Numerical Investigation of Miniature Ejector Refrigeration System Embedded with a Capillary Pump Loop.

A miniature steam ejector refrigeration system embedded with a capillary pump loop can result in a compact design which can be used for electronics cooling. In this paper, computational fluid dynamics (CFD) is employed to investigate the effects of the area ratio of the ejector constant-area mixing section to the nozzle throat, the length of the constant-area section, and the nozzle exit position (NXP), on the performance of a miniature steam ejector. Results show that the performance of the miniature steam ejector is very sensitive to the area ratio of the constant-area mixing section to the nozzle.

[White light upconversion luminescence and its mechanism of Yb3+/Ho3+/Tm3+ co-doped tellurite glass].

Yb3+ /Ho3+, Yb3+ /Tm3+ and Yb3+ /Ho3+ /Tm3+ co-doped tellurite glasses were prepared by melt-quenching method. Under the excitation of 980 nm laser, Yb3+ /Ho3+/Tm3+ co-doped glass sample shows strong blue, green and red emissions, corresponding to the transitions 1G4 --> 3H6 of Tm3+, 5F4 (5S2) --> 5 I8 of Ho3+, as well as 5F5 -->5 I8 of Ho3+ and 1G4 --> 3F4 of Tm3+ ions, respectively. It was found that the integrated emission intensity ratio of the red to green in Yb3+/Ho3+ /Tm3+ co-doped sample (3.