journal of Electrochemistry》2010,46(10):1167-1174
Distribution of citrate complexes of Co(II) and Mo(VI) in weakly acidic solutions is analyzed. It is found that the primary
cathodic process is hydrogen evolution. When cathodic polarization is increased, Co(II) reduction is possible, while more
negative potentials may result in full reduction of Mo(VI) to the metallic state. Reduction of H3O+ ions in the solutions of oxyacids occurs with participation of a ligand playing the role of proton donor. Hydrogen evolution
also remains the main electrochemical process in the molybdate solutions. It is assumed that Mo(VI) reduction occurs with
participation of atomic hydrogen, but not all molybdate is reduced to metallic state. Co(II) reduction in solutions containing
Mg(II) occurs to a higher extent but the degree of Mo(VI) reduction depends on the Co(II) concentration: increase in the latter
results in a decrease in the content of metallic molybdenum in coatings. 相似文献
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Montgomery NA Hedley GJ Ruseckas A Denis JC Schumacher S Kanibolotsky AL Skabara PJ Galbraith I Turnbull GA Samuel ID 《Physical chemistry chemical physics : PCCP》2012,14(25):9176-9184
Star-shaped molecules are of growing interest as organic optoelectronic materials. Here a detailed study of their photophysics using fluorescence depolarisation is reported. Fluorescence depolarisation dynamics are studied in branched oligofluorene-truxene molecules with a truxene core and well-defined three-fold symmetry, and are compared with linear fluorene oligomers. An initial anisotropy value of 0.4 is observed which shows a two-exponential decay with time constants of 500 fs and 3-8 ps in addition to a long-lived component. The femtosecond component is attributed to exciton localisation on one branch of the molecule and its amplitude reduces when the excitation is tuned to the low energy tail of the absorption spectrum. The picosecond component shows a weak dependence on the excitation wavelength and is similar to the calculated rate of the resonant energy transfer of the localised exciton between the branches. These assignments are supported by density-functional theory calculations which show a disorder-induced splitting of the two degenerate excited states. Exciton localisation is much slower than previously reported in other branched molecules which suggests that efficient light-harvesting systems can be designed using oligofluorenes and truxenes as building blocks. 相似文献
5.
Voltammetry and electrochemical impedance spectroscopy were applied to investigate the inhibition activity of ethyleneglycol
and its oligomers on tin electrode in strong acidic sulfate solutions. Tetraethyleneglycol was found to be the most active
substance among compounds HO–(CH2–CH2–O)
m
–H (m≤4) that retards diffusion-controlled Sn(II) reduction due to its inhibitive adsorption. This rather slow process is controlled
both by diffusion and electrosorption steps. A comparison of exchange current densities obtained in the presence of different
polyethers shows that the length of the hydrocarbon chain is the main factor responsible for inhibition activity of such substances
on tin electrode. 相似文献
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Survila Arvydas Kanapeckaitė Stasė Staišiūnas Laurynas 《Journal of Solid State Electrochemistry》2023,27(7):1813-1820
Journal of Solid State Electrochemistry - The anodic behavior of the alkaline Cu | Cu(II), glycine system was investigated by RDE voltammetry combined with EQCM measurements. Well-defined current... 相似文献
8.
The paper presents nonlinear model which stands for effective digital simulation of electrochemical behavior of partially blocked electrodes under linear potential sweep and cyclic voltammetry conditions. The model is based on a system of diffusion equations, also involving the Nernst diffusion layer. The mass transport is assumed to be regular in the entire diffusion space. The influence of the thickness of the resist layer on the behavior of the partially blocked electrodes is investigated. The agreement between the theoretical results and experimental ones is obtained to be admirable for several model electrodes with different blocking degree. 相似文献
9.
Hedley GJ Ruseckas A Liu Z Lo SC Burn PL Samuel ID 《Journal of the American Chemical Society》2008,130(36):11842-11843
Ultrafast luminescence spectroscopy has been undertaken on three iridium cored phosphorescent complexes, with the Ir(ppy)3 molecule being compared with two Ir(ppy)3 cored dendrimers. Energy dissipation by intramolecular vibrational redistribution (IVR) and cooling shows as a luminescence decay because it decreases the admixture of singlet character to the emitting triplet state. A larger amount of vibrational energy dissipates by IVR in dendrimer complexes. We have therefore found a methodology of obtaining unambiguous information on the IVR process and show its potential to study IVR rates as a function of vibrational energy. 相似文献
10.
A femtosecond luminescence and transient absorption study of fac-tris(2-phenylpyridine) iridium(III) [Ir(ppy)3] is reported. An emission with a lifetime component of 230 fs in the spectral region 500–560 nm is assigned to the population equilibration between electronic substates of the lowest excited triplet state, with energy dissipation by intramolecular vibrational redistribution. At shorter wavelengths a strong emission with a faster decay was observed and is attributed to a state with a higher admixture of singlet character. A slower decay on a 3 ps time scale is attributed to vibrational cooling. The results contribute to an understanding of the photophysics of transition metal complexes. 相似文献