Traditional space-coiled acoustic metamaterials have been widely used in the fields of low-frequency sound absorption and noise ***,they have limitations in terms of low-frequency absorption bandwidth,and the weak cou...
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Traditional space-coiled acoustic metamaterials have been widely used in the fields of low-frequency sound absorption and noise ***,they have limitations in terms of low-frequency absorption bandwidth,and the weak coupling effect under complex coiled structures also limits their *** this work,we introduce the composite structure changing the characteristic impedance of acoustic metamaterials to enhance the coupling ***,the perforated plates with inclined design instead of traditional partitions greatly improve the sound *** model and method designed in this paper show significant innovation in enhancing low-frequency absorption performance.
In this study, activated carbon was created by physically activating potato peel waste (PPW) with carbon dioxide. The potential of this approach, which uses carbon dioxide to produce actuation carbon (AC) from precurs...
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The interaction of short laser pulses with hydrogen atoms will be discussed in this paper. We chose laser pulses with photon energies lower than the ionization threshold energy of hydrogen atoms. Here, the close coupl...
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Charge transport in organic molecular crystals (OMCs) is conventionally categorized into two limiting regimes − band transport,characterized by weak electron-phonon (e-ph) interactions,and charge hopping due to locali...
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Charge transport in organic molecular crystals (OMCs) is conventionally categorized into two limiting regimes − band transport,characterized by weak electron-phonon (e-ph) interactions,and charge hopping due to localized polarons formed by strong e-ph ***,between these two limiting cases there is a less well understood intermediate regime where polarons are present but transport does not occur via *** we show a many-body first-principles approach that can accurately predict the carrier mobility in this intermediate regime and shed light on its microscopic *** approach combines a finite-temperature cumulant method to describe strong e-ph interactions with Green-Kubo transport *** apply this parameter-free framework to naphthalene crystal,demonstrating electron mobility predictions within a factor of 1.5−2 of experiment between 100 and 300 *** analysis reveals the formation of a broad polaron satellite peak in the electron spectral function and the failure of the Boltzmann equation in the intermediate regime.
The isospin dependence of spin-orbit(SO)splitting becomes increasingly important as N/Z increases in neutron-rich *** the initial independent-particle strategy toward explaining the occurrence of magic numbers,we syst...
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The isospin dependence of spin-orbit(SO)splitting becomes increasingly important as N/Z increases in neutron-rich *** the initial independent-particle strategy toward explaining the occurrence of magic numbers,we systematically investigated the isospin effect on the shell evolution in neutron-rich nuclei within the Woods-Saxon mean-field potential and the SO *** is found that new magic numbers N=14 and N=16 may emerge in neutron-rich nuclei if one changes the sign of the isospin-dependent term in the SO coupling,whereas the traditional magic number,N=20,may *** magic number N=28 is expected to be destroyed despite the sign choice of the isospin part in the SO splitting,corresponding to the strength of the SO coupling ***,the N=50 and 82 shells may persist within the single particle scheme,although there is a decreasing trend of their gaps toward extreme proton-deficient ***,an appreciable energy gap appears at N=32 and 34 in neutron-rich Ca *** these results are more consistent with those of the interacting shell model when enhancing the strength of the SO potential in the independent particle *** present study may provide a more reasonable starting point than the existing one for not only the interacting shell model but also other nuclear many-body calculations toward the neutron-dripline of the Segrèchart.
Hydrogen-based compounds have attracted significant attention in recent years due to the discovery of conventional superconductivity with high critical temperature under high pressure,rekindling hopes for finding room...
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Hydrogen-based compounds have attracted significant attention in recent years due to the discovery of conventional superconductivity with high critical temperature under high pressure,rekindling hopes for finding roomtemperature *** this study,we investigated the vibrational and superconducting properties of H_(3)Sein the Im￣3m phase under pressures of *** approach combines the stochastic self-consistent harmonic approximation and first-principles calculations to account for the quantum and anharmonic effects of *** to the results,these effects significantly modify the crystal structure,increasing the inner pressure by approximately 8GPa compared to situations in which they are *** phonon spectra suggest that when these effects are considered,the crystal stabilizes at pressures as low as approximately 61GPa,which is significantly lower than the previously predicted value of over *** calculations also highlight the critical role of quantum and anharmonic effects on the electron-phonon coupling *** these factors can result in a significant overestimation of the superconducting critical temperature(T_(c))by approximately 4K(200GPa)to 25K(125GPa).With anharmonic phonons,the T_(c) calculated from the Migdal-Eliashberg equations reaches 200K(μ⋆=0.1,λ=4.1)as the pressure decreases to 64GPa,indicating that the crystal is a rare high-Tc superconductor at moderate pressures.
Nickel-doped strontium hexaferrites, SrNixFe12-xO19 (x = 0.00, 0.03, 0.06, 0.09, 0.12), were synthesized using the co-precipitation method. X-ray diffraction (XRD) analysis confirmed the formation of an M-type hexagon...
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作者：
Tarbă, NicolaeIrimescu, Ionela N.Pleavă, Ana M.Scarlat, Eugen N.Mihăilescu, MonaDoctoral School
Computer Science and Engineering Department Faculty of Automatic Control and Computers National University of Science and Technology POLITEHNICA Bucharest Romania Applied Sciences Doctoral School
National University of Science and Technology POLITEHNICA Bucharest Romania CAMPUS Research Center
National University of Science and Technology POLITEHNICA Bucharest Romania Physics Dept
National University of Science and Technology POLITEHNICA Bucharest Romania Physics Dept
Research Center for Applied Sciences in Engineering National University of Science and Technology POLITEHNICA Bucharest Romania
We introduce a method to evaluate the similarities between classes of objects based on the confusion matrices coming from the multi-class machine learning (ML) predictors that operate in the vector space generated by ...
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As a common oxide-semiconductor interface, SiO2/Si plays an important role in silicon-based electronics and optoelectronics. In order to effectively obtain an ultra-smooth and thin SiO2/Si interface, a hybrid tuning p...
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A series of glass samples of the composition 60 % B2O3 -35 % Pb3O4 - (5-x) % ZnO - x % Y2O3 with x = 0, 0.5, 1, 1.5, 2, 2.5, and 3 was prepared by the melt quenching technique. The amorphous nature of the prepared sam...
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A series of glass samples of the composition 60 % B2O3 -35 % Pb3O4 - (5-x) % ZnO - x % Y2O3 with x = 0, 0.5, 1, 1.5, 2, 2.5, and 3 was prepared by the melt quenching technique. The amorphous nature of the prepared samples was confirmed by X-ray diffraction technique. The structural changes in the glass network were inspected by the density and molar volume mea-surements, as well as by the FT-IR analysis. The density of the prepared samples was realized to decrease while the molar volume increased with the more addition of Y2O3. Some theoretical parameters were evaluated for a better understanding of the glass structure such as, glass and oxygen packing densities, average crosslink density, number of bonds per unit volume, bond stretching force and average single bond strength. FT-IR analysis was employed to investigate the existence of different structural borate units and estimating the N4 ratio. The UV-Vis absorbance spectra was measured and employed to estimate the optical band gap energy. The band gap energy was found to firstly decreased with increasing of the Y2O3 content and then revert back to increase in the highest yttrium doped sample. The Urbach energy, refractive index, molar refraction, molar polarizability and optical basicity were also calculated and discussed.
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