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71.
Ivan M. Safonov Igor A. Sukhoivanov Oleksiy V. Shulika Volodymyr V. Lysak 《Superlattices and Microstructures》2008
Knowledge of the energy band diagram is very important in semiconductor physics due to the fact that the band diagram influences almost all parts of the physics of a semiconductor device. In this paper we examine a piecewise-constant approximation of the potential profile through a comparison with a comprehensive self-consistent model, with regard to the active regions of QW semiconductor lasers and amplifiers. The validity of this approximation is then defined, thus giving an insight into the physics of QW structures. 相似文献
72.
Oleksiy S. Kononenko Yuriy V. Gandel 《International Journal of Infrared and Millimeter Waves》2007,28(4):267-274
For the first time rigorous theory is developed for eigen traveling TM modes in the resonator of the coaxial cavity gyrotron
with a corrugated insert. This mathematical model can be applied for any corrugation parameters and wavelengths. Gyrotron
simulation software is developed and allows to calculate mode eigenvalues, electromagnetic field components and Ohmic losses
for eigen TE and TM modes. Results of the numerical investigations are presented for the ITER relevant 170 GHz coaxial cavity
gyrotron developed in Forschungszentrum Karlsruhe, Germany. 相似文献
73.
74.
Olga A. Guselnikova Pavel S. Postnikov Premysl Fitl David Tomecek Petr Sajdl Roman Elashnikov Zdenka Kolska Mohamed M. Chehimi Vaclav Švorčík Oleksiy Lyutakov 《Journal of Polymer Science.Polymer Physics》2017,55(4):378-387
Conductive polymer (poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) is an attractive platform for the design of flexible electronic, optoelectronic, and (bio)sensor devices. Practical application of PEDOT:PSS often requires an incorporation of specific molecules or moieties for tailoring of its physical–chemical properties. In this article, a method for covalent modification of PEDOT:PSS using arenediazonium tosylates was proposed. The procedure includes two steps: chemisorption of diazo‐cations on the PEDOT:PSS surface followed by thermal decomposition of the diazonium salt and the covalent bond formation. Structural and surface properties of the samples were evaluated by XPS, SEM‐EDX, AFM, goniometry, and a range of electric and optical measurements. The developed modification procedure enables tuning of the PEDOT:PSS surface properties such as conductivity and optical absorption. The possibility to introduce various organic functional groups (from hydrophilic to hydrophobic) and to create new groups for further functionalization makes the developed procedure multipurpose. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 378–387 相似文献
75.
Oleksiy A. Ignatyev 《Applied mathematics and computation》2010,216(2):388-394
The linear autonomous system of difference equations x(n+1)=Ax(n) is considered, where is a real nonsingular k×k matrix. In this paper it has been proved that if W(x) is any homogeneous polynomial of m-th degree in x, then there exists a unique homogeneous polynomial V(x) of m-th degree such that ΔV=V(Ax)-V(x)=W(x) if and only if where are the eigenvalues of the matrix A. The theorem on the instability has also been proved. 相似文献
76.
Olga Guselnikova Grard Audran Jean-Patrick Joly Andrii Trelin Evgeny V. Tretyakov Vaclav Svorcik Oleksiy Lyutakov Sylvain R. A. Marque Pavel Postnikov 《Chemical science》2021,12(11):4154
The nature of plasmon interaction with organic molecules is a subject of fierce discussion about thermal and non-thermal effects. Despite the abundance of physical methods for evaluating the plasmonic effects, chemical insight has not been reported yet. In this contribution, we propose a chemical insight into the plasmon effect on reaction kinetics using alkoxyamines as an organic probe through their homolysis, leading to the generation of nitroxide radicals. Alkoxyamines (TEMPO- and SG1-substituted) with well-studied homolysis behavior are covalently attached to spherical Au nanoparticles. We evaluate the kinetic parameters of homolysis of alkoxyamines attached on a plasmon-active surface under heating and irradiation at a wavelength of plasmon resonance. The estimation of kinetic parameters from experiments with different probes (Au–TEMPO, Au–SG1, Au–SG1–TEMPO) allows revealing the apparent differences associated with the non-thermal contribution of plasmon activation. Moreover, our findings underline the dependency of kinetic parameters on the structure of organic molecules, which highlights the necessity to consider the nature of organic transformations and molecular structure in plasmon catalysis.Kinetic study of alkoxyamine homolysis revealed the impact of non-thermal effects in plasmon-assisted reactions. 相似文献
77.
Oleksiy Ignatyev 《PAMM》2007,7(1):2080005-2080006
In this paper we investigate the compact support property of the solutions of hyperbolic Stochastic PDE (SPDE) providing that initial condition function is deterministic and has compact support property. First, to approach this problem, we consider semi-SPDE. It turns out that in the semi-SPDE case solution u (t, x) preserve compact support property. When we consider SPDE, we use the stochastic differential-difference equations (SDDE) approach. It turns out that in SPDE case solution u (t, x) does not preserve compact support property. So, if we compare the semi-SPDE and SPDE then it becomes obvious that differentiation in space in SPDE plays crucial role and influence the behavior of the solution. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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79.
Valeriya G. Makhankova Oleksiy V. Khavryuchenko Vladimir N. Kokozay Oleg V. Shishkin Brian W. Skelton 《Journal of solid state chemistry》2010,183(11):2695-2702
A facile one-pot procedure, or so-called “direct synthesis,” was used to prepare the novel heterometallic complexes [M2Mn(OAc)6(bpy)2], where M=Cu (1), Co (2), Zn (3), bpy=2,2′-bipyridyl, with high yields via oxidative dissolution of pure metals in a liquid phase. The complexes were characterized by an elemental analysis, single crystal X-ray diffraction method and FTIR. These complexes are proposed as precursors, whose thermal degradation may lead to the formation of solids possessing nano- to microsize levels of dispersity. The thermal behavior of the complexes obtained was studied by thermal analysis (TG/DTA/DTG) in both air and N2 and also by TPD mass-spectrometry in vacuo. The FTIR, X-ray powder diffraction (PXRD) and thermoanalytical data were used for the identification of the solid products of thermal degradation. The morphology and microstructure of the solid residues were analyzed, using scanning electron microscopy with energy dispersive X-ray microanalysis (SEM/EDX) at mkm and sub-micro levels. 相似文献
80.
Dmytro V. Piatnytskyi Oleksiy O. Zdorevskyi Sergiy M. Perepelytsya Sergey N. Volkov 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2015,69(11):255
Changes in the medium of biological cells under ion beam irradiation has been considered as a possible cause of cell function disruption in the living body. The interaction of hydrogen peroxide, a long-lived molecular product of water radiolysis, with active sites of DNA macromolecule was studied, and the formation of stable DNA-peroxide complexes was considered. The phosphate groups of the macromolecule backbone were picked out among the atomic groups of DNA double helix as a probable target for interaction with hydrogen peroxide molecules. Complexes consisting of combinations including: the DNA phosphate group, H2O2 and H2O molecules, and Na+ counterion, were considered. The counterions have been taken into consideration insofar as under the natural conditions they neutralise DNA sugar-phosphate backbone. The energy of the complexes have been determined by considering the electrostatic and the Van der Waals interactions within the framework of atom-atom potential functions. As a result, the stability of various configurations of molecular complexes was estimated. It was shown that DNA phosphate groups and counterions can form stable complexes with hydrogen peroxide molecules, which are as stable as the complexes with water molecules. It has been demonstrated that the formation of stable complexes of H2O2-Na+-PO4 - may be detected experimentally by observing specific vibrations in the low-frequency Raman spectra. The interaction of H2O2 molecule with phosphate group of the double helix backbone can disrupt DNA biological function and induce the deactivation of the cell genetic apparatus. Thus, the production of hydrogen peroxide molecules in the nucleus of living cells can be considered as an additional mechanism by which high-energy ion beams destroy tumour cells during ion beam therapy. 相似文献