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We explore a simulation model of drilling micro-hole in sticking plaster heated with a dual CO2 laser beam. This paper applied numerical simulation of temperature by using finite element analysis software Ansys to study a model of drilling on sticking plaster. A dual CO2 laser spot sizes ranged from 0.15 to 0.2mm radius with axial irradiance power levels of 50-100w. For temperatures above 450°C, sticking plaster would be vaporized. The size of ventilation holes changed with beam power and laser spot diameter. The width of the hole is increases with the increasing laser diameter and with the increasing laser power. These results can guide to laser drilling experiments.

We explore the terahertz (THz) wave generation based on surface-emitted difference frequency generation (SEDFG) in periodically-inverted GaAs crystals. One scheme applying collinear quasi phase matching (QPM) is proposed. The wave propagation of the higher frequency pump wave is parallel to the wave propagation of the lower frequency pump wave, and both of them are perpendicular to the domain wall of the nonlinear crystal. The THz wave is emitted perpendicular to the surface of the nonlinear crystal. We calculated the grating period of periodically-inverted GaAs at the range of 100-1000μm (0.3-3THz). Our estimates illustrate that THz wave output corresponds to the power conversion efficiency of 0.015% at a frequency of 1THz. The result is shown that this scheme is efficient to obtain THz wave.

We explored the methods of computational statistics in the application of ability assessment for university students. This paper used both exploratory factor analysis and confirmatory factor analysis carried out by statistical analysis software SPSS18.0 and lisrel 8.7, aimed to study a questionnaire which could be used to assess the comprehensive ability of university students. The retest reliability and the Cronbach reliability of the questionnaire were 0.88 and 0.90 respectively. And the structural equation model of university students ability suggested there were five factors: learning ability, innovation, career planning ability, communicative skills and psychological qualities. The indexes of RMSEA, GFI, AGFI, NNFI, NFI and CFI of the model were 0.075, 0.91, 0.91, 0.90, 0.93, and 0.92 respectively. The indexes of reliability and validity met the statistical criteria. The results can provide a guide for the ability assessment of university students.