Experimentation Technology in the Process of Preschoolers’ Fine Arts Activity

AbstractThe article presents scientific and methodical substantiation of the technology of organizing experimentation in the process of fine arts activity by senior preschool age children. The article defines the significance and types of children's experimentation, shows peculiarities of its mastering by senior preschool age children. The study presents scientific and methodical substantiation of the technology of the organization of the experimentation of senior preschool age children in the process of fine arts activity. Special attention is paid to the description of the stages of organization of children's experimentation: incentive-stimulating, constructive-forming and initiative-creating

Electron irradiation induced reduction of the permittivity in chalcogenide glass (As2S3) thin film

We investigate the effect of electron beam irradiation on the dielectric properties of As2S3 Chalcogenide glass. By means of low-loss Electron Energy Loss Spectroscopy, we derive the permittivity function, its dispersive relation, and calculate the refractive index and absorption coefficients under the constant permeability approximation. The measured and calculated results show, to the best of our knowledge, a heretofore unseen phenomenon: the reduction in the permittivity of <40%, and consequently a modification of the refractive index follows, reducing it by 20%, hence suggesting a significant change on the optical properties of the material. The plausible physical phenomena leading to these observations are discussed in terms of the homopolar and heteropolar bond dynamics under high energy absorption.Comment: 22 pages, 7 figures, manuscript in preparation to send to Physical Review

Nano-sized phase inclusions in As₂S₃ glass, films and fibers based on this glass

In this report, the comparative analysis using Raman spectroscopy of the short-range order in amorphous As₂S₃ films deposited with different evaporation rates, volume glass and fiber based on this glass is presented. With increasing the film deposition rate, their structure becomes more non-uniform as compared to that of glass. Raman spectra excited by laser radiation with energy bigger than the width of the optical gap indicate photomodification of the structure of As₂S₃ glass and fiber based on it

Chalcogenide glass thin films: Z-Scan measurements of refractive index changes

Nonlinear properties of chalcogenide glass As2S3 thin films have been measured with a self-diffraction (Z-Scan) technique. Photostructural changes and dynamical effects have been measured

Creation of long-living ordered electron-hole structures in a disordered system: Slow nonlinear response and formation of a beam channel by weak pumping

Experimental and theoretical studies of an amorphous As2S5 semiconductor show the appearance of a nonlinear variation of the refractive index An, produced by a weak He-Ne laser beam. The refractiveindex variation needs long-time exposure (hours) and survives for a long time {afew days) after the laser is switched off. The main feature of the theoretical model proposed here is the existence of electron and hole trapped states resulting in slow relaxation and recombination, and the dependence of generation and recombination rates in a given trap on the space distribution of electron-hole ordering. This dependence results in spatial electron-hole ordering: the ordered state is long living and gives a contribution to the refractive-index variation. Some experimental results supporting the presented model are also reported