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11.
Surface pressure-area isotherms of Langmuir films of C70/arachidic acid mixed films were measured at the water (pH=2)-air interface, at several temperatures and concentrations. Our results for the case of 25 °C and 1:1 mixtures, differ from those presented by Jehoulet, et al. (1992), and are closer to the results for C60/arachidic acid mixed films presented by those authors. 相似文献
12.
Carmen Varea De Alvarez J.P. Walter R.W. Boyd M.L. Cohen 《Journal of Physics and Chemistry of Solids》1973,34(2):337-345
The energy band structure, reflectivity, modulated reflectivity and imaginary part of the frequency dependent dielectric function are calculated for InAs and InSb using the empirical pseudopotential method. Comparison is made with the measured reflectivity and modulated reflectivity and prominent features in the experimental spectra are identified and associated with interband transitions in specific regions of the Brillouin zone. The wavefunctions obtained from our calculated band structures are used to calculate the electronic charge density as a function of position in the unit cell. 相似文献
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Emilien Demory Karthik Devaraj Andreas Orthaber Paul J. Gates Lukasz T. Pilarski 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(40):11931-11935
(Pinacolato)boryl ortho‐silyl(hetero)aryl triflates are presented as a new class of building blocks for arylation. They demonstrate unique versatility by delivering boronate or (hetero)aryne reactivity chemoselectively in a broad range of transformations. This approach enables the unprecedented postfunctionalization of fluoride‐activated (hetero)aryne precursors, for example, as substrates in transition‐metal catalysis, and offers valuable new possibilities for aryl boronate postfunctionalization without the use of specialized protecting groups. 相似文献
15.
Simultaneous measurements of OH,mixture fraction and velocity fields to investigate flame stabilization enhancement by electric field 总被引:1,自引:0,他引:1
Armelle?CessouEmail author Emilien?Varea Karine?Criner Gilles?Godard Pierre?Vervisch 《Experiments in fluids》2012,52(4):905-917
Simultaneous stereoscopic PIV, OH and acetone planar laser-induced fluorescence measurements are performed to analyze the
processes involved in the enhancement of flame stabilization by electric field. Instantaneous velocity and mixture fraction
fields are measured simultaneously at the base of a lifted flame to analyze whether the flow properties in front of the flame
when electric field is applied are compatible with a mechanism involving ionic wind. The measurements conditioned on the instantaneous
flame bases with and without the electric field are compared. The velocity in front of the flame decreases with electric field
what is in agreement with the assumption involving ionic wind. To analyze the mixture in front of the flame, a joined analysis
of velocity and mixture fraction is required to show the mixture stays near stoichiometry when the electric field is applied.
The need of a joined analysis illustrates the interest of performing the three laser diagnostics simultaneously. 相似文献
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We describe a search for solidlike singlet distribution functions in a system of hard spheres. The procedure, which is based on Widom's relation between the activity and the density in a nonuniform fluid, is applied to a sequence of hardcore lattice gases with increasingly extended interactions. When the system is defined on a Bethe lattice we obtain exact solutions for arbitrary external field and size of the hard core. This includes the limit in which the number of excluded neighbors goes to infinity while the lattice spacing is made to vanish. The study of the first few members in this family of models suggests the existence of an infinite sequence, beginning with the next-nearest-neighbor problem, of first-order sublattice ordering transitions occurring before close packing and at zero field. The periodic solutions for the density originate at bifurcation points located at uniform close packing.On leave from Facultad de Química, Universidad Nacional Autónoma de México, 04510 México, Distrito Federal 相似文献
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Carine Jacques Emilien L. Jamin Elisabeth Perdu Hélène Duplan Alain Mavon Daniel Zalko Laurent Debrauwer 《Analytical and bioanalytical chemistry》2010,396(5):1691-1701
An original method was developed to separate, identify and quantify the different benzo(a)pyrene (B(a)P) metabolites formed through oxidative and conjugative pathways. All B(a)P metabolites were separated by an improved high-performance liquid chromatography method, then detected and quantified relatively
by online radioactivity detection. At the same time, metabolite structures were characterised by tandem mass spectrometry
using two complementary ionisation modes: electrospray ionisation in the negative mode and atmospheric pressure chemical ionisation
in the positive mode. This method was successfully applied to the analysis of B(a)P metabolites, produced by incubation of B(a)P with the ex vivo pig ear skin model. These include glucuronic acid and sulphate conjugates of B(a)P-OHs and B(a)P-diols, as well as direct phase I metabolites: B(a)P-tetrol, B(a)P-diones, B(a)P-catechols, B(a)P-diols and B(a)P-OHs. 相似文献
19.
Diego A. Alonso Mónica Fuensanta C. Nájera Montserrat Varea 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5-6):1119-1131
Abstract The use of π-electron-deficient aryl sulfones, especially 3,5-bis(trifluoromethyl) phenyl alkyl sulfones (BTFP-sulfones) as soft nucleophiles, as caboxylic acid protecting group and in Julia–Kocienski olefination reactions is described. In the case of α-(arylsulfonyl)acetates dialkylation, reactions are performed under phase-transfer analysis (PTC) conditions using K 2 CO 3 as base. Esters derived from 2-(arylsulfonyl)ethanol can be deprotected using aqueous NaHCO 3 . Alkyl BTFP sulfones are coupled with carbonyl compounds using KOH or P4-t-Bu as bases to give the corresponding alkenes after Smiles rearrangement. 相似文献
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Emilien Tarquini 《Monatshefte für Mathematik》2007,243(1):333-339
In this paper we consider the Gross-Pitaevskii equation iu
t
= Δu + u(1 − |u|2), where u is a complex-valued function defined on
\Bbb RN×\Bbb R{\Bbb R}^N\times{\Bbb R}
, N ≥ 2, and in particular the travelling waves, i.e., the solutions of the form u(x, t) = ν(x
1 − ct, x
2, …, x
N
), where
c ? \Bbb Rc\in{\Bbb R}
is the speed. We prove for c fixed the existence of a lower bound on the energy of any non-constant travelling wave. This bound provides a non-existence
result for non-constant travelling waves of fixed speed having small energy. 相似文献