Антиферродисторсионная мягкая мода в кристалле PbZr-=SUB=-0.024-=/SUB=-Ti-=SUB=-0.976-=/SUB=-O-=SUB=-3-=/SUB=-

The antiferrodistortive soft mode was detected at the M point of the Brillouin zone in a crystal PbZr0.024Ti0.976O3 using the method of inelastic scattering of synchrotron radiation. The performed group-theoretical analysis and calculations of inelastic structural factors made it possible to relate the detected critical excitation to oxygen octahedra rotations. The traced temperature evolution of the soft mode frequency obeys the Curie-Weiss law with Curie temperature T AFD = 438 ± 5 K, which is close to the ferroelectric Curie temperature T FE = 479.5 K.

Charge/mass yields in the fission of highly excited heavy actinides

The charge (mass) distributions of fission fragments resulting from low- and high-energy fission of the isotopes of Fm and No are studied with the statistical scission-point fission model. The calculated results are compared with the available experimental data. The transformation of the shape of the charge distribution with increasing isospin and excitation energy occurs gradually. At some critical excitation energy the the saturation of the symmetric component of the charge (mass) yield is demonstrated.

Analytical and Numerical Investigations on a Bistable System for Energy Harvesting Application

This paper aims at an analytical and numerical analysis of a bistable Duffing equation. One purpose lies in the identification of suitable oscillations for a robust energy harvesting device, i.e. a system that is well suited for a broad bandwidth excitation. A map is constructed illustrating the dependence of the harvested energy on the predominant oscillation type. It shows that inter-well oscillations lead to the highest energy harvest compared to intra-well and cross-well oscillations under harmonic excitation. The determination of the critical excitation parameters necessary to maintain inter-well oscillations is essential for the design of bistable energy harvesters. Therefore, investigations are made to attain an analytical description of the inter-well oscillation region. On this basis, a design criterion is derived for nonlinear energy harvesters.