The effects of colored noise on self-propelled particles in a two-dimensional potential are investigated. The resonance phenomenon was found as the the average velocity has a maximum value with increasing x direction noise intensity. The average velocity takes its maximal value as the parameters (the y direction noise intensity, the self-propelled angle noise intensity, and so on) take suitable values. The y direction noise and the self-propelled angle noise have great effects on the x direction particles transport. The y direction noise and the self-propelled angle noise cannot induce x direction particles transport in the absence of x direction noise. The ratchet effect should disappear when there is no coupling between the x direction potential and the y direction potential. 相似文献
The superconductivity and magnetoresistance (MR) of epitaxial bilayers consisting of YBa2Cu3O7?δ (YBCO) and La0.67Sr0.33MnO3 (LSMO) are investigated with respect to the proximity and spin polarization effects. In the region of the mixed vortex state near the onset temperature of the superconducting transition, the diffusion of the spin-polarized quasiparticles from the LSMO to the YBCO is evidenced by their distinct magnetotransport behaviors, which are characterized by two superconducting transitions. It is revealed that the second transition is strongly dependent on the applied magnetic field, demonstrating an abnormal pair-breaking effect. This effect, together with the reduced MR, is believed to arise from an increase in the spin injection efficiency induced by the suppressed interfacial spin scattering, disclosing a new perspective for understanding the magnetotransport phenomena in proximity-coupled superconductor/ferromagnet (S/F) hybrids. 相似文献
Ferromagnet/superconductor/ferromagnet (F/S/F) spin-valve systems in the dirty limit, described by Usadel equations, was theoretically investigated with respect to superconducting transition temperature. Their superconducting characteristics strongly depend not only on the mutual orientation and thickness of the ferromagnetic layers, but also on the interface transparency as well as magnetic scattering. Especially, the introduction of magnetic scattering drastically reduces the spin-valve effect in our work. The obtained results could be used to understand experimental values of and to provide guidelines for optimizing the experimental systems. 相似文献
In this study, a dynamic model for herringbone planetary gears is proposed which can be applied in the dynamic analysis of variable speed processes (including acceleration, deceleration, and large speed fluctuation process, etc.). The dynamic responses of the acceleration process of an example of a herringbone planetary gear set are simulated in cases where the profile error excitations are ignored and included. The phenomenon of tooth separations can be observed as the rotating speed increases in the simulation, and the effect of the profile error excitations on the phenomenon is also investigated. Furthermore, the effects of the profile error excitations on the vibrations and dynamic meshing forces are investigated before and after the appearance of tooth separations. Moreover, the dynamic characteristics of the herringbone planetary gear set are also compared with that of the spur/helical herringbone planetary gear set briefly. Finally, some advice for the design of planetary gear sets is given to avoid the phenomena of tooth separation and tooth back contacts and suppress the vibrations and dynamic meshing forces. 相似文献
Z-scheme heterojunction photocatalysts based on g-C3N4 generally need to recombine g-C3N4 and a wide bandgap semiconductor. This structure is limited by the large bandgap of the constituent material, which can effectively suppress carrier recombination while limiting the absorption of visible light. Due to the superior up-conversion photoluminescence properties of the carbon quantum dots (CQDs), this dilemma can be solved ingeniously by adding CQDs to the composite. Moreover, the charge reservoirs of CQDs are conducive to the charge carrier separation effect. In this work, a novel CQDs-modified Z-type photocatalyst is constructed and the successful implantation of CQDs is demonstrated. The composite catalyst exhibits broad-spectrum response to visible light and the overall performance is obviously superior to that of the binary MoO3/g-C3N4 heterojunction. The high efficiency and versatility of the degradation imply that the newly prepared CQDs/g-C3N4/MoO3 is a versatile photocatalyst for the removal of various target pollutants in the environment.