Browsing Внеуниверситетские публикации ученых БНТУ by Title
Now showing items 173-192 of 4457
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Semiconductor A3B5 nanostructures for infrared femtosecond lasers
(Institute of Physics, 2013)Two techniques were suggested and tested for the recovery time shortening of saturable absorbers on a base of A3B5 compounds including quantum wells. The first one, proposed by authors, is the sample post-growth treatment by UV laser radiation; it implied generation of point defects, which, in its turn, led to electron-hole recombination acceleration and to recovery time shortening ...2016-05-11 -
The Shape of the Magnetic Fluid Surface above a Magnetizable Sphere in a Uniform Magnetic Field
(2015)The shape of the free surface of a magnetic fluid above a spherical ferromagnetic body immersed in it in a uniform magnetic field is investigated experimentally. The effect of the direction and magnitude of the magnetic field on the deformation characteristics of the free surface of the magnetic fluid with various magnetic properties and geometrical parameters is established.2017-11-23 -
Size-Dependent Non-FRET Photoluminescence Quenching in Nanocomposites Based on Semiconductor Quantum Dots CdSe/ZnS and Functionalized Porphyrin Ligands
(2011)We review recent experimental work to utilize the size dependence of the luminescence quenching of colloidal semiconductor quantum dots induced by functionalized porphyrin molecules attached to the surface to describe a photoluminescence (PL) quenching process which is different from usual models of charge transfer (CT) or Foerster resonant energy transfer (FRET). Steady-state ...2017-05-27 -
Solving the spatial contact problem for the hinge joints of the beam support by the elastic quarter-space and one eighth of the elastic space
(Колорград, 2020)The article discusses the solution of the spatial contact problem arising when calculating a reinforced concrete rafter beam pivotally supported by concrete walls. The walls are modeled by the elastic quarterspace on the left and by one-eighth of the elastic space on the right. This contact problem is solved using the numerical method - the Zhemochkin method. For this purpose, ...2022-07-22 -
Some aspects of sherardizing implementation during anti-corrosion protection of heat-treated metal parts
(2015)The article reveals the peculiarities of obtaining Zn anticorrosive diffusion layers on heat-treated metal parts using sherardizing method. It is shown that sherardizing processes can be successfully used as a final heat treatment operation for some metal parts after hardening in a temperature gap between 350-700 degrees C. 380-450 degrees C. are the most efficient temperatures ...2018-03-15 -
Some principles of teaching translation
(АГУ, 2013)Перепечко, Н. Н. Some principles of teaching translation / Н. Н. Перепечко // Межкультурная коммуникация и СМИ : материалы IV Международной научно-практической конференции, Барнаул, 15 июня 2013 г. – 2013. – С. 71-74.2014-03-31 -
Spectral Рeculiarities of NH-Tautomerism in Isocycle-Containing Porphyrins and their Covalently Linked Dimers
(1984)It has been found experimentally that a whole class of isocycle-containing porphyrins, including synthetic and natural objects and their covalently linked dimers, shows NH-tautomerism which manifests itself in isotropic solutions in normal electronic spectra both at 77 K and higher temperatures (up to 500 K).2017-05-18 -
Spectroscopic and photoluminescence characterization of Eu 3+-doped monoclinic KY(WO4)2 crystal
(Elsevier, 2014)Monoclinic 2 at% Eu-doped KY(WO4)2 is grown by top-seeded solution growth method. Polarizationresolved absorption and stimulated-emission cross-section spectra are determined for this crystal. Spectroscopic properties of Eu:KY(WO4)2 are modeled within conventional Judd–Ofelt theory, as well as theory of f–f transition intensities for systems with anomalously strong configuration ...2016-02-08 -
Spectroscopy and femtosecond laser performance of Yb3+:YAlO3 crystal
(Optical Society of America, 2008)We report what we believe to be the first demonstration of cw and passively mode-locked Yb3+:YAlO3(Yb:YAP) laser operation under diode pumping. Spectroscopic properties of a 0.6 at.%Yb3+-doped YAP single crystal were investigated. Output power up to 1.2 W with slope efficiency of 64.5% in the cw regime and 225 fs pulse duration with average power of 0.8 W from a mode-locked Yb:YAP ...2012-01-23 -
Spectroscopy of interchromophoric interactions in self-organized porphyrin and chlorin complexes
(1995)Spectral-luminescent properties of multimolecular complexes (triads and pentads, complexation constants range from 5∙10⁶ to 5∙10⁷ M⁻¹) formed by two-fold coordination of dipyridyl and tetra-pyridyl substituted porphyrin or related molecules with Zn-porphyrin and Zn-chlorin dimers having various spacers between macrocycles (-CH₂-CH₂- or phenyl ring) have been studied in methylcyclohexane ...2017-05-18 -
Spectroscopy of tetragonal Eu:NaGd(WO4)2 crystal
(2016)We report on growth and detailed spectroscopic study of Eu3ю-doped tetragonal sodium gadolinium double tungstate, Eu:NaGd(WO4)2, a new promising crystal for deep-red lasers. Large-volume crystal doped with 4.9 at.% Eu is grown by Czochralski method along the [001] crystallographic direction. Absorption of Eu3ю ions is studied at room temperature (RT) and at 6 K. For the absorption ...2017-11-18 -
Statics of Magnetic Fluid Drop with Compound Magnetic Core in a Wedge-Shaped Channel
(Sumy State University, 2013)A behavior of magnetic fluid drop with compound magnetic core in a wedge-shaped channel was studied experimentally. The study examines influence of magnetic fluid properties, its volume and magnetic field on statics of the system compound magnet – magnetic fluid drop in wedge-shaped channel. The possibility to change the static conditions of such system by altering magnetic field ...2016-03-29 -
Steric interactions influence on electron transfer efficiency in meso-nitrophenylporphyrins and their chemical dimers
(2001)Steric interactions upon mono- and di-meso-phenyl substitution in octaethylporphyrins (OEP) and their chemical dimers with the phenyl spacer manifests itself in the dramatical T₁-state lifetimes shortening at 293 K (from ms down to μs in degassed toluene solutions) without any influence on spectral-kinetic parameters of S₀- and S₁-states. This effect is explained by non-planar ...2017-05-26 -
Stokes and anti-Stokes luminescence from cubic elpasolite Cs2NaYF6 crystals doped with Er3+and Yb3+ ions
(Elsevier, 2016)Er3þ and Yb3þ doped cubic elpasolite Cs2NaYF6 crystals including stoichiometric compositions Cs2NaErF6 and Cs2NaYbF6 have been synthesized under hydrothermal conditions. Absorption, stimulated-emission and gain cross-sections spectra have been determined for the 2F5/2-2F7/2 (Yb3þ) and 4I13/2-4I15/2 (Er3þ) transitions at room-temperature. The maximum σSE values are 1.8 10 21 cm2 ...2016-05-12 -
Stratigraphic ichthyofauna assemblages of the Devonian deposits in the east and southeast of Belarus
(Научно-производственный центр по геологии, 2015)The paper presents the results of the palaeoichthyological study of the сoге from fifteen boreho/es drilled in the territory of the eastern part of the Pripyat Trough, Bobruysk Buried Ridge, Zhlobin Saddle and the northwestern slope of the Voronezh Antec/ise. Some references with data of the Devonian ichthyofauna within the investigated area are cited to complete the information. ...2019-03-11 -
Stratigraphy of middle devonian deposits of the western part of the Pripyat Trough (according то results of the study of ichthyofauna)
(Научно-производственный центр по геологии, 2014)The paper presents the results of palaeoichthyological study of the core from the Pinsk-10 and Pinsk-26 boreholes, drilled in the territory of the western part of the Pripyat Trough within the Turov and Starobin Centroclines. References with data on vertebrates of the Middle Devonian within the investigated area are given to complete the information. According to the vertebrate ...2019-03-11 -
Structural Dynamics and Relaxation Processes with Participation of Excited Singlet and Triplet States in Sterically Hindered Porphyrins and Their Chemical Dimers
(2014)Paper presents an overview of mutual Belarussian-Russian collaboration in the field of sterically hindered porphyrins compared with the relevant literature data. Typically, the conformational dynamics of a non-planar tetrapyrrole macrocycle at 295 K manifests itself in bathochromic absorption and fluorescence shifts (∆ν ~ 1100 cm⁻¹), the increase of the Stokes shift (∆νₛ ~ 900 ...2017-05-27 -
Structure and nonlinear optical properties of novel transparent glass-ceramics based on Co2+:ZnO nanocrystals
(2016)Transparent glass-ceramics (GCs) based on Co2+:ZnO nanocrystals (mean diameter, 11 nm) are synthesized on the basis of cobalt-doped glasses of the K2O–ZnO–Al2O3–SiO2 system. For these GCs, the absorption band related to the 4A2(4F) → 4T1(4F) transition of Co2+ ions in tetrahedral sites spans until ~1.73 μm. Saturation of the absorption is demonstrated at 1.54 μm, with a saturation ...2017-11-18 -
Structure-phase condition and tribological properties of coatings based on self-fluxing nickel alloy PG-12N-01 after laser surfacing
(Kluwer Academic/Plenum Publishers, 2017)Some parameters of laser surfacing of self-fluxing nickel alloy PG-12N-01 are considered. Different structures containing a low-melting -Ni – Ni3B eutectic and a -Ni – Cr3C2 eutectic that crystallizes at a higher temperature and forms the strength skeleton of the coating may form depending on the rate of the surfacing. The effect of the rate of the surfacing on the wear resistance ...2022-08-09 -
Surface engineering of slider valves of fluid power motors made of tool steels by using boriding saturation mixture
(Aleksandras Stulginskis University, 2015)The technique for producing compact boride layers for the effective hardening of slider valves of fluidpower motors and distributives valve of Belarusian origin made of tool steel has been designed. The effect of temperature and time parameters in boriding powder saturation mixture on the thickness and phase composition of the diffusion layers and the morphology of the upper ...2016-03-09