Femtosecond pulse enhancement in an external resonator: impact of dispersive and nonlinear effects

The effect of the high-order dispersions on a femtosecond pulse enhancement in an external resonator is analyzed. It is shown that the degradation of the enhancement factor can be partially compensated by adjustment of group-delay, dispersion and incident pulse width. Presence of a Kerr-medium inside an external resonator results in the stable quasi-soliton formation that improves the enhancement factor. This provides the enhancement factor growth as well as its robustness against the high-order dispersions, when the fourth-order dispersion is negative. PACS  42.65.Re; 42.65.Tg; 42.60.Da; 42.60.Lh     

Reduction of the laminar compound of graphite with FeCl3 by hydrogen at high pressure

Conclusions A method is proposed for the reduction of laminar graphite compounds at hydrogen pressure up to 70 kbar, which has a number of significant advantages relative to reported methods. This method may be used to obtain new acceptor LGC.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 450–452, February, 1986.The authors express their gratitude to P. B. Fabrichnyi for assistance in the Moessbauer spectral study of these compounds.     

Study of continuity of random sequences by constructing proximity points

A method of estimation of time-uniform continuity of random sequences is considered that makes it possible to interpret previous methods from a single point of view.Translated from Problemy Ustroichivosti Stokhasticheskikh Modelei — Trudy Seminara, pp. 52–57, 1980.     

Propagation of perturbations in processes described by degenerate parabolic equations with nonpower nonlinearities

The paper deals with the homogeneous first boundary-value problem for a one-dimensional quasilinear second-order parabolic equation without any assumptions about the nonlinear solution functions and their derivatives to be of power type. A criterion for the finiteness of the velocity of the propagation of perturbations is found. The influence of the zero order of the initial function at an inner point on the evolution of the corresponding component of the solution support is investigated.Translated from Trudy Seminara imeni I. G. Petrovskogo, No. 10, pp. 118–134, 1984.     

Adhesive Wear of Copper Friction Pair in Inert Atmosphere Reduced by Nitrogen Ion Implantation

Russian Physics Journal - The paper studies mechanisms of increasing the adhesive wear resistance of the copper specimens after the bombardment by the nitrogen ions, which are coupled with a...     

Modern Russian mass spectrometers for the atomic industry

Product quality control within the nuclear fuel cycle is a subject of special concern in Russia nowadays. Earlier, mass spectrometers of foreign production were commonly used for elemental and isotope analysis of samples. Currently, a series of domestic mass spectrometers MTI-350 has been developed and their production has been organized in Russia. The series comprises an automated MTI-350G mass spectrometer for the isotope analysis of uranium hexafluoride; thermal ionization MTI-350T mass spectrometer for the isotope analysis of uranium, plutonium, and mixed oxide (MOX) fuels; an MTI-350GS mass spectrometer for controlling the production of uranium hexafluoride; and an MTI-350GP mass spectrometer for the determination of the impurity concentration in uranium hexafluoride. The article considers operation principles, analytical characteristics, and the advantages of the above mass spectrometers.