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.
(a) Schematic of a flow-type gas testing system for NH3 detection. (b)Response of the PAA fibrous membrane coated QCM sensors exposed to various concentrations of NH3. (Reprinted with permission from32. © 2005 Elsevier Ltd.) (c) Schematic diagram of a static-type testing system for humidity detection. (d) Frequency shifts of polyelectrolyte coated QCM sensors as a function of the relative humidity.
(Reprinted with permission from22. © 2010 IOP Publishing Ltd.)
