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61.
Ayhan
zmen Asli Karaka Ülfet Atav Yusuf Yakar 《International journal of quantum chemistry》2003,91(1):13-19
A general analytic formula is obtained for the two‐center Coulomb integrals over Slater‐type orbitals in elliptical coordinates. Finite series expansions are used in the evaluation of the radial part of the integrals. The analytic formula is expressed in terms of a product of the well‐known auxiliary functions Ak(p) and Bk(p) and incomplete gamma functions. Recursive relations for the computer evaluation of these functions are given as well. The recursive relations are stable and our computer results are in good agreement with the benchmark values given in the literature. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003 相似文献
62.
N-Substituted homochiral pyrrole derivatives were synthesized by the ring-closure reaction of cis-1,4-dichloro-2-butene with various amine compounds on a silica surface under microwave irradiation. 相似文献
63.
A novel proton conducting polymer blend was prepared by mixing poly(vinylphosphonic acid) (PVPA) with poly(1-vinylimidazole) (PVI) at various stoichiometric ratios via changing molar ratio of monomer repeating unit to achieve the highest protonation. The polymer network having the most suitable stoichiometric ratio for substantial proton conductivity was prepared and characterized by FT-IR spectroscopy and proton conductivity measurements. The network was used for immobilization of invertase and some important kinetic parameters such as the maximum reaction rate (Vmax) and Michaelis-Menten constant (Km) were investigated for the immobilized invertase. Additionally, optimum temperature and pH were determined to acquire the best conditions for the highest enzyme activity. Operational stability of the entrapped enzyme was also examined. The results reveal that the most stable and highly proton conducting polymer network may play a pioneer role in the biosensors applications as given by FT-IR, elemental analysis, impedance spectroscopy and storage stability experiments. 相似文献
64.
Maria Maares M. Menaf Ayhan Kai. B. Yu A. Ozgur Yazaydin Kevser Harmandar Hajo Haase Jens Beckmann Yunus Zorlu Gündoğ Yücesan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(48):11214-11217
A new family of porous metal–organic frameworks (MOFs), namely alkali phosphonate MOFs, is reported. [Na2Cu(H4TPPA)] ⋅ (NH2(CH3)2)2 ( GTUB-1 ) was synthesized using the tetratopic 5,10,15,20-tetrakis[p-phenylphosphonic acid] porphyrin ( H8-TPPA ) linker with planar X-shaped geometrical core. GTUB-1 is composed of rectangular void channels with BET surface area of 697 m2 g−1. GTUB-1 exhibits exceptional thermal stability. The toxicity analysis of the ( H8-TPPA ) linker indicates that it is well tolerated by an intestinal cell line, suggesting its suitability for creating phosphonate MOFs for biological applications. 相似文献
65.
Yeliz Yikilmaz Ozgur Kuzukiran Ekrem Erdogan Filiz Sen Ozlem Kirmizibayrak Ayhan Filazi 《Biomedical chromatography : BMC》2020,34(10):e4926
We aimed to develop a rapid, simple and reproducible method based on LC–tandem mass spectrometry (LC–MS/MS) to analyze β-agonist residues (clenbuterol, zilpaterol, ractopamine and isoxsuprine) in bovine tissues. The method was validated in accordance with the European Council Decision 2002/657/EC. The samples were homogenized, and then 10 mL of an acetate buffer was added to a 5-g sample. The sample was then centrifuged at 12,000 rpm and filtered. Sodium hydroxide (2 m ) was added to adjust pH of the sample that was centrifuged again. The extract was filtered through a solid-phase extraction column. The residue was re-dissolved in 250 μL acetonitrile and then subjected to LC–MS/MS. The separation was done on a C18 column. The mobile phase consisted of 0.1% formic acid in deionized water and 0.1% formic acid in methanol. The mean recoveries of β-agonists were in the range of 84.3%–119.1% with relative standard deviations (%RSDs) of 0.683%–4.05%. Decision limits and detection capabilities of the analytes ranged from 0.0960 to 4.9349 μg/kg and from 0.0983 to 5.0715, respectively. This method was used to detect four β-agonists in 100 bovine muscle, 100 liver and 100 kidney tissues from a slaughterhouse. No residue was found above the maximum residue limit level. 相似文献
66.
In this article, we introduce and examine some properties of new difference sequence spaces of fuzzy numbers defined using a sequence of modulus functions. 相似文献
67.
Bekir Çak?r Yusuf Yakar Ayhan Özmen M. Özgür Sezer Mehmet ?ahin 《Superlattices and Microstructures》2010
The binding energy and wavefunctions of the 1s, 1p, 1d and 1f energy states of a spherical quantum dot (QD) with parabolic potential were calculated by using a method which is a combination of the quantum genetic algorithm (QGA) and the Hartree–Fock–Roothaan (HFR) approach. In addition, the linear and the third-order nonlinear optical absorption coefficients based on optical transitions in QDs with and without impurity were calculated. The results show that the parabolic potential has a great effect not only on the binding energies and but also on the optical absorption coefficients. Moreover, the calculated results also reveal that the linear and nonlinear optical absorption coefficients are strongly affected by the existence of impurity and the incident optical intensity. 相似文献
68.
Steady state heat conduction in a convectively cooled sphere having arbitrarily located spherical heat sources inside is treated with the method of Green’s function accompanied by a coordinate transform. Green’s function of the heat diffusion operator for a finite sphere with Robin boundary condition is obtained by spherical harmonics expansion. Verification of the analytical solution is exemplified in some generic cases related to the pebbles of South-African PBMR as of year 2000 with 268 MW thermal power. Analytical results for different sectors of the sphere (pebble) are compared with the results of computational fluid dynamics code FLUENT™. This work is motivated through a modest effort to assess the stochastic effects of distribution and volumetric effects of fuel kernels within the pebbles of future-promising pebble bed reactors. 相似文献
69.
We focus on tandem queues with subexponential service time distributions. We assume that number of customers in front of the
first station is infinite and there is infinite room for finished customers after the last station but the size of the buffer
between two consecutive stations is finite. Using (max, +) linear recursions, we investigate the tail asymptotics of transient
response times and waiting times under both communication blocking and manufacturing blocking schemes. We also discuss under
which conditions these results can be generalized to the tail asymptotics of stationary response times and waiting times. 相似文献
70.
Gülgün Ayhan Kilcigil Rahmiye Ertan Süheyla
zbey Engin Kendi 《Journal of heterocyclic chemistry》1998,35(6):1485-1492
In this study, it is aimed to investigate the synthesis and the calcium antagonistic activity of some flavone derivatives which contain the 1,4-dihydropyridine ring system at the A ring of the flavone nucleus. For this purpose we first synthesized 6-formylflavone and then twelve 1,4-dihydropyridine derivatives were synthesized by the reaction of 6-formylflavone with alkylacetoacetates, acetoacetanilide and methyl or ethyl aminocrotonate. Conformational analysis was performed for compound 3a . The calcium antagonistic activity of compound 2a was examined using nifedipine as the reference compound. 相似文献