Simulation of Dampers Made of Viscoelastic Materials

Technical Physics - Taking damping into account in the problems of structural dynamics is an important and nontrivial problem. Its complexity is primarily determined by the required specification...     

Evolution of a Non-Uniform Deformed State in the Structure of Zinc-Chalcogenide Cubic Crystals Doped by 3 d Ions

The real structure of bulk Zn1 – хМхSe (S) crystals of diluted magnetic semiconductors with М = V, Cr, Fe, Co, Ni 3d impurities is characterized by neutron diffraction. These impurities are known to greatly destabilize even the initial lattices of pure zinc chalcogenides. Data on the resulting non-uniform microstrain field induced by atomic displacements are obtained from the structural peaks along the tangential and radial directions on the above crystals within a dopant concentration range of 0.01 ≤ х ≤ 0.10. Additional nodes with q = (1/3 1/3 1/3) 2π/a (q is the wave vector and a is the cubic unit cell) emerging in the reciprocal lattice of the cubic structure are considered as evidence for a pre-transition to the fcc (face-centered cubic)–hcp (hexagonal close-packed) phase state, which implies transitions from the fcc lattice along an 8-ray non-Lifshitz star with the wave vector k5 = μ(b1 + b2 + b3), where b1, b2, b3 are the reciprocal lattice vectors and μ ≈ 1/3.     

Acoustic Signals Induced in a Copper Target under Irradiation by a Low-Energy High-Current Electron Beam

Russian Physics Journal - Results of investigations of acoustic signals induced in a copper plate irradiated with a microsecond lowenergy high-current electron beam (LEHCEB) are presented. The...     

On a guaranteed guidance problem under incomplete information

We discuss the problem of guaranteed guidance of a linear control system by a fixed time under the assumption that the system is subject to an unknown disturbance. We consider the case when a part of state coordinates are measured and the set of unknown initial states is finite. We specify a solution algorithm based on the combination of the package approach, the theory of dynamic inversion, and the extremal shift method.     

Correction to: The effect of small silver inclusions on the palladium activity in formicacid oxidation reaction and corrosion stability

A PdAg deposit containing ~ 25 at.% Ag is obtained by the electrochemical codeposition from an aqueous solution of Pd and Ag sulfates (Au support, 0.5 M H₂SO₄). The deposit is characterized by means of various physical, physicochemical, and electrochemical methods. The PdAg deposit demonstrates the ~ 2 times higher specific activity (per the electrochemically active surface area (EASA) of Pd) in the formic acid oxidation reaction (FAOR) as compared with the individual Pd deposit prepared under the same conditions. The effect of silver additions on the palladium activity depends on many factors. The corrosion stability of PdAg is studied in 0.5 M H₂SO₄ solution based on the overall cyclic voltammograms (CVAs) and also on anodic and cathodic half-cycles in the region E = 0.3 − 1.25 V (vs. reversible hydrogen electrode (RHE)). The electrochemical estimates are compared with the results of direct analytical determination of dissolution products in solution after anodic polarization of deposits. The total amounts of Pd dissolved substantially increase with incorporation of Ag, which is associated, first of all, with the considerable increase in the EASA; at the same time, the specific dissolution of Pd also substantially increases. The possible factors determining the active dissolution of PdAg deposits are discussed; in particular, the specific mechanism of their dissolution via silver adatoms is proposed.

     

Generation of a Hetero Spin Complex from Iron(II) Iodide with Redox Active Acenaphthene-1,2-Diimine

The reaction of the redox active 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-BIAN) and iron(II) iodide in acetonitrile led to a new complex [(dpp-BIAN)Fe^III₂] (1). Molecular structure of 1 was determined by the single crystal X-ray diffraction analysis. The spin state of the iron cation in complex 1 at room temperature and the magnetic behavior of 1 in the temperature range of 2–300 K were studied using Mossbauer spectroscopy and magnetic susceptibility measurements, respectively. The neutral character of dpp-BIAN in 1 was confirmed by IR and UV spectroscopy. The electrochemistry of 1 was studied in solution and solid state using cyclic voltammetry. The generation of the radical anion form of the dpp-BIAN ligand upon reduction of 1 in a CH₂Cl₂ solution was monitored by EPR spectroscopy.     

Specific features of the unsteady combustion of planar Ti–2B–αCu samples

The modes of spin gasless combustion of plate- and disk-shaped Ti–2B–Cu samples are investigated using frame-by-frame filming. The combustion process takes place under unsteady conditions. An increase in the diameter of the reaction sample makes the pattern of movement of the reaction front more complicated.     

Study of Structural Changes in LiNi0.8Co0.1Mn0.1O2 Cathode Material for Lithium-Ion Batteries by X-Ray Diffraction Analysis in the In Situ Mode

Russian Journal of Applied Chemistry - Structural changes in a promising cathode material LiNi0.8Co0.1Mn0.1O2 for lithium-ion batteries were in situ studied by X-ray diffraction analysis in the...