The Effect of Electric Energy Accumulation by Hydrated ZrO2 – Nanoparticles

The dimensional effect of the accumulation of an electric charge with a density of up to 270 μF/g by the system of compacted zirconium dioxide nanoparticles during exposure in an electric field (5000 V/m) under normal physical conditions is determined. Based on a qualitative complex analysis of the forms of appearance of the effect, it is shown that the place of localization of different charge carriers is the surface of nanoparticles. The supposed mechanism of this effect is considered using the theory of dispersed systems, the band theory, and the theory of contact phenomena in semiconductors. It was concluded that this mechanism is due to the phenomenon of localization of electron-type charge nanoparticles in the near-surface zone of the material in contact with the adsorption ion atmosphere. This effect is relevant for modern nanoelectronics, microsystem technology, and printed electronics.

Vibration Band Gap Characteristics of Two-Dimensional Periodic Double-Wall Grillages

In this article, the wave finite element method (WFEM) is used to calculate the band gap characteristics of two-dimensional (2D) periodic double-wall grillages (DwGs), which are verified by the grillage model vibration measurement experiment and finite element calculation. To obtain the band gap characteristics of periodic DwGs, the finite element calculation model is established according to the lattice and energy band theory and the characteristic equation of the periodic unit cell under the given wave vector condition is solved based on Bloch theorem. Then, the frequency transfer functions of finite-length manufactured and finite element models are obtained to verify the band gap characteristics of periodic DwGs. Finally, the effects of material parameters and structural forms on band gap characteristics and transfer functions are analyzed, which can provide a reference for engineering structure vibration and noise reduction design.

Non-Hermitian Bulk-Boundary Correspondence and Singular Behaviors of Generalized Brillouin Zone

The bulk boundary correspondence, which connects the topological invariant, the continuum band and energies under different boundary conditions, is the core concept in the non-Bloch band theory, in which the generalized Brillouin zone (GBZ), appearing as a closed loop generally, is a fundamental tool to rebuild it. In this work, it can be shown that the recovery of the open boundary energy spectrum by the continuum band remains unchanged even if the GBZ itself shrinks into a point. Contrastively, if the bizarreness of the GBZ occurs, the winding number will become illness. Namely, we find that the bulk boundary correspondence can still be established whereas the GBZ has singularities from the perspective of the energy, but not from the topological invariant. Meanwhile, regardless of the fact that the GBZ comes out with the closed loop, the bulk boundary correspondence can not be well characterized yet because of the ill-definition of the topological number. Here, the results obtained may be useful for improving the existing non-Bloch band theory.