Steering Smith-Purcell radiation angle in a fixed frequency by the Fano-resonant metasurface.

Smith-Purcell radiation (SPR) is a kind of electromagnetic wave radiation that happens when an energetic beam of electrons passes very closely parallel to the surface of a ruled optical diffraction grating. The frequency of radiation waves varies in the upper and lower space of the grating for different electron velocity, satisfying the SPR relationship. In this study, a Fano-resonant metasurface was proposed to steer the direction of the SPR waves at the fixed resonant frequency by changing the velocity of the electron beam without varying the geometric parameters or adding extra coupling structure.

Insights into the Assembly of the Pseudogemini Surfactant at the Oil/Water Interface: A Molecular Simulation Study.

The interfacial assembly process and configuration of the pseudogemini surfactant fabricated by sodium dodecyl benzene sulfonate (SDBS) and 4,4'-oxydianilinium chloride (ODC) were studied using quantum mechanical calculations and molecular dynamics (MD) simulations. The MD simulation results revealed that SDBS and ODC showed the vertical and horizontal arrangements at the oil/water interface, respectively, and the interfacial assembled configuration presented an unexpected "H" shape rather than the traditional "U" shape. The radial distribution functions between the head groups and water molecules were employed to explore the effects of the surrounding water molecules on the SDBS/ODC interaction.