Coherent transients at dressed levels

Possibilities for the control of the parameters of free-polarization decay (FPD), optical nutation, and photon echo (PE) using the dressing field are studied. Coherent transients are generated with the Stark switching technique and are detected in the radiation of the probe field polarized orthogonally to the dressing field. The evolution-operator technique is employed in the calculations. The experiments are performed at the R(4, 3) transition of the 0 ? 1 v₃ ¹³CH₃F vibrational band with the radiation of a cw CO₂ laser. It is theoretically and experimentally demonstrated that FPD and PE are suppressed upon an increase in the intensity of the dressing field. The observed shapes of the transient FPD and PE signals and their variations with the dressing field intensity are in qualitative agreement with the results of the calculations.     

Catalytic synthesis and stereostructure of 1,2,3-trisubstituted decahydroisoquinolines

Liquid-phase catalytic reduction of 1,2,3-substituted 5,6,7,8-tetrahydroisoquinolinium perchlorates was investigated. The reaction proceeds stereodirectionally affording cis-decahydroisoquinolines. The probable scheme of reaction products formation is suggested. The structure of compounds obtained was established by IR and ¹³C NMR spectroscopy.     

Multi-level defense system models: overcoming by means of attacks with several phase constraints

The Germeyer “defense–attack” model is modified to allow for an echeloned defence system in a given direction. The model is a special case of the terminal-type discrete optimal control problem, and it can be solved using the subgradient-descent method. The posed control problem refines the resource level-distribution problem for a given direction, counting more general constraints with allowance for the action abilities of defense tools at various borders.     

Modified stimulated photon echo with hyperfine structure of resonant levels

The intensity and polarization of a modified stimulated photon echo generated on resonant levels with hyperfine structure are obtained. It is proposed that the polarization properties of this kind of a photon echo can be used for the identification of the structure of the resonant transitions on which the echo is formed as well as for the separation of the modified stimulated photon echo pulse from the third exciting pulse.     

Chemistry of 1,5-diketones: II. Specificity of transformations of polycyclic 1,5-diketones in acid media

2-(1,3-Diaryl-3-oxopropyl)cyclohexan-1-ones underwent carbo-and heterocyclization in a mixture of acetic acid with acetic anhydride in the presence of perchloric acid. The transformation of 2-(1,3-diaryl-3-oxopropyl)cyclohexan-1-ones into 2,4-diaryl-5,6,7,8-tetrahydrochromenylium salts was shown to involve intermediate 2,4-diarylbicyclo[3.3.1]non-2-en-9-ones. The structure of 2,4-diaryl-substituted bicyclo[3.3.1]non-2-en-9-ones and products of their reactions with halogens and hydroxylamine hydrochloride was confirmed by ¹H and ¹³C NMR spectroscopy.     

Multilayered Attack–Defense Model on Networks

Computational Mathematics and Mathematical Physics - The classical Germeier’s attack–defense game is generalized for the case of defense in depth (multilayered defense) that has a...