Radiative decays of ρ and ω mesons

The results of the measurements of radiative decays of ρ and ω mesons with the Neutral Detector at thee ⁺ e ^? collider VEPP-2M are presented. The branching ratio of the decay ω→π ⁰γ was measured with higher than in previous experiments accuracy: $${\rm B}(\omega \to \pi ^0 \gamma ) = 0.0888 \pm 0.0062$$ . The ρ⁰→π ⁰ γ branching ratio was measured for the first time: $$B(\rho ^0 \to \pi ^0 \gamma ) = (7.9 \pm 2.0) \cdot 10^{ - 4} $$ . The decays ρ, ω→ηγ were studied. Their branching ratios with the assumption of constructive ρ?ω interference are: $$\begin{gathered} B(\omega \to \eta \gamma ) = (7.3 \pm 2.9) \cdot 10^{ - 4} , \hfill \\ B(\rho \to \eta \gamma ) = (4.0 \pm 1.1) \cdot 10^{ - 4} \hfill \\ \end{gathered} $$ . The branching ratios of ρ, ω→ηγ and ω→e ⁺ e ^? decays were also measured: $$\begin{gathered} B(\omega \to \pi ^ + \pi ^ - \pi ^0 ) = 0.8942 \pm 0.0062, \hfill \\ B(\omega \to e^ + e^ - ) = (7.14 \pm 0.36) \cdot 10^{ - 5} \hfill \\ \end{gathered} $$ . The upper limit for the ω→π ⁰ π ⁰ γ branching ratio was placed: B(ω→π ⁰ π ⁰ γ)<4·10^?4 at 90% confidence level.     

Influence of Ionizing Radiation on the Properties of a Nanodispersed PdO/CeO<Subscript>2</Subscript> Catalyst in the Reaction of Low-Temperature Carbon Monoxide Oxidation

The effect of electron-beam irradiation on the catalytic properties of PdO/CeO₂ has been examined. It has been found that irradiation in the range of 15–30 kGy results in an increase in the concentration of the radical anion [O^?], thereby enhancing the catalytic activity of PdO/CeO₂.     

Heterogeneous doping of sulfide-conducting phases based on calcium and barium thiolanthanates

The chemical method of preparation of oxide precursors was used to obtain sulfide-conducting ionic salts of CaY₂S₄, BaSm₂S₄ and heterogeneous additives of ZrS₂ and SiS₂, accordingly. The sintering modes for obtaining the heterogeneous systems of CaY₂S₄–ZrS₂ and BaSm2S4–SiS2 were chosen. Samples were characterized using the methods of X-ray phase analysis and microprobe analysis. The methods of thermogravimetric and differential thermal analysis were used to determine thermal stability of samples. The temperature and concentration dependences of conductivity and average ionic transport numbers were studied. The range of compositions of heterogeneous mixtures is determined in which conductivity considerably exceeds conductivity of the basic sulfide-conducting solid electrolytes.     

Synthesis and thiocyanation of <Emphasis Type="Italic">N</Emphasis>-alkyl(trifluoromethyl)sulfonyl 1,4-benzoquinone monoimines

New N-alkyl(trifluoromethyl)sulfonyl 1,4-benzoquinone monoimines were synthesized, and their thiocyanation gave 5-alkyl(trifluoromethyl)sulfonylamino-1,3-benzoxathiol-2-ones. An intermediate thiocyanation product, 5-trifluoromethylsulfonylamino-1,3-benzoxathiol-2-imine, was isolated for the first time.     

<Emphasis Type="Italic">sym</Emphasis>-triazines. 8. Synthesis and some reactions of 4,6-disubstituted 2-(1H-pyrrolyl)-1,3,5-triazines

We have studied the reaction of 2,5-dimethoxytetrahydrofuran with 4,6-disubstituted 2-amino-1,3,5-triazines with the aim of obtaining novel coupled polyheterocyclic systems with potential bioactivity. Reaction conditions were optimized. A series of novel 4,6-disubstituted 2-(1H-1-pyrrolyl)-sym-triazines was obtained. It was found that the product yields depended on the nature of the substituent in the 4 and 6 positions of the triazine ring and on the reaction conditions. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 440–451, March, 2008.     

Reactions of <Emphasis Type="Italic">N</Emphasis>-aryl(methyl,trifluoromethyl)sulfonyl-1,4-benzoquinone monoimines with sodium sulfinates

In reactions with sodium sulfinates of N-substituted 1,4-benzoquinone monoimines with the quinoid ring having free positions 2 and/or 6 the fraction of products of 1,4-addition of the sulfinate ion grows in the series ArSO₂ → MeSO₂ → CF₃SO₂. In the case of 2,6-dimethyl derivatives the 1,6-addition is preferable, and the amount of products of 6,1-addition decreases.     

Thermal Study of a Deposit Formed in Extraction of Hydrogen Chloride from Its Mixture with Air by Water-Sprayed Steel Chips

A deposit formed on the surface of steel chips in the course of prolonged interaction of their water-sprayed bed with air containing small amounts of hydrogen chloride was studied by thermogravimetry. The quantitative and qualitative composition of the deposit was established.