A viscoelastic rheological model was proposed to simulate the relaxation process of isometric knee extension.
The results show that this internal friction peak is originated from the relaxation process within the interfaces.
This internal friction peak is suggested to be associated with the relaxation process of the unstable interface.
Photoacoustic phase shows the special ability of measuring the optical and thermal properties, studying the nonradiative relaxation processes and analyzing the depth profile of the sample and so on.
The exciton coherent transport in above aggregates is analysed to be a transfer before vibrational relaxation process.