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101.
102.
V. V. Mazurenko A. N. Rudenko Ya. O. Kvashnin V. G. Mazurenko Yu. N. Novoselov V. A. Pustovarov A. I. Kukharenko S. O. Cholakh 《Journal of Experimental and Theoretical Physics》2011,112(5):877-883
The ab initio numerical calculations of the electronic structure of simple oxides BeO and SiO2 and complex oxides Be2SiO4 and Be2Si
x
Ge1 − x
O4 with the phenacite structure have been performed using the electron density functional theory. The calculations indicate
that the main feature of the systems under investigation is the presence of oxygen states in both the valence and conduction
bands. The splitting of the bottom of the conduction band has been revealed in the electronic structure of the Be2Si
x
Ge1 − x
O4 system. The splitting width is about 1.5 eV. The main contribution to the formation of a narrow subband of the conduction
band comes from the 2s and 2p states of oxygen and the 4d state of germanium. Microscopic models of the spatial localization of the electron density on lower energy states of the
conduction band of oxide crystals have been developed using the Wannier function technique. The reflection spectra of BeO,
SiO2, and Be2SiO4 have been analyzed. The reported calculations of the electronic structure imply the exciton nature of the 9.7-eV reflection
peak in the Be2SiO4 crystal. 相似文献
103.
104.
V. N. Klementyev A. Yu. Golubikhin V. V. Potekhin N. P. Novoselov 《Russian Journal of General Chemistry》2016,86(5):1008-1010
Heat of mixing of propylene oxide with N,N-dimethylformamide and ethylene glycol has been determined by means of microcalorimetry. Theoretically suggested choice of the aprotic solvent as a selective separating agent for the propylene oxide–methanol binary mixture has been experimentally justified. 相似文献
105.
The energy and current balances in the diode unit of a high-current pulsed electron accelerator (350–500 keV, 60 ns, 250 J per pulse) are compared for an explosive emission cathode (made of graphite, copper, or carbon felt) and a multipoint (graphite or copper) cathode. The planar diode with the continuous cathode is shown to be more efficient in terms of conversion of the applied energy to electron energy (more than 90%) despite a delay in the plasma surface formation. With the impedance of the planar diode matched to the output resistance of the nanosecond generator, the efficiency of the diode does not depend on the time of plasma formation on the cathode. In the case of the graphite cathode, the plasma formation delay reduces the fraction of slow electrons in the forming electron beam and reduces electron losses in anode foil when the beam is extracted from the vacuum space of the diode chamber into the reactor. 相似文献
106.
Giant intrinsic carrier mobilities in graphene and its bilayer 总被引:8,自引:0,他引:8
Morozov SV Novoselov KS Katsnelson MI Schedin F Elias DC Jaszczak JA Geim AK 《Physical review letters》2008,100(1):016602
We have studied temperature dependences of electron transport in graphene and its bilayer and found extremely low electron-phonon scattering rates that set the fundamental limit on possible charge carrier mobilities at room temperature. Our measurements show that mobilities higher than 200 000 cm2/V s are achievable, if extrinsic disorder is eliminated. A sharp (thresholdlike) increase in resistivity observed above approximately 200 K is unexpected but can qualitatively be understood within a model of a rippled graphene sheet in which scattering occurs on intraripple flexural phonons. 相似文献
107.
Explicit expressions have been derived for the volume dependence of electron-phonon coupling strength (λ) and the Coulomb pseudopotential (μ*) considering the variation of Fermi momentum (κ
F) and Debye temperature (θ
D) with volume. Ashcroft’s model pseudopotential and RPA form of dielectric screening have been used for obtaining pressure
dependence of transition temperature (T
C) and the logarithmic volume derivative (Φ) of the effective interaction strength (N
0
V) for metallic glass superconductor Mg70Zn30. It has been observed that T
C of the metallic glass Mg70Zn30 decreases rapidly with increase of pressure and the superconducting phase disappears at about 30% decrease of volume, for
which the μ* curve shows a minimum and an elbow is formed in the Φ graph. 相似文献
108.
JETP Letters - The combination of density functional theory with dynamic mean field theory (DFT + DMFT) was applied for the investigation of the magnetic properties of Ca2 – xSrxRuO4. We... 相似文献
109.
Sorokin B. P. Novoselov A. S. Kvashnin G. M. Luparev N. V. Asafiev N. O. Shipilov A. B. Aksenenkov V. V. 《Acoustical Physics》2019,65(3):263-268
Acoustical Physics - The paper demonstrates for the first time the possibility of using aluminum nitride–scandium as an effective piezoelectric material in composite acoustic resonators on... 相似文献
110.
E. G. Tolstopyatova Ya. K. Saidova A. M. Smolin N. P. Novoselov V. V. Kondrat’ev 《Journal of Analytical Chemistry》2016,71(2):195-200
Conditions are studied for the synthesis of water dispersions of polymer composites containing palladium and the possibility of their use for the fabrication of modified electrodes is estimated. Water dispersions of the polymer poly(3,4-ethylenedioxythiophene), including a polystyrene sulfate polyanion (PEDOT:PSS) and Pd particles, were obtained by the redox reaction of Pd(II) with the polymer. The electrochemical behavior of composite PEDOT:PSS/Pd films in the medium of a phosphate buffer solution with pH 6.86 is studied. It is shown that, in the presence of hydrazine in a phosphate buffer solution, one wave of hydrazine oxidation on metal inclusions, Pd particles, is observed on the electrode. Specific features of the process of hydrazine oxidation are studied and a possibility using the obtained material for the creation of an electrochemical sensor for hydrazine is demonstrated. 相似文献