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In present work, the evolution of scalar field and electromagnetic field under the background of the charged black-bounce spacetimes are investigated, and we obtain an obvious echoes signal which appropriately reports the properties of the charged black-bounce spacetimes and disclose the physical reasons behind such phenomena. Furthermore, by studying the quasinormal ringdown, we analyze the three states of the charged black-bounce spacetimes in detail, our results show that the echoes signal only appears when (| Q | ≤ m) and (| l | > m + m 2 - Q 2 ) in this spacetime, while when the parameters demand (| Q | > m) , the echoes signal will be transformed into a quasinormal ringdown of the two-way traversable wormhole, and the charged black-bounce is a regular black hole with normal horizons by requiring (| Q | ≤ m) and (| l | < m - m 2 - Q 2 ) . [ABSTRACT FROM AUTHOR]

An effective technique is proposed for identifying the track modulus, i.e., the foundation stiffness of the rails, using the contact-point response of the moving test vehicle. First, for a simple beam resting on an elastic foundation under a moving sprung mass, closed-form solutions are derived for the responses of the vehicle and its contact point with the rail. It is shown that the track modulus can be well identified via the first rail frequency (RF) extracted from the contact-point response, in that (1) the first RF is most outstanding compared with the other RFs in the vehicle-generated responses; and (2) the contact-point response outperforms the vehicle response as it is free of the disturbing effects of the vehicle and driving frequencies. The proposed technique is then verified numerically along with the key parameters assessed. The main conclusions are: (1) the first RF can be easily recognized as the "cliff" of the RF "plateau" in the contact-point spectrum; (2) the track irregularity has a little effect on the identification of track modulus; (3) a moderate speed is recommended for the test vehicle for a balance between efficiency and accuracy; and (4) the efficacy of the proposed technique remains good even with the presence of track damping and irregularity. Moreover, the application of the proposed technique to detecting the damage modeled by variation in foundation stiffness is demonstrated. [ABSTRACT FROM AUTHOR]

A series of aspects of the quantum gravity predict a modification in the Heisenberg uncertainty principle to the generalized uncertainty principle (GUP). In the present work, using the momentum space representation, we study the behavior of the Kemmer oscillator in the context of the GUP. The wave function, the probability densities, and the energy spectrum are obtained analytically. Furthermore, the thermodynamic properties of the system are investigated by using the numerical method and the influence of GUP on thermodynamic functions are also discussed. [ABSTRACT FROM AUTHOR]

The geometrical structures, relative electronic and magnetic properties of small AlCo (1 ≤ n ≤ 9) clusters are systematically investigated within the framework of density functional theory at the BPW91 level. The single Co doping can dramatically affect the ground state geometries of the 1 Al clusters. At the same time, the resulting geometries show that the lowest energy AlCo clusters prefer to be three dimensional structures. Here, the relative stabilities are investigated in terms of the calculated average binding energies, fragmentation energies, and second-order energy differences. Moreover, the result of the highest occupiedlowest unoccupied molecular orbital energy gaps indicates that AlCo clusters have the highest chemical stability for AlCo (1 ≤ n ≤ 9) clusters. Furthermore, the natural population analysis reveals that the charges in AlCo clusters transfer from the Al frames to the Co atom. Additionally, the analyses of the local and total magnetic moments of the AlCo clusters show that the magnetic effect mainly comes from the Co atom. [ABSTRACT FROM AUTHOR]

Our work aims to understand the effects of shielding on the induction of biological damage by heavy charged particles and to compare the shielding effects of different materials at the same LET from two aspects: the biological effectiveness including or not including secondary particles emitted at large angles and the biological effectiveness at different angles with respect to the beam direction. We designed and conducted biological experiments to determine the biological effectiveness of 200 MeV/u carbon ions after traversing different shielding materials (Lucite and aluminium). Whole blood samples, which were either attached to the shielding material (48 mm Lucite or 29 mm aluminium)or positioned at 300 cm away from it at different angles with respect to the beam axis, were exposed to carbon ion beams. For comparison, whole blood samples were exposed directly to 200 MeV/u carbon ions. Chromosomal aberrations in lymphocytes were scored. The results indicated that the biological effectiveness per unit dose was not significantly changed by 48 mm Lucite or 29 mm aluminium, and no significant differences were observed in lymphocytes attached to the target and in lymphocytes positioned at a distance of 300 cm away from the target, at 0º angle of the beam axis. However, when plotted as a function of the number of ions hitting the shielding target, the curves are separated and the shield increases the effectiveness per unit ion. The frequency of chromosomal aberrations at tilted angles behind 29 mm Al and 48 mm Lucite was almost the same. These lesions were considered to be caused by secondary particles due to the passage of particles through the shielding materials. [ABSTRACT FROM AUTHOR]

This research investigates the microstructure and mechanical properties of ultrafine WC-10Co cemented carbides fabricated by an electric-discharge compaction (EDC) process, from powder synthesized by a spray-conversion process (SCP). Due to a short holding time during EDC, a grain size as small as 120 nm can be achieved. We also found that dispersion of pores in WC-Co cemented carbides may contribute to fracture toughness, besides the bridging ligament mechanism. [ABSTRACT FROM AUTHOR]

The mechanical properties and corresponding microstructure development of the AZ31 Mg alloy after treatment with equal channel angular pressing (ECAP) and subsequent electropulsing (ECP) was investigated. Comparing the ECAP+ECP-treated AZ31 alloy with the ECAP-treated alloy, the elongation to failure was improved significantly, while the yield stress and the ultimate tensile strength were not decreased, the grain sizes were slightly increased and more homogeneous, and the texture was barely changed. The main mechanism for the evolution of the structures and properties might be ascribed to the increased nucleation rate on recrystallization and the decreased dislocation density during the ECP treatment. It was reasonable to expect that the ECAP+ECP treatment would provide a promising approach for enhancing the mechanical properties of the Mg alloys. [ABSTRACT FROM AUTHOR]