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101.
Anderson PE Badlani RN Mayer J Mabrouk PA 《Journal of the American Chemical Society》2002,124(35):10284-10285
This contribution reports the first synthesis of conducting polymers (CPs), specifically, polyaniline (PAn) and polypyrrole (PPy), in supercritical carbon dioxide (scCO2). CPs synthesized electrochemically in scCO2 were characterized with cyclic voltammetry (CV), four-point probe conductivity, scanning electron microscopy (SEM), and UV-vis spectroscopy. Preliminary data indicate that CPs synthesized by this method exhibit novel morphology and high conductivity comparable to that synthesized by traditional methods. 相似文献
102.
A model of heterogeneous medium taking into account the friction between the particles and liquid, as well as the relaxation
of the small-size particles to the equilibrium on the stress, has been proposed to describe the propagation of the elastic
waves in a suspension. A system of wave equations describing the propagation of a plane longitudinal wave has been formulated
for the components of the medium. Analytical expressions for the sound velocity in a suspension has been obtained in the approximation
in which the particles are completely carried away by liquid in the limiting cases in which the particles are in equilibrium
under stress with the liquid or equilibrium is absent. The dependence of the sound velocity in the medium on the volumetric
portion and the size of the inclusions has been studied. The obtained results agree with the experimental data and obtained
analytical expressions for the sound velocity. The dynamics of the components of the medium at the propagation of the plane
longitudinal monochromatic wave has been studied. 相似文献
103.
104.
Robert Buras Bernhard Mayer 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(3):434-7735
We present five new variance reduction techniques applicable to Monte Carlo simulations of radiative transfer in the atmosphere: detector directional importance sampling, n-tuple local estimate, prediction-based splitting and Russian roulette, and circum-solar virtual importance sampling. With this set of methods it is possible to simulate remote sensing instruments accurately and quickly. In contrast to all other known techniques used to accelerate Monte Carlo simulations in cloudy atmospheres - except for two methods limited to narrow angle lidars - the presented methods do not make any approximations, and hence do not bias the result. Nevertheless, these methods converge as quickly as any of the biasing acceleration techniques, and the probability distribution of the simulation results is almost perfectly normal. The presented variance reduction techniques have been implemented into the Monte Carlo code MYSTIC (“Monte Carlo code for the physically correct tracing of photons in cloudy atmospheres”) in order to validate the techniques. 相似文献
105.
106.
N. S. Eremina K. M. Degtyarenko R. M. Gadirov T. N. Kopylova G. V. Mayer L. G. Samsonova S. B. Meshkova Z. M. Topilova 《Russian Physics Journal》2011,53(12):1223-1228
Organic thin-film structures based on Eu(III), Tb(III), and polyvinylcarbazole coordination compounds are synthesized. Their
photo- and electroluminescent properties and volt-ampere and volt-brightness characteristics are investigated. 相似文献
107.
The methyl cation and CF(3)(+) attack saturated, acyclic ketones to make vibrationally excited adduct ions. Despite their high internal energies and short lifetimes, these adducts undergo deep-seated rearrangements that parallel slower processes in solution. Observed pathways include alkene and alkane expulsions, in addition to (in the case of CF(3)(+)) the precedented loss of CF(2)O + HF. For the vast majority of ketones, the principal charged products are the CF(3)(+) adducts of lighter carbonyl compounds, ions that are not easily prepared by other avenues. Evidence for ion structures comes from collisionally activated unimolecular decomposition and bimolecular ion-molecule reactions. Typical examples are di-n-propyl and diisopropyl ketones (both of which produce CH(3)CH=OCF(3)(+) as the principal ion-molecule reaction product) and pentamethylacetone (which produces (CH(3))(2)C=OCF(3)(+) as virtually the sole ion-molecule reaction product). Isotopic labeling experiments account for mechanisms, and DFT calculations provide a qualitative explanation for the relative abundances of products from unimolecular decompositions of the chemically activated CF(3)(+) adduct ions that are initially formed. 相似文献
108.
The high propensity of organosilanes towards polycondensation and reaction with nucleophilic moieties has facilitated the formation of new organic-inorganic hybrids based on the lacunary divacant heteropolyanion [gamma-SiW10O36]8-. Depending on the experimental conditions two different types of derivatives were obtained with the general formula [gamma-SiW10O36(RSi)2O]4- (1) (>90% yield) and [gamma-SiW10O36(RSiO)4]4- (2) (>85% yield) (R = H (1a, 2a), vinyl (1b), -C3H6OC(O)C-(Me)=CH2 (1c, 2c), phenyl (1d, 2d)). The structures of the hybrid anions have been inferred from spectroscopic data, in particular from multinuclear (29Si and 183W) NMR solution studies and from MALDI-TOF mass spectrometry. Both species correspond to the grafting of an oxo-bridged siloxane unit onto the surface of the lacunary polyoxoanion. 相似文献
109.
C60 inclusion complexes in γ-cyclodextrin are studied by molecular mechanics and semi-empirical methods with the aim of comparing measured and calculated induced circular dichroism (ICD) spectra. Low energy geometries of the complexes are generated by Monte Carlo simulations, also accounting for solvation effects by an aqueous environment. The ICD spectrum of the complex is then obtained from an exciton model based on semi-empirical calculations of the transition energies and the corresponding transition moments. Highly symmetric, tightly bound complexes of two γ-cyclodextrins and buckminsterfullerene are found as the most probable structures. The main bands of the experimentally derived ICD spectrum are assigned to the excitation transitions of the chromophore and are discussed in comparison to calculations on the magnetic circular dichroism (MCD) spectrum of C60. 相似文献
110.
Udo Mayer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》1972,84(4):176-176