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61.
Sh. M. Alekperova I. A. Akhmedov G. S. Gadzhieva Kh. D. Dzhalilova 《Physics of the Solid State》2007,49(3):512-515
Isotropic giant negative magnetoresistance (from ?42 to ?52%) in magnetic fields of 6–9 kOe is revealed for the first time when studying kinetic phenomena and the magnetoresistive effect in silver sulfoselenide (n-Ag4SSe) in the vicinity of a first-order phase transition. The electron transport and the magnetoresistive effect in n-Ag4SSe are studied for the first time. 相似文献
62.
Hanif?HadipourEmail author Seyed?Akbar?Jafari 《The European Physical Journal B - Condensed Matter and Complex Systems》2015,88(10):270
Local density approximation (LDA) and Green function effective Coulomb (GW) calculations are performed to investigate the effect of electronic correlations on the electronic properties of both graphene and graphane. The size of band gap in graphane increases from 3.7 eV in LDA to 4.9 eV in GW approximation. By calculating maximally localized Wannier wave functions, we evaluate the necessary integrals to get the Hubbard U and the exchange J interaction from first principles for both graphene and graphane. Our ab-initio estimates indicate that in the case of graphene, in addition to the hopping amplitude t ~ 2.8 eV giving rise to the Dirac nature of low lying excitations, the Hubbard U value of ~8.7 eV gives rise to a super-exchange strength of J AFM ~ 3.5 eV. This value dominates over the direct (ferromagnetic) exchange value of J FM ~ 1.6 eV. This brings substantial Mott-Heisenberg aspects into the problem of graphene. Moreover, similarly large values of the Hubbard and super-exchange strength in graphane suggests that the nature of gap in graphane has substantial Mott character. 相似文献
63.
Encapsulation of Cu(II) complexes of methyl-2-(2-hydroxybenzylideneamino)-4,5,6,7-tetrahydrobenzo[b]-thiophene-3-carboxylate (HL1) and 2-ethyl-4-methyl 5-(2-hydroxybenzylideneamino)-3-methylthiophene-2,4-dicarboxylate (HL2) in the supercages of zeolite NaY was performed by the flexible ligand method. The neat and encapsulated complexes were characterized by physicochemical and spectroscopic methods and employed as catalysts for oxidation of benzyl alcohol and phenol. The encapsulated complexes were both more reactive and stable as catalysts than the corresponding free complexes. The encapsulated complexes could be reused several times. Complexes of HL2 were more reactive than those of HL1, probably due to the electron-withdrawing effect of the CO2Et group. 相似文献
64.
65.
Moradi Sima Shareghi Behzad Saboury Ali Akbar 《Monatshefte für Chemie / Chemical Monthly》2020,151(4):637-647
Monatshefte für Chemie - Chemical Monthly - In this study, the structure and stability of acid phosphatase in its interaction with Co3O4 nanoparticles are evaluated through absorbance, enzyme... 相似文献
66.
67.
Hoda Molavi Abbas Yousefpour Akbar Mirmostafa Ali Sabzi Sepideh Hamedi Milad Narimani Nazanin Abdi 《Chromatographia》2017,80(7):1129-1135
Methanol in insulating oil has been proposed as a new marker for condition assessment of the solid insulation system of power transformers. In the current work, as a first step of using the new marker, an analytical static headspace gas chromatography/mass spectrometry method has been developed, optimized, and validated to measure methanol and ethanol contents in the insulating mineral oil. The analyzing setup consists of a 6890 N gas chromatograph equipped with a 5973 network mass spectrometer (MS) in the absence of a costly headspace autosampler, and the chromatography separation was performed on a 60 m × 320 µm × 0.5 µm VF-WAXms GC column. Calibration curves have been provided using several concentrations of the alcohols, and also limit of detection (LOD), limit of quantification (LOQ), and relative standard deviation percentage (RSD%) have been determined. 相似文献
68.
The suitability of 1-nitroso-2-naphthol (NN) as a complexing agent for on-line preconcentration of cobalt using C(18) microcolumn with FI-FAAS system has been tested. Various parameters affecting the complex formation and its elution were optimized. Reagent solution (2.5x10(-3) mol l(-1)) and aqueous sample solution acidified with 0.1% (v/v) nitric acid were on-line mixed in a reaction coil set at 65+/-1 degrees C and flowed through the microcolumn for 30 s. The pH of the mixed solution was adjusted to 3 approximately 4 by adding HNO(3) (1 mol l(-1)) or NaOH (1 mol l(-1)) in the reagent solution. The adsorbed complexes in the microcolumn were eluted with ethanol (acidified to 1% nitric acid) in 10 s into the nebulizer of FAAS. A good precision (1.6% for 100 mug l(-1) Co(II), n=10), high enrichment factor 17.2, with detection limit (3sigma) 3.2 mug l(-1), and sample throughput (90 h(-1)) were obtained. The method was applied on the certified reference materials (CRMs) i.e. NBS-362 and NBS-364 (special low alloy steel), for the determination of cobalt and the results were in good agreement with the certified values. 相似文献
69.
A. V. Vorogushin M. D. Reshetova N. G. Akhmedov Yu. A. Ustynyuk I. L. Eremenko S. E. Nefedov A. I. Zinin 《Russian Chemical Bulletin》1998,47(4):699-703
The reaction of Cr(CO)6 with 7,7-dichloro-3,4-benzobicyclo[4.1.0]heptane gave the correspondingexo- andendo-chromium tricarbonyl complexes in a ratio of 4.5:1. The structures of the resulting compounds were established by NMR spectroscopy,
mass spectrometry, and X-ray structural analysis. Reduction of dichlorobenzobicycloheptane and its chromium tricarbonyl complexes
with LiAlH4 affordedexo- andendo-7-chloro-3,4-benzobicyclo[4.1.0]heptanes in a 3.5:1 ratio.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 720–724, April, 1998. 相似文献
70.