Study of the interaction in the ZnS (ZnO)-Dy2S3 system

The exchange reactions of the impurity ZnO in zinc sulfide produced by self-propagating high-temperature synthesis with the additive Dy₂S₃ were studied by IR spectroscopy and diffuse reflectance electron spectroscopy. It was found that the main products of the interaction in the ZnS (ZnO)-Dy₂S₃ system are ZnS and Dy₂O₂S. The exchange character of the interaction was modeled by the systems ZnO-Dy₂S₃ (2: 1) and Dy₂S₃-Dy₂O₃ (1: 2). The possibility of estimating the ZnO impurity content of zinc sulfide was demonstrated, which allows one to optimize the zinc sulfide synthesis conditions.     

Interaction,composition, and optical properties of the MgF<Subscript>2</Subscript>(MgO)-EuF<Subscript>3</Subscript> system

The interaction between MgO and EuF₃ resulting in the formation of magnesium fluoride and europium(III) oxyfluorides of variable composition are investigated. A substantial difference between the diffuse reflection spectra of the fluoride phase and oxyfluoride phases of europium(III) is found, specifically, an intense band peaked at 260–270 nm appears in the latter. The effect of silicon and high vacuum as reducers on the systems containing the oxide phase is investigated. For these phases, europium(II) compounds are found, which is confirmed by X-ray powder diffraction analysis and diffuse reflection and luminescence spectroscopy. The character of thermogravimetric curves for the MgF₂-EuF₃-Si and MgO-EuF₃-Si systems is fundamentally different, which allows us to propose a new method for estimating the MgO content in MgF₂.     

Recurrence of trajectories of a stable compact invariant set of a holomorphic mapping

We show that the trajectories of all points of a stable compact invariant set of a holomorphic mapping are Poisson stable (recurrent).     

Calculation of Prompt Fission Neutron Lifetimes by the Monte Carlo Method

An algorithm for calculation of prompt fission neutron lifetimes in a nuclear reactor by the Monte Carlo method is described. Evaluation of the importance function is carried out with solution of the neutron transport equation without solving the adjoint equation. The results of the prompt neutron lifetime calculations performed within some critical experiments are presented and compared with the experimental results.     

Smooth almost Δ-bundles over polyhedrons

In this paper, we construct and study a category of principal fiber bundles with the following properties: 1) The base of a bundle is a polyhedron and the structure group is a k-dimensional torus. 2) The transition functions of the bundle atlas are smooth on simplexes of the base. 3) On the base, a simplicial action of a finite group Δ is given which has a multivalued lifting to the total space of the bundle. We study invariant connections and construct integer-valued realizable characteristic classes.     

Polyfluoroalkyl Phosphates Bearing Propargyl Substituents

Russian Journal of General Chemistry - Polyfluoroalkyl dichlorophosphates react easily with propargyl alcohol under mild conditions (22–62°С, 3 h, pyridine-toluene) to form...     

Right Limits and Reflectionless Measures for CMV Matrices

We study CMV matrices by focusing on their right-limit sets. We prove a CMV version of a recent result of Remling dealing with the implications of the existence of absolutely continuous spectrum, and we study some of its consequences. We further demonstrate the usefulness of right limits in the study of weak asymptotic convergence of spectral measures and ratio asymptotics for orthogonal polynomials by extending and refining earlier results of Khrushchev. To demonstrate the analogy with the Jacobi case, we recover corresponding previous results of Simon using the same approach.     

Comparative investigation of zein isolated from gluten by various methods

A comparative study has been made on zein preparations isolated from gluten by extraction with 70% ethanol and precipitation under various conditions; by dialysis, and by the addition of a 0.1 M solution of sodium sulfate or of acetone. An investigation of absorption spectra and of electrophoresis in polyacrylamide gel has shown the advantage of the method using acetone for precipitating the protein preparation.Scientific-Research Institute of Biology, Dnepropetrovsk State University. Translated from Khimiya Priorodnykh Soedinenii, No. 5, pp. 695–699, September–October, 1989.     

Synthesis and structure of a platinum-palladium complex [η3-C3H5Pd(μ-OAc)2PtPPh3(OAc)]

Conclusions A novel type of platinum-palladium heteronuclear complex containing bridging acetate ligands, namely, (³-allyl)palladium(II)triacetatotriphenylphosphine) platinum(II), has been prepared by reaction of bis[³-allyl)chloropalladium] with triacetatoargento(I)triphenyl-phosphineplatinum(II); the complex was characterized on the basis of x-ray structural analysis, and its IR, PMR, and³¹P-NMR spectral data.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1894–1897, August, 1988.