Effect of hot rolling on the structure and the mechanical properties of nitrogen-bearing austenitic–martensitic 14Kh15AN4M steel

The effect of the rolling temperature and strain on the structure and the properties of corrosionresistant austenitic–martensitic 14Kh15AN4M steel is studied. The steel is shown to exhibit high ductility: upon rolling in the temperature range 700–1100°C at a reduction per pass up to 80%, wedge steel specimens are uniformly deformed along and across the rolling direction without cracking and other surface defects. Subsequent cold treatment and low-temperature tempering ensure a high hardness of the steel (50–56 HRC). Austenite mainly contributes to the hardening upon rolling in the temperature range 700–800°C at a reduction of 50–70%, and martensite makes the main contribution at higher temperatures and lower strains. Texture does not form under the chosen deformation conditions, which indicates dynamic recrystallization with the nucleation and growth of grains having no preferential orientation.     

Study of neuroblastomas in children using a complex of monoclonal antibodies

The possibility to reveal the following types of neuroblastoma is described: with c-ALL-antigen; with Thy-1-antigen (ICO-10); with granulocytic antigen (ICO-G2); with B-cell antigen (IPO-10). Immunocompetent cells in the tumour may be studied with the use of monoclonal antibodies ICO-1, ICO-11, ICO-GM-1, OKT3, IPO-3.     

Effect of heat treatment on the structure and properties of a high-nitrogen austenitic corrosion-resistant 03Kh20AG11N7M2 steel

The structure and mechanical and corrosion properties of a high-strength austenitic 03Kh20AG11N7M2 steel after quenching and aging at 500 and 800°C are analyzed. The phase composition of the steel and the mechanism of the decomposition of austenite during heat treatment are studied by electron-probe microanalysis and transmission electron microscopy. This steel is thermally stable upon heating to 800°C for 1 h and is stable to the γ → α and γ → ɛ martensitic transformation during deformation up to tensile strains leading to fracture. The homogeneous decomposition of a supersaturated γ solid solution at 500°C leads to the formation of disperse CrN nitrides, which increase the strength of the steel and insignificantly decrease its plasticity. In this case, the stress corrosion cracking resistance slightly decreases and the passivation of the steel increases in an corrosive medium without loading.     

The importance of studies of the glycosaminoglycans in the peripheral blood leukocytes of patients in the diagnosis of the phases of chronic myeloleukemia]

To elucidate new diagnostic markers of chronic myeloid leukemia (CML) phases, we investigated quantitative and qualitative composition of glycosaminoglycans (GAG) of leukocytes from peripheral blood of 72 patients. Chronic CML phase was characterized by elevated GAG levels (2 times compared to normal values), weakening of anionic properties of chondroitin sulfate (CS) and high amount of heparan sulfate (HS). In CML transformation in the progressive phase overall concentration of GAG grew still higher, GAG fraction composition changed. In the blast crisis there was a sharp fall in the overall GAG, new electrophoretic fractions emerged. In the myeloid variant of the crisis an additional GAG component appeared (GAG-m), whereas in the lymphoid variant another component was found (GAG-1). It is suggested that the number and composition of GAG in peripheral blood leukocytes may serve markers of CML phase.     

Improved accuracy of individual determinations of human arterial blood pressure parameters

A method is given for analytically calculating human arterial blood pressure parameters and improving their accuracy while individualizing the results. The possibility of implementing instrumentation is demonstrated.Translated from Izmeritel'naya Tekhnika, No. 3, pp. 10–12, March, 1995.     

Preparation of powdered carbon nitride C<Subscript>3</Subscript>N<Subscript>4</Subscript>

The basic principles of the preparation of powdered carbon nitride C₃N₄ in bulk amounts are developed. Synthetic carbon nitride C₃N₄ was identified using X-ray powder diffraction, infrared absorption, and reduction melting in a carrier gas (helium) flow with subsequent chromatographic separation.Original Russian Text Copyright © 2004 by Fizika i Khimiya Stekla, Mohammad Arif, Blinov, Lappalainen, Filippov.     

On-line system for university-level training of technical specialists

A method is proposed for using a telecommunications network for the on-line instruction of students in universities. Various aspects of creating electronic textbooks with the use of multimedia technologies and situational modeling are examined. The article discusses the feasibility of using problem-solving techniques in the texts as a cognitive aid. Translated from Izmeritel'naya Tekhnika, No. 5, pp. 26–28, May, 1999.