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We theoretically analyze the rise of photovoltage oscillations in hexagonal boron-nitride (h-BN) encapsulated monolayer graphene (h-BN/graphene/h-BN) when irradiated with terahertz radiation. We use an extension of the radiation-driven electron orbit model, successfully applied to study the oscillations obtained in irradiated magnetotransport of GaAs/AlGaAs heterostructures. The extension takes mainly into account that now the carriers are massive Dirac fermions. Our simulations reveal that the photovoltage in these graphene systems presents important oscillations similar to the ones of irradiated magnetoresistance in semiconductor platforms but in the terahertz range. We also obtain that these oscillations are clearly affected by the voltages applied to the sandwiched graphene: a vertical gate voltage between the two hBN layers and an external positive voltage applied to one of the sample sides. The former steers the carrier effective mass and the latter the photovoltage intensity and the oscillations amplitude. The frequency dependence of the photo-oscillations is also investigated. This work is supported by the MINECO (Spain) under grant PID2020-117787GB-I00 and by the Madrid Government (Comunidad de Madrid- Spain) under the Multiannual Agreement with UC3M in the line of Excellence of University Professors (EPUC3M14), and in the context of the V PRICIT (Regional Programme of Research and Technological Innovation). We also acknowledge the CSIC Research Platform on Quantum Technologies PTI-001.

This article proposes a series of techniques for the study of positioning a website on the internet. These techniques must provide enough information to allow the analyst to make judgements that allow the appropriate selection of effective and productive strategies for improvement.

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid. Facultad de Medicina, Departamento de Cirugía. Fecha de lectura: 8 de Junio de 2012.

En este estudio se analizaron las implicaciones de la soledad y la agresividad directa y relacional, en distintos indicadores de ajuste escolar (expectativas académicas, rendimiento académico e integración escolar). El estudio se realizó con 784 adolescentes de educación secundaria, a los que se les administró tres cuestionarios. Los resultados del estudio mostraron que la experimentación de la soledad se relaciona con la percepción de una peor integración escolar entre las chicas, pero no entre los chicos. Por otra parte, con independencia de su sexo, los estudiantes con una alta implicación en conductas agresivas directas informaban de peores expectativas académicas, peor rendimiento académico y peor integración escolar. Por último, la implicación en conductas de agresión relacionales se relacionó con peores expectativas académicas e integración escolar sólo en el caso de los chicos. This study analyzed the implications of loneliness and direct and relational aggression over three school adjustment variables (academic expectations, academic performance and school integration). Three questionnaires were administered in a sample of 784 secondary schools students. The results showed that loneliness is associated with a poorer perception of school integration among girls but not among boys. Moreover, regardless of participants’ sex, students with high involvement in direct aggressive behaviors reported worse academic expectations, poorer academic performance and poorer school integration. Finally, involvement in relational aggressive behaviors was associated with poorer academic expectations and school integration only among boys.

2 páginas.

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de la Materia Condensada. Fecha de lectura: 14-11-2011