• Composites Research
• /
• v.24 no.2
• /
• pp.9-13
• /
• 2011

,In this paper, the symmetric axis parameter method, which was proposed to identify defects, dislocations and stacking fault, with perfect structures in the zinc-blende materials, was introduced as a way to distinguish between elastic and plastic deformation. LAMMPS, a molecular dynamics programme of Sandia National Laboratories, was used to perform nanoindentation simulation on silicon, a zinc-blende material. Defects in silicon (111) under spherical indentation showed the threefold pattern and the slip system in the form of ring crack. Also simulation results show good agreement with experimental results and existing theoretical analyses.

• Journal of Biomedical Engineering Research
• /
• v.16 no.2
• /
• pp.129-138
• /
• 1995

High-energy and high-dose X-ray and electron beam have been used in radiation therapy after developing particle accelerators. It is recommended to irradiate patients exect real dose for improving therapy effectiveness by International Committee on Radiation Units and Measurement. The radiation detector for daily beam checks of medical accelerators is described. Using thirteen silicon diodes, we have designed the diode detector providing information about calibration, beam symmetry, flatness, stability variation according to radiation damage, time and general quality assurance for both photon and eletron beams. we also compared these measurement values with those of using ionization chamber, film and semiconductor dosimeter.