scholarly journals Recombination luminescence of CaSO4:Tb3+ and CaSO4:Gd3+phosphors

Open Physics ◽  
2012 ◽  
Vol 10 (4) ◽  
Author(s):  
Irina Kudryavtseva ◽  
Aleksandr Lushchik ◽  
Aarne Maaroos ◽  
Zhannur Azmaganbetova ◽  
Turlybek Nurakhmetov ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Energy Transfer ◽  
Comparative Study ◽  
Cation Vacancy ◽  
Charge Compensation ◽  
Photostimulated Luminescence ◽  
Electron Hole ◽  
Recombination Luminescence ◽  
Released Energy ◽  
Thermal Stability Of

AbstractA comparative study of the excitation of luminescence by VUV radiation as well as of thermally and photostimulated luminescence has been carried out for CaSO4:Tb3+ and CaSO4:Gd3+ phosphors, where Na+ or F− ions are used for charge compensation. The distinction in hole processes for the phosphors with Na+ or F− compensators is determined by the differing thermal stability of the holes localized at/near Tb3+Na+ and Gd3+Na+ (up to 100–160 K) or at/near Tb3+F− V Ca and Gd3+F− V Ca centers involving also a cation vacancy (up to 400–550 K). Tunnel luminescence in the pairs of localized electrons and holes nearby Tb3+ or Gd3+ has been detected. The mechanisms of electron-hole, hole-electron and tunnel recombination luminescence as well as a subsequent released energy transfer to RE3+ ions are considered.

Intrinsic Thermal Stability of Anisotropic Thin-Film Superconductors

1990 ◽  
Vol 112 (1) ◽  
pp. 10-15 ◽  
Author(s):  
M. I. Flik ◽  
C. L. Tien
Keyword(s):  
Thin Film ◽  
Thermal Stability ◽  
Stability Criterion ◽  
High Temperature Superconductors ◽  
Stability Criteria ◽  
Anisotropic Thermal Conductivity ◽  
Operating Current ◽  
Released Energy ◽  
The Stability ◽  
Thermal Stability Of

Intrinsic thermal stability denotes a situation where a superconductor can carry the operating current without resistance at all times after the occurrence of a localized release of thermal energy. This novel stability criterion is different from the cryogenic stability criteria for magnets and has particular relevance to thin-film superconductors. Crystals of ceramic high-temperature superconductors are likely to exhibit anisotropic thermal conductivity. The resultant anisotropy of highly oriented films of superconductors greatly influences their thermal stability. This work presents an analysis for the maximum operating current density that ensures intrinsic stability. The stability criterion depends on the amount of released energy, the Biot number, the aspect ratio, and the ratio of the thermal conductivities in the plane of the film and normal to it.

Enhanced red emission and thermal stability of Ca(MoO4)0.8(WO4)0.2:xDy3+, yEu3+ phosphors by charge compensation

2022 ◽  
Vol 241 ◽  
pp. 118504
Author(s):  
Zhongxu Han ◽  
Shuchen Lü ◽  
Qingyu Meng ◽  
Mengsi Sun ◽  
Yandong Ren
Keyword(s):  
Thermal Stability ◽  
Charge Compensation ◽  
Red Emission ◽  
Thermal Stability Of

Study on Acrylic Emulsion Adhesive Modified by Double Siloxane

2013 ◽  
Vol 395-396 ◽  
pp. 367-370
Author(s):  
Cai Hua Gao ◽  
Wen Lu Guo ◽  
Zhi Ming Jin
Keyword(s):  
Thermal Stability ◽  
Comparative Study ◽  
Heat Resistance ◽  
Chemical Process ◽  
Water Resistance ◽  
Orthogonal Experiment ◽  
Acrylic Emulsion ◽  
Macroscopic Properties ◽  
The Stability ◽  
Thermal Stability Of

The acrylic emulsion adhesive was modified by D4 and KH570 with chemical process, and we can get the modified product successfully via the best technology parameter which was confirmed by orthogonal experiment. The structure of acrylic was characterized by FTIR, while there was a comparative study on the macroscopic properties and thermal stability of the unmodified and modified product. The results showed that when m(D4):m(KH570) was 2:1, the dosage of emulsifier was 3.0%, the dosage of KPS was 4.0%, the monomer(soft and hard) ratio was 1:1, the stability of the acrylic emulsion adhesive modified by double siloxane was good, and its viscosity, water resistance, heat resistance were improved greatly.

Comparative study of the oxidative and thermal stability of vegetable oils to be used as lubricant bases

2012 ◽  
Vol 111 (2) ◽  
pp. 1437-1442 ◽  
Author(s):  
José Roberto dos Santos Politi ◽  
Paulo Roberto Rodrigues de Matos ◽  
Maria José Araújo Sales
Keyword(s):  
Thermal Stability ◽  
Comparative Study ◽  
Vegetable Oils ◽  
Thermal Stability Of
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