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排序方式: 共有133条查询结果,搜索用时 26 毫秒
41.
42.
Gulsiye Ozturk Urut Seher Aydin Derya Topkaya Elif Sahin Serap Alp 《Journal of fluorescence》2018,28(3):735-741
New fluorescent thiophenyl group containing oxazol-5-one fluorophores of 3a (4-(3-thiophenylmethylene)-2-phenyloxazol-5-one), 3b (4-(3-thiophenylmethylene)-2-(4-tolyl)oxazol-5-one) and 3c (4-(3-thiophenylmethylene)-2-(4-nitrophenyl)oxazol-5-one) were synthesized and characterized. The newly synthesized oxazol-5-ones absorption and fluorescence characteristics were studied in some solvents of varying polarities. The heterocyclic chromophores were fluorescent, with two of them, 3a and 3b, emitting blue light, whilst the other one, 3c, emitting green light. The emission maxima of the derivatives varied between 415 and 572 nm according as the extent of conjugation and solvent polarity. As solvent polarity increased, 3c derivatives emission spectra displayed a large bathochromic shift, which revealed the considerable change of the dipole moment of the fluorescent structure because of an intramolecular charge transfer interaction. Furthermore, oxazolones polymerization ability via the thiophenyl group linked to the oxazol-5-one heterocycle showed that copolymerization of 3a was achieved, but homopolymerization was not observed. 相似文献
43.
Y. Atalay A. Baolu D. Avc M. Arslan T. Ozturk E. Ertas 《Physica B: Condensed Matter》2008,403(12):1983-1989
The synthesis and optical properties of the 5,5′,6,6′-tetraphenyl-2,2′-bi([1,3]dithiolo [4,5-b] [1,4]dithiinylidene)–2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) complex thin film were investigated by the optical characterization. The optical constants such as refractive index, extinction coefficient and absorption coefficient were determined using the transmittance T(λ) and reflectance R(λ) spectra and the refractive index dispersion was analyzed using single oscillator of Wemple–Didomenico model. The single oscillator energy E0 and the dispersion energy Ed were calculated. The effect of temperature on refractive dispersion and optical band gap Eg is also discussed. As a result, the annealing temperatures have an important effect on refractive index of thin film. 相似文献
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A Monte Carlo power study of 10 multivariate normality goodness-of-fit tests is presented. First, multivariate goodness-of-fit methods and non-normal alternatives are classified according to their characteristics. Then, a measurement tool is defined, validated, and used to assess the performance of the methods, which are then ranked by type of alternative they best detect. Finally, Monte Carlo-derived empirical critical values for the 8 procedures, valid when samples are too small to invoke asymptotic theory, are provided. 相似文献
46.
Ozturk B Behin-Aein G Flanders BN 《Langmuir : the ACS journal of surfaces and colloids》2005,21(10):4452-4457
Harnessing the spontaneous behavior of a population of particles is an attractive approach to the fabrication of targeted nanostructures. Underlying this goal is the interparticle potential, as it dictates the spontaneous behavior of the system. To this end, we present methodology for using quantitative film balance studies of trioctylphosphine oxide (TOPO) stabilized CdSe nanoparticles to determine their effective interparticle potential on the air-water interface. A simple protocol for reducing the quantity of excess TOPO to negligible levels of surface activity is established. In studying clean populations of 2.08, 2.22, 2.36, 2.49, 2.63, and 2.91 nm nanoparticles, quantitative agreement between their pressure-area isotherms and the Carnahan-Starling hard-disk equation of state is achieved. This analysis indicates that CdSe nanoparticles of a given diameter behave how hard disks with significantly smaller diameters would behave. This finding suggests that an attractive contribution to the interparticle potential, such as the dipolar potential, plays a significant role in the spontaneous organization of these particles. 相似文献
47.
Novel 5-oxazolone derivatives containing an N-phenyl-aza-15-crown-5 moiety were synthesized for the first time. The structures of the new derivatives were confirmed by 1H NMR, 13C NMR and FT-IR. In addition, evaluation of the visible absorption and emission properties of the structures were carried out in eight different solvents. The products show intense visible absorption maxima in the range 467-524 nm, and fluoresced strongly, with emission maxima from 496 to 689 nm in all the solvents tested. 相似文献
48.
Ozturk Tugba Cengiz Elif Ceylan Demir-Cakan Rezan Erbil H. Yildirim 《Journal of Solid State Electrochemistry》2022,26(8):1747-1759
Journal of Solid State Electrochemistry - Porous cathodes are preferred to be used in lithium-sulfur (Li–S) batteries for better impregnation of the active material. On the other hand, the... 相似文献
49.
Recep Isci Dilara Gunturkun Ahsen Sare Yalin Turan Ozturk 《Journal of polymer science. Part A, Polymer chemistry》2021,59(1):117-123
Two novel copolymers of 4-thieno[3,2-b]thiophen-3-ylbenzonitrile (TT-CN), possessing electron withdrawing cyano moiety, with anthracene (P1) and biphenyl (P2) were prepared via Suzuki coupling. Optic, electronic, and thermal properties of the copolymers were investigated through UV–Vis spectroscopy, cyclic voltammetry, gel permeation chromatography, and thermal gravimetric analysis. The polymers with anthracene and biphenyl had electronic band gaps of 2.01 and 1.90 eV, respectively. Both polymers demonstrated excellent large Stokes shifts of 101 (anthracene) and 105 nm (biphenyl) as well as very good thermal properties. As they had good optical, electronic, and thermal properties, they are promising candidates for electronic applications. 相似文献
50.