Now showing items 65-84 of 1046

    • Highly efficient continuous-wave diode-pumped Er, Yb:GdAl3(BO3)4 laser 

      Kisel, V. E.; Gorbachenya, K. N.; Yasukevich, A. S.; Maltsev, V. V.; Leonyuk, N. I.; Kuleshov, N. V. (Optical Society of America, 2013)
      We report the highly efficient continuous-wave diode-pumped laser operation of Er, Yb:GdAl3 BO3 4 crystal. Absorption and stimulated emission spectra, emission lifetimes, and efficiencies of energy transfer from Yb3 to Er3 ions were determined. A maximal output power of 780 mWwas obtained at 1531 nm at absorbed pump power of 4 W with slope efficiency of 26%.
      2016-01-05
    • Ho:KLuW microchip laser intracavity pumped by a diode-pumped Tm:KLuW laser 

      Serres, J. M.; Loiko, P. A.; Mateos, X.; Yumashev, K. V.; Kuleshov, N. V.; Petrov, V.; Griebner, U.; Aguilo, M.; Diaz, F. (Springer, 2015)
      A compact intracavity-pumped microchip Ho laser is realized using stacked Tm:KLuW/Ho:KLuW crystals pumped by a laser diode at 805 nm; both crystals are cut for light propagation along the Ng optical indicatrix axis and emit with polarization along the Nm axis. Maximum CW output power of 285 mW is achieved at a wavelength of 2080 nm for 5.6 W absorbed pump power in the Tm:KLuW ...
      2018-09-14
    • Identification and assignment of porphyrin-CdSe Hetero-nanoassemblies 

      Zenkevich, E. I.; Blaudeck, T.; Shulga, A. M.; Cichos, F.; Borczyskowski, C. von (2007)
      Hetero-nanoassemblies in toluene solution are formed via anchoring pyridyl substituted free base porphyrin molecules on the colloidal core-shell semiconductor nanocrystals CdSe/ZnS. The formation can be identified via quenching of semiconductor photoluminescence and followed via spectral changes of porphyrin spectral properties such as fluorescence, fluorescence decay and absorption. ...
      2017-05-27
    • In-band pumped room-temperature Er:KY(WO4)2 laser emitting around 1:6 mm 

      Gorbachenya, K. N.; Kisel, V. E.; Yasukevich, A. S.; Pavlyuk, A. A.; Kuleshov, N. V. (Maik Nauka-Interperiodica Publishing, 2013)
      We present efficient continuous-wave operation of an Er:KY(WO 4)2 crystal under in-band pumping by a compact diode-pumped Er, Yb:GdAl3(BO3)4 laser. Maximum slope efficiency of 27% and output power of 35 mW at 1609.5 nm were obtained with beam propagation factor M2 < 1:2. Absorption and stimulated emission cross-section spectra, as well as the radiative lifetime of the 4I13=2 ...
      2016-05-12
    • Influence of Brownian Diffusion on Levitation of Bodies in Magnetic Fluid 

      Bashtovoi, V. G.; Reks, A. G.; Klimovich, C.; Motsar, A.; Ryapolov, P. A.; Storozhenko, A.; Shabanova, I. (Sumy State University, 2013)
      The present work deals with experimental investigation of the levitation of magnetic and non-magnetic bodies in a magnetic fluid when essentially influenced by Brownian diffusion of magnetic particles in it. It is established that the point of levitation of bodies in a magnetic fluid varies with time.
      2016-03-29
    • Influence of Shell Parameters on Optical Properties of Spherical Metallic Core-Oxide Shell Nanoparticles 

      Pustovalov, V. K.; Astafyeva, L. G. (2015)
      Different metal homogeneous nanoparticles have been extensively studied in recent years due to their wide range of potential applications. It is very interesting to investigate core-shell nanoparticles with oxide shell from core metal. The formation of oxide shell on metallic nanoparticles can be achieved by different chemical and physical methods including also natural oxidation ...
      2017-11-04
    • Influence of Single Dye Molecules on Temperature and Time Dependent Optical Properties of CdSe/ZnS Quantum Dots: Ensemble and Single Nanoassembly Detection 

      Zenkevich, E. I.; Stupak, A. P.; Kowerko, D.; Borczyskowski, C. von (2012)
      Optical spectroscopy on ensembles and single CdSe/ZnS semiconductor quantum dots (QDs) demonstrates a competition of trap and near band edge photoluminescence (PL). This competition can be markedly influenced by a few surface attached pyridyl functionalized dye molecules (porphyrins or perylene diimides) forming nanoassemblies with well defined geometries. Temperature variation ...
      2017-05-27
    • Influence of the meridional flow and thermomagnetic convection on characteristics of magnetic fluid seal 

      Krakov, M. S.; Nikiforov, I. V. (Maik Nauka-Interperiodica Publishing, 2011)
      For the low-speed magnetic fluid seals, the influence of the meridional flow, induced by the shaft rotation, on the distribution of magnetic particles concentration, is studied. Influence of the thermomagnetic convection on the structure of this flow and on the temperature distribution in high-speed magnetic fluid seals is investigated also. The problems were examined by numerical ...
      2016-03-29
    • Insensitivity of the Stationary Distribution of State Probabilities in an Open Network with Non-Active Customers 

      Kruk, Yu. S.; Dudovskaya, Yu. E. (2015)
      We study the stationary operation of an open queueing network with non-active customers and informational signals. The amount of work to service a claim is a random value with an arbitrary distribution. The stationary distribution of network state probabilities has a multiplicative form and is insensitive with respect to the functional form of the distribution of the work needed ...
      2017-11-21
    • Interaction of multiporphyrin systems with molecular oxygen in liquid solutions: Extra-ligation and screening effects 

      Sagun, E. I.; Zenkevich, E. I.; Knyukshto, V. N.; Shulga, A. M.; Starukhin, D. A.; Borczyskowski, C. von (2002)
      Steady-state and time-resolved studies indicate that for a sequence of porphyrin or chlorin chemical dimers Zn-cyclodimer → (ZnOEP)₂Ph → (ZnOEP)₂ → (ZnHTPP)₂ → (ZnOEChl)₂ with relative lowering of excited S₁- and T₁-states, the extra-ligation by pyridine (PYR) does not influence essentially on fluorescence parameters but leads to an increase of T₁-states non-radiative decay (the ...
      2017-05-26
    • Internal scheme of the body assessment in an experiment with environmental uncertainty 

      Lukashevich, U. A.; Vasuk, V. E.; Tarasevich, M. I.; Mankevich, S. M.; Paramonova, N. A. (2017)
      The aim of the work was to analyze the influence of various environmental factors forming environmental uncertainty on the nature of the transformation of the "internal scheme of the body". Materials and methods. For the study, a group of healthy volunteers (n = 90) was selected. The results in this paper are median, 75 and 25 percentiles (Me [UQ / LQ]). The study was conducted ...
      2022-08-29
    • International higher education cooperation under conditions of fuzzy terminology: intellectual mobility vector 

      Mannanov, U. V.; Gancherenok, I. I. (2030 Uzbekistan Research Online, 2020)
      Terminology analysis of higher education internationalization process concerning joint educational programs is fulfilled. Fuzziness of used terminology is demonstrated. Joint higher education establishments development in the framework of fractal model is suggested as a strategic direction of higher education internationalization, enhancement of its quality and a concept of ...
      2020-07-17
    • Investigations of Chl α aggregates cross-linked by dioxane in 3-methylpentane 

      Oksanen, J. A. I.; Zenkevich, E. I.; Knyukshto, V. N.; Pakalnis, S.; Hynninen, P. H.; Korrpi-Tommola, J. E. I. (1997)
      In this work, dioxane-bound aggregates of chlorophyll a are prepared in 3-methylpentane. The properties of the aggregates are studied by using steady-state and time-resolved spectroscopies. The Qy-region absorption spectrum of the chlorophyll α-dioxane aggregate shows four clearly resolvable narrow bands with comparable intensities. The band maxima are located at 683, 689, 698 ...
      2017-05-25
    • The issues of ensuring regional economic security in the conditions of formation of innovative economy in the Customs Union of Belarus, Kazakhstan and Russia 

      Brovka, G. M. (BW Jan Brodzinski, 2014)
      One of the features of the integration of transformations in the post-Soviet space is not only a different speed of their implementation, but also the gradual achievement of the maximum use of regional integration association of a higher level under the existing mechanisms of a lower stage of integration. The driving force behind the ongoing transformation is to ensure the economic ...
      2019-04-05
    • Kelvin probe error compensation based on harmonic analysis of measurement signal 

      Tyavlovsky, A. K.; Zharin, A. L.; Gusev, O. K.; Kierczynski, K. (2014)
      Kelvin probe error compensation based on harmonic analysis of measurement signal / A. K. Tyavlovsky [et al.] // Przeglad Elektrotechniczny. – 2014. – Vol. 90, № 3. – P. 251-254.
      2015-07-06
    • Laboratory Investigation of Load Incremental Effect on the Deformation of Clay Under Axially Loaded Modeled Circular Piles 

      Adejumo, T. W.; Alhassan, M.; Boiko, I. L. (2013)
      This paper presents the results of recent experimental investigation of load incremental effect on the deformation of clay under axially loaded modeled wooden circular piles in clay. The modeled piles consist of 20 mm diameter, 200 mm length, made up of single pile, 4 No pile group of 2x2 with centre to centre a = 4d, and 9 No pile group of 3x3 with centre to centre a = 3d, were ...
      2018-03-10
    • Laser confocal and spatially-resolved fluorescence spectroscopy of porphyrin distribution on plasma deposited polymer films 

      Zenkevich, E. I.; Martin, J.; Borczyskowski, C. von; Ageeva, T. A.; Titov, V. A.; Knyukshto, V. N. (2008)
      Laser confocal microscopy and spatially-resolved fluorescence spectroscopy have been used for the study of the interaction of di(p-aminophenyl)etioporphyrin (DAPEP) and tetra(p-aminophenyl)porphyrin (TAPP) molecules with the surface of thin (7-15 μm) polypropylene films treated by 0.5 M KCl solution and activated by air non-equilibrium plasma at the normal atmospheric pressure. ...
      2017-05-27
    • Laser Performance of Er,Yb:YAl3(BO3)4 Crystals with Different Erbium Concentrations 

      Gorbachenya, K. N.; Kisel, V. E.; Yasukevich, A. S.; Maltsev, V. V.; Leonyuk, N. I.; Kuleshov, N. V. (2014)
      The effect of erbium concentration on the laser performance of Er,Yb:YAl3(BO3)4 crystals was investigated. A maximal output power of 1.6 W in CW and 2.7 W in QCW regimes was obtained at 1522 nm.
      2017-11-22
    • Laser performance of in-band pumped Er : LiYF4 and Er : LiLuF4 crystals 

      Gorbachenya, K. N.; Kurilchik, S. V.; Kisel, V. E.; Yasukevich, A. S.; Kuleshov, N. V.; Nizamutdinov, A. S.; Korableva, S. L.; Semashko, V. V. (Turpion Ltd., 2016)
      Spectroscopic properties of Er : LiLuF4 and Er : LiYF4 crystals in the spectral region near 1.5 mm and the lasing characteristics of these crystals under in-band pumping at a wavelength of 1522 nm are studied. With the Er : LiLuF4 crystal, the maximum slope efficiency with respect to the absorbed pump power was 44 % at a wavelength of 1609 nm. Continuous-wave operation of an ...
      2016-03-29
    • Life cycle assessment of biomass production from drained wetlands areas for composite briquettes fabrication 

      Rodzkin, A. I.; Kundas, S. P.; Wichtmann, W. (2017)
      The area of wetlands after peat mining in Belarus is about 190,000 hectares and once peat harvesting has ceased it is impossible to grow any cultural plants for some years. One of the perspective directions is rewetting wetlands after peat extraction that stimulate vegetation of natural grass, like reed, rush and others which are growing in natural conditions. The grass biomass ...
      2021-07-19