About: http://webisa.webdatacommons.org/6539207

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	In addition, some material such as calcium oxide, strontium oxide, or barium oxide can be coated onto the surface of the filaments to increase the efficiency of the hot-electron emanation.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com