Jan Długosz University

About: Jan Długosz University is a education organization based out in Częstochowa, Poland. It is known for research contribution in the topics: Crystal structure & Luminescence. The organization has 749 authors who have published 2311 publications receiving 19395 citations. The organization is also known as: Higher Teacher Education School.

Transition metals induce control of enhanced NLO properties of functionalized organometallic complexes under laser modulations

Abstract: The molecular engineering of organometallic complexes has recently attracted renewed interest on account of their potential technological applications for optoelectronics in general and optical data storage. The transition metal which induces control of enhanced nonlinear optical properties of functionalized organometallic complexes versus not only the intensity but also the polarization of the incident laser beam is original and important for all optical switching. This makes organometallic complexes valuable and suitable candidates for nonlinear optical applications. In the present work, we report the synthesis and full characterization of four organometallic complexes consisting of N, N-dibutylamine and azobenzene fragments but differ by auxiliary alkynyl ligands or metal cations. Thus, a ferrocenyl derivative 1 and three ruthenium complexes 2–4 have been prepared. The nonlinear optical properties of the four new azo-based ruthenium and iron organometallic complexes in the solid state, using polymethylmethacrylate as matrix, have been thoroughly studied. This concept is extended to computing the HOMO and LUMO energy levels of the considered complexes, dipole moment, first and second order hyperpolarizabilities using the 6–31 + G(d,p) + LANL2DZ mixed basis set. The second and third nonlinear optical properties of the resulting polymer composites were obtained by measuring SHG and THG response by means of the Maker fringe technique using a laser generating at 1,064 nm with a 30 ps pulse duration. The values of the second and third order NLO susceptibilities of the four organometallic complexes were found to be higher than the common references used. Theoretical calculation shows that the large first and second order hyperpolarizablities are caused by strong intramolecular charge transfer between the transition metal parts and the ligands though a conjugated transmitter. These results indicate that the present organometallic complexes are valuable candidates for optoelectronic and photonic applications.

Topology and chemical order in AsxGexSe1 − 2x glasses: A high-resolution X-ray photoelectron spectroscopy study

Abstract: The evolution of topology and chemical order along the As x Ge x Se 1 − 2 x composition-line within the As–Ge–Se glass-forming region is studied by high-resolution X-ray photoelectron spectroscopy. It is shown that cation–cation bond formation becomes a dominant process for the compositions with x > 0.09. The results explain the peculiarities observed around this composition recently in the temperature-modulated differential scanning calorimetry data. Substitution of two selenium atoms within constituent structural units (pyramids and/or tetrahedra) by corresponding cations explains a second peculiarity point at x > 0.16 compositions observed recently with the above technique. The present observations show segregation of As and then Ge at high concentrations of cations in the system ( x > 0.20).

Fractional thermoelasticity problem for a plane with a line crack under heat flux loading

Abstract: Symmetric stress distribution in an infinite isotropic plane with a line crack, in which surfaces are exposed to the heat flux loading is considered in the framework of fractional thermoelasticity....

Informatization of technical vocational schools: Theoretical foundations and practical approaches

Abstract: The aim of this study was an experimental research in vocational schools intended to the development of the system of educational process informatization taking into account the structure of the ICT competence of skilled workers and the trends of the information society. Representative sample of over 800 students of 10 vocational schools from different regions of Ukraine, 80 teachers, 17 specialists of VET centers allowed to study and analyze the state of informatization of VET schools, as well as to determine the degree of influence of education informatization on the quality of workers’ training. The system of educational process informatization at a technical vocational school, i.e. the creation of the ICT-saturated educational environment was implemented. This is a set of interrelated activities that comprise learning management systems; information and analytical databases; computer simulation of professional actions; programs of control of knowledge; application of ICT for writing diploma papers; computer methods of competence diagnostics; simulation training complexes; expert and decision support systems. The experiment showed that the use of the developed methods of skilled workers’ informational training, of applying pedagogical software tools at technical vocational school and of training vocational school teachers how to use ICT contributes to the improvement of graduates’ professional competence.