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71.
Chen YF Banerjee IA Yu L Djalali R Matsui H 《Langmuir : the ACS journal of surfaces and colloids》2004,20(20):8409-8413
Ferrocene nanotubes were fabricated by binding carboxylic acid-derivatized ferrocenes onto template peptide nanotubes via hydrogen bonding. When these ferrocene-functionalized nanotubes were incubated with beta-cyclodextrin (beta-CD) self-assembled monolayers (SAMs) coated on patterned Au substrates in solution, the ferrocene nanotubes recognized and attached onto the beta-CD SAMs via host-guest molecular recognition. The ferrocene nanotubes were also observed to recognize the certain cavity size of CD. The attachment/detachment of nanotubes on the beta-CD SAMs was controlled electrochemically by tuning the redox states of ferrocene nanotubes. This electric field-responsive building block may be applied to build nanometer-sized switching components in electronics and sensors. 相似文献
72.
Ipsita Mandal 《The European Physical Journal B - Condensed Matter and Complex Systems》2016,89(12):278
We revisit the Ising-nematic quantum critical point with an m-dimensional Fermi surfaceby applying a dimensional regularization scheme, introduced in [I. Mandal, S.S. Lee, Phys.Rev. B 92, 035141 (2015)]. We compute the contribution from two-loop andthree-loop diagrams in the intermediate energy range controlled by a crossover scale. Wefind that for m =2, the corrections continue to be one-loop exact for both the infraredand intermediate energy regimes. 相似文献
73.
Gavrilo Šekularac Milica Košević Ivana Drvenica Aleksandar Dekanski Vladimir Panić Branislav Nikolić 《Journal of Solid State Electrochemistry》2016,20(11):3115-3123
Ruthenium oxide coating on titanium was prepared by the sol–gel procedure from well-defined colloidal oxide dispersions synthesized by the microwave (MW)-assisted hydrothermal route under defined temperature and pressure heating conditions. The dispersions were characterized by dynamic light scattering (DLS) measurements and scanning electron microscopy (SEM). The electrochemical properties were analyzed as capacitive performances gained by cyclic voltammetry and electrochemical impedance spectroscopy and as the electrocatalytic activity for oxygen evolution from acid solution. The obtained dispersions were polydisperse and contained regular particles and agglomerates of increasing surface energy and decreasing particle size as the MW-assisted heating conditions were intensified. Owing to these features of the precursor dispersions, the obtained coatings had considerably improved capacitive performances and good electrocatalytic activity for oxygen evolution at high overpotentials. 相似文献
74.
Ipsita Devi 《Tetrahedron letters》2005,46(34):5727-5729
Condensation of malonic acid 1 and ureas 2a-f proceeds smoothly in the presence of acetic anhydride 3 under microwave irradiation in solvent-free conditions to give 6-hydroxy-uracils 4 in excellent yields. Under identical conditions, the condensation of cyanoacetic acid 5 and ureas 2a,b,g and h in the presence of acetic anhydride 3, followed by cyclization in the presence of sodium hydroxide affords 6-amino-uracils 6 in high yields. The work-up procedures are simple and products need no purification. 相似文献
75.
76.
77.
V. Pani? J. Jovanovi? B. Adnadjevi? S. Velickovi? 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(9):1558-1562
Hydrogels based on crosslinked polymethacrylic acid were synthesized via free-radical polymerization in aqueous solution,
using N,N′-methylene bisacrylamide as a crosslinking agent and 2,2′-azobis-[2-(2-imidazolin-2-yl)propane] dihydrochloride
as an initiator. The influence of the reaction parameters (the neutralization degree of methacrylic acid and the initial monomer
concentration) on the equilibrium swelling degree, the swelling kinetic parameters and the basic structural properties of
xerogels was investigated. The change of synthesis parameters leads to the change of the basic structural parameters of xerogel,
as well as the equilibrium swelling degree and the initial swelling rate of the hydrogels. It is found that there are power
form relationships between the equilibrium swelling degree, the initial swelling rate and the structural xerogel’s properties
and the change of the neutralization degree of monomer, i.e. the monomer concentration. The examined correlations proved that
the crosslinking density is the crucial parameter which determines all the other investigated structural and swelling parameters.
The article is published in the original. 相似文献
78.
Sanja Stevanović Vladimir Panić Dušan Tripković Vladislava M. Jovanović 《Electrochemistry communications》2009,11(1):18-21
The contribution of carbon functional groups (CFG) to methanol oxidation at carbon-supported Pt catalysts is studied in this work. Platinum black, attached in a form of a thin layer to electrochemically treated glassy carbon (GC), is investigated as a model system. Impedance measurements reveal significant changes in capacitive response of GC anodically polarized in H2SO4 solution in comparison to unoxidized state. XPS analyses show the increased fraction of oxygen-containing CFGs upon electrochemical treatment of GC. The activity of Pt black attached to oxidized GC for methanol oxidation is more than two times larger in comparison to the catalyst attached to unoxidized GC. Increased activity is most likely due to the promotion of COads removal by increased content of CFGs. 相似文献
79.
Stevanović SI Panić VV Dekanski AB Tripković AV Jovanović VM 《Physical chemistry chemical physics : PCCP》2012,14(26):9475-9485
We report on new insights into the relationships between structure and activity of glassy carbon (GC), as a model material for electrocatalyst support, during its anodization in acid solution. Our investigation strongly confirms the role of CFGs in promotion of Pt activity by the "spill-over" effect related to CO(ads) for methanol electrooxidation (MEO) on a carbon-supported Pt catalyst. Combined analysis of voltammetric and impedance behaviour as well as changes in GC surface morphology induced by intensification of anodizing conditions reveal an intrinsic influence of the carbon functionalization and the structure of a graphene oxide (GO) layer on the electrical and electrocatalytic properties of activated GC. Although GO continuously grows during anodization, it structurally changes from being a graphite inter-layer within graphite ribbons toward a continuous GO surface layer that deteriorates the native structure of GC. As a consequence of the increased distance between GO-spaced graphite layers, the GC conductivity decreases until the case of profound GO exfoliation under drastic anodizing conditions. This exposes the native, yet abundantly functionalized, GC texture. While GC capacitance continuously increases with intensification of anodizing conditions, the surface nano-roughness and GO resistance reach the highest values at modest anodizing conditions, and then decrease upon drastic anodization due to the onset of GO exfoliation. We found for the first time that the activity of a GC-supported Pt catalyst in MEO, as one of the promising half-reactions in polymer electrolyte fuel cells, strictly follows the changes in GC nano-roughness and GO-induced GC resistance. The highest GC/Pt MEO activity is reached when optimal distance between graphite layers and optimal degree of GC functionalization bring the highest amount of CFGs into intimate contact with the Pt surface. This confirms the promoting role of CFGs in MEO catalysis. 相似文献
80.
S. Arul Veda Manickam Kannan K. Moudgalya Amiya K. Pani 《Journal of Applied Mathematics and Computing》2004,15(1-2):1-28
We first apply a first order splitting to a semilinear reaction-diffusion equation and then discretize the resulting system by anH 1-Galerkin mixed finite element method in space. This semidiscrete method yields a system of differential algebraic equations (DAEs) ofindex one. Apriori error estimates for semidiscrete scheme are derived for both differential as well as algebraic components. For fully discretization, an implicit Runge-Kutta (IRK) methods is applied to the temporal direction and the error estimates are discussed for both components. Finally, we conclude the paper with a numerical example. 相似文献