Application of exterior cartan forms in classical field theory

Attempts at a consistent construction of field theory in terms of exterior forms are expounded. The concept of the variation of a form and differentiation with respect to a form are defined. A variant of decoupling space-time forms on the basis of the τ formalism is proposed. In frames of reference without rotation, the longitudinal components of the potential and the momentum of the electromagnetic field in curved space are eliminated.     

57Fe Mössbauer study of hydrides and deuterides of manganese

Hydrides and deuterides of manganese with hydrogen-to-metal ratiosx between 0.65 and 0.93 were studiéd by Mössbauer spectroscopy on dilute substitutional⁵⁷Fe probes. No traces of magnetic ordering were found. Experiments on⁵⁷Fe in MnD_0.77 in external magnetic fields show that the iron has no measurable magnetic moment. The shapes of the Mössbauer patterns are compatible with superstructure ordering of the interstitials of the anti-Cdl₂ type nearx=0.5, while the dependence of the isomer shifts onx shows that there are no substantial iron-hydrogen interactions.     

Investigation of the hydrides of Ni0.70Cu0.30 by57Fe Mössbauer spectroscopy and magnetization measurements

Hydrides of Ni_0.70Cu_0.30 prepared both electrolytically and under high pressures of hydrogen gas were studied by Mössbauer spectroscopy on dilute⁵⁷Fe probes and by magnetization measurements. At hydrogen-to-metal ratios abovex≈0.3 no ferromagnetism is observed down to 4.2 K. The dependence of the mean change of the isomer shift on the hydrogen content of the samples reveals a repulsive interaction between the hydrogen interstitials and the iron probes. The effect of this interaction is, however, less pronounced than for⁵⁷Fe in the hydrides of pure nickel. This difference can be attributed to a competition of the repulsive Fe?H and Cu?H interactions.     

Zero-motion correlations in high-energy proton elastic scattering on40Ca with noneikonal nucleon-nucleon amplitude

Using a noneikonal expression for the two-body scattering amplitude, consistent with the proton-nucleon scattering data, the cross-section of the 1.04 GeV-proton elastic scattering on⁴⁰Ca is calculated by the Glauber-Sitenko theoretical scheme in the framework of the coherent density fluctuation model (CDFM) as well as of the independent-particle model (IPM). It is shown that the use of the noneikonal amplitude in the CDFM calculation improves the agreement with the experimental data especially at larger scattering angles in contrast to the case of the independent-particle model. To that end a decisive role play the zero-motion flucton correlations taken into account in the CDFM.