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61.
O. V. Kirichenko V. G. Peschanskii R. A. Hasan 《Journal of Experimental and Theoretical Physics》2007,105(1):160-164
The linear response of the electron system of a layered conductor to the temperature gradient in this system in a strong magnetic field is investigated theoretically. Thermoelectric emf is studied as a function of the magnitude and orientation of a strong external magnetic field; the experimental investigation of this function, combined with the study of the electric and thermal resistance, allows one to completely determine the structure of the energy spectrum of charge carriers. 相似文献
62.
Hasan Kırmızıbekmez Yiğit İnan Rengin Reis Hande Sipahi Ahmet C. Gören Erdem Yeşilada 《Natural product research》2019,33(17):2541-2544
Phytochemical investigations on the EtOH extract of Clematis viticella led to the isolation of six flavonoid glycosides, isoorientin (1), isoorientin 3′-O-methyl ether (2), quercetin 7-O-α-L-rhamnopyranoside (3), quercetin 3,7-di-O-α-L-rhamnopyranoside (4), manghaslin (5) and chrysoeriol 7-O-β-D-glucopyranoside (6), one phenylethanol derivative, hydroxytyrosol (7), along with three phenolic acids, caffeic acid (8), (E)-p-coumaric acid (9) and p-hydroxybenzoic acid (10). The structures of the isolates were elucidated on the basis of NMR and HR-MS data. All compounds were isolated from C. viticella for the first time. Compounds 7 and 8 showed significant anti-inflammatory activity at 100 μM by reducing the release of NO in LPS-stimulated macrophages comparable to positive control indomethacin. Compounds 3 and 7 exhibited anti-inflammatory activity through lowering the levels of TNF-α while 1, 3 and 5 decreased the levels of neopterin better than the positive controls. 相似文献
63.
In this paper, we develop a tabu search procedure for solving the uniform graph partitioning problem. Tabu search, an abstract heuristic search method, has been shown to have promise in solving several NP-hard problems, such as job shop and flow shop scheduling, vehicle routing, quadratic assignment, and maximum satisfiability. We compare tabu search to other heuristic procedures for graph partitioning, and demonstrate that tabu search is superior to other solution approaches for the uniform graph partitioning problem both with respect to solution quality and computational requirements. 相似文献
64.
Hasan Nemati Kurosh Sedighi Mohammad Mohammadi Pirouz Ehsan Fattahi 《International Journal of Computational Fluid Dynamics》2013,27(3-4):83-94
A numerical investigation of the two-dimensional laminar flow around side-by-side rotating circular cylinders using Lattice Boltzmann method is conducted. The effects of variation of rotational speed ratio β and different gap spacings g* at Reynolds number of 100 are studied. A various range of rotational speed ratio 0 ≤ β ≤ 2 for four different gap spacings of 3, 1.5, 0.7 and 0.2 are investigated. Flow conditions and its characteristics, such as lift and drag coefficients and Strouhal number, is studied. The results indicated that as β increases, the flow changes its condition from periodic to steady after a critical rotational speed. Results also indicated that variation of the gap spacing and rotational speed has significant effect on wake pattern. Wake pattern in turn has significant effect on the Strouhal number. Finally, the result is compared with experimental and other numerical data. 相似文献
65.
Kazem?NouriEmail author Hassan?Ranjbar Leila?Torkzadeh 《Mediterranean Journal of Mathematics》2018,15(3):140
In this paper, by composite previous-current-step idea, we propose two numerical schemes for solving the Itô stochastic differential systems. Our approaches, which are based on the Euler–Maruyama method, solve stochastic differential systems with strong sense. The mean-square convergence theory of these methods are analyzed under the Lipschitz and linear growth conditions. The accuracy and efficiency of the proposed numerical methods are examined by linear and nonlinear stochastic differential equations. 相似文献
66.
Coordination polymers of 1,4-bis(2′-hydroxyphenylazomethine) phenylene have been prepared with the metal ions Ti(III), Cr(III), Fe(III), Mn(II), Ni(II), and Cu(II). They were characterized by elemental analysis, IR, and electronic spectra. The metal contents in all polymers were found to be consistent with a 1:1 (metal:ligand) stoichiometry. The thermal behavior of these coordination polymers has been studied by thermogravimetric analysis in air up to 750°C, and the data showed that they are thermally stable up to 200°C. Physical properties such as the solubility and viscosity of the polymer complexes were also determined. Electrical conductivity measurements of the synthesized polychelated polymers showed that they are insulators except for the Ni(II) complex which shows a semiconducting character. Mössbauer data clearly establish the 3 + oxidation state for the iron complex polymer. 相似文献
67.
Qamrul Hasan Ansari Mahboubeh Rezaie Jafar Zafarani 《Journal of Global Optimization》2012,53(2):271-284
In this paper, we consider different kinds of generalized vector variational-like inequality problems and a vector optimization problem. We establish some relationships between the solutions of generalized Minty vector variational-like inequality problem and an efficient solution of a vector optimization problem. We define a perturbed generalized Stampacchia vector variational-like inequality problem and discuss its relation with generalized weak Minty vector variational-like inequality problem. We establish some existence results for solutions of our generalized vector variational-like inequality problems. 相似文献
68.
Chemical effects on Kβ/Kα X-ray intensity ratios for some Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn compounds are studied experimentally. The X-ray spectra were measured by using a Si (Li) solid state detector with high resolution. The vacancies were produced by heavily filtered 241Am gamma rays. It is found that the Kβ/Kα X-ray intensity ratios measured with compounds deviated up to 43% from the corresponding values of the pure elements. The values for pure elements are compared with the other experimental and with theoretical values. 相似文献
69.
Saeed Aminzadeh Hossein Naderi-Manesh Khosro Khajeh Bijan Ranjbar Naser Farrokhi 《Applied biochemistry and biotechnology》2010,160(7):1921-1932
Acid-induced unfolding of a Tetracoccosporium sp. polygalacturonase enzyme (PG) was studied by a comprehensive series of biophysical and biochemical techniques. At pH 1.0,
PG acquires partially folded state, which reveals characteristics of molten globule (MG) state, i.e., reduction of defined
tertiary structure with minimal changes in the secondary structure. In this study PG unfolds exposing its hydrophobic surface
to a greater extent than the native form at acidic pH with more tryptophan residues exposed to the solvent. Collectively,
our data imply the presence of MG state of PG at low pH, suggesting the phenomenon of hydrophobic collapse model for folding
and integration into cell membrane. 相似文献
70.
Ahmad Hasan Carla R. Lambert Prem C. Srivastava 《Journal of heterocyclic chemistry》1990,27(7):1877-1883
The imidazole nucleosides, 4(5)-bromo-5(4)-nitro-1-β-D-ribofuranosylimidazoles, have been prepared via glycosylation of the trimethylsilylated aglycone, 4(5)-bromo-5(4)-nitroimidazole, with tetra-O-acetyl-β-D-ribo-furanose followed by removal of the acetyl protecting groups. The 5-bromo-4-nitro-1-β-D-ribofuranosylimidazole nucleoside was acetonated to produce 5-bromo-4-nitro-1-(2,3-O-isopropylidene-β-D-ribofuranosyl)-imidazole which was cyclized to provide the corresponding anhydronucleoside 5,5′-anhydro-4-nitro-5-oxo-1-(2,3-O-isopropylidene-β-D-ribofuranosyl)imidazole. Sodium hydrosulfide treatment of 5-bromo-4-nitroimidazole nucleoside provided 5-mercapto-4-nitro-1-β-D-ribofuranosylimidazole 5-sodium salt which was alkylated with E-1,5-diiodopent-1-ene to yield 5-(E-1-iodo-1-penten-5-yl)thio-4-nitro-1-β-D-ribofuranosylimidazole. The corresponding iodine-125-labeled compound was prepared similarly using radiolabeled diiodopentene. The 5-bromo-4-nitroimidazole, 5-mercapto-4-nitroimidazole, and 5-iodopentenylthio-4-nitroimidazole nucleosides were cytotoxic to Molt-3 cells in vitro at concentrations higher than 10 μg/mL. The radiolabeled 5-iodopentenylthio-4-nitroimidazole nucleoside showed 2-fold higher uptake in a rapidly growing tumor as compared to uptake in a relatively slower growing tumor in mice. 相似文献