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991.
Gennari S Anselmi-Tamburini U Maglia F Spinolo G Munir ZA 《The journal of physical chemistry. B》2006,110(14):7144-7152
Interest in the mode of propagation of self-sustaining reactions has been motivated by the influence of the mode on the microstructure and composition of the final product. However, comprehensive studies relating the onset of the various propagation modes to the chemical and phase transformations taking place in the sample are still lacking. In the present work propagation instabilities in self-propagating high-temperature synthesis (SHS) of transition metal aluminides are studied using a computer simulation approach. The results are presented for the SHS of NiAl, CoAl, TiAl, and NbAl(3). Particular emphasis is made with respect to the influence of process variables and system parameters on the onset of propagation instabilities, in relation to the physicochemical processes taking place during the propagation of the combustion front. 相似文献
992.
[reaction: see text] An efficient approach to the azaspirane core of FR 901483 is described employing lithiated methoxyallene as a crucial C3 building block and a suitably protected enantiopure ketimine as the second component. The resulting dihydropyrrole derivative was smoothly converted into a spiro keto aldehyde which under acidic conditions provided a novel azanorbornane derivative 15. Under basic reaction conditions, the desired 5-azatricyclo[6.3.1.0(1,5)]dodecane skeleton 16 was generated. The ratio of diastereomers strongly depends on the reaction conditions employed with l-proline in DMSO providing the highest selectivity in favor of one azaspirane product. 相似文献
993.
Ragno R Simeoni S Valente S Massa S Mai A 《Journal of chemical information and modeling》2006,46(3):1420-1430
Docking simulation and three-dimensional quantitative structure-activity relationships (3D-QSARs) analyses were conducted on four series of HDAC inhibitors. The studies were performed using the GRID/GOLPE combination using structure-based alignment. Twelve 3-D QSAR models were derived and discussed. Compared to previous studies on similar inhibitors, the present 3-D QSAR investigation proved to be of higher statistical value, displaying for the best global model r2, q2, and cross-validated SDEP values of 0.94, 0.83, and 0.41, respectively. A comparison of the 3-D QSAR maps with the structural features of the binding site showed good correlation. The results of 3D-QSAR and docking studies validated each other and provided insight into the structural requirements for anti-HDAC activity. To our knowledge this is the first 3-D QSAR application on a broad molecular diversity training set of HDACIs. 相似文献
994.
995.
R. Piat T. Böhlke O. Deutschmann S. Dietrich B. Drach J.-M. Gebert T. Gross A. Li B. Reznik G. Stasiuk I. Tsukrov A. Wanner 《PAMM》2010,10(1):719-720
Material parameter identification of the carbon/carbon composites was provided using numerical implementation of semi-analytical methods and FE-calculations. The distribution of the fibers and pores obtained from microstructural studies is used as input for homogenization schemes for the determination of the effective elastic constants. The predictions are compared to experimental results. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
996.
In this paper we study an application of nonlinear B‐bounded semigroups introduced in a previous paper. The application is similar to the particle transport problem which led to B‐bounded linear semigroups. We deal with a nonlinear particle transport problem, which can be solved by using B‐bounded nonlinear semigroups. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
997.
PACMAN (Passive and Active Compensability Multicriteria ANalysis) is a multiple criteria methodology based on a decision maker oriented notion of compensation, called compensability. A basic step of PACMAN is the construction of compensatory functions, which model intercriteria relations for each pair of criteria on the basis of compensability. In this paper we examine a simplified version of PACMAN, which uses the so-called linear compensatory functions and consistently reduces the overall complexity of its implementation in practical cases. We use Mathematica® to develop a computer-aided graphical interface that eases the interaction among the actors of the decision process at each stage of PACMAN. We also propose the possibility to perform a sensitivity analysis in this simplified version of PACMAN as a nonlinear optimization problem. 相似文献
998.
Stefano Zanini Claudia Riccardi Elisa Grimoldi Claudia Colombo Anna Maria Villa Antonino Natalello Pietro Gatti-Lafranconi Marina Lotti Silvia Maria Doglia 《Journal of colloid and interface science》2010,341(1):53-58
This work deals with the optimization of argon plasma-induced graft-polymerization of polyethylene glycol acrylate (PEGA) on polypropylene (PP) films in order to obtain surfaces with a reduced protein adsorption for possible biomedical applications. To this end, we examined the protein adsorption on the treated and untreated surfaces. The graft-polymerization process consisted of four steps: (a) plasma pre-activation of the PP substrates; (b) immersion in a PEGA solution; (c) argon plasma-induced graft-polymerization; (d) washing and drying of the samples. The efficiency of these processes was evaluated in terms of the amount of grafted polymer, coverage uniformity and substrates wettability. The process was monitored by contact angle measurements, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray Photoelectron Spectroscopy (XPS) and atomic force microscopy (AFM) analyses. The stability of the obtained thin films was evaluated in water and in Phosphate Buffer Saline (PBS) at 37 °C. The adsorption of fibrinogen and green fluorescent protein (GFP) – taken as model proteins – on the differently prepared surfaces was evaluated through a fluorescence approach using laser scanning confocal microscopy with photon counting detection. After plasma treatments of short duration, the protein adsorption decreases by about 60–70% with respect to that of the untreated film, while long plasma exposure resulted in a higher protein adsorption, due to damaging of the grafted polymer. 相似文献
999.
Phosphinines with pendant phenol or catechol functionalities and their gold(I) complexes were synthesised and characterised by spectroscopic data and in one case by a single‐crystal X‐ray diffraction study. Reactions of ligands or complexes with TiO2 or chloropropyl modified hexagonal mesoporous silica were then studied with the aim to immobilise ligands or complexes on the carrier by covalent tethering. 31P MAS NMR studies revealed that immobilisation on TiO2 was accompanied by complete degradation of the phosphinine moiety. Base induced coupling with chloropropyl modified silica produced a material that contained a mixture of several surface‐bound phosphorus compounds. 31P MAS NMR studies revealed that approx. 40 % of the ligand had retained its integrity whereas the remaining fraction had been converted into further, not unambiguously identified structures. 相似文献
1000.
Influence of MWCNT morphology on dispersion and thermal properties of polyethylene nanocomposites 总被引:1,自引:0,他引:1
Silvia Barus Pierangiola Bracco Angelica Chiodoni 《Polymer Degradation and Stability》2010,95(5):756-1360
In this study a series of multi-walled carbon nanotube (MWCNT)/Polyethylene (PE) composites with different kinds and several concentrations of carbon nanotubes (CNTs) were investigated. The morphology and degree of dispersion of the fillers in the polymer matrix at different length scales was investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Both individual and agglomerated MWCNTs were evident but a good dispersion was observed for some of them. TGA measurements were performed on nanocomposites in order to understand if CNTs affect the stabilization mechanism during thermal and oxidative degradation. The analysis demonstrates that MWCNTs presence slightly delays thermal volatilisation (15-20 °C) without modification of thermal degradation mechanism. In contrast, thermal oxidative degradation in air is delayed up to about 100 °C dependently from MWCNTs concentration, in the range used here (0.1-2.0 wt%), and degree of dispersion. The stabilization is due to the formation of a thin protective layer of entangled MWCNTs kept together by carbon char generated on the surface of the nanocomposites as shown by SEM images taken on degradation residues. 相似文献