Normal state Acoustic detection 2 Acoustic signals 2 DC bias 2 DC transformers 2 Data statistics 2 Distribution regularities 2 Early-warning method 2 Multiparameters 2 Operation state 2 Power transformers 2 Transformer 2 Transformer substations 2 acoustic detection 2 data statistics 2 transformer 2 Bilayer Graphene 1 Flavor symmetry 1 Global phase diagrams 1 Graphene 1 Hartree-Fock calculations 1 Magic angle 1 Phase diagrams 1 Strain-dependent 1 Surface structure 1 Symmetric phase 1 Symmetry breakings 1 Twisted bilayers 1