Figure 1.
(a) A natural honeycomb structure; (b) the designed honeycomb core inspired by nature. (c) board components: the top shell, and the merged bottom shell and core.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.