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251.
Danuta Kaczmarek Damian Wojcieszak Jaroslaw Domaradzki Eugeniusz Prociow Frank Placido Steffen Lapp Rafal Dylewicz 《Central European Journal of Physics》2011,9(2):349-353
In this work, the influence of Tb-doping on structure, and especially hardness of nanocrystalline TiO2 thin films, has been described. Thin films were formed by a high-energy reactive magnetron sputtering process in a pure oxygen
atmosphere. Undoped TiO2-matrix and TiO2:Tb (2 at. % and 2.6 at. %) thin films, had rutile structure with crystallite sizes below 10 nm. The high-energy process produces
nanocrystalline, homogenous films with a dense and close packed structure, that were confirmed by X-ray diffraction patterns
and micrographs from a scanning electron microscope. Investigation of thin film hardness was performed with the aid of a nanoindentation
technique. Results of measurements have shown that the hardness of all manufactured nanocrystalline films is above 10 GPa.
In the case of undoped TiO2 matrix, the highest hardness value was obtained (14.3 GPa), while doping with terbium results in hardness decreasing down
to 12.7 GPa and 10.8 GPa for TiO2:(2 at. % Tb) and TiO2:(2.6 at. % Tb) thin films, respectively. Incorporation of terbium into TiO2-matrix also allows modification of the elastic properties of the films. 相似文献
252.
Damian Wojcieszak Danuta Kaczmarek Jaroslaw Domaradzki Eugeniusz L. Prociow Antoni W. Morawski Magdalena Janus 《Central European Journal of Physics》2011,9(2):354-359
In this work photocatalytic properties of TiO2 thin films doped with different amount of Tb have been described. Thin films were prepared by high energy reactive magnetron
sputtering process. Comparable photocatalytic activity has been found for all doped TiO2 thin films, while different amounts of Tb dopant (0.4 and 2.6 at. %) results in either an anatase or rutile structure. It
was found that the terbium dopant incorporated into TiO2 was also responsible for the amount of hydroxyl groups and water particles adsorbed on the thin film surfaces and thus photocatalytic
activity was few times higher in comparison with results collected for undoped TiO2 thin films. 相似文献
253.
Louis Cottier Grard Descotes Estelle Viollet Jaroslaw Lewkowski Romuald Skowroski 《Journal of heterocyclic chemistry》1995,32(3):927-930
The oxidation of 5-hydroxymethylfurfural (1) or 5-hydroxymethylfurfurylideneacetophenone (4) with various 4-substituted 2,2,6,6-tetramethylpiperidine radicals (TEMPO) 3a-d and supporting co-oxidants gave corresponding aldehydes 2 or 5 in fair yields. 相似文献
254.
The molecular structure of fluids composed of dendrimers of different generations is studied using nonequilibrium molecular dynamics (NEMD). NEMD results for dendrimer melts undergoing planar Couette flow are reported and analyzed with particular attention paid to the shear-induced changes in the internal structure of dendrimers. The radii of gyration, pair distribution functions and the fractal dimensionality of the dendrimers are determined at different strain rates. The location of the terminal groups is analyzed and found to be uniformly distributed throughout the space occupied by the molecules. The fractal dimension as a function of strain rate displays crossover behavior analogous to the Newtonian/non-Newtonian transition of shear viscosity. 相似文献
255.
Nonequilibrium molecular-dynamics simulations are used to investigate the molecular shape of dendrimers and linear polymers in a melt and under shear. Molecules are modeled at the coarse-grained level using a finitely extensible nonlinear elastic bead-spring model. The shape of dendrimers and linear polymers at equilibrium and undergoing planar Couette flow is analyzed quantitatively and it is related to the shear viscosity. The shape of dendrimers responds differently to the influence of shear compared with linear polymers of equivalent molecular mass. However, in both cases the transition from Newtonian to non-Newtonian viscosity behavior corresponds to significant changes in molecular symmetry. This suggests that a shape analysis could be used to estimate the onset of shear thinning in polymers. 相似文献
256.
257.
Christopher?Altman Jaroslaw?Pykacz Romàn?R.?ZapatrinEmail author 《International Journal of Theoretical Physics》2004,43(12):2435-2445
We introduce superposition-based quantum networks composed of (i) the classical perceptron model of multilayered, feedforward neural networks and (ii) the algebraic model of evolving reticular quantum structures as described in quantum gravity. The main feature of this model is moving from particular neural topologies to a quantum metastructure which embodies many differing topological patterns. Using quantum parallelism, training is possible on superpositions of different network topologies. As a result, not only classical transition functions, but also topology becomes a subject of training. The main feature of our model is that particular neural networks, with different topologies, are quantum states. We consider high-dimensionaldissipative quantum structures as candidates for implementation of the model. 相似文献
258.
JPC – Journal of Planar Chromatography – Modern TLC - Acomplex mixture of sunscreens of different lipophilicity was quantified for the first time by thin-layer chromatography (TLC)... 相似文献