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101.
A potential energy surface (PES) is developed for C60 designed to describe vibrational motions valid in the anharmonic limit. The PES is based on a previously existing one that is fit to the harmonic fundamentals and is then modified to generate anharmonicity of all orders and in all terms, but without additional fitted parameters. The resulting Cartesian vibrational motions are decomposed into normal modes, and the anharmonic expansion coefficients are calculated including 2-mode couplings and up to 4th order. The resulting PES is used in a vibrational self-consistent field (VSCF) algorithm to calculate the anharmonically corrected fundamental frequencies. The parameters are then fit to fundamental infrared and Raman frequencies. While it is not possible to assign combination and overtone transitions with sufficient experimental accuracy, conclusions about the effects of anharmonic vibrational coupling in C60 are described.  相似文献   
102.
New indolizidines, quinolizidines, and octahydro-pyrido[1,2-a]azepines of lactam type were synthesized from 2-nitromethylene-pyrrolidine, -piperidine, and -hexahydroazepine, respectively, by [3+3] cyclizations with α,β-unsaturated carboxylic acid chlorides. In the case of quinolizidines, a double bond migration was observed, and explained in terms of amidity percentage. Cyanomethylene-pyrrolidine gave indolizidines of lactam type, while transformations of 1-cyanomethylene-tetrahydoisoquinoline resulted in lactams as well as ketones, when simple open-chain acid chlorides or cinnamoyl chloride were used, respectively.  相似文献   
103.
Philadelphus coronarius is a versatile plant and its use in folk medicine has a long tradition; however, scientifically, the medical utilization of the herb is a less explored research field. The aim of our study was to identify and determine the quantity of the bioactive compounds of both the leaf and the flower and prepare a lyophilized product of them, from which medical ointments were formulated, since the topical application of P. coronarius has also not been studied. In vitro drug release, texture analysis and biocompatibility experiments were carried out, as well as the investigation of microbiological, antioxidant and anti-inflammatory properties. According to our results the composition and the selected excipients of the ointments have a great impact on the drug release, texture and bioavailability of the preparation. During the microbiological testing, the P. coronarius leaf was effective against Escherichia coli and Staphylococcus aureus, but it did not significantly decrease IL-4 production when it was tested on HaCaT cells. P. coronarius is a promising herb, and its topical application in antimicrobial therapy can be a useful addition to modern medical therapy.  相似文献   
104.
JPC – Journal of Planar Chromatography – Modern TLC - This paper reports a recently developed technique, coupling of optimum-performance laminar chromatography (OPLC) with online...  相似文献   
105.
Journal of Thermal Analysis and Calorimetry - Energy efficient buildings are unimaginable without highly insulating thermal envelopes. Mineral wool among others is a popular material for thermal...  相似文献   
106.
107.
Journal of Solid State Electrochemistry - An electrochemical quartz crystal nanobalance (EQCN) has been used to study the deposition (adsorption) and dissolution (desorption) during the redox...  相似文献   
108.
Despite of the fact that resolution is an extremely important process in the pharmaceutical and agrochemical industries, the development of the separation of enantiomers is still based on trial-and-error experiments. In order to compare the different procedures, the resolution of 8-(phenylsulfinyl)-1-naphthoic acid 1 was carried out by chiral organic bases using heat facilitated diastereomeric crystallization, enantioselective liquid–liquid extraction and chiroselective transport. The results give valuable information about the interactions in the racemate/resolving agent/solvent system, which helps with the understanding and development of resolution processes. Diastereomeric crystallization with brucine as a resolving agent afforded enantiomerically pure (?)-1.  相似文献   
109.
Gergő Nemes 《Acta Appl Math》2017,150(1):141-177
In this paper, we reconsider the large-argument asymptotic expansions of the Hankel, Bessel and modified Bessel functions and their derivatives. New integral representations for the remainder terms of these asymptotic expansions are found and used to obtain sharp and realistic error bounds. We also give re-expansions for these remainder terms and provide their error estimates. A detailed discussion on the sharpness of our error bounds and their relation to other results in the literature is given. The techniques used in this paper should also generalize to asymptotic expansions which arise from an application of the method of steepest descents.  相似文献   
110.
We show how the Implicit Regularization Technique (IRT) can be used for the perturbative renormalization of a simple field theoretical model generally used as a test theory for new techniques. While IRT has been applied successfully in many problems involving symmetry-breaking anomalies and nonabelian gauge groups, all at one-loop level, this is the first attempt at a generalization of the technique for perturbative renormalization. We show that the overlapping divergent loops can be given a completely algebraic treatment. We display the connection between renormalization and counterterms in the Lagrangian. The algebraic advantages make IRT worth studying for perturbative renormalization of gauge theories.  相似文献   
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