Assertion: nitrogen's property | /r/HasProperty | established in 1970
Facets:
value: firmly
type: MANNER
value: based on the optical measurements
type: CAUSE
Source sentences:
text: The microscopic model and most optical properties of ensembles of the N-V− centers have been firmly established in the 1970s based on the optical measurements combined with uniaxial stress and on the electron paramagnetic resonance.