1,871 research outputs found
Modelling of potentials for interparticle interactions between methanol molecules
Peculiarities of interparticle interactions between methanol molecules in the
methanol vapor are investigated. The bare potential is considered as a sum of
repulsive, dispersive and electrostatic forces. It is supposed that H-bond is
of electrostatic nature (the irreducible contribution caused by overlapping of
electronic shells is unessential). The dispersive interaction is approximated
with London's formula, the electrostatic interaction is modelled by a multipole
expansion up to dipole-octupole contribution. The multipole moments are assumed
to be equal to their experimental values or to quantum chemical calculations.
The repulsion is modelled by power potential, whose parameters are fitted to
the second virial coefficient and to the parameters of dimers. Along with the
bare potential, the averaged potential of interparticle interaction is
analyzed. It is shown that the repulsive potential has an exponent . The
multipole potential, presented in this paper, is scrupulously compared with the
potential known as the OPLS.Comment: 10 pages, 4 figures, 8 table
Goldstone mode of Skyrmion Crystal
We discuss the Goldstone mode of skyrmion crystal in a model of
two-dimenssional ferromagnet with Dzyaloshinskii-Moriya interaction in magnetic
field. We use stereographic projection approach to construct skyrmion crystal
and consider skyrmion's displacement field. The small overlap of the individual
skyrmion images restricts the potential energy to the interaction of nearest
neighboring displacements. The closed form of the Goldstone mode dispersion is
found and its dependence on the magnetic field is studied. We use semiclassical
quantization to define the Green's function and show that the propagation of
displacements through the crystal changes its tensorial form from isotropic to
anisotropic one at large distances.Comment: 6 pages, 4 figure
Theoretical and Methodological Approaches to the Formation of Prices of Company Теоретико-методические подходы к формированию цены предприятия
The article deals with the theoretical and methodological principles for the price formation during the period of market relations. Theoretical and methodological basis of the study served as the theory of marketing and scientific methods of scientific knowledge. In order to justify the high level of scientific accuracy to the definition of the strategy and tactics of pricing has been investigated the concept of "price policy", "pricing strategy" and "pricing tactics" as the result revealed differences in some of these concepts by scientists of the field of research, which suggests a certain ambiguity about in the interpretation of certain concepts. An association between has been established these concepts. Supporting the claim that the price strategy is a means of achieving competitive strategies of the company, and pricing is an element of marketing. In addition, for effective pricing there is a need to introduce a systematic approach, which is a well-structured scheme of the formation of the strategy and tactics of pricing in marketing with certain components of the system, the interrelation and the logical sequence of which may be the key of successful result in the formation of pricing mechanism in the system of strategic marketing. Requested to carry out the practical pricing activities of modern enterprises with marketing point.<br>В статье рассмотрены теоретические и методологические положения стратегического формирования цены в период рыночных отношений. С целью обоснования высокого уровня научной точности в определении стратегии и тактики ценообразования, были исследованы понятия «ценовая политика», «ценовая стратегия» и «ценовая тактика», в результате чего были выявлены различия в определении данных понятий, что позволяет говорить об определенной неоднозначности в их толковании. Была установлена взаимосвязь между данными понятиями. Подтверждается, что ценовые стратегии являются средством достижения конкурентных стратегий фирмы, а ценообразование представляет собой элемент маркетинга. Кроме того, для эффективного ценообразования существует необходимость применения системного подхода, который представляет собой четко структурированную схему процесса формирования стратегии и тактики ценообразования в маркетинге с отдельно установленными компонентами системы, взаимосвязь и логическая последовательность которых может стать залогом успешного результата в формировании механизма ценообразования в системе стратегического маркетинга. Предложено осуществлять практическое ценообразование в деятельности современных предприятий с позиции маркетинга
Generation of powerful terahertz emission in a beam-driven strong plasma turbulence
Generation of terahertz electromagnetic radiation due to coalescence of
upper-hybrid waves in the long-wavelength region of strong plasma turbulence
driven by a high-current relativistic electron beam in a magnetized plasma is
investigated. The width of frequency spectrum as well as angular
characteristics of this radiation for various values of plasma density and
turbulence energy are calculated using the simple theoretical model adequately
describing beam-plasma experiments at mirror traps. It is shown that the power
density of electromagnetic emission at the second harmonic of plasma frequency
in the terahertz range for these laboratory experiments can reach the level of
1 with 1% conversion efficiency of beam energy losses to
electromagnetic emission
NANOPARTICLES OF SOME ELEMENTS DURING THE INITIAL PERIOD OF SPRING WHEAT
The work was carried out within the framework of the section of the state task No. 121041600036-6
Magnon topological transition in skyrmion crystal
We study the magnon spectrum in skyrmion crystal formed in thin ferromagnetic
films with Dzyalosinskii-Moria interaction in presence of magnetic field.
Focusing on two low-lying observable magnon modes and employing stereographic
projection method, we develop a theory demonstrating a topological transition
in the spectrum. Upon the increase of magnetic field, the gap between two
magnon bands closes, with the ensuing change in the topological character of
both bands. This phenomenon of gap closing, if confirmed in magnetic resonance
experiments, may deserve further investigation by thermal Hall conductivity
experiments.Comment: 6 pages, 4 figure
The features of the spatial structure of the gramicidine A-cesium complex
AbstractEarlier obtained two-dimensional 1H-NMR spectroscopy data were used to analyze the spatial structure and conformational mobility of the double right ↑↓ ππLD7.2 helix of the complex formed by gramicidine A and Cs+ ions in an organic solvent (a chloroform-methanol mixture). Analysis of the experimental data permitted the determination of a set of conformations for each of the high-mobility residue side chains in the solution. The energy refinement of the most probable conformation of the double right ↑↓ ππLD7.2 helix was made and conformational rearrangements of the tryptophan residue side chain were studied in detail
- …