A stochastic model of the influence of buffer gas collisions on Mollow spectra

In this paper, using the idea introduced in (K. Wódkiewicz, Noise in strong laser-atom interaction, Proceedings of the VI International School of Coherent Optics, Ustron, Poland, September (1985) 19–26) and developed in (Cao Long Van, Stochastic Models of Isolated Collisions: Applications to Optical Phenomena, paper presented in LAMP Conference’89, Trieste, Italy (1989) II) we consider the influence of collisional fluctuations on the Mollow spectra of resonance fluorescence (RF). The fluctuations are taken into account by a simple shift of the constant detuning, involved in a set of optical Bloch equations by collision frequency noise which is modelled by a two-step random telegraph signal (RTS). We consider in detail the Mollow spectra for RF in the case of an arbitrary detuning of the laser frequency, where the emitter is a member of a statistical ensemble in thermodynamic equilibrium with the buffer gas at temperature T which is treated as a colored environment, and velocity v is distributed with the Maxwell-Boltzmann density.     

Pulse propagation in an autoionization medium with double Fano profile

We discuss the propagation of a short laser pulse in an auto- ionizing (AI) medium with degenerate double Fano model. By solving numerically the coupled equations for atoms and fields we show that by the proper choice of Fano parameters involved in the problem (contrary to the case considered in (E. Paspalakis, N. J. Kylstra, and P. L. Knight, Phys. Rev. A60 (1999)) we have now two Fano asymmetry parameters) one can eliminate almost completely the absorption in the pulse propagation. It means that we have the transparency in the medium. From the connection between population trapping in short pulsed laser field and transparency in the propagation of the laser pulse which has been fixed by Paspalakis et al., Phys. Rev. A60 (1999) we conclude that this proper choice leads to the presence of the population trapping (or the existence of the “dark” states) in the atomic system. Moreover, instead of one value of the laser detuning for which the dark states exist in the case of one AI level, we find numerically two such values in the case of two AI levels.     

Pseudodifferential operators with real analytic symbols and approximation methods for pseudodifferential equations

This paper introduces some methods (including an approximation method) for investigating pseudodifferential equations and related problems (Cauchy problems, boundary value problems,…) based on the technique of pseudodifferential operators with real analytic symbols.     

Nontrivial periodicity in discrete delay models of population growth

In this paper, we will study the periodicity in discrete model An+1=λAn+F(An−m) of population growth, where the delay m is large enough and the nonlinearity F is unimodal function. Actually, we prove that there is a slowly oscillated periodic solution. Our method is Browder nonextremal fixed point theorem.     

Hydroxid-bewirkte Halogenwasserstoff-Abspaltungen aus vic-Dihalogeniden unter heterogenen Bedingungen: Reaktionssteuerung dank überraschender Solvens- und Metall-Einflüsse

Hydroxide-Promoted Dehydrohalogenation of vic-Dihalides under Heterogeneous Conditions: Control Over the Reaction Outcome Due to Surprising Solvent and Metal Effects Selective elimination of either one or two molecules of hydrogen halide from vic-dihalides can be conveniently achieved by employing solid sodium or potassium hydroxide in the presence of solvents such as glycol dimethylether or tetraethyleneglycol dimethylether.     

Synthese de C-nucleosides—IX : Purines substituees en position 8 par le desoxy-2 ribose

Benzyl 2-deoxy-3,5-di-O-p-toluyl-d-erythro-pentofuranosyl thioformimidate 3, prepared from nitrile 1, reacts with α-aminocyanoacetic acid derivatives to yield C-imidazole nucleosides which are further cyclized into purines. The 6-mercapto purine 2 is obtained in two different ways.     

Determination of rational structure for spherofibrous plastics

A complete set of elastic constants for various structures of triorthogonally reinforced plastics with a matrix dispersely reinforced by spherical particles has been determined on the basis of the proposed algorithm. Approximate equations are obtained for determination of all integral parameters from data on the components and structure geometry. It is established that for the reinforcement schemes investigated, the shear moduli of the composites have the lowest possible values and are calculated with a higher accuracy than the other elastic constants.A. A. Blagonravov Institute of Machine Science, Russian Academy of Sciences. Moscow, Russian. Translated from Mekhanika Kompozitnykh Materialov, Vol. 33, No. 2, pp. 155–160, March–April, 1997.