Jiangxi University of Science and Technology

About: Jiangxi University of Science and Technology is a education organization based out in Ganzhou, China. It is known for research contribution in the topics: Microstructure & Alloy. The organization has 6958 authors who have published 5576 publications receiving 50650 citations.

Upconversion luminescence enhancement and temperature sensing behavior of F− co-doped Ba3Lu4O9:Er3+/Yb3+ phosphors

Abstract: A series of Ba3Lu4O9:Er3+/Yb3+ (EYBLO) phosphors co-doped with F− ions were synthesized by a simple solid-state reaction method. The results showed that the primary rhombohedral structure was maintained and the crystal lattice began to shrink when F− ions were introduced into the host matrix to occupy the O2− site. The agglomerations and the impurities (OH− and CO2) with higher phonon energy on the sample surface could be minimized and the sample crystallinity could be improved. Under 980 nm laser diode excitation, the green and red UC emissions of the EYBLO:0.4F− sample show nearly 5- and 7.5-fold enhancements in contrast to F−-free EYBLO. The upconversion luminescence can be finely tuned from yellow to red light to some extent by increasing F− concentration. Based on pump-power dependence and decay lifetime analysis, the energy level diagram was illustrated and the upconversion energy-transfer mechanism was discussed. The green and red emission enhancements are attributed to the modification of the local crystal field of Er3+ ions and reduction of crystal site symmetry. The cross-relaxation and back-energy-transfer processes play an important role to enhance the red/green UC emission intensity ratios. The fluorescence intensity ratio technique was employed to investigate the temperature sensing behavior of the synthesized phosphors. The temperature sensing properties can be enhanced by doping of F− ions, and the maximum sensitivity is found to be 44.57 × 10−4 K−1 at 523 K. It is promising to provide an alternative approach for enhancing UC luminescence and the temperature sensitivity in oxide matrixes and then obtain high-quality optical temperature-sensing materials by simply co-doping F− ions.

A Comparative Analysis of the Impact of Political Trust on the Adoption of E-Government Services

Abstract: This study sought to examine the differential effects of political trust on the adoption of e-government services between foreign and Chinese students. Political trust was integrated into the Unifi...