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141.
In this letter,the Lie point symmetries of the time fractional Fisher(TFF) equation have been derived using a systematic investigation.Using the obtained Lie point symmetries,TFF equation has been transformed into a different nonlinear fractional ordinary differential equations with the Erd′elyi–Kober fractional derivative which depends on the parameter α.After that some invariant solutions of underlying equation are reported. 相似文献
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An investigation into the effects of unsteady parameters on the aerodynamics of a low Reynolds number pitching airfoil 总被引:1,自引:0,他引:1
The growing applications of low Reynolds number (LRN) operating vehicles impose the need for accurate LRN flow solutions. These applications usually involve complex unsteady phenomena, which depend on the kinematics of the vehicle such as pitching, plunging, and flapping of a wing. The objective of the present study is to address the issues related to LRN aerodynamics of a harmonically pitching NACA0012 airfoil. To this end, the influence of unsteady parameters, namely, amplitude of oscillation, d, reduced frequency, k, and Reynolds number, Re, on the aerodynamic performance of the model is investigated. Computational fluid dynamics (CFD) is utilized to solve Navier–Stokes (N–S) equations discretized based on the Finite Volume Method (FVM). The resulting instantaneous lift coefficients are compared with analytical data from Theodorsen’s method. The simulation results reveal that d, k, and Re are of great importance in the aerodynamic performance of the system, as they affect the maximum lift coefficients, hysteresis loops, strength, and number of the generated vortices within the harmonic motion, and the extent of the so-called figure-of-eight phenomenon region. Thus, achieving the optimum lift coefficients demands a careful selection of these parameters. 相似文献
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Beshare Hashemi Mojtaba Shamsipur Zahra Seyedzadeh 《Journal of separation science》2016,39(10):2006-2012
An analytical method is reported for the preparation of K+‐imprinted nanoparticles using cryptand 222 as the complexing agent, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinker and 2,2′‐azobisisobutyronitrile as the radical initiator. The prepared particles have a diameter of 200–250 nm. The maximum adsorption capacity of potassium ion‐imprinted polymer particles was 120 μmol/g. The optimum pH for quantitative extraction was 9.0. The nature of the eluent, eluent concentration, adsorption and desorption times, weight of the polymer material, aqueous phase, and desorption volumes were also studied. The relative selectivity coefficients of K+/Li+, K+/Na+, K+/Rb+ and K+/Cs+ were 48.10, 4.80, 29.70, and 43.4, respectively. The relative standard deviation and limit of detection of the method were obtained 1.61% and 4.62 ng/L, respectively. Finally, the method was applied for the determination of potassium ions from different samples using flame photometry. 相似文献
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Three‐Step Synthesis of Novel 2‐Aryl‐3‐benzamidobenzofurans: Regiospecific Reactions Catalyzed by Molybdate Sulfuric Acid
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Fatemeh Hashemi Bahador Karami Saeed Khodabakhshi 《Journal of heterocyclic chemistry》2014,51(2):322-326
A solvent‐free and synthetic pathway to novel benzofuran derivatives, starting from oxidation of phenyl ketones to arylglyoxals in three steps was developed. The molybdate sulfuric acid catalyzed the reaction of arylglyoxals with benzamide and phenols to afford 2‐aryl‐3‐benzamidobenzofurans in high yield. The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR, 1H NMR, and 13C NMR spectral data. The present methodology offers several advantages such as non‐hazardous reaction condition, simple operation, and work‐up procedure. 相似文献
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Physical–chemical hybrid transiency: A fully transient li‐ion battery based on insoluble active materials
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Yuanfen Chen Reihaneh Jamshidi Kathryn White Simge Çınar Emma Gallegos Nastaran Hashemi Reza Montazami 《Journal of Polymer Science.Polymer Physics》2016,54(20):2021-2027
Transient Li‐ion batteries based on polymeric constituents are presented, exhibiting a twofold increase in the potential and approximately three orders of magnitude faster transiency rate compared to other transient systems reported in the literature. The battery takes advantage of a close variation of the active materials used in conventional Li‐ion batteries and can achieve and maintain a potential of >2.5 V. All materials are deposited form polymer‐based emulsions and the transiency is achieved through a hybrid approach of redispersion of insoluble, and dissolution of soluble components in approximately 30 min. The presented proof of concept has paramount potentials in military and hardware security applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2021–2027 相似文献