Measuring high-energy γ-ray emission accompanying the spontaneous fission of <Superscript>252</Superscript>Cf nuclei

The probability of high-energy γ-ray emission accompanying the spontaneous fission of ²⁵²Cf nuclei in the energy range of 5–60 MeV was measured experimentally. The γ rays were detected by a BGO detector with a size of ∅7.6 × 7.6 cm in coincidence with neutrons detected by an organic polystyrene-based scintillator with a size of ∅6.0 × 2.0 cm. To reject events associated with the cosmic background, we propose an original method that combines rapid digitizing of the pulse shape and the time-of-flight method.     

Analysis of double surface plasmon resonance by the discrete source method

The discrete source method is modified in order to mathematically simulate and study the scattering properties of nonspherical particles located on the surface of a conducting film deposited on a glass prism. Both differential and integral scattering properties of metal nanoparticles are examined. It is shown that the scattering cross section behind the film can be increased by 10⁷ times by deforming the particle and shifting it with respect to the film. It is also shown that the scattered intensity distribution in the prism is localized in two directions, forming sharp narrow fingers with the intensity exceeding the incident wave amplitude by 15–30 times.     

Generalized empirical laws of starting discontinuity dynamics associated with the startup of underexpanded jets

Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 5, pp. 22–26, September–October, 1991.     

Associated production of ϕ mesons and neutral kaons in the EXCHARM experiment

The features of the associated production of ? mesons and neutral kaons are studied on the basis of data obtained at the EXCHARM spectrometer (Serpukhov accelerator) in neutron—carbon interactions at neutron-beam energies in the range 20–70 GeV. The cross section for the inclusive associated production of ? and K ⁰/-K ⁰ is obtained. The fraction of processes allowed by the Okubo-Zweig-Iizuka rule is estimated in the reactions of ?-meson inclusive production.     

On the importance of anisotropic exchange coupling on to the structure of spin-polarized clusters in layered cuprates

The low energy spectrum of spin-polarized clusters in layered cuprates is examined. Two types of clusters confining the motion of oxygen holes are discussed. The ground state of the pentanuclear copper cluster has a total spin S = 2, whereas the one of the tetranuclear copper cluster is characterised by S= 3/2. Anisotropic exchange coupling splits the magnetic ground state into a sequence of state, which in a natural way provide e.g. an explanation of EPR data for La₂CuO_4+δ compounds.     

Copper and copper-palladium catalysts of aliphatic thiols oxidation in biological objects: Quantum-chemical DFT simulation

DFT calculations (M06, PBE0/Def2-TZVP) of coordination compounds used in reactions of selective oxidation of thiols to disulfides were performed. Primary active centers of the catalysts are polynuclear scaffolds {L₂M(μ-OH)₂ML₂}²⁺ and {L₂M(μ-OH)₂M′(μ-OH)₂ML₂}²⁺ (M = Cu^I, Cu^II, Pd^II; M' = Cu^II; L = NH₃). Cu^II ions in combination with PdII ions are capable of formation of polynuclear active center {PdII(μ-OH)₂Cu^II(μ-OH)₂Pd^II}²⁺ bringing together a large number of mutually oriented RS^– groups and thus affecting the rate of formation of disulfide R₂S₂.     

Preparation of vitamin <Emphasis Type="Italic">K</Emphasis><Subscript>3</Subscript> by oxidation of the methylnaphthalene fraction

The reaction conditions were optimized for 2-methylnaphthalene oxidation to 2-methyl-1,4-naphthoquinone (fat-soluble vitamin K ₃) with sodium dichromate in aqueous sulfuric acid.