export net files of thematic evolution map

[BiChenMIGRATION]

Dear everyone, How to export net files of each stage when using the following code to draw thematic evolution map?

`years=c(2004,2008,2012)

B<- thematicEvolution( M, field = "DE", years, n = 1500, minFreq = 2, size = 0.5, ngrams = 1, stemming = FALSE, n.labels = 1, repel = TRUE, remove.terms = NULL, synonyms = NULL )`

[BiChenMIGRATION]

I seem to have a method, use the following code to import vosviewer and then export the net file。 N<-B$Net net2VOSviewer(N[[1]])