Pulse energy optimization of passively Q-switched flash-lamp pumped Er:glass laser

An approach to the energy optimization of the passively Q-switchedEr:glass laser is considered. The optimization procedure is represented in the maximally verifiable and usable graphical form, which is applied to the flash-lamp pumped Er:glass laser passively Q-switchedwith the Co²⁺-doped MgAl₂O₄ and LaMgAl₁₁O₁₉ saturable absorbers. Received: 6 December 2001 / Revised version: 5 March 2002 / Published online: 8 August 2002     

Dynamic shadow effect in the energy loss of protons

Summary The nonrelativistic quantum-mechanical approach for the stopping power has been developed by means of the Glauber-Franco approximation for the inelastic-scattering amplitude. It takes into account excitation and ionization processes in the amorphous target by heavy charged particles. The calculations of the stopping power of protons in H and He targets are in excellent agreement with the available experimental data due to the effect of nuclear dynamic blocking (shadow) and the rescattering processes by the electrons of the target atom. Formulae of the stopping-power calculations, taking into account individual atom shell effects, have been derived. On this basis, the case of violation of Bragg’s additivity rule is discussed.     

Approximation of Markov chains

Conditions are obtained, as well as quantitative estimates, of Markov chains with a common set of states that are uniformly continuous in time. Within the framework of the method under consideration, it is possible to show that such chains can be finitely approximated.Translated from Problemy Ustoichivosti Stokhasticheskikh Modelei — Trudy Seminara, pp. 4–12, 1980.     

Infrared instability of QCD at finite temperatures

The infrared behaviour of the transversal gluon propagator in QCD at T≠0 is investigated within the ghost-free axial gauge. The singularities found in this propagator for the momentum p ～ g²T remain for any choice of the gauge and indicate the infrared instability of QCD at finite temperatures.     

Synthesis of C-terminal peptide fragments of the heavy chain of hemagglutinin of influenza virus of subtypes H1 and H3

It is proposed to use the chromogenic 2-[4-phenylazo)benzylsulfonyl]ethyl group, which can be eliminated by organic bases in aprotic solvents, for the protection of a C-terminal carboxy group in the synthesis of peptides. The synthesis of a number of 10–16-membered peptides corresponding to C-terminal fragments of the heavy chain of the hemagglutination of influenza virus of subtypes H1 and H3 has been performed with the use of this group.All-Union Scientific-Research Institute of Molecular Biology, Kol'tsovo, Novosibirsk Oblast. Vektor Scientific-Industrial Association, Ministry of the Medical and Biological Industry of the USSR, Novosibirsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 732–738, September–October, 1988.     

Stability analysis of queueing systems

This paper contains a survey of some results on the stability of queueing systems obtained by the authors by means of the method of trial functions (developed from Lyapunov's direct method). In addition, the paper contains a series of new results on the stability of regenerative processes. All the qualitative statements are accompanied by the construction of quantitative estimates.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 87, pp. 41–61, 1979.     

Structural state and phase composition of nickel surface layers modified by high-intensity implantation of titanium ions

This paper reports on the results of experimental investigations into the microstructure and the elemental and phase compositions of ion-alloyed nickel surface layers modified by high-intensity implantation of titanium ions. It is established that the implantation of titanium ions into nickel surface layers up to 1600 nm thick leads to the formation of intermetallic phases (namely, NiTi, Ni₃Ti, and NiTi₂), a solid solution of titanium in nickel, titanium oxides of different stoichiometries, and titanium carbide TiC. It is demonstrated that the phases formed in the ion-alloyed nickel surface layers have a nanocrystalline structure. The average size of the nanocrystal grains is equal to 40 nm.