Numerical simulation of a double-gate MOSFET with a subband model for semiconductors based on the maximum entropy principle

A nanoscale double-gate MOSFET is simulated with an energy-transport subband model for semiconductors formulated starting from the moment system derived from the Schr?dinger–Poisson–Boltzmann equations. The system is closed on the basis of the maximum entropy principle and includes scattering of electrons with acoustic and non-polar optical phonons. The proposed expression of the entropy combines quantum effects and semiclassical transport by weighting the contribution of each subband with the square modulus of the envelope functions arising from the Schr?dinger–Poisson subsystem. The simulations show that the model is able to capture the relevant confining and transport features and assess the robustness of the numerical scheme.     

High-resolution infrared and ab initio investigation of CHD2 79Br: Ro-vibrational analysis of the ν6 fundamental and the 2ν6−ν6 hot band

The high-resolution infrared spectrum of CHD₂ ⁷⁹Br has been investigated by Fourier transform spectroscopy in the range 540–615?cm^?1 at an unapodised resolution of 0.0035?cm^?1. This spectral region is characterised by the ν₆ fundamental (584.8510?cm^?1), corresponding to C–Br stretching mode, and its hot band 2ν₆?ν₆ (578.4333?cm^?1). The spectral analysis resulted in the identification of 3430 transitions (J’?≤?73 and K'_a ?≤?18) for the ν₆ fundamental and 1212 transitions (J’?≤?49 and K'_a ?≤?11) for the hot band 2ν₆?ν₆. The assigned data have been fitted using the Watson’s S-reduced Hamiltonian in the I^r representation and new constants for the ground state from about 24,600 combination differences and sets of parameters for the v ₆?=?1 and 2 vibrational states have been obtained. From spectral simulations the intensity ratio between 2ν₆?ν₆ and ν₆ has been estimated to be 0.15?±?0.02. High-quality ab initio calculations have also been performed at the CCSD(T) level of theory in order to support the experimental investigation through the calculation of molecular parameters relevant to ro-vibrational spectroscopy.     

Square-integrability modulo a subgroup

We prove a weak form of the Frobenius reciprocity theorem for locally compact groups. As a consequence, we propose a definition of square-integrable representation modulo a subgroup that clarifies the relations between coherent states, wavelet transforms and covariant localisation observables. A self-contained proof of the imprimitivity theorem for covariant positive operator-valued measures is given.

     

The nucleolus is well-posed

The lexicographic order is not representable by a real-valued function, contrary to many other orders or preorders. So, standard tools and results for well-posed minimum problems cannot be used. We prove that under suitable hypotheses it is however possible to guarantee the well-posedness of a lexicographic minimum over a compact or convex set. This result allows us to prove that some game theoretical solution concepts, based on lexicographic order are well-posed: in particular, this is true for the nucleolus.     

Linear spaces on v points with v−2 mutually intersecting long lines

Finite linear spaces on v points with v–2 mutually intersecting long lines are completely characterized.Dedicated to Professor Giuseppe Tallini on the occasion of his 60^th birthday.Work supported by Italian M.P.I. 8nd by GNSAGA of CNR     

New synthesis of optically active 5-isoxazolidinones and beta-amino acids

A new simple and stereoselective synthesis of 5-isoxazolidinones based on the reaction of lithiated 2-isopropyl-2-oxazolines with nitrones is described. A chiral version of such a methodology allows the preparation of highly enantioenriched 5-isoxazolidinones which are useful precursors for the synthesis of beta-amino acids