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21.
Mehmet Bağmancı Muharrem Karaaslan Emin Ünal Oguzhan Akgol Cumali Sabah 《Optical and Quantum Electronics》2017,49(7):257
A new metamaterial absorber (MA) is investigated and shown numerically for solar energy harvesting for future solar cell applications. The structure consists of two metals and one dielectric layer having different thicknesses. Owing to this combination, the structure exhibits plasmonic resonance characteristics. In the entire spectrum of visible frequency region, the obtained results show that investigated structure has perfect absorptivity which is above 91.8%. Proposed structure also has 99.87% absorption at 613.94 THz and 99% absorption between 548 and 669 THz. The proposed structure also shows both polarization and angle independency for the entire visible region. The MA based solar cell proposes high absorption with an upper ratio of 90% in the widest range of visible spectrum comparing to the studies in literature. Hence, the proposed metamaterial absorber solar cells can be used for invisibility in entire spectrum of visible light. The absorption characteristics of the solar absorber are also investigated for infrared and ultraviolet region. The enhancement of absorption of the structure will provide new type of sensors in these frequency ranges. 相似文献
22.
Osman Dayan Muharrem Diner Bekir etinkaya Namk
zdemir 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):m315-m318
In the title compound, [CuCl2(C11H15N3O2)], the CuII ion is five‐coordinated in a strongly distorted trigonal–bipyramidal arrangement, with the two methyloxime N atoms located in the apical positions, and the pyridine N and the Cl atoms located in the basal plane. The two axial Cu—N distances are almost equal (mean 2.098 Å) and are substantially longer than the equatorial Cu—N bond [1.9757 (15) Å]. It is observed that the N(oxime)—M—N(pyridine) bond angle for five‐membered chelate rings of 2,6‐diacetylpyridine dioxime complexes is inversely related to the magnitude of the M—N(pyridine) bond. The structure is stabilized by intra‐ and intermolecular C—H⋯Cl hydrogen bonds which involve the methyl H atoms, except for one of the two acetylmethyl groups. 相似文献
23.
Muharrem Diner Namk
zdemir Ahmet etin Tekin Keser Orhan Büyükgüngr 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(11):o639-o642
In the title compound, C22H25N5OS·2H2O, the molecules are stacked in columns running along the b axis. In this arrangemant, the molecules are linked to each other by a combination of one two‐centre N—H⋯O hydrogen bond and four two‐centre O—H⋯O hydrogen bonds containing two types of ring motif, viz.R44(10) and R33(11). In the crystal structure, centrosymmetric π–π interactions between the triazole rings, with a distance of 3.691 (2) Å between the ring centroids, also affect the packing of the molecules. 相似文献
24.
Tuncay Karakurt Muharrem Dinçer Alaaddin Çukurovali 《International journal of quantum chemistry》2012,112(2):394-413
The molecular geometry, vibrational frequencies, and gauge including atomic orbital (GIAO) 1H‐ and 13C NMR chemical shift values of the title compound in the ground state have been calculated using the Hartree‐Fock (HF) and density functional theory (DFT) methods with 6‐31G(d) basis sets, and compared with the experimental data. The calculated results show that the optimized geometries can well reproduce the crystal structural parameters and the theoretical vibrational frequencies, and 1H‐ and 13C NMR chemical shift values show good agreement with experimental data. To determine conformational flexibility, the molecular energy profile of the title compound was obtained by semiempirical (AM1) calculations with respect to the selected torsion angle, which was varied from ?180° to +180° in steps of 10°. The energetic behavior of the title compound in solvent media was examined using the B3LYP method with the 6‐31G(d) basis set by applying the Onsager and the polarizable continuum model (PCM). The results obtained with these methods reveal that the PCM method provided more stable structure than Qnsager's method. By using TD‐DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD‐DFT method and the experimental one is determined. The predicted nonlinear optical properties of the title compound are much greater than ones of urea. In addition, the molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis, NBO analysis and thermodynamic properties of the title compound were investigated using theoretical calculations. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012 相似文献
25.
An efficient one pot asymmetric synthesis of tetrahydropyrano[2,3-c]pyrazoles has been developed. This class of biologically active heterocycles can be obtained via a secondary amine catalyzed asymmetric Michael/Wittig/oxa-Michael reaction sequence. Remarkably, the title compounds were accessible in good to very good yields and very good to excellent enantioselectivities after a single purification step. 相似文献
26.
Acrylamide concentrations in grilled foodstuffs of Turkish kitchen by high performance liquid chromatography-mass spectrometry 总被引:3,自引:0,他引:3
Olcay Kaplan Gokce Kaya Cemile Ozcan Muharrem Ince Mehmet Yaman 《Microchemical Journal》2009,93(2):173-179
For over ten years, there has been a considerable interest in determination of acrylamide in foodstuffs. It was known that both protein-rich and carbohydrates-rich foods cooked at high-temperatures can cause acrylamide formation. However, carbohydrates-rich foods such as potato chips and biscuit samples have been the common studied foods compared with protein-rich foods such as meat samples.In this study, determination of acrylamide in these two group foods was examined using HPLC-MS. For this purpose, firstly, the parameters that are thought to affect the response in the HPLC-MS analysis were optimized. The optimized conditions were found to be 0.3 ml min− 1 for flow rate of mobile phase, 40 µl for injection volume, 5 °C for column temperature and 70 V for fragmentor potential. The optimized method was applied for the determination of acrylamide levels in Turkish foodstuffs including grilled meat and chicken samples, potato chips, coffee and biscuit. The obtained concentrations for all studied foods were in the range of 20–250 µg kg− 1. The results showed that acrylamide concentrations highly varied depending on the kind of food samples. 相似文献
27.
In this paper, we study a type of modified Boussinesq equations which is called g-Bénard problem. We show the existence and uniqueness of strong solutions of the problem in two dimensions, and then, we investigate the continuous dependence of the solutions on the viscosity parameter. 相似文献
28.
Yrjö Kauko und Muharrem Içel 《Fresenius' Journal of Analytical Chemistry》1954,142(6):401-406
Ohne ZusammenfassungDie führliche Darstellung dieser Arbeit wird als Doktorarbeit von Muharrem Içel demnächst in französischer Sprache erscheinen in der Zeitschrift: A. Ü. Fen Fakultesi Mecmuasi, Ankara. 相似文献
29.
The present study on tetrazole compounds, which have a wide area of application, proposes a new, simple and highly effective method. A series of 5-substituted 1H-tetrazoles were synthesised in DMF via the [3 + 2] cycloaddition reaction, in which different aryl nitriles with sodium azide were used and copper(I) chloride served as a catalyst. Short reaction times, high yields and simple procedures rendered this method attractive and useful for the organic synthesis of 5-substituted 1H-tetrazoles. A further advantage was the use of an environmentally friendly catalyst. 相似文献
30.
In this work, four new Nd (III) and Sm (III) complexes of two pentadendate ligands (L1 and L2) were prepared and their molecular structures were determined by single crystal X‐ray diffraction studies. X‐ray analysis showed that the Nd (III) and Sm (III) complexes of L1 sits on a twofold crystallographic axis while the complexes of L2 does not show crystallographically imposed symmetry. Absorption and photoluminescence properties of the complexes were studied both in the solid state and DMF solutions. The fluorescence sensing of nitro‐aromatic compounds [nitrobenzene (NB), 4‐nitrophenol (NP), 2,4‐dinitrophenol (DNP) and 2,4,6‐trinitrophenol (TNP)] were studied by photoluminescence spectroscopy. All four complexes showed better sensitivity towards nitrophenol (NP) with low LOD values. 相似文献