Crystal structure of new polymorphic modification β-Ca<Subscript>3</Subscript>B<Subscript>2</Subscript>SiO<Subscript>8</Subscript>, β-α phase transition and thermal expansion of α- and β-modifications

Single crystals of the β-Ca₃B₂SiO₈ new monoclinic modification have been obtained by cooling the melt of a stoichiometric composition. The crystal structure has been determined from the single crystal X-ray diffraction data and refined with R = 0.059 (wR = 0.069) in the monoclinic space group P2₁/m. The thermal behavior of the synthetic borosilicate has been studied. At 472 ± 5°С, a reversible phase transition of the first order occurs, leading to the formation of the orthorhombic α-Ca₃B₂SiO₈ modification. The thermal expansion of α- and β-modifications of Ca₃B₂SiO₈ is anisotropic: (α₁₁ = 15, α₂₂ = 16, α₃₃ =–1, α _V = 30 × 10^–6°С–1) and α₁₁ = 9, α₂₂ = 28, α₃₃ = 1, α _V = 38 × 10^–6°C–1, respectively.     

Functional observer design using linear matrix inequalities

It is shown that the problem of observer design for estimating a set of linear combinations of state variables of a plant can be formulated in terms of linear matrix inequalities. An algorithm for constructing functional observers is proposed based on a nonsingular transformation of a plant model in the state space by matrix canonization with subsequent solution of the system of linear matrix inequalities.     

乌拉尔有色冶金矿山采矿方法的完善

本文叙述了鸟拉尔地区黄铜矿床的地质特征及其给采矿带来的开采强度低、有自燃发火倾向等问题。采矿方法从充填法改为分段崩落法、阶段崩落法及分段空场嗣后充填法，使采矿方法不断改进和完善，提高了矿山生产能力和矿石回收率。     

Tests of a Two-Stage Core at the KV-1 Test Facility: Physical Aspects and Results

Atomic Energy - The physical aspects and main results of reactor tests of a two-stage core consisting of fresh fuel assemblies and a significant number of fuel assemblies from the previous core,...     

Basic principles and proposals for rehabilitation of radioactively contaminated objects and grounds of the kirovo-chepetsk chemical works

The results of an examination of objects and grounds of the Kirovo-Chepetsk Chemical Works are presented. The methods used to perform a radiation survey are described briefly. The data obtained are used as a basis for a concept of rehabilitation of radioactively contaminated objects and grounds of the works. The radwaste volumes are determined for each object and possible ways to handle them are proposed. The technologies for handling radwastes are examined. The primary problems that must be solved without delay are determined.     

Front formation and dynamics in one reaction-diffusion-advection model

The paper is concerned with the asymptotic behavior of a solution with an inner transition layer (front) in the reaction-diffusion-advection mathematical model to describe an in-situ combustion process.