Figure 2.
SEM images of BC-0 (a), BC-1 (b), BC-2 (c), and BC-3 (d).
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.