About: http://webisa.webdatacommons.org/247092053

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	By refractory metals it is meant metals of elements of the groups 4, 5 and 6 of the periodic table, including titanium (Ti), tantalum (Ta), tungsten (W), and nitrides or alloys thereof, which are resistant to high temperatures.
http://www.w3.org/ns/prov#wasQuotedFrom	freshpatents.com