Search

With the rapid development of current electronic equipment, electromagnetic microwave absorption (EMA) materials with higher design requirements under special circumstances have attracted great attention. Herein, a flexible polyurethane composite foam assisted by coral‐like CNT@Fe3O4/graphene nanocomposites is fabricated by a facile solvothermal and moisture self‐foaming method. The composite foam with 15 wt% nanofillers exhibits an outstanding temperature cycle stability with gradually improved EMA performance at elevated temperature and excellent resilience stability with a tensile strength of 4.81 MPa. An enhanced minimum reflection loss (RLmin) of −59.44 dB at 10.38 GHz with a thickness of 2.28 mm is achieved, while the ultrawide absorption bandwidth of 6.09 GHz nearly covers the full X‐band. This benefits from interface impedance matching, dielectric and magnetic dual losses, and multiple reflections depending on the interior open microcellular structures. It is expected to become a promising thermally tunable microwave absorber in harsh environments. [ABSTRACT FROM AUTHOR]

The influence of complex lattices with P T -symmetry on dynamic localization (DL) in optics, particularly higher-order DL, has been examined in this study. We found an intriguing result: the order of DL is equal to the frequency of light passing through the first Brillouin zone's boundary during a half-period of DL oscillation. Additionally, the DL is still possible below the P T -symmetry breaking point, but beam power evolution differs from Bloch oscillation in P T -symmetry systems. Similar to damped vibration, the amplitude of beam power oscillation diminishes as propagation distance increases. The nonreciprocal beam propagation behavior is also found at the P T -symmetry breaking point, which is comparable to the optical Bloch oscillation in the P T -symmetry system. • The order of DL equals the frequency of light passing through the first Brillouin zone's boundary during a half-period of beam oscillation. • Below the PT-symmetry breaking point, beam power oscillation decreases with the light propagation which is similar to damped vibration. • At the PT-symmetry breaking point, the beam propagation has significant nonreciprocal behavior. [ABSTRACT FROM AUTHOR]