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321.
Automatic grid generation is very important in industrial applications. Furthermore, in several applications discretization grids are needed which provide an anisotropic refinement and an accurate approximation of the derivatives of the solution. These requirements are fulfilled by semi‐unstructured grids. In this paper, we report how semi‐unstructured grids are used in the laser simulation program LASCAD [3]. 相似文献
322.
323.
Gelatin was modified with glycidyl methacrylate. The methacrylated gelatins were cross-linked by electron irradiation. The cross-linking process was studied by FT-Raman and EPR spectroscopy. 相似文献
324.
Julianna A. Altmann Nicholas C. Handy Victoria E. Ingamells 《International journal of quantum chemistry》1996,57(4):533-542
The performance of numerical basis sets in relation to Gaussian basis sets is examined, by studying 20 small sulfur-containing molecules. The results of geometry optimization calculations are reported for each molecule using both density functional and Hartee-Fock methods. In comparison with experimental data, it is shown that the use of numerical bases tend to overestimate structural parameters, particularly bond lengths, and, in most cases, more than Gaussian basis sets. It is also shown that the use of a larger Gaussian basis set in DFT calculations has the effect of reducing bond lengths. © 1996 John Wiley & Sons, Inc. 相似文献
325.
Dr. Christian Paul Bold Dr. Daniel Lucena-Agell Dr. Dr. María Ángela Oliva Dr. José Fernando Díaz Prof. Dr. Karl-Heinz Altmann 《Angewandte Chemie (International ed. in English)》2023,62(5):e202212190
We describe the total synthesis of the macrodiolide C(13)/C(13′)-bis(desmethyl)disorazole Z through double inter-/intramolecular Stille cross-coupling of a monomeric vinyl stannane/vinyl iodide precursor to form the macrocycle. The key step in the synthesis of this precursor was a stereoselective aldol reaction of a formal Evans acetate aldol product with crotonaldehyde. As demonstrated by X-ray crystallography, the binding mode of C(13)/C(13′)-bis(desmethyl)disorazole Z to tubulin is virtually identical with that of the natural product disorazole Z. Likewise, C(13)/C(13′)-bis(desmethyl)disorazole Z inhibits tubulin assembly with at least the same potency as disorazole Z and it appears to be a more potent cell growth inhibitor. 相似文献
326.
Stefan Spange Annett Graeser Petra Rehak Christian Jger Marcus Schulz 《Macromolecular rapid communications》2000,21(3):146-150
Cationic polymerization of cyclohexyl vinyl ether (CHVE) within mesoporous, siliceous molecular sieves (MCM‐41) yields novel MCM‐41‐polyCHVE host‐guest hybrid materials. Initiation within the channel can be achieved by triphenylmethylium or bis(4‐methoxyphenyl)methylium silanolate ion pairs, as well as by mobile acidic silanols to a certain extent. Generation of the carbenium ions on MCM‐41 is investigated by a special UV/VIS technique. The structure of poly(vinyl ether) generated within the channels of MCM‐41 depends on the mechanism of initiation as shown by means of solid state 13C{1H} and 29Si{1H} CP MAS NMR spectroscopy. 相似文献
327.
Nara Altmann Peter J. Halley Justin Cooper‐White Jakob Lange 《Macromolecular Symposia》2001,169(1):171-177
Highly filled thermosets are used in applications such as integrated circuit (IC) packaging. However, a detailed understanding of the effects of the fillers on the macroscopic cure properties is limited by the complex cure of such systems. This work systematically quantifies the effects of filler content on the kinetics, gelation and vitrification of a model silica‐filled epoxy/amine system in order to begin to understand the role of the filler in IC packaging cure. At high cure temperatures (100°C and above) there appears to be no effect of fillers on cure kinetics and gelation and vitrification times. However, a decrease in the gelation and vitrification times and increase the reaction rate is seen with increasing filler content at low cure temperatures (60‐90°C). An explanation for these results is given in terms of catalysation of the epoxy amine reaction by hydrogen donor species present on the silica surface and interfacial effects. 相似文献