Hall effect in the ternary ordered alloys Ni3(Mn,Fe) and Ni3(Mn,Co) II. Ordered solid solutions

An experimental study was made of the changes in the normal and anomalous Hall constants R₀ and R_s, respectively, the internal saturation induction B_s, and the resistivity ? during the ordering of quasibinary Ni₃Mn-Ni₃Fe and Ni₃Mn-Ni₃Co alloys. The concentration dependences of R₀, R_s, B_s, and ? were also studied in the ordered state of these alloys. It is concluded from an analysis of the experimental results that the decreases inR₀ and ? during the ordering of Ni₃Mn and as a result of the alloying of ordered Ni₃Mn with slight amounts (～5 at. %) of iron are due primarily to a decrease in the hole contribution to transport and to a decrease in the state density in the 3d band of these alloys near the Fermi level. The experimental data are in satisfactory agreement with the curve calculated by Yamashita et al. [6] for the density of 3d states in ordered Ni₃Mn and Ni₃Fe alloys.     

Lower limit for disappearance rate of F-centers in irradiated alkali halide compounds

Conclusions A study was made of the destruction rate of the F-centers In NaCl, KC1, KBr, and Csl monocrystals at room and higher temperatures; the rate constants and activation energies were measured. The process for the destruction of the F-centers is independent of the temperature below a certain temperature.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1164–1166, May, 1976.     

On the Applicability of the Relations of the Cubic Timoshenko-Type Theory of Shells to the Study of the Postcritical Behavior of Rods

The question of whether the nonlinear Timoshenko-type theory of shells can be applied to the study of the initial postcritical behavior of a rod under compression is considered. The Koiter asymptotic theory in the Budyanskii form is used. The exact solution of the problem is obtained and a formula for the coefficient of postcritical behavior allowing for the effect of lateral-shear strains is derived. It is shown that the expressions (specified to within cubic terms) for lateral-shear strains and curvature permit us to use the nonlinear theory of shells to analyze the initial supercritical behavior of rods     

Relative molecular diffusion

We study both analytically and numerically the motion of a passive floating admixture subject to molecular collisions in a random velocity field. Within the framework of the one-dimensional model, we study the phenomena of relative molecular diffusion and the closely related fluctuations of the density of a cluster of particles that were initially located in the same physically infinitesimal volume. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 43, No. 4, pp. 456–467, September, 2000.     

Investigation of contactless electron transmission through dielectric channels

The effect of the contactless transmission (guiding) of 10 keV electrons through cylindrical dielectric channels and planar channels formed by glass plates is studied. The capture and propagation of an electron beam along the channel axis, usual in these cases, are observed in the experiments with two plates. The deviation of the reflection angle from the specular angle and its dependence on the plate length and beamcurrent value under beam reflection from a single plate are investigated.     

Defining the distribution function of mosaic crystal grains on orientation angles using synchrotron radiation

A new method of measuring the angular distribution function of grains in mosaic crystals is proposed and studied.     

New adsorbent based on zeolite modified with hyperbranched polyesterpolybenzoylthiocarbamate

A new hybrid adsorbent based on zeolite modified with hyperbranched polyesterpolybenzoylthiocarbamate is presented. The structure and morphology of the sorbent are characterized by potentiometric titration, IR, ¹H and ¹³C NMR spectroscopy, and electron microscopy. The fundamental possibility of extracting transition metal ions has been demonstrated using the examples of Cu^II and Co^II ions. It is shown that the sorption capacity of the adsorbent to Cu_II salt is 25.34 mg g^?1. A method of sorbent regeneration is proposed.

     

Theoretical analysis of two-gap superconductivity of magnesium diborades and iron pnictides in the generalized α model

A generalized ?? model for computing the superconducting parameters of real two-band superconductors is proposed based on an analysis of the properties of two-band equations in the theory of superconductivity. Using this model, we calculate the heat capacity and optical properties of Ba(Fe_{1 ? x} Co _x )₂As₂ superconducting compound and obtain the temperature dependences of the gaps and energies of the Leggett modes in the Mg_{1 ? x} Al _x B₂ superconducting system. Good quantitative coincidence of the calculated data and experimental results is demonstrated.