Dye molecules with pyridyl side substituents (porphyrins and heterocyclic perylene diimides) coordinatively attached to semiconductor CdSe/ZnS quantum dots (QDs) surface form quasi-stable “QD-Dye” nanocomposites of various geometry in the competition with capping molecules (tri-n-octyl phosphine oxide or long chain amines) exchange. This results in photoluminescence (PL) quenching ...

This paper considers suprasegmental parameters such as intonation, stress and speech rhythm. Correct articulation of sounds and correct pronunciation in the target language depend on prosodic structures presented by standard intonation patterns. Linguistic and acoustic resources provide the basis for computer-aided intonation training in and outside the classroom. There is a great ...

The optical absorption and up-conversion luminescence of oxyfluoride glasses in the system SiO2–PbO–PbF2–CdF2 coactivated by Yb3+–RE3+ ions (where RE = Er, Tm, Ho, Dy, Pr, or Tb) are investigated. Excitation with a laser diode in the IR range (960 nm) gives intense green, blue, and red luminescence. The color characteristics of the up-conversion luminescence in the CIE 1931 system ...

The goal of this work is the micro-Raman study of molecular hydrogen localized in cone-shaped defects, which are formed on the surface of previously helium implanted and annealed Czochralski Si wafers as a result of hydrogen plasma treatment. The line at ≈ 4158 cm corresponding to molecular hydrogen is observed in the Raman spectra when the laser beam is focused both on cone-shaped ...

This paper presents a mathematical model for predicting the thickness of coatings deposited by means of spraying onto rotating parts with circular symmetry, for the case of time-dependent material feed rate. A procedure for calculating the material feed rate control law providing production of coatings with uniform thickness or coatings with a predefined law of thickness variation ...

The principles and approaches in the development and improvement of steel heating technology in the furnaces of rolling manufacture of various structural design, based on the systematic study of thermal physical and technological processes, including mathematical modeling, industrial experiments, development of rational temperature-thermal modes.

Well-defined structurally organised porphyrin triads of a controlled geometry andnanoscale size have been formed in liquid solutions using the combination of a covalent approach and non-covalent self-assembly. The triads contain zinc-octaethylporphyrin chemical dimer, (ZnOEP)₂Ph, with covalently linked electron acceptors (p-benzoquinone, Q or pyromellitimide, Pim), and additional ...

On the basis or experiments Ihe oscillator model has been established for individual NH tautomers or porphyrins with asymmetrical substitution. CNDO/2 calculations explain the inversion of Q ₓ (O.O) and Q y (O.O) electronic transition intensities in NH tautomers as a consequence of the inversion of LUMO coefficients c₁ and c₂ for fixed x and y molecular oscillators.

In the present paper, the bonding strength of Fe-based self-fluxing alloy coating deposited by plasma spraying, gluing and laser remelting and alloying on the steel substrate have been investigated. When flame melting, a globular structure is formed. Against the background of the solid solution carbide-boride phases are clearly distinguishable, between which the Fe-Fe2B and Fe-FeB ...

The Article analyses the use of n-butanol (biobutanol) in mixtures with petrol in spark-ignition (SI) internal combustion engines (ICE). Analysis of the scientific literature allowed determining that n-butanol content had a different effect on the same engine parameters in different tests, thus a decision was made to conduct additional research, where, having assembled the necessary ...