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Femtosecond laser with ultrashort pulse (≤35fs) is used to investigate the damage threshold and light-to-electric conversion efficiency of gallium arsenide solar cells. Different from nanosecond or picosecond lasers, the damage threshold of the solar cell illuminated by femtosecond laser is slightly higher than that under the illumination of continuous-waves laser with the same wavelength. Because the thermal non-equilibrium effect becomes obvious, heat conduction phenomenon no longer obeys the law of Fourier, when the heating pulse time of femtosecond laser is equal to or shorter than the electron-phonon coupling time. The photovoltaic properties of gallium arsenide solar cells under femtosecond pulse laser illumination are measured. The device shows better short circuit current and the light-to-electric conversion efficiency under femtosecond pulse laser than that under continuous-waves laser of the same wavelength.

A secondary development of the ADINA software for Duncan-Chang E-B nonlinear elastic constitutive model was conducted in this paper, and the veracity of calculation results was verified. To contrast linear constitutive model and Duncan-Chang nonlinear constitutive model, the deformation of YuXi basin profile model under gravity action was calculated by both of the constitutive models. The results show that the subsidence in the linear results is about 12% larger than the nonlinear results, and the nonlinear model has advantages in parameter choosing. Meanwhile, a modified model of YuXi basin which depends on the latest data from our recent work in YuXi area was built to compare with the original model, the calculation results show that the changes in the basin basement structure and basin depth have great influence on the distribution and maximums of the deformation results, when the changes in the internal structure and sequence influence relatively little.

Soil dynamic nonlinear experimental results have significant impacts on the seismic response of engineering site, but how reasonable and effective to select soil samples for soil test, there is no good solution. Using detailed drilling velocity, density data, and rich soil test data of Shanxi Linfen Iron and Steel Hospital engineering site, four models are established and are analyzed for this problem. The results showed that: less than 3 meters of soil layer, each layer select one soil sample, for the thick soil layer, the rules of selecting one soil sample about every 3m thickness for the soil test, are recommended. If selecting one soil sample about every 5m~6m thickness for the thick soil layer, the calculation error is about ±10%.

A computational study of the bandgap structure in one-dimensional photonic crystals (PhCs) built with an elementary cell consisting of two sub-layers or four sub-layers is presented. The computational approach uses a finite element method to solve the differential systems with the continuous jump conditions. It is well known that the band structure and its features are strongly influenced by the number of periods, the lattice constant and the material dispersion. By choosing the geometrical parameters of the elementary cell optimally and controlling the band structure, we study the relationship between the gap and the number of periods, the lattice constant and the material dispersion. Then the optimal design of one-dimensional photonic crystals can be obtained by the numerical simulation. The numerical results show our finite element algorithm is efficient.