ABSTRACT
The Sm3+ doped SrO-Nb2O5-Al2O3-Ga2O3-SiO2 glasses in this work were prepared using the conventional melt quenching method. The effects of Al2O3/Ga2O3 ratio on the structure and orange light emission properties were studied by XRD, Raman spectroscopy, spectrophotometer and J-O theory, respectively. With the increase of Al2O3 content, the absorption coefficient of the glass sample gradually increases, which might be attributed to an increase in non-bridged oxygen bonds caused by a change in the glass network structure. Under 403 nm excitation, the emission spectra show clear peaks at 602 nm and 649 nm, representing the 4G5/2 â 6H7/2, and 4G5/2 â 6H9/2 transitions, respectively. When the Al2O3/Ga2O3 ratio is 0.25, the sample luminescence intensity is the highest, and the emission cross section of A2 glass sample is 4.34 × 10-22 cm2. The CIE color coordinates, color purity, and color temperature values of all samples were determined, and they were all located in the orange-red light region. The experiments results reveal that the prepared silica-aluminum-gallium glasses has a potential application prospect in orange-red LEDs, solid state lasers and other fields.
ABSTRACT
This paper examines the impact of the digital economy on sustainable development, using panel data from cities at the prefecture level and above in China from 2011 to 2019. The results indicate: (1) The digital economy is conducive to boosting growth, increasing employment, reducing energy consumption, and cutting emissions, thereby promoting sustainable development. These findings prove robust. (2) Mechanism test outcomes reveal that, from the perspective of technological innovation, the digital economy can promote sustainable development through increasing R&D input and enhancing innovation output. (3) An extended analysis of the risk of a digital "divide" demonstrates that "dividend" of the digital economy is primarily manifests in spurring economic growth, enhancing energy efficiency, and strengthening environmental protection in lagging regions, while the digital "divide" effect is manifested in the stronger employment stimulating effect of developed regions versus backward areas. The results of this study not only enrich the relevant research system, but also provide empirical evidence to support accelerating digital transformation, strengthening technological innovation governance, and advancing sustainable development.
