物理最新文献

The immobilization of iron (III) oxide (Fe₂O₃) particles on substrates through methods such as low-pressure chemical vapor deposition, hydrothermal, or chemical bath processes often entails prolonged synthesis durations (in hours if not days), substantial equipment costs, and/or elevated operational expenses due to high electrical power consumption (in kW). Indeed, high electrical power consumption is directly associated with increased CO₂ emissions in the generation of electrical power, especially in regions where the energy relies heavily on fossil fuels. These synthesis methods are not favored for achieving Carbon Net Zero in the year 2050. Thus, the drawbacks pose significant impediments to the widespread industrial application of Fe₂O₃ particles as visible light-driven photocatalysts for treating organic effluents on a large scale. In this study, a rapid and innovative synthesis of Fe₂O₃ particles immobilized on wires within a mere 10-min timeframe and consuming low electrical power (50 W.h) was demonstrated. This was achieved by the development of a novel direct heating (DH) method. The influence of heating duration on the structural, morphological, and photocatalytic properties of Fe₂O₃ particles was investigated. These Fe₂O₃particles demonstrated positive photocatalytic activity, degrading 33.29% of Rhodamine B (RhB) dye and 81.4% of chromium Cr (VI) within 90 min under visible light irradiation. The good photocatalytic performance, coupled with the simplicity and cost-effectiveness of DH method, establishes a promising alternative for the development of visible light-active photocatalysts for the removal of both organic dyes and metal ions removal.

This paper investigates global projective anti-synchronisation in the mean-square sense in the asymptotic and exponential schemes of space–time discrete Markovian Lur’e dynamical networks with uncertain transition probabilities and Dirichlet boundary values. The findings of this study are noteworthy with regard to global projective asymptotic and exponential anti-synchronisation in the mean-square sense for the proposed discrete Markovian networks. The networks incorporate the Lyapunov–Krasovskii functional, which includes a double sum representing the delay-dependent components. Furthermore, the findings of this study indicate that the global projective asymptotic and exponential anti-synchronisation of space–time discrete Markovian Lur’e dynamical networks with uncertain transition probabilities can be achieved through the design of small diffusion intensities. It was unexpected to discover that the uncertain transition probabilities have no influence on the conditions that guarantee the global projective asymptotic and exponential anti-synchronisation of the networks. This paper presents a framework for exploring the issues of global projective asymptotic or exponential anti-synchronisation for space–time discrete Markovian networks, with the objective of identifying potential applications in a range of contexts. In conclusion, an illustrative example is provided to demonstrate the efficacy of the aforementioned method.

We studied synchrotron radiation of a massive charged under visible and hidden sector groups, moving in equatorial plane around spherically symmetric weakly magnetized black hole. As a model of dark matter we choose the one, in which Maxwell field is coupled to the additional U(1)-gauge field envisaging the dark sector, the so-called dark photon model. Magnetization of a black hole also stems from Maxwell-dark photon electrodynamics. One found the radiation power and energy loss of the particle and looked for the imprints of dark matter on those phenomena.

A temperature-compensated magnetic field sensor based on a hollow core Bragg fiber (HCBF) Fabry-Perot interferometer (FPI) is proposed. The two ends of the HCBF are fused with optical single-mode fibers (SMF) and adhered to magnetostrictive rods. The temperature and magnetic field response can be demodulated by 2 × 2 sensitivity matrix method, achieving multiparametric demodulation of dual parameters. Experimental results indicate that the error rate of demodulated magnetic field is only 1.9%, while the error rate of demodulated temperature is only 0.8%. The ease of fabrication, high accuracy and temperature compensation suggest that the proposed fiber sensor is suitable for practical magnetic field sensing applications.

The performance of QKD systems in airborne environments is significantly hindered by optical distortions and perturbations caused by the boundary layer around high-speed aircraft. This paper proposes an optimization scheme to enhance airborne QKD system performance by analyzing the flow field around the transmitter and strategically positioning it under specific flow conditions. Using ray tracing and two distinct airborne QKD models, we evaluate system performance across various installation positions. Our results show that the largest beam deflection occurs when the transmitter is placed at the center of the wing in air-to-ground scenarios, while the QBER remains consistent across different wing positions, indicating minimal boundary layer effects on QBER. In air-to-air scenarios, optimizing the quantum source placement reduces the photon offset by 6.3 m, with QBER consistently measured at 6% ± 1% across wing positions. These findings offer critical insights for the design and deployment of QKD systems in practical airborne applications.

In this study, the findings of research conducted into the thermodynamic properties of a molecular complex ion in a 2D quantum ring characterized by Gaussian-type potentials are presented. The Schrödinger equation for a singly ionized double donor complex was solved by a two-dimensional diagonalization method. The results obtained show that at the internuclear distance, where there is coupling between the Coulomb centers such that the electron is shared by both impurity atoms, the mean energy and entropy of the system are minimal. A further finding is that in the regime where the distance between impurity atoms is comparable to the inner radius of the quantum ring, the heat capacity of the system undergoes significant changes with temperature.

The femtoscopic study of pairs of identical pions is particularly suited to investigate the effective source function of particle emission, due to the resulting Bose–Einstein correlation signal. In small collision systems at the LHC, pp in particular, the majority of the pions are produced in resonance decays, which significantly affect the profile and size of the source. In this work, we explicitly model this effect in order to extract the primordial source in pp collisions at (sqrt{s}~=~13) TeV from charged (uppi )–(uppi ) correlations measured by ALICE. We demonstrate that the assumption of a Gaussian primordial source is compatible with the data and that the effective source, resulting from modifications due to resonances, is approximately exponential, as found in previous measurements at the LHC. The universality of hadron emission in pp collisions is further investigated by applying the same methodology to characterize the primordial source of (textrm{K})–(textrm{p}) pairs. The size of the primordial source is evaluated as a function of the transverse mass ((m_{textrm{T}})) of the pairs, leading to the observation of a common scaling for both (uppi )–(uppi ) and (textrm{K})–(textrm{p}) , suggesting a collective effect. Further, the present results are compatible with the (m_{textrm{T}}) scaling of the (textrm{p})–(textrm{p}) and p(-Lambda ) primordial source measured by ALICE in high multiplicity pp collisions, providing additional evidence for the presence of a common emission source for all hadrons in small collision systems at the LHC. This will allow the determination of the source function for any hadron–hadron pairs with high precision, granting access to the properties of the possible final-state interaction among pairs of less abundantly produced hadrons, such as strange or charmed particles.