Search

Absorption spectra, emission spectra of nanoized erbium implanted mesoporous silica functionalized with and without bis(perfluoromethylsulfonyl)amine as ligand were studied. Luminescence with high intensity has been obtained. The Judd-Ofelt strength parameters Ω t ( t =2,4,6)were calculated as Ω 2 ＝1.88×10 -20 cm 2 ， Ω 4 ＝5.45×10 -20 cm 2 and Ω 6 ＝3.11×10 -20 cm 2 , respectively. Oscillator strength, spontaneous emission probability, branching ratio and emission lifetime of each energy levels of Er 3+ were given. The peak intensity of emission spectra varying with the pump power was discussed. Stimulated emission cross section ( σ em ＝10.9×10 -21 cm 2 ) was calculated and compared with that of other host materials.

This paper discusses the influence of the polarization of incident X-vay on the reconstructed atomic image by numerical simulation and reconstruction, using a crystalstructure composed of 27 Fe atoms arranged in a cubic lattice as the model. Calculated results show that the choice of polarization is crucial for the atom observability. This paper proposes a new reconstructing algorithm which can eliminate the polarization effect of incident X-ray source and twin images inherent to holography at the same time. Numerical simulation and reconstruction results show that the reconstructing algorithm is effective and can be used to eliminate the influence of polarization of incident light source and twin image in experiments.

It is difficult for the nondestructive detection of inertial fusion capsule. Based on this requirement we constructed a physical model of low Z material wrapped by strongly absorbing medium. By simulation and experiments，we investigate the effect of some factors on phase contrast imaging quality，such as X-ray energy，distance of object to detector, thickness of strongly absorbing materials and so on. We find it feasible to realize the high resolution and nondestructive detection of inertial fusion capsule by X-ray phase contrast imaging.