排序方式: 共有26条查询结果,搜索用时 0 毫秒
1.
Pure titania porous layers consisted of anatase and rutile phases, chemically and structurally suitable for catalytic applications, were grown via micro-arc oxidation (MAO). The effect of applied voltage, process time, and electrolyte concentration on surface structure, chemical composition, and especially photocatalytic activity of the layers was investigated. SEM and AFM studies revealed that pore size and surface roughness of the layers increased with the applied voltage, and the electrolyte concentration. Moreover, the photocatalytic performance of the layers synthesized at medium applied voltages was significantly higher than that of the layers produced at other voltages. About 90% of methylene blue solution was decomposed after 180 min UV-irradiation on the layers produced in an electrolyte with a concentration of 10 g l−1 at the applied voltage of 450 V. 相似文献
2.
Saeid Zanganeh Amir Kajbafvala Navid Zanganeh Matin Sadat Mohajerani Aidin Lak M. R. Bayati H. R. Zargar S. K. Sadrnezhaad 《Applied Physics A: Materials Science & Processing》2010,99(1):317-321
A flower-like boehmite nanostructure was prepared through a template-free chemical route by the self-assembly process of nanosize
petals 800–1000 nm long, 200–250 nm wide, 20–50 nm thick and having an average crystallite size of about 2.21 nm. X-ray diffraction
analysis (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), DTA/TGA analyses and Brunauer–Emmet–Teller
(BET-N2) analyses were used in order to characterize the product obtained. XRD results exhibited that the obtained nanostructures
composed of pure orthorhombic AlOOH phase. The effects of Cl− ions and TEA on the growth of boehmite three-dimensional nanoarchitectures in the presence of
NO3-\mathrm{NO}_{3}^{-}
ions were investigated. BET analyses of as-prepared material demonstrate that this nanostructure material has a high specific
surface area, as high as 123 m2 g−1. 相似文献
3.
M.R. Bayati Roya Molaei F. Golestani-Fard 《Colloids and surfaces. A, Physicochemical and engineering aspects》2011,373(1-3):51-60
This study sheds light on the effect of vanadium doping on hydrophilicity properties of micro arc oxidized TiO2 porous layers. Pure and V-doped titania layers, with a pore size of 50–400 nm, were grown by micro arc oxidation method. Morphology and topography of the layers were studied by SEM and AFM techniques where formation of a porous structure with a rough surface was confirmed. Moreover, phase structure and chemical composition of the samples were investigated employing XRD and XPS techniques. The pure TiO2 layers consisted of anatase and rutile phase. Vanadia phase was also detected in V-doped layers. It was also revealed that V2O5 not only dispersed in the TiO2 matrix, but also doped into the crystalline lattice. Optical properties and band gap energy of the synthesized layers were evaluated by a UV-Vis spectrophotometer. Our results showed that the band gap energy decreased when vanadium was introduced into the titania lattice. Finally, hydrophilicity of the pure and the doped layers was studied under ultraviolet and visible illuminations by measuring the water contact angle on their surface. The V-doped layers, especially those which were grown under intermediate voltages, revealed an enhanced hydrophilicity when compared to the pure TiO2 layers. 相似文献
4.
Basil Bayati Philippe Chatelain Petros Koumoutsakos 《Journal of computational physics》2011,230(1):13-26
We present an algorithm for adaptive mesh refinement applied to mesoscopic stochastic simulations of spatially evolving reaction–diffusion processes. The transition rates for the diffusion process are derived on adaptive, locally refined structured meshes. Convergence of the diffusion process is presented and the fluctuations of the stochastic process are verified. Furthermore, a refinement criterion is proposed for the evolution of the adaptive mesh. The method is validated in simulations of reaction–diffusion processes as described by the Fisher–Kolmogorov and Gray–Scott equations. 相似文献
5.
Diethylmethyl chitosan as an antimicrobial agent: Synthesis, characterization and antibacterial effects 总被引:1,自引:0,他引:1
M.R. Avadi A.M.M. Sadeghi Kh. Bayati M.J. Zohuriaan-Mehr 《European Polymer Journal》2004,40(7):1355-1361
Chitosan with excellent biodegradable and biocompatible characteristics has received attention as an oral drug delivery vehicle. A quaternized chitosan (i.e., N-diethylmethyl chitosan, DEMC) was prepared based on a modified two-step process via a 22 factorial design to optimize the preparative conditions. DEMC was fully characterized using FTIR and 1H-NMR spectroscopies. As calculated using NMR-based data, high degree of quaternization was achieved through the optimized two-step process. The highly quaternized biopolymeric derivative was subjected to microbial experiments. The antimicrobial activities of chitosan and DEMC against Escherchia coli were compared by calculation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Our data indicates that although the antimicrobial activity of DEMC is higher than that of chitosan in acetic acid medium, the both compounds are pH dependent and an increase in concentration of acetic acid results in a significant decrease in both MIC and MBC. 相似文献
6.
Roth C Hussain I Bayati M Nichols RJ Schiffrin DJ 《Chemical communications (Cambridge, England)》2004,(13):1532-1533
Fullerene-Pt nanoparticle assemblies were prepared by attachment and immobilisation of different Pt nanoparticles on a gold electrode using molecular layers of C60 as a linker system. These assemblies were active for the methanol oxidation following treatment with CO. 相似文献
7.
Solmaz Bayati Karl‐Erik Bergquist Kaizheng Zhu Bo Nyström Jan Skov Pedersen Luciano Galantini Karin Schillén 《Journal of Polymer Science.Polymer Physics》2017,55(19):1457-1470
Mixed micelle formation between two oppositely charged diblock copolymers that have a common thermosensitive nonionic block of poly(N‐isopropylacrylamide) (PNIPAAM) has been studied. The block copolymer mixed solutions were investigated under equimolar charge conditions as a function of both temperature and total polymer concentrations by turbidimetry, differential scanning calorimetry, two‐dimensional proton nuclear magnetic nuclear Overhauser effect spectroscopy (2D 1H NMR NOESY), dynamic light scattering, and small angle X‐ray scattering measurements. Well‐defined and electroneutral cylindrical micelles were formed with a radius and a length of about 3 nm and 35 nm, respectively. In the micelles, the charged blocks built up a core, which was surrounded by a corona of PNIPAAM chains. The 2D 1H NMR NOESY experiments showed that a minor block mixing occurred between the core blocks and the PNIPAAM blocks. By approaching the lower critical solution temperature of PNIPAAM, the PNIPAAM chains collapsed, which induced aggregation of the micelles. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1457–1469 相似文献
8.
9.
In this paper we derive a formula of the Ihara zeta function of a cone over a regular graph that involves the spectrum of the adjacency matrix of the cone. We show that the Ihara zeta function and the spectrum of the adjacency matrix of the cone determine each other and we characterize those cones that satisfy the graph theory Riemann hypothesis. 相似文献
10.
To probe the effect of lipid fluorination on the formation of lipid domains in phospholipid bilayers, several new fluorinated and non-fluorinated synthetic lipids were synthesised, and the extent of phase separation of these lipids from phospholipid bilayers of different compositions was determined. At membrane concentrations as low as 1% mol/mol, both fluorinated and non-fluorinated lipids were observed to phase separate from a gel-phase (solid ordered) phospholipid matrix, but bilayers in a liquid disordered state caused no phase separation; if the gel-phase samples were heated above the transition temperature, then phase separation was lost. We found incorporation of perfluoroalkyl groups into the lipid enhanced phase separation, to such an extent that phase separation was observed from cholesterol containing bilayers in the liquid ordered phase. 相似文献