Browsing Внеуниверситетские публикации ученых БНТУ by Title
Now showing items 53-72 of 4457
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CW and Q-switched diode-pumped laser operation of Yb 3+:NaLa(MoO4)2
(Springer, 2005)Continuous wave (CW) and Q-switched diode-pumped laser operation of Yb3+:NaLa(MoO4)2 single crystal was to our knowledge, demonstrated for the first time. A CW output power of 220 mW and slope efficiency of 46% were obtained. Q-switched laser operation was achieved with a pulse duration of 60 ns average output power of 70mW and slope efficiency of 22%.2016-03-24 -
Damping of a Solution of Linear Autonomous Difference–Differential Systems with Many Delays Using Feedback
(2015)For linear autonomous difference-differential systems with commensurable delays, the problem of damping the solution by using a linear difference-differential controller with a state feed-back is solved. A generalization of these results to linear autonomous difference-differential systems of neutral type with commensurable delays in the case of a continuous solution is proposed. ...2017-11-22 -
Deactivation of excited states in nanostructures containing cu-porphyrin subunit
(Ивановский государственный химико-технологический университет, 2016)Here, we present a semi-review of mutual Belarussian-German collaboration in the field of supramolecular chemistry and photophysics of tetrapyrrole compounds of various types: porphyrin chemical dimers, self-organized multiporphyrin complexes, ordered aggregates of photosynthetic pigments and nanoassemblies based on semiconductor CdSe/ZnS quantum dots and porphyrins. A special ...2020-11-11 -
Deepening the interaction between industrial and scientific organisations of the Republic of Belarus in the context of national and global development vectors
(Издательский центр БГУ, 2024)The article aims to assume the state of Belarus industrial complex and scientific organisations and release prospects based on global trends. The research proposes to carry out such an assessment based on the authors’ developed methodology, which includes several mandatory stages: analysis of the current state, identification of cooperation areas, assessment of resources and ...2024-08-27 -
The design and composition of expansion joints on big-span bridges with intensive heavy-duty traffic
(2016)In the Republic of Belarus the roads with a high intensity of transport most widely employ expansion joints with rubber and steel compensators fastened to the reinforced concrete base with embedded therein studs. While operated expansion joints are exposed to various kinds of operational and climatic impacts causing their damage. Expansion joints destruction results in a sharp ...2018-03-10 -
Development of the theory of computation of pivotally-connected beams on an elastic foundation taking into account their physical nonlinearity
(Колорград, 2019)This work presents a brief review of the literature on the theory and technique of computation of pivotally-connected structures on a linearly-elastic foundation. The authors refer to the works of B.G.Korenev, G.Ya.Popov, I.A.Simvulidi, R.V.Serebryany and A.G.Yuryev, in which investigations for calculating the pivotally-connected beams and slabs on an elastic foundation are ...2020-10-08 -
Die Stellung Weißrusslands in der Zollunion
(Verlag Recht und Wirtschaft GmbH, 2011)Brovka, G. M. Die Stellung Weißrusslands in der Zollunion / G. M. Brovka // Rechtsfragen der Eurasischen Zollunion: Tagungsband zum 15. Munsteraner Aubenwirtschaftsrechtstag 2010 / hrsg. Dirk Ehlers, Hans-Michael Wolffgang, Ulrich Jan Schroder. – Frankfurt am Main: Verlag Recht und Wirtschaft GmbH, 2011. – S. 75-91.2019-04-10 -
Diode-pumped passively mode-locked Er,Yb:YAl3(BO3)4laser at 1.5-1.6 μm
(2008)We report the first demonstration to our knowledge of passive mode locking in a diode-pumped Er3+ and Yb3+ codoped YAl3(BO3)4 laser operating in the 1.5-1.6 μm spectral region. Low-loss GaInNAs quantum-well semiconductor saturable absorber mirrors are used for the initiation and stabilization of the ultrashort-pulse generation. Pulses as short as 4.8 ps were generated at 1530 nm ...2012-01-23 -
Diode-pumped passively Q-switched self-frequency-doubled ND:CNGS laser
(Optical Society of America, 2017)With Cr4+:YAG as a saturable absorber, a passively Q-switched self-frequencydoubled (SFD) laser based on a trigonal Nd:Ca3NbGa3Si2O14 (Nd:CNGS) silicate crystal was demonstrated for the first time. The maximum average output power at 532 nm was 16.2 mW, and the corresponding pulse repetition frequency, single pulse energy, pulse duration and peak power were 2.25 kHz, 7.2 μJ, 13.7 ...2023-12-15 -
Directed energy transfer due to orientational broadenning of energy levels in photosynthetic pigment solutions
(1982)The directed non-radiative energy transfer through monomeric molecules of chlorophyll “a” and pheophytin “a” at high concentrations (c ~ 10⁻²) in a rigid matrix of polyvinylbutyral has been found by using the nanosecond laser spectrofluorimeter. The phenomenon is caused by orientational broadening of pigment molecular spectra owing to its interaction with a solvent. The observed ...2017-05-18 -
Double electrical layer in the cathode spot
(2016)The paper describes a new phenomenon of the generation of the double electrical layer above the cathode spot surface. The neutralization of this layer leads to the reverse current of free electrons, generated due to negative ions ionization. The negatively charged flame of the cathode spot periodically ignites and attenuates, so the duration of the cathode spot existence is defined ...2020-11-03 -
Dynamics of photoinduced electron transfer in multiporphyrin nanoassemblies
(World Scientific Publishing Co., 2015)In self-assembled nanoscale porphyrin triads based on Zn-octaethylporphyrin chemical dimer (donor, D) and dipyridyl substituted porphyrin free base (acceptor, A), fluorescence quenching of D (down to 1.7-10 ps) and A (by ~1.3-1.6 times) subunits is strongly dependent on the solvent polarity (toluene-acetone mixtures) and temperature (77-350 K). The obtained experimental findings ...2017-05-27 -
Effect of diffusion of magnetic particles on the parameters of the magnetic fluid seal: A numerical simulation
(Institute of Physics, University of Latvia, 2014)In the paper, a motion of magnetic nanoparticles in a high gradient magnetic field and its correlation with the characteristics of the magnetic fluid seal are numerically studied. The neutral curve defining a range of parameters, where the liquid keeps fluidity, is found. It is shown that the concentration of particles during the initial time period grows linearly and then the ...2016-03-29 -
Effect of Vertical Cross-Sectional Shape of Foundation on Settlement and Bearing Capacity of Soils
(2013)Load-settlement relationships of shallow foundation models with different vertical cross-sectional shapes on different modeled subsoil conditions are presented. Model of shallow foundations with rectangular, wedge and T-shape vertical cross-sections were studied. The study generally shows that bulk of the load resistance of subsoil bases at the instance of shallow foundations ...2018-03-10 -
Effective means of activating speaking activities in teaching English as a foreign language
(БГУИР, 2016)This article is dedicated to estimating the effectiveness of using speaking activities in teaching English as a foreign language. The author gives detailed characteristics of various speaking activation means and provides a classification table of such activities. The wide gamut of language functions, such as greetings, apologizing, congratulating, etc., is being focused on while ...2018-06-21 -
The effective technique of solving of reduced characteristics equations of radiation transfer theory
(2004)An integral equation of radiation transfer theory is considered. The method to solution of this equation based on its reduction to an infinity system of linear algebraic equations is presented. The solvability conditions in L2-space are given and the explicit series solution is constructed.2020-11-17 -
Efficiency of using cables on 6-110 kv with sticked polyethylene isolation
(EDP Sciences, 2017)The expediency of using more expensive 6-10 kV cables with XLPE insulation was proved by us on the basis of the method of multi-purpose optimization, which took into account both the resulted costs for the construction and operation of cable lines, and the reliability of its operation, as well as the convenience of installation. Without compensation of capacitive currents, ...2022-07-29 -
Efficient 1 W continuous-wave diode-pumped Er,Yb:YAl3(BO3)4 laser
(Optical Society of America, 2007)We report the spectroscopy and high-power continuous-wave (CW) diode-pumped laser operation of Er:Yb:YAl3(BO3)4 crystal. Absorption and stimulated emission spectra, emission lifetimes, and efficiency of energy transfer from Yb3+ to Er3+ ions were determined. A CW Er:Yb:YAB laser emitting at 1602, 1555, and 1531 nm with output power as high as 1 W and slope efficiency up to 35% ...2012-01-23 -
Efficient diode-pumped Tm:KYW 1.9-μm microchip laser with 1 W cw output power
(Optical Society of America, 2014)We report on a diode-pumped Tm:KYW microchip laser generating 1 W continuous-wave output power. The laser operates at a wavelength of 1.94 μm in the fundamental TEM00 mode with 71% slope efficiency relative to the absorbed pump radiation and 59% slope efficiency relative to the incident pump radiation. The optical-to-optical laser efficiency is 43%.2016-01-05 -
Electric-spark alloying technology for improving the working life of steam turbine rotor blades and equipment for its implementation
(American Society of Civil Engineers, 2016)Work is devoted to studying development of technology for forming erosion-resistant coatings for steam turbine rotor blades by electric-spark alloying. Comparative analysis is provided for current methods of steam turbine rotor blade strengthening and repair. It is shown that electric-spark coating formation on leading edges is important, and development of forming technology is ...2022-07-29