Mechanical metamaterials can be used to control wave propagation since they are flexibly adjustable. In this paper, a one-dimensional rotor-in-rotor metamaterial with internal rotor coupling is proposed. This metamaterial introduces a new connection between lattices into a rotor-in-rotor system...

In order to enhance the role of Al in the materials, Al-substituted MnAlO catalysts were synthesized via the hydrothermal-redox method at different calcination temperatures for acetone oxidation. There were Al-substituted α-MnO2 and amorphous aluminum oxide existed with homogeneous dispersion...