Irreducible first Brillouin zone for two-dimensional magnonic crystals with asymmetric complex lattices

Two-dimensional (2D) magnonic crystal (MC) with an asymmetric complex basis is proposed in this paper, and its band structures are calculated in the whole area of the first Brillouin zone (BZ). This kind of MCs is composed of two different atoms in the unit cell, and the symmetry of the unit cell is broken due to changes in the position of the second atom, so the irreducible part of the BZ is no longer the small area [Formula: see text] for square lattice, and it must be expanded to the whole first BZ. Only by investigating the whole first BZ, can we get the true full band-gap for this kind of MCs.

ESTRUTURA E AGÊNCIA NAS RELAÇÕES INTERNACIONAIS: CONSTRUÇÃO DO ESTADO E A EVOLUÇÃO DO SISTEMA POLÍTICO INTERNACIONAL

Conflicts are intrinsic to social systems and constitute an irreducible part of their development. This article analyzes the conflict between states and its effects on the evolutionary dynamics of the international political system. We discuss the ontology of each object of analysis and the causal mechanisms that connect their respective evolving trajectories. Then, the analytical model is evaluated regarding to the processes of formation of the Qin Empire in China and the construction of Nation-States in Europe. The working hypothesis is that the interactions among the strategies chosen by the agents to cope with the structural constrains and competition conditions they encounter cause changes in the international political systems, as well as on the actors themselves.

Aspects of the Solid State

Symmetries play an important role in the theory of the solid state. As will be developed in this Chapter, DFT calculations for crystalline materials are commonly performed for the irreducible part of the first Brillouin zone, an approach which relies on the use of translational and point group symmetries. Two central properties that result from a calculation in reciprocal space are the wave vector resolved energy spectra, the so called band structure, and the energy resolved density of states. For magnetic materials, atomic magnetic moment moments can be defined and calculated, as well as effective inter-atomic exchange interactions.

Strong coupling diagram technique for the three-band Hubbard model

Strong coupling diagram technique equations are derived for hole Green’s functions of the three-band Hubbard model, which describes Cu–O planes of high-[Formula: see text] cuprates. The equations are self-consistently solved in the approximation, in which the series for the irreducible part in powers of the oxygen–copper hopping constant is truncated to two lowest-order terms. For parameters used for hole-doped cuprates, the calculated energy spectrum consists of lower and upper Hubbard subbands of predominantly copper nature, oxygen bands with a small admixture of copper states and the Zhang–Rice states of mixed nature, which are located between the lower Hubbard subband and oxygen bands. The spectrum contains also pseudogaps near transition frequencies of Hubbard atoms on copper sites.

The Calculation of the Band Structure in 3D Phononic Crystal with Hexagonal Lattice

In this article, the propagation of acoustic waves in the phononic crystals (PCs) of three dimensions with the hexagonal (HEX) lattice is studied theoretically. The PCs are constituted of nickel (Ni) spheres embedded in epoxy. The calculations of the band structure and the density of states are performed using the plane wave expansion (PWE) method in the irreducible part of the Brillouin zone (BZ). In this study, we analyse the dependence of the band structures inside (the complete band gap width) on c/a and filling fraction in the irreducible part of the first BZ. Also, we have analysed the band structure of the ALHA and MLHKM planes. The results show that the maximum width of absolute elastic band gap (AEBG) (0.045) in the irreducible part of the BZ of HEX lattice is formed for c/a=6 and filling fraction equal to 0.01. In addition, the maximum of the first and second AEBG widths are 0.0884 and 0.0474, respectively, in the MLHKM plane, and the maximum of the first and second AEBG widths are 0.0851 and 0.0431, respectively, in the ALHA plane.

Accounting, Transparency and “Translation”: The Case of HUMANITARIAN Cross Cultural Governance

We have conducted a field research on philanthropic “tsunami” projects in South-eastern India that are embedded in a quiet complex governance scheme (French Firm funding, execution by local NGOs, consolidated management by a French federation of NGOs), in which the classical notions of fraud and transparency prove to very ambiguous, so that accounting cannot be the main source of control. We show that the opacity of events at microscopic operational level is a mandatory condition for institutionalization of accounted “facts”. Therefore, we establish the<br />importance of “translation” effects in the sense of Actor Network Theory (ANT). Beyond transparency that translation institutionalizes trough accounts, we raise an irreducible part of ignorance and incertitude that<br />necessarily comes with every attempt to build knowledge for governance.<br /><br /><br /><br /><br />