On the prospects of developing high-efficiency piezocomposites based on crystals of solid solutions of ferroelectric relaxors

Electromechanical properties of the 0-0-2-2 type composite based on platelike crystals of solid solutions of ferroelectric relaxors of the Pb(A_1/3Nb_2/3)O₃-PbTiO₃ system (A = Zn, Mg) have been studied for the first time. Factors accounting for the record values of some effective parameters of this composite are considered. The relationship between the components of the elastic compliance tensor of the layered structures forming the composite and the positions of maxima of the effective hydrostatic parameters is established.     

Nanostructural crack arrest

The problem of brittle crack development in a nanocrystalline material has been theoretically studied. Expressions describing the conditions of crack stability are obtained.     

The optimum characteristics of a halogen lamp pumped by transverse RF discharge

We report on the optimized characteristics of a small-size bactericidal lamp pumped by transverse RF (f=1.76 MHz) discharge, operating on a system of the molecular emission bands of chlorine in a wavelength range of 195–310 nm. The spectral characteristics of the plasma emission were measured and the intensity of chlorine emission bands were studied as functions of the total pressure and partial composition of a helium-chlorine mixture. Oscillograms of the pumping current and output radiation intensity were measured and the total output radiation power was determined. It is established that the lamp radiates predominantly in a bactericidal wavelength interval on an electron-vibrational transition at 200 nm in Cl₂** molecules. The optimum partial pressures of helium and chlorine are 100–300 and 90–120 Pa, respectively. The maximum output power of UV emission from the side cylindrical surface of the lamp reached 10 W. The lamp can be used in photochemistry, ecology, genetics, and medicine.     

广泛应用机器人技术是提高连铸安全性的重要步骤

1前言及历史背景 为避免钢水造成燃烧或破碎引起对人体的可能伤害,必须对连铸平台的平面布置进行分析.     

Radiation-induced hydrogen yield from silicon bombarded with 710-MeV bismuth ions

The behavior of hydrogen in solids under the action of intense ionizing radiation is of importance in solving numerous problems of materials science for the nuclear and thermonuclear power industry, spacecraft engineering, hydrogen energetics, and microelectronics. Experimental results are presented that provide evidence of the radiation-induced yield of hydrogen from single crystal silicon bombarded with 710-MeV bismuth ions.     

Surface Films on Zinc-Plated Steel Formed on Holding in Aqueous Extracts of Anticorrosion Pigments

The methods of X-ray photoelectron spectroscopy and Auger spectroscopy are used to study surface films formed on zinc and zinc-plated steel in the process of holding in aqueous extracts of mixtures of phosphate and calcium-containing pigments. It is shown that protective films formed mainly of zinc and calcium phosphates of different chemical structure are deposited in inhibited solutions on specimens of pure zinc and zinc-plated steel. The protective properties of these films are much better than the protective properties of the surface layers formed on the metal in the extracts of a single phosphate (or calcium-containing) pigment. The mixture of these pigments may serve as a promising substitution of chromate inhibitors in anticorrosive organic coatings.     

Interaction of NbVNi with Hydrogen

The interaction of NbVNi with hydrogen is studied over wide pressure and temperature ranges. Hydrogen absorption–desorption isotherms are measured, and the compositions of the resulting hydride phases are determined. X-ray diffraction analysis demonstrates that the incorporation of hydrogen into NbVNi leads to an isotropic expansion of its crystal lattice.