Now showing items 142-161 of 1046

    • Structural Dynamics and Relaxation Processes with Participation of Excited Singlet and Triplet States in Sterically Hindered Porphyrins and Their Chemical Dimers 

      Zenkevich, E. I. (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 

      Loiko, P. A.; Dymshits, O. S.; Vitkin, V. V.; Skoptsov, N. A.; Zhilin, A. A.; Shemchuk, D. V.; Tsenter, M. Ya.; Bogdanov, K. V.; Malyarevich, A. M.; Glazunov, I. V.; Mateos, X.; Yumashev, K. V. (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 

      Devoino, O. G.; Kardapolava, M. A.; Lutsko, N. I.; Feldshtein, E. E. (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 

      Konstantinov, V. M.; Dashkevich, V. G.; Kovalchuk, A. V. (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
    • Temperature dependent steric hindrance effects in triplet state relaxation of meso-phenyl-substituted Pd-octaethylporphyrins 

      Gorski, A.; Knyukshto, V.; Zenkevich, E.; Starukhin, A.; Kijak, M.; Solarski, J.; Semeikin, A.; Lyubimova, T. (Elsevier, 2018)
      The analysis of spectral-kinetic results of transient absorption and phosphorescence experiments has been carried out in a wide temperature range (80-293K) for a series of Pd-octaethylporphyrin derivatives (PdOEP) with increasing number of bulky meso-phenyl substituents. In order to elucidate the influence of steric hindrance interactions, as well as porphyrin macrocycle non-planarity ...
      2018-09-14
    • The Eurasian Customs Union in transition 

      Wolffgang, Hans-Michael; Brovka, G. M.; Belozerov, I. (Australia and University of Munster, 2013)
      Wolffgang, Hans-Michael. The Eurasian Customs Union in transition / Hans-Michael Wolffgang, G. M. Brovka, I. Belozerov // World Customs Journal / ed.-in-chief David Widdowson. – 2013. – Vol. 7, № 2. – P. 93-103.
      2019-04-10
    • The influence of energy-information impact on an electric vehicle 

      Savluchinsky, V. V.; Avliyokulov, Zh. S.; Valiev, J. F. (Tashkent State Transport University, 2023)
      The main results of studying the energy-informational impact on the driver of an electric vehicle. The parameters of electrical and magnetic fields recorded in the vehicle exhibit fairly complex patterns. A significant influence on the level of electromagnetic radiation comes from the electronic devices for onboard diagnostics and control, passive and active noise and vibration ...
      2024-01-04
    • Theoretical basis for an economic evaluation of road accident losses 

      Kapskij, D.; Samoilovich, T. (2009)
      The article regards the theoretical basis for estimating life value for the purpose of calculating road accident losses. The paper presents a simple structure of accident costs that could be taken into account in order to calculate the total economic value of road accidents. The article also shows the basic methods of estimating life value in different countries for different ...
      2018-03-18
    • Thermal lens study in diode pumped Ng- and Np-cut Nd:KGd(WO4)2 laser crystals 

      Loiko, P. A.; Yumashev, K. V.; Kuleshov, N. V.; Savitski, V. G.; Calvez, S.; Burns, D.; Pavlyuk, A. A. (Optical Society of America, 2009)
      A comparative study of thermal lensing effect in diode laser pumped Ng- and Np-cut Nd:KGd(WO4)2 (KGW) laser crystals was performed for laser emission polarized along the principle refractive axis, Nm. The thermal lens in the Ng-cut Nd: KGW was found to be weakly astigmatic with a positive refractive power for both the Nm- and Np-directions. For Np -cut Nd:KGW, strong astigmatism ...
      2012-01-24
    • Thermal Lensing and Multiwatt Microchip Laser Operation of Yb:YCOB Crystals 

      Loiko, P.; Serres, J. M.; Mateos, X.; Yu, H.; Zhang, H.; Liu, J.; Yumashev, K.; Griebner, U.; Petrov, V.; Aguilo, M.; Diaz, F. (2016)
      Thermal lensing is studied in monoclinic Yb:Ca4YO(BO3)(3) (Yb:YCOB) oxoborate crystals cut along the optical indicatrix axes. For all orientations, the thermal lens is positive. In the Z-cut crystal, the sensitivity factors of the thermal lens are MZ-X = 2.4 and MZ-Y = 2.8 m(-1)/W (for E parallel to X), and the astigmatism degree is as low as S/M = 14%. The positive thermal lens ...
      2018-03-18
    • Thermo-optic characterization of Yb:CaGdAlO4 laser crystal 

      Loiko, P.; Druon, F.; Georges, P.; Viana, B.; Yasukevich, A. (2014)
      Principal thermo-optic coefficients (TOCs), dno/dT and dne/dT, are measured for Yb:CaGdAlO4 crystal, for the first time, to our knowledge. At the wavelength of ~1 μm, they equal –7.6 and –8.6 (Ч10-6 K-1), accordingly. Thermal coefficients of the optical path (TCOP) are determined for this crystal for the principal crystal cuts (a-cut and c-cut) and light polarizations (π or σ). ...
      2017-11-18
    • Thermo-optic properties of Yb:Lu2O3 single crystals 

      Loiko, P. A.; Yumashev, K. V.; Schödel, R.; Peltz, M.; Liebald, C.; Mateos, X.; Deppe, B. (Springer, 2015)
      A detailed study of thermo-optic properties of 1.5 at.% Yb:Lu2O3 single crystal is performed. Thermo-optic dispersion formulas are derived for dn/dT coefficient and thermal coefficient of the optical path. At the wavelength of 1.03 μm, dn/dT = 5.8 × 10−6 K−1. High-precision temperature-dependent measurements of the thermal expansion coefficient α are performed. At the room ...
      2018-09-17
    • Thermoconvective flow velocity in a high-speed magnetofluid seal after it has stopped 

      Krakov, M. S.; Nikiforov, I. V. (Maik Nauka-Interperiodica Publishing, 2012)
      Convective flow is investigated in the high-speed (linear velocity of the shaft seal is more than 1 m/s) magnetofluid shaft seal after it has been stopped. Magnetic fluid is preliminarily heated due to viscous friction in the moving seal. After the shaft has been stopped, nonuniform heated fluid remains under the action of a high-gradient magnetic field. Numerical analysis has ...
      2016-03-29
    • Thermodynamic properties of multicomponent amorphous alloys in Fe-Si-B-Ni and Fe-Si-B-Ni-Co-Cr-Mo systems 

      Khina, B. B.; Goranskiy, G. G. (2016)
      The chemical potential of iron in a amorphous phase of multicomponent multiphase alloys Fe - 7.3% Si - 14.2% B - 8.26% Ni (alloy 1) and Fe - 0.32% Si - 4.8% B - 6.68% Ni - 2.42% Co - 8.88% Cr - 6.42% Mo (alloy 2), which contain crystalline and amorphous phases, was determined on the basis of experimental results and a theoretical model. The alloys were produced by melt quenching ...
      2021-01-21
    • Thermodynamics of Multicomponent Amorphous Alloys: Theories and Experiment Comparison 

      Khina, B. B.; Goranskiy, G. G. (2017)
      On the basis of the existing thermodynamic theories of the amorphous matter (semi-empirical Miedema model and Shao theory), the integral (enthalpy and Gibbs energy) and partial molar characteristics of a multicomponent iron-based amorphous alloy are determined. It is demonstrated that for quaternary alloy Fe – 7.3 % Si – 14.2 % B – 8.26 % Ni these approaches give substantially ...
      2017-11-27
    • Time resolved photoluminescence anisotropy of CdSe/ZnS nanoparticles in toluene at 300 K 

      Petrov, E. P.; Cichos, F.; Zenkevich, E.; Starukhin, D.; Borczyskowski, C. von (2005)
      For CdSe nanoparticles it has been theoretically and experimentally shown that at low temperatures the photoluminescence is circularly polarized in accordance with a wurtzite structure and the corresponding allowed optical transitions. In the present Letter, we report on related investigations on CdSe/ZnS colloids in toluene solution. From time resolved photoluminescence anisotropy ...
      2017-05-27
    • Tm:KLu(WO4)2 microchip laser Q-switched by a graphene-based saturable absorber 

      Serres, J. M.; Loiko, P.; Mateos, X.; Yumashev, K.; Griebner, K. U.; Petrov, V.; Aguilo, M.; Diaz, F. (2015)
      We report on the first Tm-doped double tungstate microchip laser Q-switched with graphene using a Tm:KLu(WO4)2 crystal cut along the Ng dielectric axis. This laser generates a maximum average output power of 310 mW with a slope efficiency of 13%. At a repetition rate of 190 kHz the shortest pulses with 285 ns duration and 1.6 μJ energy are achieved.
      2017-11-18
    • Two-kink solution for the Hirota–Ramani equation for degenerated parameters 

      Knyazev, M. A. (West Ukrainian Physical Society, 2018)
      The Hirota–Ramani equation is considered. Its two-kink solutions are known and may be constructed, for example, by direct methods if the parameters ki, i = 1, 2 of the solution components are not equal to each other. In this paper, such solution is constructed for k1 = k2.
      2023-12-15
    • Ultrafast laser inscribed Yb:KGd(WO4)2 and Yb:KY(WO4)2 channel waveguide lasers 

      Bain, F. M.; Lagatsky, A. A.; Thomson, R. R.; Psaila, N. D.; Kuleshov, N. V.; Kar, A. K.; Sibbett, W.; Brown, C. T. A. (Optical Society of America, 2009)
      We demonstrate laser action in diode-pumped microchip monolithic cavity channel waveguides of Yb:KGd(WO4)2 and Yb:KY(WO4)2 that were fabricated by ultrafast laser writing. The maximum output power achieved was 18.6 mW with a threshold of approximately 100 mW from an Yb:KGd(WO4)2waveguide laser operating at 1023 nm. The propagation losses for this waveguide structure were measured ...
      2012-01-23
    • Unleashing the power of Twitter 

      Khramtsova, M. V. (АГУ, 2013)
      Khramtsova, M. V. Unleashing the power of Twitter / M. V. Khramtsova // Межкультурная коммуникация и СМИ : материалы IV Международной научно-практической конференции, Барнаул, 15 июня 2013 г. – 2013. – С. 47-50.
      2014-03-31