102,265 research outputs found
An elementary proof of the rank-one theorem for BV functions
No full textWe provide a simple proof of a result, due to G. Alberti, concerning a rank-one property for the singular part of the derivative of vector-valued functions of bounded variation
An elementary proof of the rank-one theorem for BV functions
No full textWe provide a simple proof of a result, due to G. Alberti, concerning arank-one property for the singular part of the derivative of vector-valuedfunctions of bounded variation
Temperature study of CVD graphene on Cu thin films: competition between C catalysis and Cu dewetting
No full textThe regularity problem for sub-Riemannian geodesics
No full textWe study the regularity problem for sub-Riemannian geodesics, i.e., for those curves that minimize length among all curves joining two fixed endpoints and whose derivatives are tangent to a given, smooth distribution of planes with constant rank. We review necessary conditions for optimality and we introduce extremals and the Goh condition. The regularity problem is nontrivial due to the presence of the so-called abnormal extremals, i.e., of certain curves that satisfy the necessary conditions and that may develop singularities. We focus, in particular, on the case of Carnot groups and we present a characterization of abnormal extremals, that was recently obtained in collaboration with E. Le Donne, G. P. Leonardi and R. Monti, in terms of horizontal curves contained in certain algebraic varieties. Applications to the problem of geodesics' regularity are provided
Graphene membrane as suspended mask for lithography
No full textThanks to its excellent mechanical properties, graphene is particularly suited for the realization of suspended membranes. The present paper deals with one possible application of such membranes that is the realization of suspended lithographic masks for shadow evaporation onto a substrate. This technique, which is largely used for realizing mesoscopic devices, where the quality requirements for the junctions prevent the exposure to ambient air and the occurrence of quantum phenomena requires highly defined structures, can be improved by the use of pure 2-dimensional masks, like graphene ones. Advantages and differences of this material with respect to commonly employed polymers are presented and discussed
Potatura di produzione con e senza raccorciamento delle branche fruttifere: costi, equilibrio vegetativo e qualità dei frutti.
No full text
Differential UB V photometry of the short-period eclipsing binaries RW Dor, EZ Hya and V701 Cen
No full textPhotoelectric UBV differential observations of three short-period eclipsing binaries (RW Dor, EZ Hya and V701 Cen) are presented ; new times of minimum light and improved linear ephemerides have been computed
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