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11.
Melis Ulu 《International Journal of Theoretical Physics》2011,50(2):356-363
In this paper, we intend to clarify the energy-momentum problem of higher dimensional Vaidya space-time in the general theory of relativity. In this connection, Møller energy and momentum for the higher dimensional Vaidya space-time are evaluated in the frame of general relativity. We have obtained that the Møller energy distribution of higher dimensional Vaidya space-time is equal to zero, while the Møller momentum distribution of higher dimensional Vaidya space-time is not equal to zero. 相似文献
12.
Yıldırım Işıl Aktaş Aydın Celepci Duygu Barut Kırbağ Sevda Kutlu Türkan Gök Yetkin Aygün Muhittin 《Research on Chemical Intermediates》2017,43(11):6379-6393
Research on Chemical Intermediates - This article describes synthesis of N-morpholinoethylbenzimidazole (1), 2-morpholinoethyl-substituted benzimidazolium salts (NHC precursors, 2a–c), and... 相似文献
13.
For a commutative algebra R, its de Rham cohomology is an important invariant of R. In the paper, an infinite chain of de Rham-like complexes is introduced where the first member of the chain is the de Rham complex. The complexes are called approximations of the de Rham complex. Their cohomologies are found for polynomial rings and algebras of power series over a field of characteristic zero. 相似文献
14.
The Decay of Massive Scalar Field in Non-Static Gödel Type Universe with Viscous Fluid and Heat Flow
In this study, we have investigated the dynamics of non-static Gödel type rotating universe with massive scalar field, viscous fluid and heat flow in the presence of cosmological constant. For various cosmic matter forms, the behavior of the cosmological constant (Λ), shear (η) and bulk (ξ) viscosity coefficients and other kinematic quantities have studied in the early universe. We have showed the decay of massive scalar field in the non-static rotating Gödel type universe and we have obtained constant scalar field with and without source density. Also, we have investigated the effects of massive scalar field on the matter density and pressure. From solutions of the field equations, we have a cosmological model with non-zero expansion, shear, heat flux and rotation. Also some physical and geometrical aspects of the model discussed. 相似文献
15.
In order to evaluate the energy distribution (due to matter and fields including gravitation) associated with a space-time model of Szekeres class I and II metrics, we consider the Einstein, Bergmann–Thomson and Landau–Lifshitz energy definitions in the teleparallel gravity (the tetrad theory of gravitation (TG)). We have found that Einstein and Bergmann–Thomson energy distributions give the same results, Landau–Lifshitz distribution is disagree in TG with these definitions. These results are the same as a previous works of Aygün et al., they investigated the same problem by using Einstein, Bergmann–Thomson, Landau–Lifshitz (LL) and Møller energy-momentum complexes in GR. However, both GR and TG are equivalent theories that is the energy densities are the same using different energy-momentum complexes in both theories. Also, our results are support the Cooperstock’s hypothesis. 相似文献
16.
17.
Anthony Blanchard Flavien Melis Fabrice Gouanvé Jean-Matthieu Brouillat Eliane Espuche 《Journal of polymer science. Part A, Polymer chemistry》2021,59(1):70-83
The influences of the molar mass (low, medium, and high) and content of poly(vinyl alcohol) (PVOH) dispersed by melt-blending in an ethylene vinyl alcohol (EVOH) copolymer on the morphology, microstructure, thermal, mechanical, and oxygen barrier properties were investigated. Multilayer films with external low-density polyethylene layers and inner EVOH/PVOH blend layer and respective monolayer films were elaborated and characterized. EVOH/PVOH blends exhibited a good compatibility because of the initial presence of PVOH segments in EVOH. The detailed quantitative analysis of the morphology performed for all blends showed that the finest dispersion was obtained with the PVOH with the lowest molar mass. The properties of the films as a function of the PVOH content and its molar mass were determined herein. Significant improvement of barrier properties was obtained at moderated water activities (up to aw = 0.6) by using the PVOH with the lowest molar mass. Compared to the neat EVOH material, the oxygen permeability coefficients decreased by a factor 2 by adding 15 vol% PVOH while the thermal and mechanical properties remained similar. 相似文献
18.
Aydın Aktaş Ünzile Keleştemur Yetkin Gök Sevgi Balcıoğlu Burhan Ateş Muhittin Aygün 《Journal of the Iranian Chemical Society》2018,15(1):131-139
In this study, a series of unsymmetrically 2-morpholinoethyl-substituted benzimidazolium salts and their Ag(I)NHC complexes were synthesized. The 1,3-dialkylbenzimidazolium salts (1a–d) were synthesized in dimethylformamide at 80 °C temperature from the N-(2-morpholinoethyl)benzimidazole and alkyl halides. The Ag(I)NHC complexes (2a–d) were synthesized in dichloromethane at room temperature from the benzimidazolium salts and Ag2O. All compounds were characterized by spectroscopic techniques (NMR and FT-IR) and elemental analyses. Also, the salt 1c and complex 2c were characterized by single-crystal X-ray crystallography. Anticancer activities of 2-morpholinoethyl-substituted benzimidazolium salts and Ag(I)NHC complexes were investigated against the MCF-7 breast cancer cell line, and the IC30 and IC50 values of these compounds were found to be in the range of 241–490 and 6–14 µM, respectively. 相似文献
19.
Mahmut Ulusoy Hasan Karabıyık Rafet Kılınçarslan Muhittin Aygün Bekir Çetinkaya Santiago García-Granda 《Structural chemistry》2008,19(5):749-755
Copper(II) and cobalt(II) complexes of salicylaldimine obtained by the condensation of N,N-diethyl-2-methyl-1,4-phenylenediamine with 3,5-di-tert-butyl-2-hydroxybenzaldehyde have been synthesized and characterized by elemental analyses, magnetic susceptibility measurements,
cyclic voltammetry, and FT-IR and UV–Vis spectroscopy. The molecular structure of the title copper(II) complex was determined
by the single crystal X-ray diffraction technique. The Cu(II) center is coordinated by four atoms of the donor set in a compressed
tetrahedral trans-[N2O2] environment, which can be essentially ascribed to the presence of bulky fragments of the ligand. The computed bond valences
of the copper verify +2 oxidation state and indicate that the copper bonds, in particular Cu–N bonds, are elongated due to
steric effects from bulky substituents in the ligands, N-(4-diethylamino-2-methylphenyl). Intermolecular C–H···π interactions leading to centrosymmetric synthons serve to stabilize
periodic organization of the molecules. 相似文献
20.
Highly Luminescent Cesium Lead Halide Perovskite Nanocrystals with Tunable Composition and Thickness by Ultrasonication 下载免费PDF全文
Yu Tong Eva Bladt Meltem F. Aygüler Aurora Manzi Dr. Karolina Z. Milowska Verena A. Hintermayr Prof. Dr. Pablo Docampo Prof. Dr. Sara Bals Dr. Alexander S. Urban Dr. Lakshminarayana Polavarapu Prof. Dr. Jochen Feldmann 《Angewandte Chemie (International ed. in English)》2016,55(44):13887-13892
We describe the simple, scalable, single‐step, and polar‐solvent‐free synthesis of high‐quality colloidal CsPbX3 (X=Cl, Br, and I) perovskite nanocrystals (NCs) with tunable halide ion composition and thickness by direct ultrasonication of the corresponding precursor solutions in the presence of organic capping molecules. High angle annular dark field scanning transmission electron microscopy (HAADF‐STEM) revealed the cubic crystal structure and surface termination of the NCs with atomic resolution. The NCs exhibit high photoluminescence quantum yields, narrow emission line widths, and considerable air stability. Furthermore, we investigated the quantum size effects in CsPbBr3 and CsPbI3 nanoplatelets by tuning their thickness down to only three to six monolayers. The high quality of the prepared NCs (CsPbBr3) was confirmed by amplified spontaneous emission with low thresholds. The versatility of this synthesis approach was demonstrated by synthesizing different perovskite NCs. 相似文献