The evolution mechanism of intron length.

Within two years of their discovery in 1977, introns were found to have a positive effect on gene expression. Our result shows that introns can achieve gene expression and regulation through interaction with corresponding mRNA sequences. On the base of Smith-Waterman method, local comparing helps us get the optimal matched segments between intron sequences and mRNA sequences.

[Preparation and luminescence properties of nanomaterials TiO2-SiO2 doped with Eu3+].

In the present paper, the samples of nanomaterials TiO2-SiO2:Eu3+ with different proportion of Ti/Si were prepared with the sol-gel method, and influence of the proportion of Ti/Si on the luminescence properties of samples have was studied. The structure of the samples was examined by FTIR, indicating that the compound TiO2 and SiO2 reacted, forming the new chemical bond of Ti-O-Si. The TEM of samples show that TiO2-SiO2:Eu3+ are sphericity nanoparticles with monodispersion and uniform size of 35 nm.

[Preparation and luminescent properties of CaMoO4:Tb3+].

The precursor of the sample CaMoO4:Tb3+ was prepared by the coprecipitation method. TG-DTA spectra show that there is, at 850 degrees C, an energy absorption peak, suggesting that the sample reaches the activation spot of its response. The XRD pattern of the roasted sample shows that CaMoO4:Tb3+, in the single phase, is a representative scheelite structure of CaMoO4, but the peaks shift toward right, implying that tiny crystal defect in the crystal is produced.