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 $n=28$. The multipole potential, presented in this paper, is scrupulously compared with the potential known as the OPLS.Comment: 10 pages, 4 figures, 8 table

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

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

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 ${MW/cm}^3$ 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

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

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