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Il saggio si propone di illustrare le indiscutibili opportunità offerte dal PNRR in materia di istruzione e ricerca con particolare riferimento al Mezzogiorno. Vengono quindi esaminati riforme e investimenti che riguardano scuola, università e ricerca non solo relativamente alla Missione 4 dedicata a questi ambiti, ma anche a quelle missioni che tagliano trasversalmente le altre come quella relativa alla digitalizzazione e alla transizione ecologica. The essay aims to illustrate the indisputable opportunities offered by the PNRR in the field of education and research with particular reference to the South. Reforms and investments are then examined concerning schools, universities and research not only in relation to Mission 4 dedicated to these areas, but also to those missions that cut across the others such as that relating to digitization and ecological transition.

The dynamics of a one-dimensional atom driven by three-laser fields is investigated. The total electric field is made up of a fundamental laser field of intensity W cm−2 and wavelength λ = 820 nm and two weak lasers with larger wavelengths. The intensity of the two weak fields is with k = 0.25. The frequencies of the weak fields are and , with and . The three lasers have a Gaussian envelope of 72 fs FWHM. It is shown, by numerical computation and using the semiclassical theory of high-harmonic generation, that the atom interacting with this combined field is able to emit an isolated attosecond burst of radiation.

The electron of a H 2 + driven by a strong electromagnetic field induces molecular vibrations. Numerical and analytical results show that the molecule behaves as a parametric oscillator and can be treated as a kicked oscillator. The results are discussed from the point of view of the electron's periodic dressing and undressing processes.

We introduce a novel framework of electronic healthcare enabled by a Cloud platform able to host both Hospital Information Systems (HIS) and Electronic Medical Record (EMR) systems and implement an innovative model of Electronic Health Record (EHR) that is not only patient-oriented but also supports a better governance of the whole healthcare system. The proposed EHR model adopts the state of the art of the Cloud technologies, being able to join the different clinical data of the patient stored within the HISs and EMRs either placed into a local Data Center or hosted into a Cloud Platform enabling new directions of data analysis.

The radiation diffused by a one-dimensional homonuclear molecular ion driven by a laser field is studied as a function of the time. When the photon energy is resonant with the energy gap between the ground and the first excited state, the electronic probability density is seen to undergo slow and deep oscillations between the two nuclei. Synchronous to such oscillations, deep modulations of the emitted power are observed. The period of oscillation is of the order of 10 optical cycles. Detection of the variation in the intensity of the emitted electromagnetic spectrum therefore brings information on the position of the electron in the molecule.

We study the polarization of the harmonics generated by a homonuclear diatomic molecule in the presence of an intense, linearly polarized laser field. The polarization parameters of the emitted radiation are investigated as function of the angle $\theta$ between the laser electric field and the molecular axis. The calculations are carried out by assuming a single active electron model with fixed nuclei; a two-dimensional model of the system is used. We find a different dependence of the parameters of the harmonics vs $\theta$ in the first or second half of the emitted spectrum. In particular, the differences are accentuated for $0^\circ < \theta < 50^\circ$, while for higher angles, until the perpendicular orientation, almost all the harmonics present similar characteristics

In this paper we discuss isotopic effects in simple molecular ions subjected to strong laser fields. We show that the intensity of the emitted spectra strongly depends upon both the nuclear mass of the molecular ions and the laser pulse duration. In particular, for short pulse duration [up to 8 optical cycles (o.c.)], we confirm the trend described in the most studied case in which the high-order harmonic generation is more efficient for heavier isotopes; in contrast, an interesting physical phenomenon is predicted for pulses longer than 16 o.c. characterized by an inverse effect in which lighter molecular species are responsible for higher-order harmonic emission.

The soil CO2 degassing is a ected by processes of isotope exchange and fractionation during transport across the soil, which can deeply modify the pristine isotope composition. This has been observed in 10 the Solfatara volcano, upon a eld survey of 110 points, where the CO2 ux was measured, together with temperature, CO2 concentra- tion and oxygen and carbon isotopes within the soil. Furthermore, in some selected sites, the measurements were made at di erent depths, in order to analyze vertical gradients. Oxygen isotope composition 15 appears controlled by exchange with soil water (either meteoric or fumarolic condensate), due to the fast kinetic of the isotopic equilib- rium between CO2 and water. Carbon isotope composition is reliably controlled by transport-driven fractionation, due to the di erences in di usion coe cients between 13C16O2 and 12C16O2. We model the 20 processes a ecting CO2 transport across the soil in La Solfatara vol- cano by means of the Dusty Gas Model applied to a multicomponent system, to evaluate the reciprocal e ect on di usion of involved gases, i.e. 12C16O2, 13C16O2, N2 and O2 in our case. Both numerical and simpli ed analytical solutions of the equations based on the Dusty 25 Gas Model are given. The modeling results t well with the experimental data and put in evidence an isotope fractionation of carbon up to about +4:4h with respect to the source value in the soil gas. This fractionation is independent from the entity of the CO2 ux, and occurs as long as a concentration gradient exists within the soil. On 30 these grounds, the Dusty Gas Model can be applied to whichever dif- fusing gas mixture to evaluate the extent of chemical and/or isotopic fractionation that can a ect ascending gases upon di usion in any geothermal, volcanic or tectonic area.

We show that it is possible to use a piecewise constant Hamiltonian to describe the main features of the dynamics of an atom interacting with a laser field. In particular we show that using this approximation we are able to give a good description of the ionization signal, of the HHG spectra and of the attosecond pulses generated by the radiating electron. Finally, we give an explicit formula to evaluate the ionization rate in the time dependent laser field. This formula, which is a generalization of the Landau formula for the ionization rate of an atom in a static electric field, fairly well reproduces the numerical ionization rates for a broad range of laser frequency and intensity. The main advantage of this formula is that it can be used well beyond the limits of the quasi-static formula for the ionization rate of an atom.

A new scheme to generate isolated attosecond pulses is presented that involves the use of a laser field and of a unipolar field. The laser field has a pulse of intensity I = 1.5×1014 W cm−2 and wavelength λ = 820 nm. The unipolar pulse is an asymmetric pulse consisting of a sharp peak, lasting approximately half a laser period, i.e. nearly 1.4 fs, followed by a long and shallow tail. We show that on combining these two fields, it is possible to generate isolated attosecond pulses as short as 1/10 of a laser period, i.e. approximately 270 as. Moreover, it is argued that this scheme is robust either against small variations of the laser envelope, or against small changes in the delay between the laser pump and the unipolar pulse.

In this paper we investigate the single and double ionization signals of ${\text{H}}_{2}$ molecules, with fixed and moving nuclei, as a function of laser intensity, for two different values of laser wavelength ($\ensuremath{\lambda}=390\text{ }\text{nm}$ and $\ensuremath{\lambda}=780\text{ }\text{nm}$), using an approach for evaluating the ionization signals which allows the investigation of relatively long-lasting pulses. The He system is first investigated to benchmark our calculation against already known results. We confirm the evidence of nonsequentiality in the ionization processes of all the systems investigated. Furthermore, we show that the nuclei motion enhances the double ionization signals by means of a mechanism which is very similar to a charge-resonant enhanced ionization (CREI) effect [Zuo and Bandrauk, Phys. Rev. A 52, R2511 (1995)].

We study the dynamics of an electron constrained over the surface of a rigid sphere, with geometrical parameters similar to those of the C60 fullerene, embedded in a low intensity linearly polarized laser field. The model is shown to emit odd harmonics of the laser even at very low field intensity. For more intense laser fields, the spectrum presents odd harmonics and hyper-Raman lines shaped in a broad plateau. The spectrum of the model is compared to that theoretically obtained by other authors for more realistic models of C60. It is concluded that the model can be used as a paradigm for mesoscopic molecules in the fullerene family, particularly in practical applications where it is convenient to have a simple model of fullerene molecules. It is also concluded that the model is an example lending support to the concept of universality introduced by other authors some time ago.

In this paper we show how it is possible to investigate the nuclear dynamics of simple molecular ions and molecules by looking at the high-order harmonic generation spectra they emit in the presence of a laser field. In particular we investigate two different effects: the presence of sidebands in the emitted spectra around the usual odd harmonics and an isotopic effect which affects the height of the plateau lines. We further study the advantages and the limitations of the semiclassical approach.

We propose a new scheme to produce isolated attosecond pulses, involving the use of three laser pulses: a fundamental laser field of intensity I = 3.5 × 1014 W cm−2 and of wavelength λ = 820 nm, and two properly chosen weak lasers with wavelengths 1.5λ and 0.5λ. The three lasers have a Gaussian envelope of 36 fs full width at half maximum. The resulting total field is an asymmetric electric field with an isolated peak. We show that a model atom, interacting with the above-defined total field, generates an isolated attosecond pulse as short as 1/10 of a laser period, i.e. approximately 270 as.

We study the single and double ionization yields and the dissociation dynamics of a one-dimensional two-electron molecule exposed to a laser pulse of intensity IL in the range 1013 − 1015 W/cm2 and photon energy hω¯L =3.18 eV. The calculations are carried out in the case of both fixed and movable nuclei. At low IL the ionization curves have a power law shape In that is interrupted by a knee at higher intensity.

The dynamics of hydrogen-like molecules is investigated beyond the usual fixed nuclei approximation. The nuclear motion introduces in the familiar spectrum of emitted radiation additional regular lines whose separation is essentially given by the vibrational frequency of nuclear motion. A wavelet analysis of the emitted spectrum shows that the intensity of the harmonic lines is modulated with the same period of the nuclear motion; this suggests the possibility of the real-time control of the nuclear dynamics.

We study the single and double ionization yields and the dissociation dynamics of a onedimensional two-electron molecule exposed to an intense laser pulse. The double ionization yields are systematically investigated for both fixed and moveable nuclei. At low intensities the ionization curves have a power law shape, followed by a knee profile for higher intensities. A temporal correlation between the nuclear motion and the electron ionization shows that the nuclear motion deeply affects the ionization yield.

In this paper we show how it is possible to investigate the nuclei dynamics of a D2+ molecular ion by using the high harmonic generation spectra emitted by the system when subjected to an intense laser field. In particular, the emitted spectra contains, in addition to the usual odd harmonic peaks, additional satellite peaks whose frequency spacing is equal to the vibrational frequency of the nuclei.

The electromagnetic spectrum emitted by a molecule driven by a laser presents harmonics and satellite lines whose separation is equal to the oscillation frequency of the nuclei. Full quantum and semiclassical calculations are presented.

The dynamics of a diatomic one-dimensional homonuclear molecule driven by a two-laser field is investigated beyond the usual fixed nuclei approximation. The dynamics of the nuclei is treated by means of Newton equations of motion; the full quantum description is used for the single active electron. The first laser pulse (pump) excites vibrations of the nuclei, while the second very short pulse (probe) has the role of confining the electron around one of the nuclei. We show how to use the radiation scattered in these conditions by the molecule to achieve real-time control of the molecular dynamics.

We study the ionization dynamics of a model one-dimensional molecular ion as a function of the internuclear distance R, for different values of the laser intensity. The electron–nucleus potential is assumed to be a Poschl–Teller potential, whose parameters are chosen to have only two bare bound molecular states in the range of R considered. We describe three different theoretical approaches to study the dynamics of the system: an exact numerical, a semiperturbative and a phenomenological approach. All these approaches indicate the presence of a sharp ionization peak for a critical value of the internuclear distance, for which the energy difference between the two bound levels coincides with the laser photon energy. The results obtained are explained and a new model of molecular ionization in intense laser field is presented.

We study a simple model atom that has two bound states and a continuum of free states, interacting with a strong electromagnetic field. In our analysis we assume that only the continuum-continuum transitions occur- ring between degenerate free states are important for the dynamics of the atomic system; adopting this sim- plifying hypothesis, we show that it is possible to describe the time evolution of the atom by means of an infinite but discrete set of first-order differential equations describing a formal model atom that has two bound states and a degenerate quasicontinuum of states. Moreover, these equations depend on a small number of parameters of the bare atom and of the external laser pulse. The role of these parameters in the laser-atom dynamics is investigated.

The dynamics of a H2+ molecular ion driven by two laser pulses separated by a time lag is studied beyond the Born-Oppenheimer approximation. The first, short, pulse prepares the molecule in some quantum state, which is probed by the second pulse. Under suitable conditions, the molecule emits a spectrum of redshifted high-order harmonics. The value of the redshift is proportional to the harmonic order and can be used as a measure of the speed of the atoms of the molecule.

We describe, using a semiclassical approach, the molecular dynamics of a one-dimensional H2 molecule interacting with a laser, beyond the Born–Oppenheimer approximation. We observe and discuss different molecular behaviors, such as ionization and dissociation.