For the last few decades,there has been extensive research on the materials that persist to emit optical radiation long after any type of charging has stopped.Most of the established persistent luminescence(PersL)mate...For the last few decades,there has been extensive research on the materials that persist to emit optical radiation long after any type of charging has stopped.Most of the established persistent luminescence(PersL)materials emit light in the visible part of the spectrum;however,in recent years,there has been a growing interest in UV-emitting persistent phosphors in recent years.These materials have been tested for various applications,such as photocatalysis,sterilization,and anti-counterfeiting,among others.Here,we report on the X-ray and UV-activated UV-A long PersL of Ce^(3+)-doped Sr_(3)MgSi_(2)O_(8) material.We prepared samples with varied Ce^(3+)concentrations using solid-state reaction synthesis in an ambient atmosphere and conducted a thorough investigation using photoluminescence(PL),electron paramagnetic resonance(EPR),and thermally stimulated luminescence(TSL)spectroscopy methods.Our experiments show that the PersL signal of Ce^(3+)in the 300-450 nm range can be detected for at least 16 h when samples are irradiated with X-rays or UV.The TSL analysis reveals multiple discrete charge traps in the material with activation energies between 0.5 and 1.7 eV.Further EPR measurements confirm the presence of four paramagnetic centers.The thermal stability of these centers was analyzed,and it is established that one of these centers(g_(1)=2.0056,g_(2)=1.9981,and g_(3)=1.9926)gradually decays at room temperature,which is correlated with the PersL processes.展开更多
基金supported by the Latvian Council of Science,project"Defect engineering of novel UV-C persistent phosphor materials"(lzp-2021/1-0118)。
文摘For the last few decades,there has been extensive research on the materials that persist to emit optical radiation long after any type of charging has stopped.Most of the established persistent luminescence(PersL)materials emit light in the visible part of the spectrum;however,in recent years,there has been a growing interest in UV-emitting persistent phosphors in recent years.These materials have been tested for various applications,such as photocatalysis,sterilization,and anti-counterfeiting,among others.Here,we report on the X-ray and UV-activated UV-A long PersL of Ce^(3+)-doped Sr_(3)MgSi_(2)O_(8) material.We prepared samples with varied Ce^(3+)concentrations using solid-state reaction synthesis in an ambient atmosphere and conducted a thorough investigation using photoluminescence(PL),electron paramagnetic resonance(EPR),and thermally stimulated luminescence(TSL)spectroscopy methods.Our experiments show that the PersL signal of Ce^(3+)in the 300-450 nm range can be detected for at least 16 h when samples are irradiated with X-rays or UV.The TSL analysis reveals multiple discrete charge traps in the material with activation energies between 0.5 and 1.7 eV.Further EPR measurements confirm the presence of four paramagnetic centers.The thermal stability of these centers was analyzed,and it is established that one of these centers(g_(1)=2.0056,g_(2)=1.9981,and g_(3)=1.9926)gradually decays at room temperature,which is correlated with the PersL processes.
文摘研究了盐酸坦洛新(TSLS)缓释滴丸的处方工艺.采用聚乙二醇6000和聚乙二醇4000为速释性固体分散载体材料,硬脂酸及单硬脂酸甘油酯为缓释性骨架材料,熔融法制备缓释滴丸.以滴丸圆整度和丸重的RSD为指标,对TSLS缓释滴丸的制备工艺进行了优化.所得滴丸的圆整度好、丸重差异小,体外释放符合Higuchi模型,可持续释药24 h.
