Magnetic field correlation tensor in spaces of constant curvature

The concept of statistical homogeneity and isotropy for vector fields in spatial sections of constant curvature was analyzed. Solenoidality conditions for a corresponding correlation tensor were obtained for positive and negative curvature. It was shown that these conditions differ from the corresponding condition for fields in Euclidean space.     

Shell Models of MHD Turbulence and the Problem of Superequipartition

Within the framework of the shell model of turbulence, we consider the long-time evolution of the magnetic field in a turbulent flow of conducting fluid. A weak initial magnetic field rapidly increases up to magnitudes corresponding to the equipartition with kinetic energy, and then the stage of slow evolution begins. It is shown that in some cases, the magnetic energy can significantly exceed the kinetic energy of the turbulence at this stage. We discuss the possible observational evidences for such a superequipartition of the magnetic field. It is shown that the superequipartition is realized if the initial energy of the magnetic field exceeds the kinetic energy, although even in such cases the equipartition is reached in many realizations.     

Eudesmanolides derived from herbolide B

The reaction of acidic reagents with the germacranolide-herbolide B (2) and its derivatives was investigated. Cyclisation products of the eudesmanolide series were isolated in all cases. The chemical and physical data of these new compounds are described.     

Self-assembled growth of nanostructural Ge islands on bromine-passivated Si(111) surfaces at room temperature

We have deposited relatively thick (∼60 nm) Ge layers on Br-passivated Si(111) substrates by thermal evaporation under high vacuum conditions at room temperature. Ge has grown in a layer-plus-island mode although it is different from the Stranski-Krastanov growth mode observed in epitaxial growth. Both the islands and the layer are nanocrystalline. This appears to be a consequence of reduction of surface free energy of the Si(111) substrate by Br-passivation. The size distribution of the Ge nanoislands has been determined. The Br-Si(111) substrates were prepared by a liquid treatment, which may not produce exactly reproducible surfaces. Nevertheless, some basic features of the nanostructural island growth are reasonably reproducible, while there are variations in the details of the island size distribution.     

Comparison of electron and muon charged current neutrino and antineutrino interactions in a neonH2 mixture

From an exposure of the Fermilab 15 ft Neon(64 atomic %)H₂ filled bubble chamber to a single-horn-focussed $\text{ν}$ beam, we have found 60 e^?X and 35 e⁺X events, which we compare with 227 μ^?X and 202 μ⁺X events. No statistically significant departures from μ-e universality are seen in the shapes of various differential cross sections.     

Large-scale magnetic field generation by alpha effect driven by collective neutrino-plasma interaction

We suggest a new mechanism for the generation of a large-scale magnetic field in the hot plasma of the early Universe which is based on parity violation in weak interactions and depends neither on the helicity of matter turbulence resulting in the standard alpha effect nor on general rotation. The mechanism can result in a self-excitation of an (almost) uniform cosmological magnetic field.