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131.
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133.
We consider the Laplace equation in ? d?1 × ?+ × (0,+∞) with a dynamical nonlinear boundary condition of order between 1 and 2. Namely, the boundary condition is a fractional differential inequality involving derivatives of noninteger order as well as a nonlinear source. Nonexistence results and necessary conditions are established for local and global existence. In particular, we show that the critical exponent depends only on the fractional derivative of the least order. 相似文献
134.
We consider the following nonlinear viscoelastic equation together with Dirichlet-boundary conditions, in a bounded domain Ω and ρ > 0. We prove an exponential decay result for a class of relaxation functions. Our result is established without imposing the usual relation between g and its derivative (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
135.
Nasser-eddine Tatar 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2009,60(4):640-650
In this paper we consider a problem which arises in viscoelasticity. We prove exponential decay of solutions for the problem
with a memory term involving a kernel which is singular at zero. This is established by introducing an appropriate Lyapunov
type functional and using the energy method. This work extends earlier results.
相似文献
136.
A sensitive HPLC method with pre-column fluorescence derivatization using 4-Fluoro-7-Nitrobenzofurazan (NBD-F) has been developed for the determination of gabapentin in pharmaceutical preparations. The method is based on the derivatization of gabapentin with (NBD-F) in borate buffer of pH 9.5 to yield a yellow, fluorescent product. The HPLC separation was achieved on a Inertsil C(18) column (250 mm × 4.6 mm) using a mobile phase of methanol water (80:20, v/v) solvent system at 1.2 mL/min flow rate. Mexiletine was used as the internal standard. The fluorometric detector was operated at 458 nm (excitation) and 521 nm (emission). The assay was linear over the concentration range of 5 50 ng/mL. The method was validated for specificity, linearity, limit of detection, limit of quantification, precision, accuracy, robustness. Moreover, the method was found to be sensitive with a low limit of detection (0.85 ng/mL) and limit of quantitation (2.55 ng/mL). The results of the developed procedure for gabapentin content in capsules were compared with those by the official method (USP 32). Statistical analysis by t- and F-tests, showed no significant difference at 95 confidence level between the two proposed methods. 相似文献
137.
In this study, the effect of Zn-dopant on the physical properties and microstructure of hydroxyapatite (HAP) bioceramics was
investigated. The average crystallite size, phase composition and degree of crystallization of the pure hydroxyapatite and
Zn-doped hydroxyapatite bioceramic samples prepared by sol–gel method were determined by X-ray diffraction method. It was
seen that all the bioceramic samples were composed of the nanoparticles (29–46 nm). Fourier transform infrared spectroscopy
was used to determine the functional groups in the samples. The dielectric properties of the bioceramics were investigated
by dielectric impedance spectroscopy method, and the surface morphologies of them were analyzed using scanning electron microscopy
technique. When the densities of the samples were measured by Archimedes method, it was seen that the densities of the samples
increased with the increase of the molar ratio of Zn. The crystallization degree for all the samples dramatically decreased
with the increasing content of the Zn dopant. With the increase of Zn to HAP, a change was observed in the degree of the crystallization,
phase compositions, dielectric properties and microstructures of the samples. 相似文献
138.
α,α-Dibromo-2-methoxyacetophenone reacts, under mild reaction conditions, with C-, N- and O-nucleophiles via a bromophilic substitution/protonation/carbophilic substitution cascade process to afford α-monosubstituted-2-methoxyacetophenones in moderate to good yield. The only exception from this reaction pathway is the reaction with the anion derived from malononitrile in which 2-aroyl-1,1,3,3-tetracyanopropene is obtained. 相似文献
139.
Fahir Talay Akyildiz Salih Tatar Suleyman Ulusoy 《Mathematical Methods in the Applied Sciences》2013,36(17):2397-2402
This paper analyzes the existence and the uniqueness problem for an n‐dimensional nonlinear inverse reaction‐diffusion problem with a nonlinear source. A transformation is used to obtain a new inverse coefficient problem. Then, a parabolic differential operator Lλ is defined to establish the relation between the solution of Lλ = 0 and the new inverse problem. Following this, it is shown that the inverse problem has at least one solution in the class of admissible coefficients. Furthermore, it is proved that this solution is the unique solution of the undertaken inverse problem. A numerical example is given to illustrate ill‐posedness of the inverse problem. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
140.
We establish new results for the radial nonlinear wave and Schrödinger equations on the ball in and , for random initial data. More precisely, a well-defined and unique dynamics is obtained on the support of the corresponding Gibbs measure. This complements results from Burq and Tzvetkov (2008) [8], [9] and Tzvetkov (2006, 2008) [10], [11]. 相似文献