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171.
The kinetics of electron transfer reactions between acetophenones with Ce(IV) have been studied in aqueous acetic acid medium in the presence of cationic micelle Cetylpyridinium chloride (CPyCl) at different temperatures. Kinetic data reveal first-order dependence with respect to each of Ce(IV) and acetophenones. The cationic micelle, Cetylpyridinium chloride enhances the oxidation reactions. The catalysis fits to a model developed by Menger and Portnoy as well as Berezin's phase separation model. The binding and partition constants and the transfer free energy from water to micelle have been estimated and discussed, suggesting that the solubilization of both the reactants in the micellar phase, facilitates the oxidation. © 1993 John Wiley & Sons, Inc. 相似文献
172.
Lingaraj Sahu 《Proceedings Mathematical Sciences》2008,118(3):443-465
Using coordinate-free basic operators on toy Fock spaces, quantum random walks are defined following the ideas of Attal and
Pautrat. Extending the result for one dimensional noise, strong convergence of quantum random walks associated with bounded
structure maps to Evans-Hudson flow is proved under suitable assumptions. Starting from the bounded generator of a given uniformly
continuous quantum dynamical semigroup on a von Neumann algebra, we have constructed quantum random walks which converges
strongly and the strong limit gives an Evans-Hudson dilation for the semigroup. 相似文献
173.
We obtain a one-to-one tranformation of the family of multivalent symmetric close-to-convex functions of order β, onto the family of multivalent symmetric close-to-convex functions of order β with the Montel normalization. Using this transformation we determine the closed convex hull and extreme points of the latter class for β≥1. 相似文献
174.
We introduce a new class of uniformly R-subweakly commuting mappings and then using this class study the problem of approximation of common fixed points of asymptotically S-nonexpansive mappings in a Banach space with uniformly Gâteaux differentiable norm. 相似文献
175.
We calculate the baryon flow Px/A(y) in the energy range from 0.25 to 4.0A GeV in a relativistic transport model for Ni + Ni and Au + Au collisions employing various models for the baryon self-energies. We find that to describe the flow data of the FOPI Collaboration above 1A GeV the strength of the vector potential has to be reduced at high relative momentum or at high density. The latter phenomenon leads to a softening of the nuclear equation of state at high density. 相似文献
176.
L. Pearson J.S.P. Chan P. Wang J.K. Sahu W.A. Clarkson 《Applied physics. B, Lasers and optics》2007,87(1):75-78
We report on the periodic polarization of α-phase proton- exchanged LiNbO3 planar waveguides down to 5 μm period lengths using structured electrodes and electrical fields. Unlike a majority of previous
work, room-temperature electric field poling has been carried out after waveguide fabrication. Chemical etching of the large
guiding surface has revealed homogeneous and high-quality domains with duty cycles close to 0.5. Moreover, it was verified
by diffraction techniques and etching that the domain structure is preserved more than 2 μm along the thickness of the waveguide.
The excellent optical performances of single-domain α-phase waveguides were not affected by the periodic poling. 相似文献
177.
S. Verma J. J. Das A. Jhingan K. Kalita S. Barua K. S. Golda N. Madhavan P. Sugathan S. Nath T. Varughese J. Gehlot S. Mandal S. Ranjit P. K. Sahu B. John B. K. Nayak A. Saxena S. K. Datta R. Singh 《The European physical journal. Special topics》2007,150(1):75-78
Elastic scattering angular distributions have been measured for 7Be + 9Be system at Elab = 17, 19 and 21 MeV in the angular range θcm=26○–58°, and for 7Li + 9Be system at Elab= 15.75, 24 and 30 MeV.
An optical model (OM) analysis of these data have been carried out.
For the 7Li + 9Be system fusion cross sections were obtained at Elab = 15.75, 24 and 30 MeV by measuring the α-evaporation spectra from the compound nucleus at backward angles. The measured
α-evaporation spectra were reproduced by the statistical model calculations and fusion cross sections were extracted therefrom.
The ratios of the experimental fusion cross sections to the total reaction cross sections (obtained form OM analysis) were
found to be rather small. This result suggests that break-up process has a strong influence on fusion process leading to a
reduction in fusion cross section. 相似文献
178.
Philippov V Codemard C Jeong Y Alegria C Sahu JK Nilsson J Pearson GN 《Optics letters》2004,29(22):2590-2592
An Er:Yb codoped fiber amplifier chain for the generation of pulses for coherent lidar applications at a wavelength near 1.5 microm is reported. The final 1.8-m-long power amplification stage had a 50-microm core diameter and yielded a 23-dB energy gain, resulting in 0.29-mJ, 100-ns pulses at a repetition rate of 4 kHz with no Brillouin scattering and an M2 of 2.1. 相似文献
179.
180.
[reaction: see text] The first enantioselective total synthesis of valeriananoids A-C (-)-1-3 is reported starting from the readily available monoterpene (R)-carvone, employing a tandem intermolecular Michael addition-intramolecular Michael addition-alkylation sequence and an electron-transfer-mediated 6-endo-trig cyclization as key steps. 相似文献