Concentration Dependences of Molecular Oxygen and Hydrogen in Aqueous Solutions

Doklady Physics - The concentration dependences of molecular oxygen and hydrogen in aqueous solutions are studied with multiple dilutions and turbulent stirring accompanying the dilution procedure....     

Progress in the area of new energy-efficient basic elements for superconducting electronics

This review is devoted to a discussion of the prospects for solving the problem of a low degree of integration of the traditional elements for promising (due to the high performance and extremely low energy dissipation) superconducting digital electronics. We define three main directions on the path to compact multi-element Josephson electronic systems: (1) reduction of the Josephson junction to submicron size, (2) decrease of the area of standard logic cells, and (3) fabrication of a compact and rapid Josephson memory. We present the physical foundations of Josephson elements in order to show the fundamental constraints on establishing standard submicron tunnel contacts and compact logic cells/memory elements. This survey clearly demonstrates the essence of breakthrough technological solutions to create ultrasmall heterostructures with desired settings, reduce and optimize logic cells, and create memory unit cells based on Josephson junctions with magnetic layers.     

Tunneling Relaxation Mechanisms of the Jahn–Teller Complexes in a CaF2:Cr2+ Crystal

JETP Letters - The temperature dependences of attenuation and the velocity of ultrasonic waves at frequencies of 26–158 MHz in a CaF2 fluorite crystal at the substitution of...     

Properties of planar Nb/α-Si/Nb Josephson junctions with various degrees of doping of the α-Si layer

The properties of Nb/??-Si/Nb planar Josephson junctions with various degrees of doping of the amorphous silicon layer are experimentally studied. Tungsten is used as a doping impurity. The properties of the Josephson junctions are shown to change substantially when the degree of doping of the ??-Si layer changes: a current transport mechanism and the shape of the current-voltage characteristic of the junctions change. Josephson junctions with SNS-type conduction are formed in the case of a fully degenerate ??-Si layer. The properties of such junctions are described by a classical resistive model. Josephson junctions with a resonance mechanism of current transport through impurity centers are formed at a lower degree of doping of the ??-Si layer. The high-frequency properties of such junctions are shown to change. The experimental results demonstrate that these junctions are close to SINIS-type Josephson junctions.     

Algebraic and Geometric Properties of Matrix Solutions of Nonlinear Wave Equations

We improve the construction of exact matrix solutions for nonlinear wave equations by using unitary anti-Hermitian and anticommuting matrices. We prove the theorem that constructs the matrix functions u _n satisfying the nonlinear wave equation for a set of special potentials. In this case, the graph of complex solution u ₁ has a soliton-like form with a finite number of coils. Exponential representation of matrix solutions u _n is associated with continuous rotations that can be used for describing intrinsic rotations and state changes of elementary particles. We also prove the theorem on the decomposition of continuous rotation (described by solution u ₂) onto three simultaneous rotations about coordinate vectors. Each of the three constructed matrix solutions u ₃ is also decomposed into the triplet of elementary matrix solutions.     

Temperature Hysteresis in CO Oxidation on Copper Oxide Catalyst Applied to a Steel Gauze

The temperature hysteresis during the heterogeneous catalysis was studied by an example of model reaction of CO oxidation on copper oxide catalyst applied to a stainless steel gauze.     

Kinetics of methanation of carbon dioxide on a nickel catalyst

The kinetics of hydrogenation of CO₂ to methane on an NKM-4A nickel-containing catalyst was studied in a wide range of change of partial pressures of hydrogen and carbon dioxide at 498–543 K. It was shown that when hydrogen is replaced by deuterium in the reaction, a reverse kinetic isotope effect is observed. The kinetic equation of the reaction was derived and a stepwise scheme is proposed which includes the involvement of oxygen-containing intermediates in the process without preliminary dissociation of CO₂.Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 26, No. 5, pp. 620–624, September–October, 1990.     

Biocompatibility of the Ti<Subscript>81</Subscript>Nb<Subscript>13</Subscript>Ta<Subscript>3</Subscript>Zr<Subscript>3</Subscript> Alloy

Titanium-based alloy with low-toxic metals such as niobium, tantalum and zirconium (TiNbTaZr) was manufactured. The primary weight percentages of elements used for fusion were: titanium, 65%; niobium, 20%, tantalum, 10%; and zirconium, 5%. The TiNbTaZr alloy had a yield strength of about 550 MPa, a tensile strength of about 700 MPa, and a Young’s modulus of about 50 GPa, that is, it was comparable with Nitinol. A primary study of the biocompatibility of the TiNbTaZr alloy using the SH-SY5Y cells showed that the alloy did not have significant short-term toxicicity towards the cells incubated on the alloy surface. The number of non-viable cells was 2.5 times lower on the TiNbTaZr alloy than on Nitinol. The biocompatibility of TiNbTaZr was more pronounced than that of the Nitinol reference sample.