Now showing items 95-114 of 1050

    • Modern trends in improvement of steel heating technology in continuous furnaces 

      Timoshpolskiy, V. I.; Temlyantsev, M. V.; Trusova, I. A. (2016)
      The principles and approaches in the development and improvement of steel heating technology in the furnaces of rolling manufacture of various structural design, based on the systematic study of thermal physical and technological processes, including mathematical modeling, industrial experiments, development of rational temperature-thermal modes.
      2018-02-27
    • Multifrequency laser diagnostics of vibrational nonequilibrium gas media containing CO2 molecules 

      Arshinov, K. I.; Krapivnaya, O. N.; Nevdakh, V. V. (Pleiades Publishing, 2016)
      The technique for multifrequency diagnostics of a vibrational nonequilibrium gas mixture that contains CO2 molecules is proposed. The technique uses data on unsaturated gains at lines of the 0001– [1000, 0200]I, II and 0002–[1001, 0201]I, II transitions obtained with the help of a tunable CO2 laser. Results of the study of the influence of accuracy of gain measurements and the ...
      2022-07-29
    • Multistep photoinduced electron transfer in self-organised nano-scale porphyrin triads 

      Zenkevich, E. I.; Shulga, A. M.; Borczyskowski, C. von (2002)
      Well-defined structurally organised porphyrin triads of a controlled geometry andnanoscale size have been formed in liquid solutions using the combination of a covalent approach and non-covalent self-assembly. The triads contain zinc-octaethylporphyrin chemical dimer, (ZnOEP)₂Ph, with covalently linked electron acceptors (p-benzoquinone, Q or pyromellitimide, Pim), and additional ...
      2017-05-26
    • Negative ions of atoms and diatomic and triatomic molecules 

      Gretchikhin, L. I.; Kamarouskaya, V. M. (2016)
      Electron affinity is not determined by solving the Schrödinger equation, but by using a wide range of various types of interactions. In atoms, the bound between the external electron and the integrated electric dipole moment of a neutral atom mainly contributes to electron affinity. In diatomic molecules, electron affinity is defined mainly by the interaction of the external ...
      2020-11-03
    • NH-tautomerism and visible absorption spectra of porphyrins with nonsymmetrical substitution: oscillator model and mo calculations 

      Zenkevich, E. I.; Shulga, A. M.; Filatov, I. V.; Chernook, A. V.; Gurinovich, G. P. (1985)
      On the basis or experiments Ihe oscillator model has been established for individual NH tautomers or porphyrins with asymmetrical substitution. CNDO/2 calculations explain the inversion of Q ₓ (O.O) and Q y (O.O) electronic transition intensities in NH tautomers as a consequence of the inversion of LUMO coefficients c₁ and c₂ for fixed x and y molecular oscillators.
      2017-05-18
    • Nonlinear thermo-optical properties of two-layered spherical system of gold nanoparticle core and water vapor shell during initial stage of shell expansion 

      Pustovalov, V. K.; Astafyeva, L. G. (2011)
      Nonlinear thermo-optical properties of two-layered spherical system of gold nanoparticle core and water vapor shell, created under laser heating of nanoparticle in water, were theoretically investigated. Vapor shell expansion leads to decreasing up to one to two orders of magnitude in comparison with initial values of scattering and extinction of the radiation with wavelengths ...
      2018-03-06
    • On the bonding strength of Fe-based self-fluxing alloy coating deposited by different methods on the steel substrate 

      Feldshtein, E.; Kardapolava, M. A.; Dyachenko, O. V. (University of Zielona Góra, 2018)
      In the present paper, the bonding strength of Fe-based self-fluxing alloy coating deposited by plasma spraying, gluing and laser remelting and alloying on the steel substrate have been investigated. When flame melting, a globular structure is formed. Against the background of the solid solution carbide-boride phases are clearly distinguishable, between which the Fe-Fe2B and Fe-FeB ...
      2018-09-13
    • On the formation features and some material properties of the coating formed by laser cladding of a nicrbsi self-fluxing alloy 

      Devoino, O.; Feldshtein, E.; Kardapolava, M.; Lutsko, N. (Springer, 2018)
      In the present paper, the influence of laser cladding conditions on the powder flow conditions as well as the microstructure, phases, and microhardness of a Ni-based self-fluxing alloy coating is studied. The formation regularities of a coating microstructure with different cladding conditions as well as patterns of element distribution over the coating depth and in the transient ...
      2023-10-05
    • Operation of a Spark-Ignition Engine on Mixtures of Petrol and N-Butanol 

      Kukharonak, H.; Ivashko, V.; Pukalskas, S.; Rimkus, A.; Matijosius, J. (2017)
      The Article analyses the use of n-butanol (biobutanol) in mixtures with petrol in spark-ignition (SI) internal combustion engines (ICE). Analysis of the scientific literature allowed determining that n-butanol content had a different effect on the same engine parameters in different tests, thus a decision was made to conduct additional research, where, having assembled the necessary ...
      2018-03-10
    • Opportunities for bioenergy in the Baltic Sea Region 

      Silveira, S.; Khatiwada, D.; Leduc, S.; Kraxner, F.; Venkata, B. K.; Tilvikine, V.; Gaubyte, V.; Tauraite, E.; Romagnoli, F.; Blumberga, D.; Kundas, S. P.; Kalinichenko, A. S.; Peterson, K.; Utsar, K.; Vigants, E. (2017)
      Security of energy supply, promotion of the bio-economy, nutrient recycling, and innovation are prioritized policy areas in the EU Strategy for the Baltic Sea Region (EUBSR). The Baltic Sea Region (BSR) has a great bioenergy potential worth exploring in this context. This paper explores the state-of-art of bioenergy systems and synergies with eco-systems services in the BSR region ...
      2021-07-19
    • Passive mode locking of 2.09 μm Cr,Tm,Ho:Y3Sc2Al3O12laser using PbS quantum-dot-doped glass 

      Denisov, I. A.; Skoptsov, N. A.; Gaponenko, M. S.; Malyarevich, A. M.; Yumashev, K. V.; Lipovskii, A. A. (Optical Society of America, 2009)
      Passive Q-switched mode locking of a 2.09 μm flashlamp-pumped Cr3+,Tm3+,Ho3+:Y3Sc2Al3O12 laser by use of a phosphate glass doped with PbS quantum dots of 5 nm in radius was demonstrated. Mode-locked pulses of 290 ps in duration and up to 0.5 mJ in energy were registered.
      2012-01-23
    • Passive mode locking of a Tm,Ho:KY(WO4)2 laser around 2 μm 

      Lagatsky, A. A.; Fusari, F.; Calvez, S.; Gupta, J. A.; Kisel, V. E.; Kuleshov, N. V.; Brown, C. T. A.; Dawson, M. D.; Sibbett, W. (Optical Society of America, 2009)
      We report the first demonstration, to our knowledge, of passive mode locking in a Tm3+, Ho3+-codoped KY(WO4)2 laser operating in the 2000-2060 nm spectral region. An InGaAsSb-based quantum well semiconductor saturable absorber mirror is used for the initiation and stabilization of the ultrashort pulse generation. Pulses as short as 3.3 ps were generated at 2057 nm with average ...
      2012-01-23
    • Passive Q-switching of a Tm,Ho:KLu(WO4)2 microchip laser by a Cr:ZnS saturable absorber 

      Serres, Y. M.; Loiko, P. A.; Mateos, X.; Jambunathan, V.; Yasukevich, A. S.; Yumashev, K. V.; Petrov, V.; Griebner, U.; Aguilo, M.; Diaz, F. (Optical Society of America, 2016)
      A diode-pumped Tm;Ho:KLu WO42 microchip laser passively Q-switched with a Cr:ZnS saturable absorber generated an average output power of 131 mW at 2063.6 nm with a slope efficiency of 11% and a Q-switching conversion efficiency of 58%. The pulse characteristics were 14 ns∕9 μJ at a pulse repetition frequency of 14.5 kHz. With higher modulation depth of the saturable absorber, 9 ...
      2016-05-12
    • Passive Q-switching of Yb bulk lasers by a graphene saturable absorber 

      Loiko, P. A.; Serres, J. M.; Mateos, X.; Liu, G.; Zhang, H.; Yasukevich, A. S.; Yumashev, K. V.; Petrov, V.; Griebner, U.; Aguilo, M.; Diaz, F. (Springer, 2016)
      Compact Yb:KLu(WO4)2 and Yb:LuVO4 lasers diode-pumped at 978 nm are passively Q-switched by a single-layer graphene saturable absorber. The Yb:KLu(WO4)2 laser generated 165 ns/0.49 μJ pulses at 1030 nm with 170 mW average output power and 12 % slope efficiency. With the Yb:LuVO4 laser, 152 ns/0.83 μJ pulses were achieved. The output power reached 300 mW at 1024 nm, and the slope ...
      2016-05-11
    • Passively Q-Switched Thulium Microchip Laser 

      Gaponenko, M.; Kuleshov, N.; Südmeyer, T. (2016)
      We present the first passively Q-switched thulium microchip laser. The diode-pumped laser incorporates a Tm:KYW gain medium and an InGaAs semiconductor saturable absorber mirror. The laser emits pulses with a duration of 2.4 ns at a repetition rate of 1.2 MHz with an average output power of 130 mW at a wavelength of 1905 nm. It operates in a fundamental TEM00 mode with M2 < 1.1. ...
      2018-03-06
    • Pathways for photoinduced electron transfer in meso-nitro-phenyl-octaethylporphyrins and their chemical dimers 

      Knyukshto, V.; Zenkevich, E.; Sagun, E.; Shulga, A.; Bachilo, S. (1999)
      The photophysical properties of meso-nitro-phenyl-octaethylporphyrins and their dimers with electron-accepting NO₂ groups in the para-, meta- and ortho-positions of the phenyl ring were studied. For the ortho-NO₂ case in deaerated toluene at 295 K, strong fluorescence quenching is caused by the intramolecular electron transfer from the porphyrin S₁ state in the absence of phenyl ...
      2017-05-25
    • Photoelectric semiconductor converters with a large dynamic range 

      Vorobey, R. I.; Gusev, O. K.; Tyavlovsky, A. K.; Tyavlovsky, K. L.; Svistun, A. I.; Shadurskaya, L. I.; Yarzhembitskaya, N. V.; Kierczynski, K. (2014)
      Photoelectric semiconductor converters with a large dynamic range / R. I. Vorobey [et al.] // Przeglad Elektrotechniczny. – 2014. – Vol. 90, № 5. – PP. 75-78.
      2015-07-06
    • Photoinduced electron transfer dynamics for self-assembled porphyrin arrays in solutions and films 

      Zenkevich, E. I.; Kilin, D. S.; Willert, A.; Bachilo, S. M.; Shulga, A. M.; Rempel, U.; Borczyskowski, C. von (2001)
      Electronic excitation energy deactivation in self-assembled porphyrin triads has been studied by the time correlated single photon counting technique as a function of the solvent polarity (toluene-acetone mixtures), temperature (77-350 K), and mutual spatial arrangement of the donor and acceptor subunits. The donor (Zn-octaethylporphyrin chemical dimer) fluorescence quenching ...
      2017-05-26
    • Photoinduced relaxation processes in self-assembled nanostructures: multiporphyrin complexes and composites "CdSе/ZnS quantum dot-porphyrin" 

      Zenkevich, E. I.; Borczyskowski, C. von (2009)
      Here, we discuss self-assembled multicomponent organic/inorganic nanostructures. Self-assembled multiporphyrin triads were formed via non-covalent interactions of meso-phenyl bridged ZnOEP chemical dimer, (ZnOEP)₂Ph, with dipyridyl substituted tetrapyrrole extra-ligand. In tetrads, the dimer (ZnOEP)₂Ph is covalently linked via 5-mesoposition to additional electron acceptors ...
      2017-05-27
    • Photophysical and photochemical properties of potential porphyrin and chlorin photosensitizers for PDT 

      Zenkevich, E.; Sagun, E.; Knyukshto, V.; Shulga, A.; Mironov, A.; Efremova, O.; Bonnett, R.; Pinda Songca, S.; Kassem, M. (1996)
      Structural and optical properties as well as photophysical and photochemical parameters (excited S₁ and T₁ state lifetimes at 77 K and in the presence of O₂ in solution at 293 K; efficiencies of singlet oxygen, ¹Δg, generation) are presented for porphyrins and chlorins with potential for the PDT of cancer: chlorin p₆ and its trimethyl ester, chlorin e₆ and its Na₃ and K₃ salts, ...
      2017-05-25