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21.
The validity of the moving block bootstrap for the empirical distribution of a short memory causal linear process is established under simple conditions that do not involve mixing or association. Sufficient conditions can be expressed in terms of the existence of moments of the innovations and summability of the coefficients of the linear model. Applications to one and two sample tests are discussed. 相似文献
22.
Mohamed A. E. Herzallah 《Meccanica》2013,48(10):2567-2568
In this note, we show that the results in the above paper are incorrect. 相似文献
23.
Reda M. Fikry Nabila A. Ismael Adel A. El-Bahnasawy Aymen A. Sayed El-Ahl 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1227-1236
Several new 2-arylidinoamino-4-(3-coumaryl)thiazole derivatives were synthesized via the reaction of 2-amino-4-(coumaryl)thiazole with aromatic aldehydes and other reagents. Structural elucidations were based on elementary analysis and spectral data studies. 相似文献
24.
The present paper is aimed at an investigation of the temperature, displacement, and stress in a viscoelastic half space of
Kelven–Voigt type. The formulation is applied according to three theories of generalized thermoelasticity: Lord–Shulman with
one relaxation time, Green–Lindsay with two relaxation times, as well as the coupled theory. The nondimensional governing
equations are solved by the finite element method. Numerical results for the temperature distribution, displacement, and thermal
stress are represented graphically. Comparisons are made with the results predicted by the CD, L-S, and G-L theories in the
presence and absence of the viscoelastic relaxation time. 相似文献
25.
26.
The purpose of this work is to study common fixed point theorems for six mappings and sequences of mappings satisfying a contractive condition of integral type. Our results improve, extend and generalize corresponding results given by many authors. 相似文献
27.
《Comptes Rendus Chimie》2014,17(3):261-267
Solvent extraction processes have been largely used in various industries. They recently were improved through new physical concepts such as CO2 Supercritical Fluid Extraction, Ultrasound assisted process, Microwave-assisted extraction, Instant Controlled Pressure Drop DIC-assisted extraction… Systematically, a pretreatment stage of grinding takes place in order to improve the exchange surface increasing the starting accessibility. Swelling of the material structure implies an increase of the porosity thus leading to higher solvent diffusivity within the solid matrix. A new concept of expanded granule powder has recently been defined using Instant Controlled Pressure Drop DIC technology. Whatever the type of solvent is (even CO2-SFE), such a swelled structure dramatically intensifies the kinetics through a higher specific exchange surface thanks to the open pores, while improving the solution solvent–solute diffusivity within the solid. Coupled to ultrasound, the internal transfer of solute within the pore solvent can likewise be intensified by replacing molecular diffusion within the pores by an effective convection transfer. In this work, we carried out a first approach of modeling of solvent extraction kinetics of expanded granules involving higher exchange surface and greater internal diffusion process. 相似文献
28.
Journal of the Iranian Chemical Society - Utility of 4-oxo-6-styryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 1 in synthesis of a new series of fused pyrimidines was described.... 相似文献
29.
《Journal of Saudi Chemical Society》2020,24(3):321-333
Due to their structural merits that arise from their stability and high surface area, the layered double hydroxide (LDH) materials have caused strong attention. These characteristics provided intriguing possibilities with improved efficiency for catalytic applications. In this work, the preparation of 1-butyl-3-methylimidazolium hydroxide ([BMIM]+OH−) intercalated by a facile approach in a layered double hydroxide (LDH) matrix is reported and its implementation as a greener catalyst is shown. Different physico-chemical techniques such as XRD, FTIR, TGA, and N2-physisorption, HRTEM, and CO2 adsorption are implemented to characterize the structure of the fabricated catalysts. The [BMIM]+OH−/LDH exhibit outstanding catalytic performance in Knoevenagel condensation, resulting from the high LDH surface area and synergistic effects between both the intercalated ionic liquid and LDHs matrix. Knoevenagel’s fabricated catalysts can be exploited to catalyze different condensations and can be reused well. This work therefore generates good opportunities in the field of catalysis for the preparing and implementation of LDH-based catalysts. 相似文献
30.
Gouda A. A. El Sheikh R. El Sayed H. M. Khedr A. M. Al Ezz Sh. Abo Gamil W. Hamdy M. 《Journal of Applied Spectroscopy》2022,89(3):567-578
Journal of Applied Spectroscopy - A new, green, simple, and validated ultrasound-assisted dispersive microsolid-phase extraction method applying unprecedented adsorbent-modified multiwalled carbon... 相似文献