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71.
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
72.
Caroline D. Bsch Elif Abay Simon M. Langenegger Maryam Nazari Andrea Cannizzo Thomas Feurer Robert Hner 《Helvetica chimica acta》2019,102(8)
DNA‐based light‐harvesting antennae with varying arrangements of light‐absorbing phenanthrene donor units and a pyrene acceptor dye were synthesized and tested for their light‐harvesting properties. Excitation of phenanthrene is followed by rapid transfer of the excitation energy to the pyrene chromophore. A block of six light‐absorbing phenanthrenes was separated from the site of the acceptor in a stepwise manner by an increasing number of intervening AT base pairs. Energy transfer occurs through interposed AT base pairs and is still detected when the phenanthrene antenna is separated by 5 AT base pairs. 相似文献
73.
Halit Kantekin Elif Çelenk Zekeriya Bıyıklıoğlu Hülya Karadeniz 《Transition Metal Chemistry》2008,33(2):189-193
The synthesis of novel metal-free (H2-Pz) and metalloporphyrazines (MgPz and CoPz), peripherally substituted with eight aza-15-crown-5 moieties, is described.
The novel compounds were characterized by elemental analysis, i.r, 1H and 13C-n.m.r, UV–vis and m.s. spectral data. 相似文献
74.
Egorin Andrei Sokolnitskaya Tatiana Azarova Yuliya Portnyagin Arseniy Balanov Mikhail Misko Darya Shelestyuk Evgeny Kalashnikova Anastasia Tokar Eduard Tananaev Ivan Avramenko Valentin 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(1):243-251
Sorption of micro- and microamounts of Sr from seawater has been studied using granulated Na-birnessite. Distribution coefficients of 90Sr in the natural seawater are 0.8–1.2?×?103 ml g?1, in the model seawater they are 1.6–1.8?×?103 ml g?1. Application of Na-birnessite was shown to be prospective in sorption–desorption–regeneration regime. In dynamic sorption conditions, over 150 bed volumes of seawater can be purified till 5% breakthrough occurs at feed rate 10 BV h?1. Na-birnessite can be used for 90Sr radionuclide removal from liquid radioactive wastes containing seawater.
相似文献75.
Elif Parlak 《Journal of Dispersion Science and Technology》2018,39(10):1403-1408
Water insoluble sulfonated cellulose was prepared and applied for Cu2+ removal from water. The effects of sorbent dose, initial solution pH, temperature and initial Cu2+ concentration on the removal performance of sulfonated cellulose were investigated. Isothermal data were modeled with the Langmuir and Freundlich isotherm models. The Cu2+ sorption onto sulfonated cellulose followed the Langmuir isotherm model with the maximum sorption capacity of 8.2?mg-Cu2+/g. Removal of Cu2+ showed rapid initial kinetics; in 3?min removal of Cu2+ reached equilibrium status. Thermodynamic study revealed an exothermic sorption process. In addition, sulfonated cellulose is a kind of green and renewable sorbent because it can be easily regenerated by 0.1?M HCl. 相似文献
76.
Andrea Černá Branislav Hruška Darinka Tokarčíková Mária Chromčíková Marek Liška 《Chemical Papers》2018,72(9):2153-2158
Glass samples of barium crystal glass (handmade and produced by automatic technology) were weathered at controlled conditions. On the weathered glass surface, the high number of corrosion products of approximate size of (5–10) μm was found. On the unweathered (native) glass surfaces, only small non-homogeneities were observed. The micro-Raman spectroscopy was used for study of corrosion products observed by the optical microscopy. It was shown that surface roughness determined by atomic force microscopy (AFM) can be used for the quantification of degree of weathering. The stoichiometric corrosion products can be identified by Raman spectroscopy by application of the proper spectral database. The proposed method of quantification of the degree of weathering was confirmed by the coincidence of AFM results obtained for two kinds of glass samples (handmade and automatic produced) with the same chemical composition but with the different character of macroscopic surface irregularities. On the other hand, the micro-Raman spectroscopy confirmed the same chemical character of weathering process in both cases. 相似文献
77.
Elif Gungor Mustafa Burak Coban Hulya Kara Yasemin Acar 《Journal of Cluster Science》2018,29(3):533-540
A new open-cubane MnIII, [{(H2O)MnIIIL}{MnIIIL}]2·2(CH3OH).2(CH3CH2OH)·2Cl, 1 where H 2 L=[N-(2-hydroxyethyl)-3-methoxysalicylaldimine] has been synthesized and characterized by element analysis, FT-IR, solid UV–Vis spectroscopy and single crystal X-ray diffraction. The crystal structure determination shows an open-cubane tetranuclear complex. The Mn1 (Mn1i) ions is hexacoordinate by NO5 donor sets while the Mn2 (Mn2i) is pentacoordinate by NO4 donor sets. The solid state photoluminescence properties of complex 1 and its ligand H 2 L have been investigated under UV light at 349 nm in the visible region. H 2 L exhibits blue emission while complex 1 shows orange-red emission at room temperature. Variable-temperature magnetic susceptibility measurements on the complex 1 in the range 2–300 K indicate an antiferromagnetic interaction. 相似文献
78.
Improvement of catalytic properties of Candida rugosa lipase by sol-gel encapsulation in the presence of magnetic calix[4]arene nanoparticles 总被引:1,自引:0,他引:1
Candida rugosa lipase (CRL) was encapsulated within a chemically inert sol-gel support prepared by polycondensation with tetraethoxysilane (TEOS) and octyltriethoxysilane (OTES) in the presence of N-methylglucamine based calix[4]arene magnetic nanoparticles. The results indicate that the magnetic calix[4]arene based encapsulated lipase particularly has shown high conversion and enantioselectivity. It has also been noticed that the magnetic calix[4]arene based encapsulated lipase has excellent enantioselectivity (E = 460) as compared to the free enzyme (E = 166) with an ee value of >98% for S-Naproxen. 相似文献
79.
The substantial drop of the plasma temperature along magnetic field lines with increasing plasma density is one of the main features in tokamak divertors. As a result the temperature gradient at the divertor plates becomes very steep and the boundary condition normally applied for the parallel Mach number M at the target, Mt = 1, cannot be satisfied. In this case the value of Mt based on the general form of the Bohm criterion, Mt 1, has to be determined from the continuity of plasma parameters.In the present paper a new approach to resolve the Mach number at the target for such a situation is proposed. This method avoids the singularity problem that arises by treating the particle balance and parallel motion equations in a differential form. Instead, the integral representation of the equations is formulated for an arbitrary form of particle and momentum sources. The approach can also take into account transport perpendicular to the magnetic field lines.The proposed method is demonstrated on the example of a one-dimensional stationary model for the scrape-off layer (SOL) plasma and includes the continuity-, parallel momentum- and heat transfer equations. The recycled neutrals are described in the diffusion approximation. In the case of low density the normal condition Mt = 1 is satisfied and the results are in agreement with the two-point model. At high enough plasma density solutions with the supersonic flow at the divertor plates, Mt > 1, are found. These states correspond to a partially detached plasma with a temperature of a few eV. 相似文献
80.
V.I. Tokar 《Physics letters. A》1985,110(9):453-456
The total energy W(a0) lost by a charged particle in crossing a plate of thickness a0 is calculated. Intermediate transition to the Heaviside transformation is used. Several limiting cases of the Lorentz factor of particle and plate thickness are analyzed. Theory is compared with experiment. 相似文献