Now showing items 35-54 of 1050

    • Damping of a Solution of Linear Autonomous Difference–Differential Systems with Many Delays Using Feedback 

      Metel’skii, A. V.; Urban, O. I.; Khartovskii, V. E. (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 

      Zenkevich, E. I. (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
    • The design and composition of expansion joints on big-span bridges with intensive heavy-duty traffic 

      Busel, A.; Krotau, R. (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
    • Die Stellung Weißrusslands in der Zollunion 

      Brovka, G. M. (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 

      Lagatsky, A. A.; Kisel, V. E.; Troshin, A. E.; Tolstik, N. A.; Kuleshov, N. V.; Leonyuk, N. I.; Zhukov, A. E.; Rafailov, E. U.; Sibbett, W. (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 

      Zhang, X.; Zhou, Y.; Yasukevich, A. S.; Loiko, P. A.; Mateos, X.; Xu, X.; Guo, S.; Wang, Z. (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 

      Rubinov, A. N.; Zenkevich, E. I.; Nemkovich, N. A.; Tomin, V. I. (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 

      Gretchikhin, L. I.; Latushkina, S. D.; Kamarouskaya, V. M. (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 

      Kilin, D.; Zenkevich, E.; Borczyskowski, C. von (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 

      Krakov, M. S.; Nikiforov, I. V. (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 

      Boiko, I. L.; Alhassan, M. (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
    • Efficiency of using cables on 6-110 kv with sticked polyethylene isolation 

      Korotkevich, M. A.; Podgaisky, S.; Golomuzdov, A. (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 

      Tolstik, N. A.; Kurilchik, S. V.; Kisel, V. E.; Kuleshov, N. V.; Maltsev, V. V.; Pilipenko, O. V.; Koporulina, E. V.; Leonyuk, N. I. (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 

      Gaponenko, M. S.; Kuleshov, N. V.; Südmeyer, T. (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 

      Belyakov, A. V.; Sarantsev, V. V.; Gorbachev, A. N.; Panteleenko, F. I.; Azarenko, E. L.; Reutov, B. F. (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
    • Electric-spark alloying technology for improving the working life of steam turbine rotor blades and equipment for its implementation 

      Belyakov, A. V.; Sarantsev, V. V.; Gorbachev, A. N.; Panteleenko, F. I.; Azarenko, E. L.; Reutov, B. F. (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 ...
      2022-08-09
    • Electron transfer in porphyrin multimolecular self-organized nanostructures 

      Zenkevich, E. I.; Bachilo, S. M.; Shulga, A. M.; Rempel, U.; Willert, A.; Borczyskowski, C. von (1998)
      On the base of of covalent and non-covalent bonds nanoscale self-assembling multiporphyrin arrays with well-defined geometry, the controllable number of interacting components and their spectral and photophysical properties were formed. The deactivation of excited singlet and triplet states was studied using steady-state, time-resolved picosecond fluorescence (∆½≈30 ps) and ...
      2017-05-25
    • Energy transfer in ethane-bisporphyrins studied by fluorescence line narrowing and spectral hole burning 

      Mauring, K.; Suisalu, A.; Kikas, J.; Zenkevich, E. I.; Chernook, A. V.; Shulga, A. M.; Gurinovich, G. P. (1995)
      The quasi-line fluorescence excitation spectrum of 1,2-bis (2,3,7,8,12,13,17,18-octaethyl-21H,23 H-porphino) ethane at 4.8 K consists of two subbands with the splitting mean value of 51cm⁻¹, that are ascribed to the donor and the acceptor half of the homodimer. The donor's fluorescence is quenched by an efficient energy transfer to the acceptor. The energy transfer rate of 10¹¹ ...
      2017-05-18
    • Energy transfer in Tm,Ho:KYW crystal and diode-pumped microchip laser operation 

      Kurilchik, S. V.; Gusakova, N. V.; Demesh, M. P.; Yasukevich, A. S.; Kisel, V. E.; Pavlyuk, A. A.; Kuleshov, N. V. (Optical Society of America, 2016)
      An investigation of Tm-Ho energy transfer in Tm(5at.%), Ho(0.4at.%):KYW single crystal by two independent techiques was performed. Based on fluorescence dynamics measurements, energy transfer parameters P71 and P28 for direct (Tm→Ho) and back (Ho→Tm) transfers, respectively, as well as equilibrium constant Θ were evaluated. The obtained results were supported by calculation of ...
      2016-05-12
    • Erratum to: Thermo‑optic coefficients of Nd‑doped anisotropic KGd(WO4)2, YVO4 and GdVO4 laser crystals 

      Loiko, P. A.; Yumashev, K. V.; Kuleshov, N. V.; Pavlyuk, A. A. (2016)
      Erratum to: Thermo‑optic coefficients of Nd‑doped anisotropic KGd(WO4)2, YVO4 and GdVO4 laser crystals / P. A. Loiko [et al.] // Applied Physics B. – 2016. – Vol. 129.
      2017-11-22