Studying the properties of Fe and Fe–Co nanotubes in polymer ion-track membranes

Iron and iron–cobalt nanostructures are probed by means of Mössbauer spectroscopy combined with scanning electron microscopy, energy-dispersion analysis, and X-ray diffraction. The obtained nanostructures are single-phase Fe_{1 ? x}Co _x (0 ≤ x ≤ 1) nanotubes that have high degrees of polycrystallinity and a bcc lattice 12 μm long and 110 ± 3 nm in diameter, with walls 21 ± 2 nm thick. A random distribution of the orientations of the magnetic momenta of Fe atoms are observed for Fe nanotubes, while Fe–Co nanotubes are characterized by a magnetic texture along their axes.     

Scalar Fields in Multidimensional Gravity. No-Hair and Other No-Go Theorems

Global properties of static, spherically symmetric configurations with scalar fields of sigma-model type with arbitrary potentials are studied in D dimensions, including models where the space-time contains multiple internal factor spaces. The latter are assumed to be Einstein spaces, not necessarily Ricci-flat, and the potential V includes a contribution from their curvatures. The following results generalize those known in four dimensions: (A) a no-hair theorem on the nonexistence, in case V 0, of asymptotically flat black holes with varying scalar fields or moduli fields outside the event horizon; (B) nonexistence of particlelike solutions in field models with V 0; (C) nonexistence of wormhole solutions under very general conditions; (D) a restriction on possible global causal structures (represented by Carter-Penrose diagrams). The list of structures in all models under consideration is the same as is known for vacuum with a cosmological constant in general relativity: Minkowski (or AdS), Schwarzschild, de Sitter and Schwarzschild – de Sitter, and horizons which bound a static region are always simple. The results are applicable to various Kaluza-Klein, supergravity and stringy models with multiple dilaton and moduli fields.     

Minimum working temperature of cells with oxide solid electrolyte

Thermal e.m.f. method was used to estimate minimum working temperature of Pt, Pd, Ni, Ag, and Au electrodes for solid electrolyte ZrO₂ + Y₂O₃ cells in gaseous mixtures He + O₂, Co + Co₂, H₂ + H₂O over a temperature range of 1070-400 K.     

Synthesis, structure, and biological activity of the cis-[4-amino-2,2,6,6-tetramethylpiperidine-N,N′]dichloropalladium(ii) complex

A previously unknown palladium complex was synthesized by the reaction of 4-amino-2,2,6,6-tetramethylpiperidine with PdCl₂. The X-ray diffraction study showed that the complex formed by 4-amino-2,2,6,6-tetramethylpiperidine with PdCl₂ is a chelate, in which the bidentate ligand adopts a boat conformation with the nitrogen atoms occupying cis positions at the palladium atom. The resulting cis-[4-amino-2,2,6,6-tetramethylpiperidine-N,N′]dichloro-palladium(ii) complex exhibits strong antimetastatic activity against experimental B16 melanoma at moderate toxicity.     

One-nucleon exchange and the effective local potential in nucleus-nucleus scattering

The influence of one-nucleon exchange on the local nucleus-nucleus potential is investigated using the resonating group method. Neutron scattering on ⁴He and ¹⁶O nuclei is examined in detail. The results are compared to microscopic calculations.     

Ultrashort relativistically strong solitons in plasma

An equation that describes a reflectionless propagation of non-one-dimensional relativistically strong wave packets in plasma has been studied. A family of three-dimensional solitons is found and their stability is analytically justified. The dynamics of soliton formation and their interactions have been numerically simulated.     

Analysis of autooscillations during co oxidation on a non-uniform surface consisting of two types of sites coupled by coads diffusion

Areas of occurrence and character of autooscillations during CO oxidation on a non-uniform surface consisting of different sites M₁ and M₂, the reaction on which is kinetically connected by the diffusion of adsorbed CO (CO_ads), has been analyzed using numerical integration of an independent system and search of stationary solutions by the homotopy method.     

Synthesis and structures of complexes ofN-2-nitroxyethylpicolinamide and 2-(2-pyridyl)-2-oxazoline with PdCl2

The reaction ofN,N′-bis(2-nitroxyethyl)pyridine-2,6-dicarboxamide with PdCl₂ afforded previously unknowncis-(N-2-nitroxyethylpicolinamide-N,N′)dichloropalladium(II) andcis-[2-(2-pyridyl)-2-oxazoline-N,N′]dichloropalladium(II), which were isolated as a cocrystallizate of the molecular compounds. Its structure was established by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1604–1606, August, 1999.