Research on anthropogenic influence on satellite positioning accuracy

This paper presents the results of research into the accuracy of satellite-based positioning methods in the vicinity of operating industrial and energy facilities. Modern dual-frequency multi-system satellite receivers allow for high accuracy and productivity in compliance with the basic principles of work related to ensuring the criterion of unity of measurements and the mandatory implementation of the rules of localisation of the object and the receiver(s), as well as the study of geometric and temporal factors of satellite passage, with their subsequent application to perform quality measurements. This technique is widely and effectively used on large area and linear objects by qualified specialists in the field of geodesy. The accuracy of determinations is guaranteed by the openness of the sky and the absence of all kinds of man-made factors that potentially interfere with the reception of radio signals. This paper does not consider the extreme operation of receivers in areas of special signal suppression. It is of great interest to research the accuracy of satellite positioning methods in the vicinity of operating industrial and energy objects

Theory of combined exciton-cyclotron resonance in a two-dimensional electron gas: The strong magnetic field regime

I develop a theory of combined exciton-cyclotron resonance (ExCR) in a low-density two-dimensional electron gas in high magnetic fields. In the presence of excess electrons an incident photon creates an exciton and simultaneously excites one electron to higher-lying Landau levels. I derive exact ExCR selection rules that follow from the existing dynamical symmetries, magnetic translations and rotations about the magnetic field axis. The nature of the final states in the ExCR is elucidated. The relation between ExCR and shake-up processes is discussed. The double-peak ExCR structure for transitions to the first electron Landau level is predicted.Comment: 5 pages, 3 figures, replaced with the published versio

Shake-up Processes in a Low-Density Two-Dimensional Electron Gas: Spin-Dependent Transitions to Higher Hole Landau Levels

A theory of shake-up processes in photoabsorption of an interacting low-density two-dimensional electron gas (2DEG) in strong magnetic fields is presented. In these processes, an incident photon creates an electron-hole pair and, because of Coulomb interactions, simultaneously excites one particle to higher Landau levels (LL's). In this work, the spectra of correlated charged spin-singlet and spin-triplet electron-hole states in the first hole LL and optical transitions to these states (i.e., shake-ups to the first hole LL) are studied. Our results indicate, in particular, the presence of optically-active three-particle quasi-discrete states in the exciton continuum that may give rise to surprisingly sharp Fano resonances in strong magnetic fields. The relation between shake-ups in photoabsorption of the 2DEG and in the 2D hole gas (2DHG), and shake-ups of isolated negative X^- and positive X^+ trions are discussed.Comment: 8 pages, 8 figures. References updated, one figure added (Fig. 6). Accepted in Phys. Rev.

Perturbative Effects in the Form Factor \gamma\gamma^*\to \pi and Extraction of the Pion Wave Function from CLEO Data

We study the pion form factor F^{\pi \gamma\gamma^*}(Q^2) in the light-cone sum rule approach, accounting for radiative corrections and higher twist effects. Comparing the results to the CLEO experimental data on F^{\pi \gamma\gamma^*}(Q^2), we extract the the pion distribution amplitude of twist-2. The deviation of the distribution amplitude from the asymptotic one is small and is estimated to be a_2(\mu) = 0.12 \pm 0.03 at \mu=2.4 GeV, in the model with one non-asymptotic term. The ansatz with two non-asymptotic terms gives some region of a_2 and a_4, which is consistent with the asymptotic distribution amplitude, but does not agree with some old models.Comment: 21 pages, LaTeX, 7 eps figures; (v2): Phys. Rev. D versio

Sources of Investment Support of Production and Business Activities in the Russian Economy

The problems of determining effective and available sources of investment for the purposes of technical and organizational development of enterprises and business activities are studied. An urgent requirement is to reverse the unstable dynamics of the industrial investments volumes implemented by Russian enterprises, the low degree of renewal of fixed assets of enterprises that go to a critically high level of wear and tear, which does not allow for high resource productivity and competitiveness of Russian enterprises of processing activities in the world market. The purpose of the study is to consider the indicators of the current state and the possibility of using certain available sources of investment in production, to analyze the characteristics of state regulation of investment activity in the economy. The article uses methods of statistical grouping, analysis of cause-and-effect relations, and meaningful economic interpretation of the phenomena of the investment process in the Russian and world economy conditions. A comparative analysis of the most popular sources of investment support for production and economic activities of enterprises is carried out, their advantages and disadvantages, and features of use are shown. As a result, recommendations were formed on the choice of investment sources in relation to various economically stable groups of manufacturing enterprises operating in markets of different regulatory severity

Investigation of Shock-Wave Characteristics of Porous Multi-Component Materials Under Explosive Loading by Undisturbing Electromagnetic Method

This paper deals with developing a remote electromagnetic technique for studying shock-wave behavior of porous multi-component materials. The main peculiarity of the method proposed is that both pulse magnetic field source and inductive gauge are placed outside the tested sample. That is why this procedure does introduce no disturbances to observed processes. At the same time the method allows one to measure local parameters of shock loading in porous materials. The technique is illustrated by the application to constructing shock Hugoniots for materials with strongly different physical properties such as alumina, wheat flour and their mixture.L'article présente une méthode électromagnétique pour l'étude du comportement sous choc des matériaux composites poreux. La particularité principale de la méthode proposée réside dans le fait que la source du champ magnétique pulsé aussi bien que le senseur d'induction sont placés en dehors de l'échantillon. C'est pourquoi aucune perturbation n'est apportée aux processus étudiés. En même temps, la méthode permet de mesurer les paramètres locaux de l'arrivée de l'onde de choc dans les matériaux poreux. Cette méthode est illustrée par l'application à la construction des courbes d'Hugoniot, pour des matériaux à caractéristiques physiques très différentes, tels que l'alumine et le mélange alumine et farine de froment

Infrared reflection spectra of the films of topological insulator Pb

Infrared reflectivity spectra of the 700 nm thick topological insulator Pb1-xSnxSe films grown by the molecular beam epitaxy technique on ZnTe/GaAs substrates were studied. Using dispersion analysis of reflectivity spectra plasmon and phonon parameters for the samples under study were obtained