Effect of Zn on the microstructure, age hardening response and mechanical properties of Mg3Sn-1Al alloy which is immediately aged at 180uC after extrusion process (T5) was investigated. It was found that the Zn can refine the microstructure, remarkably improve the aging response with the peak hardness increases to 75 HV and the time to peak hardness reduces from y110 to y60 h, which is attributed to the solid solution hardening of Al, Zn and an amount of finer Mg 2 Sn precipitates. The as aged Mg-3Sn-2Zn-1Al alloy exhibits better mechanical property at room temperature or 150uC than that of Mg-3Sn-1Al alloy, which is ascribed to the fine grained microstructure and thermally stable Mg 2 Sn particles dispersed at grain boundaries and in the matrix.

A novel recyclable hydrogen bonding crosslinked polymer PEAINKH+ was prepared, which possesses outstanding thermal stability.

A fracture strength model applied at room temperature for the embedded crack was obtained based on the stress intensity factor model for embedded crack with an arbitrarily shaped front and Griffith fracture criterion. With further research on temperature effect on strength of ultra high temperature ceramics (UHTCs), a thermo‐damage strength model including the effects of temperature and crack shape was applied to each temperature phase. The fracture strengths were studied and analyzed. The conclusions were compared with the results obtained using the finite element software ABAQUS. This study will provide a theoretical basis and guidance on the design and preparation of the UHTCs.

(Zn,Lnx )MoO4 :Tb(3+) (Ln = Y(3+), Gd(3+) and Lu(3+) ) were prepared using the co-precipitation method. Phase impurity, morphology and composition were investigated by power X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The experimental results show that crystal structure is not destroyed after doping an appropriate amount of Y(3+), Gd(3+) and Lu(3+). EDS analysis reveals that Y, Gd and Lu have been successfully doped into ZnMoO4 . In addition, the morphology of the phosphors is notably improved, exhibiting homogeneous dispersion morphology and irregular shapes of particle size ~ 0.5-1 µm. The luminescent intensity of (Zn,Lnx )MoO4:Tb(3+) (Ln = Y(3+), Gd(3+) and Lu(3+)) phosphor is obviously higher than that of ZnMoO4 :Tb(3+) phosphor. The energy transfer process between trivalent rare earth ions indicates that the inert earth ions can act as an energy bridge from MoO4(2-) to Tb(3+).