933 resultados para Tie Breaking
Resumo:
We study the effect of sublattice symmetry breaking on the electronic, magnetic, and transport properties of two-dimensional graphene as well as zigzag terminated one- and zero-dimensional graphene nanostructures. The systems are described with the Hubbard model within the collinear mean field approximation. We prove that for the noninteracting bipartite lattice with an unequal number of atoms in each sublattice, in-gap states still exist in the presence of a staggered on-site potential ±Δ/2. We compute the phase diagram of both 2D and 1D graphene with zigzag edges, at half filling, defined by the normalized interaction strength U/t and Δ/t, where t is the first neighbor hopping. In the case of 2D we find that the system is always insulating, and we find the Uc(Δ) curve above which the system goes antiferromagnetic. In 1D we find that the system undergoes a phase transition from nonmagnetic insulator for U
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This research presents the explanatory model of the process of reconstruction of the ʺsocial problemʺ of Intimate Partner Violence (I.P.V) in Spain during last five years, with special attention to the role of media in this process. Using a content analysis of the three more diffused general newspapers, a content analysis of the minutes of the Parliament, and the statistics of the police reports and murders, from January of 1997 to December of 2001, it observes the relationship between the evolution of the incidence of Intimate Partner Violence (I.P.V) (measured by the number of deaths and the number of police reports) and the evolution of stories about this topic in press. It also studies the interconnection of the two previous variables with the political answer to the problem (measured by the interventions on the I.P.V. in the Senate and in the Congress). Data shows that, even though police reports have increased due to the contribution of politics and media, I.P.V murders keep on growing up.
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Saproxylic insect communities inhabiting tree hollow microhabitats correspond with large food webs which simultaneously are constituted by multiple types of plant-animal and animal-animal interactions, according to the use of trophic resources (wood- and insect-dependent sub-networks), or to trophic habits or interaction types (xylophagous, saprophagous, xylomycetophagous, predators and commensals). We quantitatively assessed which properties of specialised networks were present in a complex networks involving different interacting types such as saproxylic community, and how they can be organised in trophic food webs. The architecture, interacting patterns and food web composition were evaluated along sub-networks, analysing their implications to network robustness from random and directed extinction simulations. A structure of large and cohesive modules with weakly connected nodes was observed throughout saproxylic sub-networks, composing the main food webs constituting this community. Insect-dependent sub-networks were more modular than wood-dependent sub-networks. Wood-dependent sub-networks presented higher species degree, connectance, links, linkage density, interaction strength, and were less specialised and more aggregated than insect-dependent sub-networks. These attributes defined high network robustness in wood-dependent sub-networks. Finally, our results emphasise the relevance of modularity, differences among interacting types and interrelations among them in modelling the structure of saproxylic communities and in determining their stability.
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A single and very easy to use Graphical User Interface (GUI- MATLAB) based on the topological information contained in the Gibbs energy of mixing function has been developed as a friendly tool to check the coherence of NRTL parameters obtained in a correlation data procedure. Thus, the analysis of the GM/RT surface, the GM/RT for the binaries and the GM/RT in planes containing the tie lines should be necessary to validate the obtained parameters for the different models for correlating phase equlibrium data.
Resumo:
This experimental work aims at probing current-induced forces at the atomic scale. Specifically it addresses predictions in recent work regarding the appearance of run-away modes as a result of a combined effect of the non-conservative wind force and a ‘Berry force’. The systems we consider here are atomic chains of Au and Pt atoms, for which we investigate the distribution of break down voltage values. We observe two distinct modes of breaking for Au atomic chains. The breaking at high voltage appears to behave as expected for regular break down by thermal excitation due to Joule heating. However, there is a low-voltage breaking mode that has characteristics expected for the mechanism of current-induced forces. Although a full comparison would require more detailed information on the individual atomic configurations, the systems we consider are very similar to those considered in recent model calculations and the comparison between experiment and theory is very encouraging for the interpretation we propose.
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This article describes the process of self-determination and the creation of a territorial autonomy of the Gagauz people in the Republic of Moldova. It also analyses the situation in the autonomy after the change of government in Chisinau in 2009 and evaluates the current status of accommodation of the Gagauz’ interests in the country. Aspects of state-building and the influence of external actors are explored as well. Gagauzia (Gagauz Yeri) is one of the first post-Soviet autonomies. Since its establishment in 1994, no violent conflict has taken place there. However, the Gagauz language and culture remain relatively unprotected, and incentives as well as support for the integration of the Gagauz are low. The article outlines the potential for future disputes between the central government and local authorities, due to continuous attempts to limit Gagauzia’s self-governance and conflicting interpretations of how the autonomy should work. Furthermore, struggles between Gagauz political leaders and other local realities hamper the successful realization of Gagauz Yeri. With respect to Moldova’s efforts to resolve the Transnistrian conflict and to integrate with the European Union, compromises and cooperation through an ongoing dialogue between the centre and autonomy are clearly due. Resolving the remaining stumbling blocks could make Gagauzia a living, rather than symbolic autonomy.
Resumo:
According to the European Council decision of February 2011, the process of creating the European Union’s internal gas market should be completed by the end of 2014. Therefore, it is worth summarising the changes which have taken place in the gas markets of Central Europe so far. The past few years have seen not only a period of gradual ‘marketisation’ of the national gas sectors, but also the building of new gas infrastructure, a redrawing of the gas flow map, and changes in the ownership of the Central European gas companies. Another change in Central Europe is the fact that individual states and companies are moving away from their traditional focus on their national gas markets; instead, they are beginning to develop a variety of concepts for the regional integration of Central European markets. This publication attempts to grasp the main elements of the ongoing transformation of Central Europe’s gas markets, with particular emphasis on the situation in Poland, the Czech Republic, Slovakia and Hungary.
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Although the Minsk process brought about a de-escalation of the conflict in Eastern Ukraine, not all of its 13 points have been implemented, including a ceasefire and withdrawal of heavy weaponry. In the absence of a military option, economic sanctions have become the core instrument of the EU and the US, to respond to Russia’s aggression. At the end of June 2016, when EU Heads of State and Government meet to discuss the extension of sanctions against Russia, they should bear in mind that Russia did not implement the commitments it took upon itself in the framework of the Minsk agreements. Given the persistent deadlock in the Ukraine crisis, the leaders of the EU ought to agree to prolong the sanctions against Russia, push for the renegotiation of the Minsk II agreement and widen the ‘Normandy format’ to include the US and bolster reforms in Ukraine.
Resumo:
Fecha tomada del colofón en M4v de la cuarta secuencia