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4648. Involving CeVO4 in improving the photocatalytic activity of a Bi2WO6/allophane composite for the degradation of gaseous acetaldehyde under visible light Mirabbos Hojamberdiev, Zuhra Kadirova, Yuki Makinose, Gangqiang Zhu, Saim Emin, Nobuhiro Matsushita, Masashi Hasegawa, Kiyoshi Okada, 2017, izvirni znanstveni članek Opis: Indoor air quality is affected by hazardous chemical substances emitted from buildings, construction and decoration materials, indoor equipments or even due to human activities. In this study, the hydrothermal synthesis and mechanical mixing were applied to synthesize Bi2WO6/CeVO4/allophane composites (BW/CV/A), and their photocatalytic performance for the degradation of acetaldehyde, as a common indoor air pollutant, was evaluated under visible-light irradiation. The as-prepared composites were characterized by X-ray diffraction (XRD), Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), and UV–visible (UV–vis) spectroscopy. The results demonstrated that the prepared composites had microstructures consisting of nanosheets of hierarchical flower-like Bi2WO6 microspheres on which the CeVO4 nanocrystals were fully embedded in the presence of allophane nanoparticles. The specific surface areas of the as-synthesized and mechanically mixed BW1/CV1/A composites were in the range of 110–182 m2 g−1. The effect of the amount of CeVO4 on photocatalytic activity of the Bi2WO6/allophane composite was explored, and the highest photocatalytic activity was observed for the BW1/CV1/A composite (Bi2WO6:CeVO4 = 1:1 mass ratio). Compared with the Bi2WO6/allophane and CeVO4/allophane composites, the hydrothermally synthesized BW1/CV1/A composite showed a significantly higher photocatalytic activity for the degradation of acetaldehyde under visible-light irradiation. The enhancement in the photocatalytic activity of the Bi2WO6/allophane composite achieved by involving the CeVO4 nanocrystals is due presumably to an extended light absorption range, appropriate band structures of Bi2WO6 and CeVO4, the formed p–n heterojunction, and the co-existence of Ce3+ and Ce4+ in CeVO4, resulting in effective separation of photogenerated electron-hole pairs.
Objavljeno v RUNG: 16.08.2017; Ogledov: 4569; Prenosov: 0
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4649. Pokristjanjevanje pri Prešernu in Bevku: Domoljubne prvine in vrednote v Prešernovi pesnitvi Krst pri Savici in Bevkovi povesti Umirajoči bog TriglavZoran Božič, 2017, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Obe besedili sta nastali v prelomnih trenutkih slovenske zgodovine: Prešernova pesnitev v casu nemške politicne, gospodarske in kulturne nadvlade in porajanja zahtev po združeni Sloveniji, Bevkova povest pa v casu italijanskega fašizma in okupacije Primorske. Na prvi pogled Prešernova visoka romanticna poezija in Bevkova prejkone trivialna povest razen tematike poganstva in kršcanstva nimata nic skupnega, vendar pa gre v obeh primerih za prikrito sporocilo, pogojeno s cenzurnimi postopki tedanje oblasti, za obsodbo nasilnih tujih oblastnikov, za pozive k narodni enotnosti, za poudarjanje domoljubne zavesti in za odnos do narave, ki kot najvišjo vrednoto vzpostavlja tostranstvo in ne onostranstvo.
Ključne besede: Kobarid, leto 1331, inkvizicija, Čedad, katoliška cerkev, staroverci, poganska vera, Triglav, France Prešeren, France Bevk, Krst pri Savici, romantična pesnitev, Umirajoči bog Triglav, domoljubna povest, narodna zavest, simbolika, narava, religija
Objavljeno v RUNG: 27.07.2017; Ogledov: 5112; Prenosov: 334
 Celotno besedilo (1,87 MB) |
4650. Weak forms of shadowing in topological dynamicsSergey Kryzhevich, Danila Cherkashin, 2017, izvirni znanstveni članek Opis: We consider continuous maps of compact metric spaces. It is proved that every pseudotrajectory with sufficiently small errors contains a subsequence of positive density that is point-wise close to a subsequence of an exact trajectory with the same indices. Also, we study homeomorphisms such that any pseudotrajectory can be shadowed by a finite number of exact orbits. In terms of numerical methods this property (we call it multishadowing) implies possibility to calculate minimal points of the dynamical system.
We prove that for the non-wandering case multishadowing is equivalent to density of minimal points. Moreover, it is equivalent to existence of a family of $\varepsilon$-networks ($\varepsilon > 0$) whose iterations are also $\varepsilon$-networks. Relations between multishadowing and some ergodic and topological properties of dynamical systems are discussed.
Ključne besede: Topological dynamics, minimal points, invariant measure, shadowing, chain recurrence, $\varepsilon$-networks, syndetic sets
Objavljeno v RUNG: 27.07.2017; Ogledov: 4202; Prenosov: 0
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