Oxidation of camphor ethylene dithioacetal

(1R,1′R,2S,4R)-1,7,7-Trimethylspiro[bicyclo[2.2.1]heptane-2,2′-[1,3]dithiolane] 1′-oxide, (1R,2S,3′R,4R)-1,7,7-trimethylspiro[bicyclo[2.2.1]heptane-2,2′-[1,3]dithiolane] 1′,1′,3′-trioxide, and (1R,4R)-1,7,7-trimethylspiro[bicyclo[2.2.1]heptane-2,2′-[1,3]dithiolane] 1′,1′,3′,3′-tetraoxide were synthesized by oxidation of camphor ethylene dithioacetal with m-chloroperoxybenzoic acid at different substrate-tooxidant ratios. The structure of the products was proved by IR and NMR spectroscopy and X-ray analysis.     

Effect of the translational velocity of active particles on the properties of a photon echo

The photon echo method was used to detect an increase in the relaxation rate in the vibrational-rotational transition of fluoromethane in ¹³CH₃F gas and a ¹³CH₃F-argon mixture upon an increase in the velocity of active particles. For a photon echo in the 0–1 transition in a Yb + Xe mixture, the dependence of the relaxation parameters on the direction of the translational velocity of Yb leads to qualitative changes and a collision photon echo arises.     

Conventional and collision photon echo in ytterbium vapor

The polarization properties of the photon echo generated by two linearly polarized pulses of resonant radiation at the (6s6p)³ P ₁ ? (6s ²)¹ S ₀ transition of ¹⁷⁴Yb are investigated. A complicated polarization behavior of the photon echo versus an angle between the polarization vectors of the excitation pulses is revealed in a mixture of ytterbium vapor with inert gas. For the angles ranging from 0° to 75°, a conventional echo with its linear polarization coinciding with the second excitation pulse dominates and the echo amplitude decreases with an increasing angle. For the angles ranging from 75° to 89°, the photon echo is elliptically polarized. Finally, for an angle of 90°, the conventional echo disappears and the collision echo becomes linearly polarized along the first excitation pulse.     

Synthesis of 5-Aryl(heteryl)-1-hydroxyethyl-4-(furyl-2-carbonyl)-3-hydroxy-3-pyrroline-2-ones

5-Aryl(heteryl)-1-hydroxyethyl-4-(furyl-2-carbonyl)-3-hydroxy-3-pyrroline-2-ones were synthesized via reactions of methyl ester of furyl-2-carbonylpyruvic acid with a mixture of aromatic or heterocyclic aldehyde and ethanolamine in dioxane. Antibacterial and antifungal activities of the synthesized compounds was studied.     

New Way in Few-Body Scattering Calculations

The key features of the new general approach to solution of few-body scattering problems in hadronic, nuclear and atomic physics are presented and discussed in the paper. The approach is based on a general idea of the lattice-like discretization of few-body continuum using the stationary wave-packet basis in momentum space. The new technique includes an efficient averaging and smoothing of singular kernels of the scattering integral equations over the lattice cells. So, such an averaging procedure allows us to transform the complicated singular integral kernels into usual matrices with regular and smooth matrix elements. Such a transformation is shown to lead to an enormous simplification of the solving procedure for scattering equations.     

Self-mode-locking of the Nd3+:KGd(WO4)2 laser using a multifunctional semiconductor mirror

A multifunctional semiconductor mirror that contains a saturable absorber based on quantum wells, a broadband reflector, and a Gires-Tournois interferometer that serves as a GVD compensator is designed and created. The mirror is fully characterized using the pump-probe technique with a subpicosecond resolution and the transmission and photoluminescence spectroscopy. The mirror that simultaneously executes the three functions and that is created in a single technological cycle provides stable mode-locking in the Nd³⁺:KGd(WO₄)₂ laser.     

Synthesis of chiral 1-(imidazol-2-yl)alkanamines using neomenthanethiol as a chiral auxiliary

Diastereomeric N-(imidazol-2-ylmethylidene)neomenthane-3-sulfinamides were obtained from enantiomerically pure neomenthanethiol in three steps. The compounds obtained added Grignard reagents at the C=N bond. After separation of diastereomers, an acid resolution gave enantiomerically pure primary 1-(imidazol-2-yl)alkanamines. In this scheme, the neomenthane fragment played the role of a chiral auxiliary.     

Synthesis of new monoterpene sulfonic acids and their derivatives

The oxidation of monoterpene thiols with chlorine dioxide afforded new water-soluble sulfonic acids and their derivatives (sulfonothioates and sulfonyl chlorides). The reaction of terpene thiols with ClO₂ gave the corresponding trisulfides. Sulfonothioates with a pinane skeleton showed antibacterial and antifungal activity.     

Determination of neutron-neutron scattering length from the nd-breakup reaction: Experimental and theoretical aspects

A new experiment to determine the length of neutron-neutron scattering from the nd-breakup reaction is described. The experiment was performed on the 13–60 MeV neutron beam in the meson factory of the Institute of Nuclear Research Russian Academy of Sciences. In addition to the standard models, a new dibaryon model was used for the first time in the treatment of two- and three-nucleon interactions. Wave-packet continuum discretization was used to describe the dynamics of three-body scattering processes correctly.     

Quantum scattering theory on the momentum lattice

Here we briefly outline main results of the Wave-Packet Continuum Discretization method. The formalism uses the complete continuum discretization scheme in terms of the momentum stationary wave-packet basis, which leads to formulation of the scattering problem on a lattice in the momentum space.