Back Cover: First, hexagonal boron nitride nanosheets functionalized with hydroxyl groups are prepared, and a schematic diagram of the molecular structure BNNSs is shown in cover design. As special engineering plastic, polyether ether ketone (PEEK) widely used aerospace, automobile, highspeed rail industry, 5G fields. In article number 2100532 by Yanhua Yang co-workers, PEEK fiber to prepare hi...