Vol 46, No 12 (2019)
- Year: 2019
- Articles: 8
- URL: https://journals.rcsi.science/1068-3356/issue/view/14172
Article
Luminescent Hybrid Materials Based on Polymers of Poly(Alpha-Fluoroacrylates) Doped with Tb(III) Complex
Abstract
This study is devoted to the development of efficient luminescent hybrid materials excited by UV radiation and featuring narrow luminescence lines as well as light, humidity, and temperature resistance. As a luminescent material, a terbium ion coordination compound introduced into the matrix of an organofluorine polymer is used. It has been shown that efficient excitation transfer to electronic levels of the terbium ion can be achieved by proper ligand selection. The polymer matrix material does not affect the luminescence properties of the Tb(III) coordination compound.
Measurements of Soft X-Ray Spectra in the ECR Heating Region and Determination of the Localization Region of Suprathermal Electrons at the L-2M Stellarator
Abstract
Soft X-ray spectra coming from the ECR heating region, non-distorted by the effect of the plasma-wall interaction, are measured at the L-2M stellarator in experiments on axial and off-axial ECR heating. In both cases, the measured soft X-ray spectra turned out to be non-Maxwellian. It was found that the electrons forming the suprathermal spectral region are produced in the heating region, but do not come from the plasma-wall interaction region.
Nulling Phenomenon of the New Radio Pulsar J0810+37 at a Frequency of 111 MHz
Abstract
Pulsar J0810+37 with a period of 1.2483 s is detected at a frequency of 111 MHz during the pulsar search at the Big Scanning Antenna (BSA) radio telescope of the Lebedev Physical Institute [1]. In this paper, we present the results of the detailed study of radio emission from J0810+37 which exhibits a rare nulling effect of different durations in a very wide time interval with an average nulling fraction in “switch-on” days 〈NF〉 = 38%; considering “switch-off” days, 〈NF〉 = 74%, since radio emission from this source is interrupted on average by 2–3 days, and then it again revives on average for 1–2 days. The “switch-off” periods reach 7 days.
Determination of Charges of Superheavy Nuclei in Finding them in Nature
Abstract
The results of the search for tracks of heavy and superheavy nuclei of galactic cosmic rays in the charge range Z = 26 − 129, identified in olivine crystals from Maryalahti and Eagle Station meteorites are presented. The database including characteristics of 21743 tracks, obtained in the OLIMPIA experiment, is currently the largest one within the charge range under study. It includes three tracks of superheavy nuclei with charge 119−6+10 and a minimum lifetime estimated as several tens of years, which can be considered as a direct experimental validation of the existence of natural superheavy nuclei from the “stability island”.
Non-Stationary Photovoltage in Materials Science of Wide Band-Gap Semiconductors of Modern Adaptive Optics and Optoelectronics
Abstract
Non-stationary photovoltage excitation in silicon carbide and gallium oxide crystals is studied. The signal transient responses are measured, and the photoelectric parameters necessary for developing adaptive photodetectors, i.e., the specific photoconductivity, Maxwell relaxation time, and diffusion length of carrier transport, are determined. The sensitivity of the photodetector based on gallium oxide is determined.
Extinction Spectra of Bilayer Organometallic Nanoplatelets
Abstract
Spectra of light extinction by metal nanoprisms and nanostars coated with molecular aggregates of organic dyes are calculated and theoretically analyzed. Qualitatively different nature of the spectra of organometallic nanoparticles under study is established when using J-aggregates of various cyanine dyes as their capping layer, as well as silver and gold as the cores. This results from the implementation of various plasmon-exciton coupling modes in the systems under consideration.
Comparison of Luminescent Properties of Nd3+ Complexes with Pyrazole-Substituted 1,3-Diketone in DMSO Solutions and in KBr Pellets
Abstract
Luminescence characteristics of Nd3+ coordination compounds with pyrazole-substituted 1,3-diketonate ligand environment in KBr micropellets are studied. The luminescence decay times and the external quantum efficiencies are measured, intrinsic luminescence lifetimes of the Nd3+ ion in the complexes are estimated. The luminescence characteristics of the complexes in KBr micropellets and in DMSO solutions are compared.
Effect of Spatial Dispersion on Plasmon Resonance in Silver Nanoparticles
Abstract
Using the modified discrete sources method, the problem of calculating plasmon spectra of the characteristic energy loss of electrons during the interaction with silver nanoparticles from 2 to 8 nm in size is solved. The calculated spectra are compared with the experimental data confirming the significant spatial dispersion effect. The importance of the consideration of this factor when analyzing the properties of plasmonic nanoparticles for applications in biosensorics and biomedicine is discussed.