Funding for this research was provided by:
Guizhou Science and Technology Department ([2020]1Y107)
China National Tobacco Corporation (110201502019;110201601025 LS-05)
Doctoral Program Foundation of Guizhou Normal University (11904/0519084)
Article History
Accepted: 23 April 2020
First Online: 29 May 2020
Compliance with ethical standards
:
: the authors declare that they have no conflict of interest.The study presented in the manuscript does not involve human or animal subjects.All authors have reviewed the final version of the manuscript and agree to its submission to your journal.