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11.
Herbert Amann 《Archive for Rational Mechanics and Analysis》1986,92(2):153-192
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J. Amann 《Colloid and polymer science》1910,7(2):70-73
Ohne Zusammenfassung 相似文献
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Amann 《Fresenius' Journal of Analytical Chemistry》1899,38(2):131
Ohne Zusammenfassung 相似文献
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A. Zerga M. Carrada M. Amann A. Slaoui 《Physica E: Low-dimensional Systems and Nanostructures》2007,38(1-2):21
The formation of silicon nanoclusters embedded in amorphous silicon nitride (SiNx:H) can be of great interest for optoelectronic devices such as solar cells. Here amorphous SiNx:H layers have been deposited by remote microwave-assisted chemical vapor deposition at 300 °C substrate temperature and with different ammonia [NH3]/silane [SiH4] gas flow ratios (R=0.5−5). Post-thermal annealing was carried out at 700 °C during 30 min to form the silicon nanoclusters. The composition of the layers was determined by Rutherford back scattering (RBS) and elastic recoil detection analysis (ERDA). Fourier transform infrared spectroscopy (FTIR) showed that the densities of SiH (2160 cm−1) and NH (3330 cm−1) molecules are reduced after thermal annealing for SiN:H films deposited at flow gas ratio R>1.5. Breaking the SiH bonding provide Si atoms in excess in the bulk of the layer, which can nucleate and form Si nanostructures. The analysis of the photoluminescence (PL) spectra for different stoichiometric layers showed a strong dependence of the peak characteristics (position, intensity, etc.) on the gas flow ratio. On the other hand, transmission electron microscopy (TEM) analysis proves the presence of silicon nanoclusters embedded in the films deposited at a gas flow ratio of R=2 and annealed at 700 °C (30 min). 相似文献
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Leutbecher H Greiner G Amann R Stolz A Beifuss U Conrad J 《Organic & biomolecular chemistry》2011,9(8):2667-2673
Laccase-catalyzed oxidation of substituted catechols followed by reaction with 4-hydroxy-pyrone/-benzopyrone afforded substituted benzofuran regioisomers whose structures with only two aromatic protons in total prevent a rapid structural assignment. Based on the evaluation of (1)H-(13)C long-range coupling constants a rule of thumb could be deduced for an easy and unambiguous differentiation between the possible regioisomers formed. DFT frontier orbital calculations of the reactants offer an interesting tool to explain the regioselectivity of the key reaction. 相似文献
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Manuel Amann 《Topology and its Applications》2011,158(2):183-189
Positive Quaternion Kähler Manifolds are Riemannian manifolds with holonomy contained in Sp(n)Sp(1) and with positive scalar curvature. Conjecturally, they are symmetric spaces. In this article we are mainly concerned with Positive Quaternion Kähler Manifolds M satisfying b4(M)=1. Generalising a result of Galicki and Salamon we prove that M4n in this case is homothetic to a quaternionic projective space if 2≠n?6. 相似文献
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We show that the bifurcation scenario in a high-dimensional system with interacting moving fronts can be related to the universal U-sequence which is known from the symbolic analysis of iterated one-dimensional maps. This connection is corroborated for a model of a semiconductor superlattice, which describes the complex dynamics of electron accumulation and depletion fronts. By a suitable Poincaré section we reduce the dynamics to a low-dimensional iterated map, for which in the most elementary case the bifurcation points can be determined analytically. 相似文献
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