The simulation of two-dimensional spherical crystals consisting of a large number of particles is carried out. These shells were analyzed based on their geometric structure and energy distribution. Various types of defects formed in a state of equilibrium is considered. Being shown the ambiguity of the existing method of their interpretation. A new way of describing such defects in the close-packed two-dimensional crystals with different topology is suggested.
Keywords: topological defects, two-dimensional materials, spherical crystals, topological charge
The techniques generate a directivity diagram a slot antenna array with variable polarization. The results of calculation the characteristics of radiation for an array dimension 4x4 elements.
Keywords: AESA, microstrip antennas, spacecraft, remote sensing of the earth.
In article the statistical data of a traumatism and breakdown susceptibility in building are cited. Concepts of culture of labour safety are reflected.
Keywords: The risk, injuring factors, labour safety, culture, safety, traumatism
It describes a method of train set forming for using artificial neural networks to search inauthentic rows in databases tables. An existing methods of the reliability ensure involve the use of integrity constraints and provides a truthfulness, but there is still a possibility of entering of inauthentic data, appropriate to all constraints. A more accurate assessment of reliability is possible with the use of artificial neural networks that require a training set. The main requirement for the training set - representation includes sufficiency, diversity and evenness. The approaches to each of these requirements are describes. Also calculations a sufficient number of rows for training neural networks of various types is given, as well as the results of experiments that confirm correctness of the theoretical calculations.
Keywords: database, authenticity, artificial neural networks, training set, representation
In the present work we report on the study of local atomic and electronic structure of gold nanoparticles funnctionalised by thiol and amine containing long-chain ligands. The study of nanoscale atomic structure is performed by means of X-ray absorption spectroscopy (XANES: X-ray Absorption Near-Edge Structure) and computer simulation. In consequence of the experimantally obtained data analysis and computer simulation it was obtained that strong bonding takes place when 11-mercaptoundecanoic acid is bound to the gold nanoparticles surface, forming a chemical bond Au-S 0.25 nm in length. Weaker bonding is observed when forming bond between dodecylamine and gold nanoparticles surface atom resulting in Au-N bond 0.23 nm in length. Supplementary XANES spectra analysis by means of density functional theory reveals the nature of formation of the investigated nanoscale structure.
Keywords: nanoscale structure of matter, X-ray absorption spectroscopy, XANES, density functional theory, nanoparticles functionalisation
The paper studies the possibility of quantitative processing of the GPR data for determining the dielectric permittivity and conductivity of a medium (soil samples). Experimental studies are made using radargrams of soil samples with specified values of moisture and conductivity. New methods of quantitative processing of radargrams are proposed in this work to determine the dielectric permittivity and conductivity of soils. The methods were successfully tested on various sections of Russian railways net.
Keywords: layered road profiling, GPR, soil moisture, soil layers profiling, soil conductivity
This work deals with the study of atomic and electronic structure of kaolinite samples (Glukhovtsy deposit) and montmorillonite (Millerovsky deposit) by density functional theory. The applicability of existing exchange-correlation potential in the local density approximation (LDA) and the generalized gradient approximation (GGA) is analised for an adequate description of the physical properties of layered aluminosilicate. An experimental and theoretical study of the IR spectra of minerals, as well as the identification of the most intense absorption bands, performed in the approximation of DFT using the exchange-correlation potential PW91. The analysis of the band structure of these minerals, which showed that these compounds are direct-gap insulators.
Keywords: DFT, clay, clay minerals, phyllosilicates, atomic and electronic structure, crystalline systems, IR spectrum band strukutra, the electron density
This work deals with the integrated study of the composition and structural characteristics of the rock-forming minerals in Millerovsky bentonite clay. The qualitative and quantitative analysis of the clay samples is made by X-ray diffraction , X-ray photoelectron spectroscopy and thermal analysis . The morphological and microstructural features of minerals are investigated by scanning electron microscopy. The application of the method of direct theoretical calculation of the diffraction patterns is showm to determine the crystal-chemical parameters of the studied minerals. The results are aimed at explaining a number of physical and chemical properties of layered aluminosilicate.
Keywords: clays, clay minerals, layered silicates, x-ray diffraction, crystalline systems
The results of computational experiments to determine the characteristics of the porous piezoelectric ceramics based on the methodology, including the effective modules method, simulations of representative volumes on a simple random method and the method of Witten-Sander, finite element method to solve static piezoelectric problems for heterogeneous composite media and the accounting of inhomogeneous polarization near the pores are presented. A comparison of the results of computer simulation with the known experimental data for the porous material PZT-4 and its analogs is realized. It is concluded that the accounting of inhomogeneous polarization in the vicinity of porous provide the better agreement between numerical results and large number of known experimental data. Thus, for most effective constants the smallest errors are obtained for a representative volume of the porous piezoelectric material, constructed by Witten-Sander method.
Keywords: piezocomposite, porous piezoelectric ceramics, inhomogeneous polarization, mathematical modelling, models of representative volumes, finite element method, effective moduli
Tendencies of technological improvement of electronic chips led to reduction of their sizes, weight, development of functionality and decrease in power consumption. It allows us to discuss questions of developing renewable micro power sources which can provide power supply of autonomous microelectronic and micro circuitry systems for charge indication, paying attention to snow transfer, etc.
The purpose of the paper is researching a profile of electrostatic field potential in the mountain district which was estimated as a possible use as a renewable micro power source.
It is found out that on windward sides of snow relieves the potential of electrostatic field exceeds three times to a similar indicator for lee sides and is 80 V. The potential is 3,5kV on polymeric surfaces (Nylon, teflon).
Keywords: snow storming electricity, electrization, potential of electrostatic field, charge, the salting, the loaded particles of snow, innovation electronics, micro circuitry, renewable micro power sources.
In article the safety mechanism in construction is shown. Main types of monitoring of unique buildings and constructions are opened
Keywords: risk, construction, monitoring, labor protection, safety
This article deals with the unification of the elements of wood as on the principle of similarity with the material counterpart. Also estimated the economic benefits of the technical parameters of Glulam. As a result of optimizing the size of these elements. Unification is held on the main criterion of similarity bearing members with the solution graphically. Resulting in optimal size sections are then calculated the opportunity cost of production.
Keywords: unification, glued wooden structures
The coloration centres (CC) in crystals of rear earth gallium garnets (REGG): Gd3Ga5O12 (GGG), Gd3Sc1,6Ga3,4O12 (GSGG) и Nd3Ga5O12 (NGG) obtained by Chohraljskiy method, were investigated by methods of optical spectroscopy and spectral analysis in the wavelength range of 0,2-0,87 microns. In the case of keeping the samples under dark conditions, unstable CC were formed in the crystals of GGG and GSGG. The absorption maxima are at λmax1 = 0,243 m and λmax2 = 0,275 m at concentration of N ~ 1018 cm-3. It is suggested that the observed enlightenment is caused by the recharging of growth defects and occurring the energy levels in the band gap of garnets. It appears that these CC correspond to centres of O- holes, originated from gallium vacancies V3-Ga 3+ in tetrahedral and octahedral nots which form near clusters of [V3-Ga 3+ - V2+O2- ]
Keywords: color centers, rare earth gallium garnets, kristylly, Czochralski method, the crystal lattice
The article is devoted to the formation of scientific and methodological base management of natural and man-made risks that arise in urban areas in the realization of investment and construction projects for the development of the urban environment. The article indicated the essence of the mutual influence of economic , social and environmental processes that occur in the realization of investment and construction projects for the development of an urban environment , the purpose and objectives of risk management of urban areas are determined , the necessity of applying the relevant scientific and methodological apparatus that takes into account the main socio - and environmental factors including economic and mathematical methods and models of assessment and prediction of the level of risk is based . As a result of proposed scheme is described in detail and the strategic management of natural and technological risks of investment and construction projects of development of urban territories , which includes five elements : 1) determining the level of acceptable risk and the list of measures of regulation security development based on the socio -economic factors , and 2 ) the organization of a permanent monitoring natural and built environment conditions and the level risk of livelihoods of the population , and 3) formation of a rational allocation of resources for preventive measures and reduce the risk and the negative impactof , and 4) implementation of a complex program of measures to reduce risk , and 5) carrying out of repair work and / or reconstruction . The proposed scheme improves the efficiency and rationality of strategic urban planning of urban environment .
Keywords: natural and man-made risks, investment and construction projects, sustainable development, urban territories, strategic management
The short review of existing panoramic systems are given. The limits of such systems doesn't allow to form a panoramic video with dealing the parallax effect in real-time systems. The presented algorithm for forming a panoramic video is free of these disadvantages. An algorithm based on mathematical model of the round-view system that takes into account the location of cameras, their intrinsic parameters and model of the world. The algorithm includes following chain of coordinate transformation: from panoramic image coordinates to spherical coordinates and to Cartesian world coordinate system, from world coordinates to camera coordinate system and to input image coordinates. Geometric distortion of camera is dealt. Model of the world is represented as spherical and a hemispherical surfaces.
Keywords: panoramic image, round-view video system, camera model, camera distortion, parallax