Stefano Mortola, Sergio Steffè (1985)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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In this note we study the periodic homogenization problem for a particular bidimensional selfadjoint elliptic operator of the second order. Theoretical and numerical considerations allow us to conjecture explicit formulae for the coefficients of the homogenized operator.
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Maurizio Chicco (1983)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni
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We give some counterexamples concerning the regularity of the first (resp. second) derivatives of solutions of linear second order elliptic partial differential equations in divergence form (resp. in non-divergence form).
Maurizio Chicco (1983)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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We give some counterexamples concerning the regularity of the first (resp. second) derivatives of solutions of linear second order elliptic partial differential equations in divergence form (resp. in non-divergence form).
Antonio Leaci (1981)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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In this paper we study boundary value problems for first order partial differential equations on sets of finite perimeter in the sense of De Giorgi (see [7]). We also study a new type of boundary value problems which has been suggested by issues about the bounce problem.
Antonio Leaci (1981)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni
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In this paper we study boundary value problems for first order partial differential equations on sets of finite perimeter in the sense of De Giorgi (see [7]). We also study a new type of boundary value problems which has been suggested by issues about the bounce problem.
Lamberto Cesari (1976)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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Under sole qualitative hypotheses in the large the author has proved the existence of equibounded solutions to nonlinear operational equations in a Hilbert space when a parameter describes an interval containing a point of resonance. Applications have been made to problems of periodic solutions, and to elliptic problems.
Domenico Fusco (1980)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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In this paper we determine a class of first order quasi-linear hyperbolic systems in conservative form involving two independent and two dependent variables which are not deducible, in general, from a variational principle but can be reduced to a Godunov’s symmetric form [5], [6] where the coefficient of the field spatial derivative is a constant matrix. That enables us to extend to these systems several results obtained by G. Boillat in [8], [9] and concerning with shocks in quasi-linear...
Antonino Valenti (1982)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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After writing the equations which characterize the thermomechanics of hyperelastic continua subject to small transformations according to a recent hypothesis on the heat flux vector, we study the spherical thermomechanical waves.
Antonino Valenti (1982)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni
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After writing the equations which characterize the thermomechanics of hyperelastic continua subject to small transformations according to a recent hypothesis on the heat flux vector, we study the spherical thermomechanical waves.
Bruno Franchi, Ermanno Lanconelli, James Serrin (1985)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni
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In this paper we describe some existence and uniqueness theorems for radial ground states of a class of quasilinear elliptic equations. In particular, the mean curvature operator and the degenerate Laplace operator are considered.
Bruno Franchi, Ermanno Lanconelli, James Serrin (1985)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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In this paper we describe some existence and uniqueness theorems for radial ground states of a class of quasilinear elliptic equations. In particular, the mean curvature operator and the degenerate Laplace operator are considered.
Vincenzo De Rienzo, Angelo Messina (1982)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni
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The so-called diffraction problem for the heat equation is considered in a semi-infinite medium consisting of a sequence of different layers. Existence and uniqueness of the solution for the problem with no initial condition is proved and it is shown that periodic solutions are generated by periodic data on the boundary. A general method for calculating periodic solutions is discussed, taking into account possible thermal resistances between the layers.
Vincenzo De Rienzo, Angelo Messina (1982)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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The so-called diffraction problem for the heat equation is considered in a semi-infinite medium consisting of a sequence of different layers. Existence and uniqueness of the solution for the problem with no initial condition is proved and it is shown that periodic solutions are generated by periodic data on the boundary. A general method for calculating periodic solutions is discussed, taking into account possible thermal resistances between the layers.
Michele Carriero, Antonio Leaci, Eduardo Pascali (1982)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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In this paper we present a few results on convergence for the prime integrals equations connected with the bounce problem. This approach allows both to prove uniqueness for the one-dimensional bounce problem for almost all permissible Cauchy data (see also [6]) and to deepen previous results (see [3], [5], [7]).
Michele Carriero, Antonio Leaci, Eduardo Pascali (1982)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni
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In this paper we present a few results on convergence for the prime integrals equations connected with the bounce problem. This approach allows both to prove uniqueness for the one-dimensional bounce problem for almost all permissible Cauchy data (see also [6]) and to deepen previous results (see [3], [5], [7]).
Carlo Viola (2008)
Bollettino dell'Unione Matematica Italiana
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We recall some basic concepts in diophantine approximation, in particular the notion of irrationality measure. We describe the main aspects of the permutation group method due to G. Rhin and the author, with some arithmetical applications.
Giorgio Maria Giacometti, Alvaro Da Ros, Maurizio Brunori (1973)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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The paper reports a study on the kinetics of the transition between acid and alkaline Aplysia myoglobin. The results, obtained with the temperature-jump method, show that the observed relaxation effect corresponds to a perturbation of the equilibrium between the protonated and deprotonated forms of the protein. The pH dependence of the data and their analysis suggest that the process involves a proton-linked conformational change of the protein, in agreement with independent experiments....
Marco Degiovanni (1982)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni
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In the present paper we seek the bounce trajectories in a convex set which assume assigned positions in two fixed time instants. We find sufficient conditions in order to obtain the existence of infinitely many bounce trajectories.
Marco Degiovanni (1982)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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In the present paper we seek the bounce trajectories in a convex set which assume assigned positions in two fixed time instants. We find sufficient conditions in order to obtain the existence of infinitely many bounce trajectories.
Alberto Farina (1999)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni
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Nella prima parte di questa Nota si dimostrano dei risultati di simmetria unidimensionale e radiale per le soluzioni di in . Questi risultati sono legati a due congetture (De Giorgi, 1978 e Gibbons, 1994) riguardanti la classificazione delle soluzioni dell’equazione in . Si dimostra, in particolare, la seguente generalizzazione della congettura di Gibbons: se e se l’insieme degli zeri di è limitato nella direzione , allora , ovvero, è unidimensionale. Nella seconda parte...
Gianmaria Donida, Luisa Tabusso (1980)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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A new technique for analysing problems which extend to infinity using elements is presented. A typical situation is that of the unbounded surface wave problems, either in two or three dimensions. The strategy is to discretize the inner domain in the standard finite element manner and to discretize the outer domain which extends to infinity with special infinite elements, for these elements are here suggested a series of shape functions analogous to Lagrange polynomials, but including...
Gianmaria Donida, Luisa Tabusso (1980)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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A new technique for analysing problems which extend to infinity using elements is presented. A typical situation is that of the unbounded surface wave problems, either in two or three dimensions. The strategy is to discretize the inner domain in the standard finite element manner and to discretize the outer domain which extends to infinity with special infinite elements, for these elements are here suggested a series of shape functions analogous to Lagrange polynomials, but including...
Anna Stagni, M. Luisa Sini-Rubatta, Vincenza Morini (1980)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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Observations prolonged for two months show how aged Aelosoma viride specimens increase their asexual reproductive power. Treatment of this species with some neuropharmacological agents (norepinephrine, amphetamine, reserpine) demonstrate that: 1) noradrenaline excites the growth by increasing the number of segments; 2) amphetamine excites the growth but inhibits asexual reproduction; 3) reserpine is strongly toxic; 4) growth and asexual reproduction appear as two partially separated...
Ercole De Castro (1982)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni
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Transport phenomena of minority carriers in quasi neutral regions of heavily doped semiconductors are considered for the case of one-dimensional stationary flow and their study is reduced to a Fredholm integral equation of the second kind, the kernel and the known term of which are built from known functions of the doping arbitrarily distributed in space. The advantage of the method consists, among other things, in having all the coefficients of the differential equations and of the...
Ercole De Castro (1982)
Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti
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Transport phenomena of minority carriers in quasi neutral regions of heavily doped semiconductors are considered for the case of one-dimensional stationary flow and their study is reduced to a Fredholm integral equation of the second kind, the kernel and the known term of which are built from known functions of the doping arbitrarily distributed in space. The advantage of the method consists, among other things, in having all the coefficients of the differential equations and of the...