排序方式: 共有11条查询结果,搜索用时 78 毫秒
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Mohamed Charif Soufiane El Adraoui Mounirh Khalid Asmaa Zugari Mohamed I. Yaich Mohsine Khalladi 《Optik》2014
The current density (JE), the piecewise linear recursive convolution (PLRC) and the constant convolution recursive (CRC) techniques are developed and integrated into the transmission line matrix (TLM) algorithm. A comparison of these three schemes according to the criteria of accuracy and CPU time is presented. Numerical experiments show that JE provides the most accurate solution and requires the least CPU time; PLRC is nearly as accurate but consumes more CPU time than CRC. 相似文献
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Driowya M Puissant A Robert G Auberger P Benhida R Bougrin K 《Ultrasonics sonochemistry》2012,19(6):1132-1138
A simple and efficient synthesis of modified 1,2,3-triazole nucleosides was developed. The strategy involved sequential one-pot acetylation-azidation-cycloaddition procedure and was found to be highly effective under a cooperative effect of ultrasound activation and iron/copper catalysis. The reactions were carried out under both conventional and ultrasonic irradiation conditions. In general, improvement in rates and yields were observed when reactions were carried out under sonication compared with conventional conditions. This one-pot procedure provides several advantages such as operational simplicity, high yield, safety and environment friendly protocol. The resulting substituted nucleosides were evaluated for their anticancer activity against K562 chronic myelogenous leukemia (CML) cell line. 相似文献
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A. Pirson A. Mohsine P. Marchot B. Michaux O. van Cantfort J. P. Pirard A. J. Lecloux 《Journal of Sol-Gel Science and Technology》1995,4(3):179-185
A new method to synthesize SiO2-TiO2 gels by sol-gel process has been developed. This technique uses tetraisopropylorthotitanate [Ti(O
i
Pr)4] and tetraethylorthosilicate [TEOS]: they are mixed in the same solvent and then directly hydrolysed. This one-step reaction is possible because of the use of 2-methoxyethanol, a protic polar solvent. This alcohol plays two different specific roles: it acts as a solvent as well as a stabilizer of titanium alkoxide towards the hydrolysis-precipitation reaction. So, by an accurate adjustment of the quantity of methoxyethanol in the mixture, we can control the reactivity of the titanium precursor.Monolithic and transparent xerogels were obtained whatever the composition. Three monolithic SiO2-TiO2 gels containing 20, 50 and 75 mol% of TiO2 were prepared and studied in details.By using the TG-DSC analysis, we can follow the evolution of the loss of water and organic residues.The structural evolution of gels during calcination is characterized by IR spectroscopy and X-Ray diffraction. 相似文献
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J. P. Pirard P. Petit A. Mohsine B. Michaux F. Noville A. J. Lecloux 《Journal of Sol-Gel Science and Technology》1994,2(1-3):875-880
Zirconium propoxide and tetraethylorthosilicate were hydrolyzed in methoxyethanol which acts as stabilizer of zirconium and in presence of formamide or dimethylformamide as Drying Control Chemical Additives in order to obtain zirconia silica gels. The gels were dried at 70°C to get monolithic xerogels. The influence of zirconium content and DCCA on texture was determined. The evolution of these xerogels was investigated as a function of temperature between 70°C and 1000°C by thermogravimetry, differential scanning calorimetry, I.R. spectroscopy and R.X. diffractometry. 相似文献
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This paper presents a novel approach to model the interaction of electromagnetic waves with the magnetized plasma medium based on the Transmission Line Matrix (TLM) method. Anisotropic and dispersive characters of magnetized plasma are modeled by voltage sources, where the formulation is developed using the Current Density Recursive Convolution (CDRC) technique. Computational examples illustrate not only the improved accuracy, but also significant CPU time saving in comparison with TLM Constant Recursive Convolution (CRC-TLM) approach. 相似文献
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Nadji Moulai-Mostefa Nadjia Sabri Razika Khalladi Abdelkader HadjSadok 《Journal of Dispersion Science and Technology》2014,35(3):390-396
The aim of this work was to investigate interactions that can take place between, proteins and polysaccharides, in the presence of electrolytes. Thus, our objective was to study the influence of NaCl addition on the associative and/or segregative interactions in the case of biopolymer mixtures and fine emulsions stabilized by sodium caseinate, by analysis of the rheological properties and zeta potential. From the experimental results, it was shown that the presence of salt affects the rheological and physicochemical properties of the aqueous phase and consequently the emulsion stability. Indeed, the electrolytes can modify the conformation of proteins and polysaccharides, by electric neutralization of their charge, as they can generate a complex coacervation or increase their incompatibility. 相似文献
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As a continuation of our studies directed at the development of straightforward and sustainable methodologies, we describe herein an original example of a combined effect of ultrasonic activation and iron–copper dual catalysis that allows an efficient and ecofriendly one-pot, three-step route to a new series of nucleoside-substituted triazoles. The reactions were carried out under both conventional and ultrasonic irradiation conditions. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献