Crystal truncation rods in kinematical and dynamical x-ray diffraction theories

Crystal truncation rods calculated in the kinematical approximation are shown to quantitatively agree with the sum of the diffracted waves obtained in the two-beam dynamical calculations for different reflections along the rod. The choice and the number of these reflections are specified. The agreement extends down to at least $\sim 10^{-7}$ of the peak intensity. For lower intensities, the accuracy of dynamical calculations is limited by truncation of the electron density at a mathematically planar surface, arising from the Fourier series expansion of the crystal polarizability

Neural networks art: solving problems with multiple solutions and new teaching algorithm

A new discrete neural networks adaptive resonance theory (ART), which allows solving problems with multiple solutions, is developed. New algorithms neural networks teaching ART to prevent degradation and reproduction classes at training noisy input data is developed. Proposed learning algorithms discrete ART networks, allowing obtaining different classification methods of input

Metallurgical Properties and Phase Transformations of Barium-Strontium Modifier

Metallurgical properties and phase transformations of barium-strontium modifier were tested in laboratory conditions resembling steel processing in furnace and ladle. When heating barium-strontium modifier start of melting, kinetics of decomposition, phase and structure transformation were studied. The concentrate under consideration has been revealed to be a complex mineral compound containing barytocalcite, calcite, calciostrontianite, dolomite and siderite. The reaction kinetics of decomposing mineral components of barium-strontium modifier to oxides does not considerably affect slag formation in conditions of out-of-furnace steel processing

Dzyaloshinskii--Moriya interaction: How to measure its sign in weak ferromagnetics?

Three experimental techniques sensitive to the sign of the Dzyaloshinskii--Moriya interaction are discussed: neutron diffraction, Moessbauer gamma-ray diffraction, and resonant x-ray scattering. Classical examples of hematite (alpha-Fe2O3) and MnCO3 crystals are considered in detailComment: 5 pages, 1 figure; to be published in JETP Letter

STAGED TREATMENT OF CHILDREN WITH POSTTRAUMATIC TRACHEOESOPHAGEAL FISTULA

The article presents the analysis of treatment of posttraumatic tracheoesophageal fistula caused by long staying of a flat battery in the esophagus lumen. The analysis cover treatment of two children at the age of 8 months and 1 year 3 months with a severe chemical burn of the esophagus because of long staying of a flat battery in the esophagus lumen. A principal clinical symptom of a disease was a dysphagia. The call for medical help was delayed - from 1 to 3 days. During the first esophagoscopy the excision of battery was done. A total necrosis of a front and lateral side of the esophagus in a cervical esophagus and a backside of trachea caused by the growth of atracheoesophageal fistula. A gastric fistula was performed for food supply. An emerged tracheoesophageal fistula led to the disturbance of breathing, which is why tracheostomy was urgently performed. The first child had a one-stage plastic operation of backside of trachea defect, the second child had a cycling off fragment of the esophagus, this had made it possible to pack off the trachea and stabilize the children's condition. In three months, the children had undergone a reconstructive plastic operation - retrosternal coloesophagoplasty with an extirpation of an esophagus stump. In this case, a backside of trachea was formed from the diverticulum of trachea (a segment of the esophagus after its disconnection)