物理最新文献

The recent direct detection of neutrinos at the LHC has opened a new window on high-energy particle physics and highlighted the potential of forward physics for groundbreaking discoveries. In the last year, the physics case for forward physics has continued to grow, and there has been extensive work on defining the Forward Physics Facility and its experiments to realize this physics potential in a timely and cost-effective manner. Following a 2-page Executive Summary, we first present the status of the FPF, beginning with the FPF’s unique potential to shed light on dark matter, new particles, neutrino physics, QCD, and astroparticle physics. We then summarize the current designs for the Facility and its experiments, FASER2, FASER(nu )2, FORMOSA, and FLArE.

In this article, we aim to find out the influence of the electric charge on the occurrence (or not) of cracking or overturning, under different conditions. For this purpose, we develop a comprehensive framework to describe cracking in charged fluid distributions, incorporating dissipative processes and electromagnetic interactions in comoving coordinates by following a step-by-step procedure mentioned in Herrera and Di Prisco (Phys Rev D 109:064071, 2024). The study shows how energy loss (dissipation) affects cracking in charged fluids. Cracking is the ability of charged matter to break apart when it deviates from equilibrium. To examine the cracking in the system, we consider anisotropic models. Next, we investigate the role of dissipation in cracking and relate it to complexity measures for self-gravitating charged systems. Specifically, we link cracking in charged fluids to the condition of zero complexity factor. We also connect the mode of departing electromagnetic equilibrium with the occurrence of cracking. According to our analysis, cracking is avoided in the non-dissipative geodesic case by considering the condition of (Y_{TF}=0) (without taking into account the manner of leaving equilibrium). Cracking is also avoided by leaving equilibrium in homologous and quasi-homologous electromagnetic regimes. Our results demonstrate the importance of dissipation, charge, and scalar function (Y_{TF}) for the understanding of compact objects. Some important insights are shown by developing a relationship among electromagnetic interactions, complexity, and cracking.

ZnAl_2-xIn_xO₄ (x=0.0, 0.1, 0.15, 0.2, 0.25) samples were prepared employing the solid-state reaction approach. The structural inspection, utilizing Rietveld refinement and synchrotron x-ray diffraction patterns, revealed the substantial solubility threshold of indium within the ZnAl₂O₄ (ZAO) matrix and enabled the assessment of the inversion parameter, which expresses the distribution of cations among the tetrahedral and octahedral sites within the spinel conformation. The cation distribution fingerprint appeared on the Fourier transform infrared spectroscopy (FTIR) spectra. The transmission electron microscopy (TEM) technique revealed a little variation in particle size with an average value of 6 nm as determined from Rietveld x-ray analysis. Field emission scanning electron microscopy (FESEM) technique and energy dispersive X-ray spectroscopy (EDS) analysis were used to spot the morphology and elements inside the samples. The optical bandgap energy E_g value for ZAO is 4.43 eV and diminished to 4.41, 4.22, 4.22 and 3.96 eV for indium doping levels of x=0.1, 0.15, 0.2, and 0.25, respectively. Upon doping, optical absorption is significantly elevated in the ultraviolet region. CIE chromaticity diagrams revealed that the samples displayed cyan-blue colors depending on the amount of indium doping. The linear (LAC) and mass attenuation coefficient (MAC) values for all samples were maximum at the minimal energy value of 0.015 MeV. The LAC is elevated from 148 cm^-1 to 246 cm^-1 and MAC from 31.9 to 47.7 cm²/g for x=0.0 and 0.25, respectively. The half value layers (HVL), tenth value layers (TVL) and mean free path (MFP) values diminished as ZAO was doped with indium, indicating that the doped samples possess superior shielding properties compared to undoped ZAO. ZnAl₂O₄ doped with 0.1 or 0.15 indium disclosed marvels photoluminescence and has potential applications in phosphors, especially in light-emitting devices and displays.

In this study, we investigate the thermodynamic properties of an ideal Quark-Gluon Plasma (QGP) at a vanishing chemical potential, under the influence of quantum gravitational effects, specifically incorporating the Linear-Quadratic Generalized Uncertainty Principle (LQGUP). We analyze the impact of LQGUP on key thermodynamic quantities, including the grand canonical potential, pressure, energy density, entropy, speed of sound, and the bulk viscosity’s response to changes in the speed of sound. Furthermore, we extend our analysis to examine the time evolution of the universe’s temperature in the presence of LQGUP effects.

Exploring the universal structure of the gravitational path integral beyond semi-classical saddles and uncovering a compelling statistical interpretation of black hole thermodynamics have long been significant challenges. We investigate the statistical interpretation of the Kerr-AdS black hole thermodynamics through an ensemble-averaged theory. By extending the phase space to include all possible states with conical singularities in their Euclidean counterparts, we derive the probability distribution of different states inherited from the Euclidean gravitational path integral. Moreover, we can define a density matrix of all states in the phase space. By ensemble-averaging over all states, we show that the black hole phase transition naturally arises in the semi-classical limit. Away from the semi-classical regime, the ensemble-averaged theory exhibits a notable deviation from the conventional phase transition. Expanding around the classical saddles yields the subleading-order correction to the Gibbs free energy, which is half of the Hawking temperature. We demonstrate that the half Hawking temperature correction is a universal feature inherent to black holes in asymptotically AdS spacetime. With the subleading-order correction to Gibbs free energy, we also suggest that the whole black hole thermodynamic should be corrected accordingly.

In this study, activated carbons were obtained by carbonizing the waste laurel fruit seeds at 500°C as a result of oil extraction from laurel fruits brought from Hatay (a province in Turkey). At the same time, activated carbon was obtained by impregnating bay fruit seeds with ZnCl₂. Through the use of FTIR, BET, SEM, and TGA, the activated carbons were characterized. In order to remove methylene blue from an aqueous solution, activated carbon was used as an adsorbent. ACn and ACz activated carbons with surface areas of 783.58 and 812.25 m²/g were obtained. We looked at how temperature, pH, and starting concentration affected the amount of MB that ACz removed from an aqueous solution as a function of contact time. The kinetics parameters were also calculated. According to kinetic data, Since the R² value is large and the ARE value is small, the adsorption phenomenon is considered to be pseudo-second order.

This study investigates the mechanical performance of additively manufactured hybrid honeycomb structures, incorporating hexagonal and re-entrant geometries, fabricated from acrylonitrile butadiene styrene (ABS), widely employed thermoplastic material, under bending conditions. Through three-point bending experiments and finite element analysis (FEA), the energy absorption capacity and flexural modulus of these cellular architectures are evaluated. A comparative assessment is conducted between hollow hybrid structures and those reinforced with polyurethane (PU) foam to elucidate the effects of its integration on mechanical properties. The findings indicate that re-entrant hybrid honeycombs exhibit superior reinforcement characteristics compared to hexagonal honeycombs, attributable to their variable cell ratios and dimensions, which allow control over mechanical properties without altering cell geometry. This adaptability facilitates the manufacturing process by enabling the selection of the most straightforward geometry while varying only cell ratios. Additionally, parametric FEA studies explore the influence of structural parameters and bending load configurations on honeycomb performance, revealing that hybrid structures exhibit improved stiffness and energy absorption under three-point bending. Notably, the experimental results closely align with the FEA results, thereby enhancing the reliability of the computational models employed. This research underscores the potential of hybrid designs in the development of advanced lightweight, high-performance materials for diverse engineering applications.

The detection of gravitational waves with ground-based laser interferometers has opened a new window to test and constrain General Relativity (GR) in the strong, dynamical, and non-linear regime. In this paper, we follow an agnostic approach and we study the quasi-normal modes of gravitational perturbations of Johannsen black holes under the assumptions of the validity of the Einstein Equations and of low values of the black hole spin parameter and deformation parameters. We find that the deformation parameter (alpha _{13}) has a stronger impact on the quasi-normal modes than the other leading order deformation parameters ((alpha _{22}), (alpha _{52}), and (epsilon _{3})). We derive a fitting formula for the fundamental modes with (l=2) and (l=3) for the deformation parameter (alpha _{13}) valid in the slow rotation approximation ((a_* < 0.4)). Finally, we constrain (alpha _{13}) from the event GW170104; within our analysis, we find that the data of GW170104 are consistent with the predictions of GR.

The raw material, graphite powder, was processed by means of the modified Hummers’ method to yield graphene oxide (GO). The rare-earth yttrium (Y) ion was added to it in controlled concentrations to get Y–GO nanocomposites. The morphology of the samples was studied using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses. Analysis of the TEM and SEM images revealed agglomerated nanoclusters of yttrium along with rolled sheets of graphene and wrinkled surface morphology for the samples. The structural analysis was done using X-ray diffraction studies (XRD) and compared with the standard data. The electron diffraction rings were indexed using selected area electron diffraction (SAED) with the help of CrysTBox software. The weight and atomic percentages of individual chemical constituents in the composites were analyzed using energy-dispersive X-ray (EDX) spectroscopy. The confocal Raman spectra of the samples provide helpful information on their optical band transitions. The UV–Vis reflectance spectral analysis supports the findings of the Raman studies. Additionally, DC electrical conductivity studies of the samples in the low-temperature region indicate their semiconducting nature, and the Arrhenius plots were used to determine their activation enthalpies. A comparative study of Mott variable range hopping (VRH) and its modified version, Efros–Shklovskii VRH, was applied in the low-temperature region to study the charge carrier transport properties of the samples.

Graphical abstract