物理最新文献

This work integrates PC1D simulation, Box–Behnken design (BBD), and machine learning models (artificial neural network—ANN and particle swarm optimization-artificial neural network—PSO-ANN) to optimize monocrystalline silicon solar cells. Using the global desirability function, the optimal efficiency of 23.29% is obtained under certain conditions: p-type doping concentration (3.32 × 10¹⁷ cm⁻³), n-type doping concentration (6 × 10¹⁷ cm⁻³), textured wafer pyramid height (1 µm), textured wafer pyramid angle (80.67°), and temperature (20 °C). Notably, the PSO-ANN model outperforms the ANN model with an RMSE of 0.0149 and a correlation coefficient of 0.9997. This study demonstrates the effectiveness of advanced modeling and machine learning in increasing solar cell efficiency and highlights the superior performance of the PSO-ANN model.

Making use of Hadamard-gate transformations and controlled-NOT transformations, we construct a seven-particle maximally entangled state, and obtain a ((2N+1))-particle ((N>3)) maximally entangled state through this construction method. Then, using this seven-particle entangled state to serve as quantum channel, we suggest a three-party cyclic protocol for cloning three different unknown single-particle states with help of the state preparer and the permission of the controller. The first phase of this protocol needs a controlled cyclic quantu teleportation (CCQT), where Alice transmits an arbitrary unknown single-particle state to Bob, Bob teleports an arbitrary unknown single-particle state to Charlie, meanwhile, Charlie also convey an arbitrary unknown single-particle state to Alice under the consent of the controller. In the second phase, after receiving the three-particle measurement result from the preparer, three different unknown single-qubit states or their orthogonal complement states are cloned simultaneously and probabilistically at the positions of Alice, Bob, and Charlie respectively. Subsequently, we will extend the above three-party cyclic protocol to the case of (2N + 1)-party loops by exploiting the (2N + 1)-particle maximally entangled state act as quantum channel. Additionally, taking the controlled three-party cyclic protocol through non-maximally entangled channel as an example, we analyze the assisted cloning protocol for arbitrary unknown single-particle states from three perspectives: projective measurement, positive operator-value measurement (POVM), and generalized Bell-state measurement. We also point out that by increasing the number of state preparers or controllers, the above schemes can be promoted to meet the needs of future versatile quantum networks.

Multibutterfly memristive chaotic systems (MMCSs) exhibit intricate multistable behavior and heightened randomness, making them highly advantageous for secure communications and image encryption. The paper provides a new five-dimensional chaotic system that incorporates two memristors into a 3D chaotic framework, leading to the creation of multibutterfly chaotic attractors. The quantity of multibutterfly chaotic attractors is capable of being managed by varying the parameters (mathrm M) and (mathrm N). We conduct an in-depth analysis of the five-dimensional MMCS dynamics through methods like Lyapunov exponents, Poincare maps, phase diagrams, and bifurcation diagrams. We depicted the basin of attraction for exploring the system’s coexisting attractors. Furthermore, the five-dimensional MMCS exhibits the coexisting attractors through variations in the initial values. By tuning parameters (k_{1}) and (k_{2}), the system’s amplitude can be adjusted. To validate the practical applicability of this system, we design a chaotic circuit based on the five-dimensional MMCS. The system is implemented on a Cyclone IV E series platform with the EP4CE15F23C8N FPGA as the primary chip. The FPGA implementation results align numerical simulations, confirming the practical applicability of the multibutterfly memristive chaotic circuit.

The investigation of the thermo-optic characteristics of a material is vital in understanding the nonradiative relaxation processes occurring within the sample. Pyrromethene 567 a member of the laser dye family, has gained significant attention due to its excellent photo-physical characteristics, such as excellent laser efficiency, photostability, and quantum yield. The investigation of the photothermal studies in Pyrromethene 567 remains unexplored. Herein, a dual-beam thermal lens technique was performed to analyze the thermal lensing behaviour of Pyrromethene 567 in various solvents. The thermal diffusivity of Pyrromethene 567 in different solvents was calculated. There were no previous reports measuring the thermal diffusivity of Pyrromethene 567 dye. Thermal lens spectroscopy offers several advantages over conventional techniques because of its high sensitivity. The work also discusses the factors that influence the thermal lens signal in Pyrromethene 567. The influence of detector positioning, chopper frequency, and sample positioning, on thermal lens measurements was discussed. Additionally, the thermal lens experiments should be performed at intensities where diffraction patterns due to spatial self-phase modulation are absent to minimise experimental errors.

In this work, iron-oxide nanoparticle formation in the spray-flame synthesis (SFS) process of the standardized SpraySyn 2.0 burner was investigated in situ using laser-induced incandescence (LII). For the evaluation of these measurements, prior LII-experiments within iron-oxide aerosols (Fe₃O₄ and α-Fe₂O₃) with known primary particle size distribution and morphological properties were performed to determine the thermal accommodation coefficient (TAC) α, which led to approx. α = 0.08. The applicability of the TAC results within the flame was validated using spectrally and temporally resolved measurements in the flame at 65 mm HAB employing a spectrograph. Data for a bimodal particle size distribution, obtained from Transmission Electron Microscopy (TEM), were used in the LII-evaluation. The validated TAC was then used to evaluate the primary particle size evolution from in situ Time-Resolved (TiRe) LII-measurements using PMTs along the centre axis of the burner, ranging from 10 mm to 50 mm HAB. These measurements reveal a relatively constant effective particle diameter along HAB with d_p,eff ≈ 300 nm. To further investigate particle formation in SFS, 2-dimensional time-resolved LII-measurements in the SFS flame were performed, showing a clear particle formation region up to approx. 30 mm HAB, from where on a constant particle mass is observed.

A strong effort will be dedicated in the coming years to extend the reach of ab initio nuclear-structure calculations to heavy doubly open-shell nuclei. In order to do so, the most efficient strategies to incorporate dominant many-body correlations at play in such nuclei must be identified. With this motivation in mind, the present work analyses the step-by-step inclusion of many-body correlations and their impact on binding energies of Calcium and Chromium isotopes. Employing an empirically-optimal Hamiltonian built from chiral effective field theory, binding energies along both isotopic chains are studied via a hierarchy of approximations based on polynomially-scaling expansion many-body methods. More specifically, calculations are performed based on (i) the spherical Hartree–Fock–Bogoliubov mean-field approximation plus correlations from second-order Bogoliubov many-body perturbation theory or Bogoliubov coupled cluster with singles and doubles on top of it, along with (ii) the axially-deformed Hartree–Fock–Bogoliubov mean-field approximation plus correlations from second-order Bogoliubov many-body perturbation theory built on it. The corresponding results are compared to experimental data and to those obtained via valence-space in-medium similarity renormalization group calculations at the normal-ordered two-body level that act as a reference in the present study. The spherical mean-field approximation is shown to display specific shortcomings in Ca isotopes that can be understood analytically and that are efficiently corrected via the consistent addition of low-order dynamical correlations on top of it. While the same setting cannot appropriately reproduce binding energies in doubly open-shell Cr isotopes, allowing the unperturbed mean-field state to break rotational symmetry permits to efficiently capture the static correlations responsible for the phenomenological differences observed between the two isotopic chains. Eventually, the present work demonstrates that polynomially-scaling expansion methods based on unperturbed states that possibly break (and restore) symmetries constitute an optimal route to extend ab initio calculations to heavy closed- and open-shell nuclei.

Although the use of verditer, a synthetically produced copper carbonate pigment chemically analogous to azurite (Cu₃(CO₃)₂(OH)₂), in early modern wall paintings is regularly reported in grey literature, its detection in wall paintings is typically unavailable in a public forum. This article focusses on two particular samples (M9 and T1) initially suspected to contain copper blue pigments from decorative wall painting schemes in domestic houses across a range of status groups, in eastern and south-eastern England, dated to 1550-1650. Interest in verditer synthesis procedures is found in textual sources including both historic manuals and current scientific literature. The unreliability of the synthesis, particularly for blue verditer, however, is widely documented. Here, we report a multimodal study employing SEM-EDX, SR-(mu)PXRD mapping, and SR-(mu)XANES spectroscopy to characterise the phases present in two wall painting samples, one c. 1600/early 1600s (M9) and the other c. 1600 (T1). In addition to assessment of the presence of verditer, this study presents the first identification of rouaite, a synthetic copper hydroxynitrate mineral (Cu₂(NO₃)(OH)₃), in wall painting samples. Rouaite, shown in a previous publication to be a common byproduct of replications of the historical verditer synthetic recipes, appears in combination with verditer and alone. Its infrequent identification in paintings and murals is considered in light of analytical challenges. The presence of copper hydroxychlorides is also discussed in the context of rouaite stability and degradation. These results represent a significant development in our knowledge of the early modern palette in England and historical verditer synthesis and advances our understanding of how these painting schemes may be best preserved in the future.

This study explores the high harmonic generations in GaAs/Al_xGa_1-xAs asymmetric coupled cylindrical quantum well wires (CCQWWs) under varying intense laser fields (ILFs). The structural parameters and theoretical framework are detailed, including the Schrödinger equation for the CCQWW heterojunction and the Floquet method to model ILF effects. Numerical simulations reveal alterations in the confinement potential and energy states of CCQWWs with increasing ILF intensity. Notably, significant changes occur in the potential well shape, influencing the localization of energy states. Transition energies and dipole moment matrix elements are analyzed, highlighting shifts in resonance peaks and their intensities. The study identifies blue-shift points at α₀ (ILF parameter) values of 4.4 nm, 4.7 nm, and 3.7 nm for transition energies E₂₁, E₃₁/2, and E₄₁/3, respectively, followed by red-shift trends as α₀ increases further. Maximum enhancements are observed in the second harmonic generation coefficient at ILF α₀ = 6 nm and the third harmonic generation coefficient at α₀ = 8 nm, which is 1000 times higher than at α₀ = 0 nm. These findings underscore the potential for enhancing semiconductor device production through optimized ILF induced high harmonic generation.

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The chemical in situ study of red coloring matter from Paleolithic cave art is challenging because the same trace elements can be present both in the matter and in the calcitic support, and the two present a heterogeneous composition. In this study, thirteen red iron oxide-based coloring matter samples obtained at drip points coming from eight locations within the Techo de los Polícromos, Altamira cave (Spain), have been analyzed by highly sensitive synchrotron-induced micro-X-ray fluorescence (SR-µXRF). Our analyses improved the characterization of red Paleolithic pigments by establishing characteristic trace element patterns, additionally facilitating a comparison of the distinct representations within the cave. Furthermore, new differentiation criteria between the composition of the calcitic walls and that of the red coloring matter could be established, helping to improve future non-invasive analyses.

In this paper, we have presented a power law cosmological model and its dynamical system analysis in (f(T,phi )) gravity, where T is the torsion scalar and (phi ) is the canonical scalar field. The two well-motivated forms of the non-minimal coupling function (F(phi )), the exponential form and the power law form, with exponential scalar field potential, are investigated. The dynamical system analysis is performed by establishing the dimensionless dynamical variables, and the critical points were obtained. The evolution of standard density parameters is analysed for each case. The behaviour of the equation of state (EoS) and deceleration parameter agree with the result of recent cosmological observations. The model parameters are constrained using the existence and the stability conditions of the critical points describing different epochs of the evolution of the Universe.