Demonstration of toroidal metasurfaces through near-field coupling of bright mode resonators

Bright mode resonances are not well-acknowledged for inducing mode hybridizations. However, we demonstrate multiple bright resonators coupled through electromagnetic fields can induce resonance mode hybridizations. Although one of the hybridized modes shows parallel magnetic moments but the other mode demonstrates anti-parallel magnetic moments leading to magnetic toroidal resonances. Normally excitation of toroidal modes demands complex structures and/or bright-dark mode interactions. However, in this work, we employ solely bright resonators to excite toroidal modes. Unlike bright-dark mode coupling, exclusive bright mode resonance coupling enables larger free space energy merging into the metasystem leading to stronger energy confinement in the metasurface array.

Social Bonding in Initial Acquaintance: Effects of Modality and Modality Order

In this experimental study, unacquainted dyads engaged in a get-acquainted task using two modes of communication across two segments of interaction. The dyads either first disclosed in text-based computer-mediated communication (CMC) and then disclosed face-to-face (FtF) or the reverse. The participants completed reaction measures after each segment of interaction. After the first segment, dyads who communicated FtF reported more positive outcomes (e.g., liking, closeness) than dyads who engaged in CMC. Furthermore, dyads who began in CMC and then transitioned to FtF increased in their positive reactions, whereas dyads who began in FtF and transitioned to CMC either experienced no change (in liking, closeness, and perceived similarity) or experienced a decrease (in fun/enjoyment and perceived responsiveness). Implications of the results are discussed both for the classic social psychology question of how people become acquainted and for current interest in how mixed-mode interactions generate social bonds that can help meet belonging needs.

Nonlinear Resonant Responses, Mode Interactions, and Multitime Periodic and Chaotic Oscillations of a Cantilevered Pipe Conveying Pulsating Fluid under External Harmonic Force

The nonlinear resonant responses, mode interactions, and multitime periodic and chaotic oscillations of the cantilevered pipe conveying pulsating fluid are studied under the harmonic external force in this research. According to the nonlinear dynamic model of the cantilevered beam derived using Hamilton’s principle under the uniformly distributed external harmonic excitation, we combine Galerkin technique and the method of multiple scales together to obtain the average equation of the cantilevered pipe conveying pulsating fluid under 1 : 3 internal resonance and principal parametric resonance. Based on the average equation in the polar form, several amplitude-frequency response curves are obtained corresponding to the certain parameters. It is found that there exist the hardening-spring type behaviors and jumping phenomena in the cantilevered pipe conveying pulsating fluid. The nonlinear oscillations of the cantilevered pipe conveying pulsating fluid can be excited more easily with the increase of the flow velocity, external excitation, and coupling degree of two order modes. Numerical simulations are performed to study the chaos of the cantilevered pipe conveying pulsating fluid with the external harmonic excitation. The simulation results exhibit the existence of the period, multiperiod, and chaotic responses with the variations of the fluid velocity or excitation. It is found that, in the cantilevered pipe conveying pulsating fluid, there are the multitime nonlinear vibrations around the left-mode and the right-mode positions, respectively. We also observe that there exist alternately the periodic and chaotic vibrations of the cantilevered pipe conveying pulsating fluid in the certain range.