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Functionalized graphene offers great potential in the field of rapid detection of gases at room temperature. We performed first-principles calculations to study the suitability of 4-sulfobenzenediazonium salts (4SBD) as bandgap modifier in graphene. The signature of unpaired spins is evidenced near the Fermi level owing to the symmetry breaking of graphene sublattices. 4SBD-chemisorbed on graphene is found to be electronically sensitive to the presence of ammonia NH3 with increasing gas concentration.

We observed room-temperature intersubband transitions at 1.26 microns in n-doped type-II In$_{0.3}$Ga$_{0.7}$As/AlAs strained quantum wells. An improved tight-binding model was used to optimize the structure parameters in order to obtain the shortest wavelength intersubband transition ever achieved in a semiconductor system. The corresponding transitions occur between the first confined electronic levels of the well following mid-infrared optical pumping of electrons from the barrier X-valley into the well ground state., To appear in Applied Physics Letters

Effect of electric field on spin splitting in SiGe quantum wells (QWs) has been studied theoretically. Microscopical calculations of valley and spin splittings are performed in the effective $sp^3d^5s^*$ tight-binding model. The splittings oscillate as a function of the QW width due to inter-valley reflection of the electron wave off the interfaces. In accordance with the symmetry considerations additional electric-field-induced terms appear in the electron spin-dependent Hamiltonian. The oscillations of splitting are suppressed in rather low electric fields. The tight-binding calculations have been analyzed by using the envelope function approach extended to asymmetrical QWs., 8 pages, 3 figures

We present a case of rupture of the right diaphragm, due to an automobile accident, discovered after a period of eight years and presenting a clinical picture of pleuropneumonia. The radiologic appearances of traumatic hernia of the diaphragm are more difficult to appreciate on the right side because of the presence of the liver and delayed symptoms. This may be dangerous or sometimes fatal.

Based on density functional theory, the electronic and optical properties of hybrid organic/perovskite crystals are thoroughly investigated. We consider the monocrystalline 4F-PEPI as material model and demonstrate that the optical process is governed by three active Bloch states at the Gamma point of the reduced Brillouin zone with a reverse ordering compared to tetrahedrally bonded semiconductors. Giant spin-orbit coupling effects and optical activities are subsequently inferred from symmetry analysis.