Structure and properties of 1-acylpyrazolines

Proton magnetic resonance spectroscopy and the method of dipole moments demonstrated that 1-acylpyrazolines exist primarily in the s-trans form, which is stabilized by the repulsion of like-charged nitrogen and oxygen atoms. Simultaneous reduction of the C =O and C =N bonds was observed during the action of lithium aluminum hydride on 1-formyl-and 1-trifluoroacetylpyrazolines, which is explained by the relatively high polarity of the C=N bond.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 488–491, April, 1972.     

Broadband radiation of a degenerate optical parametric oscillator operating above threshold in information applications

Information applications of the essentially multimode (in time) radiation of a degenerate optical parametric oscillator operating above the oscillation threshold, such as protocols of quantum parallel dense coding and multimode quantum teleportation, have been considered. The stream of Shannon mutual information as a function of the spectral width of Alice’s signal and the spectral fidelity of transmission of a multimode quantum signal are evaluated from the estimates of the achievable radiation squeezing that occurs as the oscillation threshold is approached. The advantages of the multimode scheme over the single-mode scheme are discussed.     

Experimental Cross Sections of Fission Fragments of Thorium-232 Irradiated with Medium-Energy Protons

This paper is focused on fission of Th-232 nuclei induced by protons with energies ranging from 20 to 140 MeV. This energy range is the most informative for studying the competition between asymmetric and symmetric fission modes. Experimental cross sections of production of radionuclides in thorium targets have been determined a year after irradiation. The corresponding theoretical values are calculated using the cascade–evaporation–fission model. The theoretical and experimental cross sections (literature data included) are compared.     

Quantum holography upon resonant adiabatic interaction of fields with an atomic medium in a Λ-configuration

We study the quantum memory protocol for spatially multimode light based on an atomic ensemble in the Λ-configuration. We analytically solve a system of partial differential equations that describe the evolution of the medium and field for the case where the interaction time considerably exceeds the lifetime of the excited state. This time ratio makes it possible to apply the adiabatic approximation. Unlike problems aimed at storage the time profile of the signal field, we propose optimizing the relation between the writing and reading times and the optical density of the medium, which ensures a high retrieval efficiency of the quantum image.