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.

Filament-induced self-written waveguides in glassy As 4 Ge 30 S 66

Abstract: The filamentation of femtosecond laser pulses and filament-induced self-writing of a permanent waveguide are observed in As4Ge30S66 chalcogenide glass. The radial profile of the self-written waveguide is extracted from the defocused transmission microscopic images via a two-step procedure: at first the phase image of the waveguide is computed using the transport-of-intensity equation and then the index profile is obtained from the phase image by applying the inversed Abel transform.

Synthesis and Optoelectronic Properties of Hexahydroxylated 10‐O‐R‐Substituted Anthracenes via a New Modification of the Friedel–Crafts Reaction Using O‐Protected ortho‐Acetal Diarylmethanols

Abstract: A new modification of the Friedel-Crafts type intramolecular cyclization involving O-protected ortho-acetal diarylmethanols as a new type of reactant, was carried out for the first time in a medium containing a large amount of water at room temperature and enabled synthesis of a series of electron-rich, hexahydroxylated 10-O-R-substituted anthracenes, where R is an alkyl (Me, nBu, n-C(16)H(33)) or arylalkyl group (CH(2)Ph, CH(2)-2-Napht, CH(2)C(6)H(4)CH(2)OAr) and also evaluation of their electronic and optoelectronic properties in solution, crystal, and solid thin film. In this transformation, a central 10-O-R-substituted benzene ring was formed, fused to rings originating from two independent aromatic aldehydes. The reaction proceeded via two identified mechanisms involving acetal and/or free aldehyde groups. The acid sensitive acetal and dibenzyl alkoxy functions have never been used together in the intramolecular Friedel-Crafts type cyclization. The new compounds revealed deep blue fluorescence and quantum yields in solution around 0.3. The electrical properties investigated for thin films obtained by vacuum deposition on glass were 10-O-R-substituent dependent and showed much faster transient current decay in the case of the 10-O-CH(2)Ph derivative than for the material with a 10-O-Me substituent (the lifetime of charge carriers was 25 times shorter in this case). The AFM images of thin films, Stokes shifts, and X-ray analysis of π-stacking interactions in crystals of the new materials have been also obtained.

Three Areas of Taekwon-do Identification and Practice

Abstract: At present the traditional taekwon-do is reported to have three areas of practice including self-defence, health and sport and also education. The pragmatic training model, including sports competition among others, provides a necessary motivating element to put in more physical effort. Sports competition requires more intensive training and more engagement. It makes it possible to verify athletes’ skills and abilities and also makes them respond to new more and more serious challenges. Next, the educational training model reinforces the mental and philosophical factor and significantly modifies the adolescent inadequacy displayed in juvenile delinquency. Whereas, the utilitarian training model is applied in order to enhance self-defence skills. It is mostly developed in the police and armed forces, including their special units. An ideal, thus most desired training model should comprise all those factors as a disturbance in the balance between them on a long-term basis might result in pathology. This means that taekwon-do might then lose its self-defence features and become a school for breeding aggressiveness or might open to certain movement forms, thus upsetting the general combat rule involving direct contact between opponents. © Idōkan Poland Association “IDO MOVEMENT FOR CULTURE. Journal of Martial Arts Anthropology”, Vol. 14, no. 3 (2014), pp. 22–26 DOI: 10.14589/ido.14.3.3

The Heusler-type alloy MgZn2Ce

Abstract: Single crystals of the MgZn2Ce alloy (magnesium dizinc cerium) were synthesized by a two-step method which couples the thermal treatment of pressed pellets of the pure elements with subsequent arc melting. The compound crystallizes in a Heusler-type (MnCu2Al) structure in the space group Fm\overline{3}m, with one Zn site (site symmetry \overline{4}3m), one Ce and one Mg site (both with m\overline{3}m site symmetry). All inter­atomic distances indicate metallic type bonding.