Investigation on defect dynamic echo waveform of friction stir welding;

Acoustic band gaps and defect states in two-dimensional composite materials;

Based upon them, we found that the eigenfrequency of defect state is red-shifted with the increasing geometry thickness of defect layer in right-handed materials.

The defect state was formed by introducing the defect layer into period structure.

The defect states in two-dimensional phononic crystal homogeneity dislocation structures has been studied by means of the plane-wave expansion method in combination with a supercell technique.

Made some scientific research on the electronic radiation defect states isochronal and isothermal anneling characteristic properties of high resistance (80￣110Ω·cm) NTD FZ Si P +n in vacuum,and obtain five defect energy evels.

UV　laserinduced　damage　threshold　in　fused　silica　was　theoretically　investigated　based　on　the　model　that　the　conduction　band　electrons　were　produced　from　defect　states　via　linear　absorption　and　from　valence　band　via　twophoton　absorption.

The frequencies of defect modes are dependent on the rod radius (r_2) of square lattice with a larger periodic constant, and the relationship of the defect modes and r_2 is almost independent of a_2.