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91.
Mehmet Akkurt Sema
ztürk Hakan Üngren Mustafa Samac Hoong‐Kun Fun Yunus Akamur 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(10):o598-o600
The title compound, C24H25NO7, is a racemic mixture of 2,3‐dihydro‐1H‐pyrrol‐3‐ones. It crystallizes in the triclinic system, space group P1, with Z = 2. The asymmetric unit contains two enantiomorphic molecules and the structure is stabilized by hydrogen‐bond contacts. 相似文献
92.
Mustafa Samac evket Hakan Üngren Yunus Akamur Cengiz Arc Diner Ülkü 《Heteroatom Chemistry》2005,16(3):235-241
Furan‐3(2H)‐ones ( 3 ) were obtained from some 2,3‐dihydro‐furan‐2,3‐diones with a few Wittig reagents ( 2 ). The compounds of 3 with glycin and hydrazines ( 4a,b ) produced 2,3‐dihydro‐1H‐pyrrol‐3‐ones ( 5a–d ). All the reaction mechanisms were discussed by utilizing the similar reaction pathways. Structures of these compounds were determined by the IR, NMR, elemental analysis, and X‐ray diffraction method. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:235–241, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20115 相似文献
93.
Thin films of tin sulphide (SnS) were deposited on tin oxide conducting glass substrates by thermal evaporation technique. The transmission spectrum of the SnS film in the wavelength range from 300 to 1100 nm has been obtained. X-ray diffraction has been used to determine the structure of the films. The film thickness and refractive index have been estimated from the transmission spectra. The results showed that the refractive index of the SnS thin films is thickness independent in the wavelength range 590 ≤ λ ≤ 1100 nm and found to be ~ 1.72. This result indicates that the SnS thin films are homogeneous and isotropic. The energy band gaps were found to be between 1.06 and 1.32 eV, which is in good agreement with literature values. The energy dependence of the obtained refractive index is also investigated. 相似文献
94.
Shankar A. Hallad N. R. Banapurmath T. M. Yunus Khan M. A. Umarfarooq Manzoore Elahi M. Soudagar Anand M. Hunashyal Sandeep V. Gujjar Jayachandra S. Yaradoddi Sharanabasava V. Ganachari Ashraf Elfasakhany Md Irfanul Haque Siddiqui Masood Ashraf Ali 《Molecules (Basel, Switzerland)》2021,26(14)
Epoxy resins, due to their high stiffness, ease of processing, good heat, and chemical resistance obtained from cross-linked structures, have found applications in electronics, adhesives coatings, industrial tooling, and aeronautic and automotive industries. These resins are inherently brittle, which has limited their further application. The emphasis of this study is to improve the properties of the epoxy resin with a low-concentration (up to 0.4% by weight) addition of Multi-Walled Carbon Nanotubes (MWCNTs). Mechanical characterization of the modified composites was conducted to study the effect of MWCNTs infusion in the epoxy resin. Nanocomposites samples showed significantly higher tensile strength and fracture toughness compared to pure epoxy samples. The morphological studies of the modified composites were studied using Scanning Electron Microscopy (SEM). 相似文献
95.
96.
Guney E Kaya Y Yilmaz VT Gumus S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1171-1178
New palladium(II) and platinum(II) complexes of saccharinate (sac) with 2-(2-pyridyl)benzimidazole (pybim) have been synthesized and characterized by elemental analysis and spectroscopic techniques. From the experimental studies, these complexes were formulated as [Pd(pybim)(sac)2] (1), and [Pt(pybim)(sac)2]·4H2O (2). The ground-state geometries of both complexes were optimized using density functional theory (DFT) methods at the B3LYP level. A bidentate pybim ligand together with two N-coordinated sac ligands form the square-planar MN4 coordination geometry around the palladium(II) and platinum(II) ions. The calculated IR and UV-vis spectral data have been correlated to the experimental results. Thermal analysis data support the molecular structures of both complexes. 相似文献
97.
In this article we study two problems raised by a work of Conrey and Ghosh from 1989. Let ζ(k)(s) be the k-th derivative of the Riemann zeta-function, and χ(s) be factor in the functional equation of the Riemann zeta-function. We calculate the average values of ζ(j) and χ at the nontrivial zeros of ζ(k). 相似文献
98.
Saeideh Ebrahimiasl Wan Md. Zin Wan Yunus Anuar Kassim Zulkarnain Zainal 《Solid State Sciences》2010,12(8):1323-1327
Transparent conductive films of tin oxide were deposited on glass substrates under various deposition conditions. Taguchi analysis was used to model the dependence of the grain size, thickness and absorbance of nanocrystalline tin oxide on the process parameters namely pH value, concentration, time of deposition and bath temperature. The effect of the mentioned process parameters on the grain size, thickness and absorbance of deposited layer during the deposition of nanocrystalline was investigated using X-ray diffraction (XRD) technique, atomic force microscopy (AFM) and UV–Visible spectroscopy. Comparison between the model predictions and the experimental observations predicted a remarkable agreement between them. The predictions of the model and sensitivity analysis showed that among the effective process parameters, deposition time and concentration were the main parameters having significant effect on crystalline size. Bath temperature had the most significant effect on absorbance and deposition time had a dominant effect on thickness. 相似文献
99.
Sibel Alkan Bülent Zeybek Alev Doğan Rahmi Kasımoğulları Yunus Erdoğan Esma Kılıç 《Monatshefte für Chemie / Chemical Monthly》2009,140(4):381-386
Abstract Stoichiometric ionization constants of some pyrazole carboxylic acids [4-benzoyl-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic
acid, 4-benzoyl-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid, 4-(ethoxycarbonyl)-1,5-diphenyl-1H-pyrazole-3-carboxylic
acid, 4-(ethoxycarbonyl)-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid, 4-(ethoxycarbonyl)-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic
acid] were determined in ethanol–water mixtures of 50, 60, 70% ethanol (v/v) by a potentiometric titration method. Titrations
were performed in an ionic strength of 0.10 M NaCl at 25.0 ± 0.1 °C using an Orion 960 automatic titrator under a nitrogen
atmosphere. Using the potentiometric titration data, ionization constants were calculated in three different ways. The effects
of structure and solvent on the acidity of pyrazole carboxylic acids are also discussed.
Graphical abstract
相似文献
100.
Z.A. Talib W.M. Daud E.Z.M. Tarmizi H.A.A. Sidek W.M.M. Yunus 《Journal of Physics and Chemistry of Solids》2008,69(8):1969-1973
Homogeneous CaO-P2O5 and Cu2O-CaO-P2O5 glasses were prepared using a melt-quenched method under controlled conditions. The binary glasses were found to be colourless and transparent while the ternary glasses changed from light green to dark green as the Cu2O content increased. From the absorption edge studies, the values of the optical band gap, Eopt and Urbach energy, ΔE were evaluated. The position of the absorption edge and hence the optical band gap were found to depend on the glass composition. Analysis of the optical band gap shows that for the binary glasses, the value increases as the content of CaO decreases, while for the ternary glasses, the value of the optical band gap increases as the content of the Cu2O decreases. The density of the glasses was also measured and was found to increase with the increase in CaO and Cu2O contents. 相似文献