Vibratory drier for the chemical industry

Modern designs are examined, and technical data presented for vibratory electric and convection driers, driers with infra-red sources, and steam driers.     

Hydrocarbon impurities in SiF<Subscript>4</Subscript> and SiH<Subscript>4</Subscript> prepared from it

Using gas chromatography and high-resolution Fourier-transform IR spectroscopy, we have determined the concentrations of C₁–C₄ hydrocarbon impurities in isotopically unmodified silicon tetrafluoride before and after fine purification and in ²⁸Si-enriched SiF₄. The concentrations of C₁–C₄ hydrocarbon impurities in silicon tetrafluoride for SiH₄ synthesis have been shown to correlate with those in the synthesized silane.     

Production of hot-dipped tin plate 0.45–0.50 mm thick

Magnitogorsk Metallurgical Combine. Translated from Metallurg, No. 2, p. 37, February, 1991.     

Transport properties of Nd1.85Ce0.15 δ single crystals: The narrow-band model

The anisotropy of the resistivity and thermoelectric power (TEP)S of Nd_1.85Ce_0.15CuO_4?δ single crystal (T _c =17 K) has been investigated. In the temperature rangeT _c <T<300 K the ratioρ _c/ρ_ab≈10⁴ and the dependencesρ _ab (T) andρ _c (T) change from quadratic to linear atT～200 K. The dependencesS _ab (T) andS _c (T) reach a maximum atT>T _c and then decrease almost linearly with increasing temperature, changing sign from positive to negative nearT～ 150 K. The features of the resistivity and TEP temperature dependences (the lawρ∝T ² changing toρ∝T, the change in the sign of S with temperature, and the low TEP anisotropy at largeρ anisotropy) have been interpreted in the framework of the narrow-band model.     

An Inductive Pulse Power-Amplifying Stage with Electric-Explosion Circuit Switching

An inductive power-amplifier stage based on a two-coil assembly and two electrically exploded conductors used as circuit breakers is described. Owing to the magnetic flux conservation, the interruption of the current in the first of the storage coils causes an increase of the current in the second coil, which results in a rapid thermal burst of the second electrically exploded conductor. As a result, the load-current rise-time is 20 times less than the charging-current rise time and the amplitude of the current increases.     

Effect of irradiation with low-energy Ar ions on the characteristics of the working and rear sides of single-crystal GaAs substrate

Contactless methods were used to study the characteristics of the front and rear sides of single-crystal GaAs wafers whose rear side was irradiated with low-energy Ar ions. Variations in the optical and photoelectric properties of irradiated and unirradiated sides were detected. A solitonic mechanism for the penetration of defects into the crystal bulk is suggested.     

The stabilization of cortical evoked potentials during selective visual attention

The event-related potentials (ERP) to lateralized moving visual stimuli (administered to the right and to the left of the subject) were recorded in six derivations in eight healthy subjects during passive viewing and selective attention to one of the stimuli (the relevant one), which demanded precise and rapid motor reaction. It was shown that during the selective voluntary attention correlation between successive ERP was substantially higher than that under conditions of passive (involuntary) attention, i.e. the ERP in the occipital, parietal, and frontal derivations during voluntary attention were more stable. The less was correlation between the ERP at passive viewing, the greater was the difference between the values of correlation coefficients during selective and passive attention. It is suggested that role of selected attention consists in stabilization of activity of the cortical structures, which are involved in solving the behavioral task.