The results of numerical simulation of the optical properties of a one-dimensional (1D) photonic crystal with a defect based on semiconductor-dielectric layers in the near-IR range are presented. The ...simulations used layers of silicon and silicon dioxide with optical thicknesses 3λ/4, λ/4 and 10λ/4. The influence of radiation incident angle on the spectral position of the defect’s guidance band has been studied. It is shown that the sensitivity to the rotation angle lies within the limits of 6–20 nm/deg and 1.7–5.5 dB/deg, depending on the geometry of the sensor and the measurement method. This makes these photonic crystals promising for use in the rotation angle sensors as a sensitive element.
The photolysis of silver nitrate in a polyvinyl alcohol solution under the action of 405-nm continuous laser radiation has been investigated. It has been shown that the laser radiation generates ...silver nanoparticles, which exhibit a plasmon resonance, and luminescent carbon quantum dots on the substrate surface. The mean size of silver nanoparticles is 10–50 nm. At a high irradiation dose, they form 3D fractal clusters.
It is shown by methods of Raman spectroscopy that irradiation of amorphous silicon film 50 nm thick by focused electrons with energies of 5–10 keV results in its crystallization at temperatures much ...less, than the temperatures of melting and annealing of silicon. Analyses have shown that crystallization is caused by the formation of negative charge area on a film surface, by the action of secondary electrons on chemical bonds and mutual location of silicon atoms, and also by the ionic field emission of silicon ions and their field migration to the irradiated zone from surrounding regions. These processes result in the change of equilibrium location of silicon atoms, typical for amorphous phase. The increase of electron energy leads to the increase of crystallization process efficiency.
Abstract
The work investigated the durability of the labelling of sports equipment made of composite materials. Professional hockey sticks were taken for research. Research has been done on hockey ...stick wear for different players: centre and winger and defender. In addition, a study was made of hockey sticks for left-handers and right-handers. In the study of the wear of printed elements, sports equipment of various lengths was used. Contact research was carried out during training and competition. The study of the number of contacts was carried out on the basis of video recordings of trainings and games of the teams “Energija” - ElektrÄnai (Lithuania) and the national team of the Belarusian Republic. The study carried out showed that the hockey stick wear of the centre striker and the winger during the competition and training is similar. During the competition, the hockey sticks of the centre strikers are most often in contact. It was found that the difference between contacts during training and playing depends on the intensity of the game, penalty time and strategy. When conducting a study of the wear of the printed elements applied to the hockey stick, depending on the position of the player, it was found that the wear of the sticks of the winger and the defender is the same, but that of the centre striker is different. When conducting a study of hockey stick wear depending on its length, the following conclusion was made: the taller the player, the longer his hockey stick and the maximum contact area. Research has shown that hockey stick wear is not affected by how the player holds the hockey stick, i.e. whether he is left-handed or right-handed. To study the abrasion of elements using the UGRA method, an original stand was created. With the help of this stand, studies of the abrasion of printed elements were carried out. Based on the study, it was concluded that the abrasion of printed elements most often occurs at the moment of contact of the objects of research, both with each other and with objects on the playing field. As a result, the printed elements split, peel off and become less noticeable, in addition, the name of the manufacturer's company is worn out and the hockey stick loses the player's personal identification data printed on the hockey stick. Recommendations are given on the peculiarities of printing and the location of printed elements on sports equipment.
The microalgae
sp. IPPAS C-70 produces eicosapentaenoic acid. Several stresses cause the formation of fatty acid peaks that resemble hexadecadienoic acids. We used the integrated technique including ...TLC, HPLC, and GC-MS to search and determine these fatty acids. Double bond positioning in these fatty acids indicated that they were conjugated dienes and allenes. We identified and described natural nine isomers of C16 polyunsaturated fatty acids, including common methylene-interrupted dienes (Δ6,9-16:2, Δ7,10-16:2, Δ9,12-16:2), and unusual conjugated dienes (Δ6,8-, Δ7,9-, Δ8,10-, Δ9,11-, and Δ10,12-16:2), as well as allenic diene (Δ9,10-16:2). We hypothesize that the formation of conjugated dienes and allenes among fatty acids is the result of oxidative stress caused by H
O
. Hydrogen peroxide also caused an increase in saturated at the expense of unsaturated fatty acids, suggesting inhibition either fatty acid desaturases activities or the corresponding gene expression.
We propose a new approach to the solvability of ordinary as well as partial differential equations in the theory of linear differential equations and also in the theory of integral equations.
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