The study of tertiary layered machinable TizAIN ceramic is reviewed in respect of its electronic structure, mechanical property, oxidation behavior and thermoelectric property. Especially, the reason is explained for the lower fracture toughness and Vickers hardness but higher electrical conductivity of TizAIN compared with Ti2 AIC. Furthermore, the latest preparation and future applications of TizAIN are introduced.

Description is made of the separation of rhenium by extraction, ion-exc separation, and activated carbon adsorption,as well as the analysis of rhenium by MS and other methods. The characteristics of different methods and their applicat the development trend of the separation and analysis methods is reviewed.

Brief description is made of the main features and applications of laser technology in the field of material processing in respect of perforing,cutting and welding. And the laser surface modification and la- ser new material preparation is also introduced. Its prospect for development in the near future is pointed out.

YAG：Ho^3＋,1%Yb^3＋nanocrystal was synthesized by a sol-gel process from the mixed solution containing aluminum nitrate and rare earth oxide. The technological conditions to synthesize its xerogel were determined by orthogonal tests. DTA-TG,XRD and TEM techniques were used to study the synthe- sis process of the xerogel and characterize the crystal structure and morphology of the prepared YAG.1 Ho3＋ , 1%Yb3＋. The results show that monophase YAG crystallite can be formed without any intermediate phase after calciningthe xerogel at 1 200℃ Absorption spectrum and upconversion emission spectrum of YAG. 1 % Ho3＋, 1% Yh3＋ nanocrystal were investigated. Yb3＋ ions have the function of transferring energy in the luminescence process. Contributed to the Ho^3＋ transition, strong red and green upconversion fluorescence can be observed centered at 650 nm and 540 nm,respectively.

Si-Y2O3 infiltration coating was prepared from the Nb-Si-based ultrahigh-temperature alloy surface by the pack infiltration of heating for 10 h at 1 050 ℃ ,1 150℃ and 1 250℃ ,respectively. The effects of Y element on coating morphology and crack formation were investigated by SEM, EDS and XRD. Both prepared by the pack infiltration at the same temperature and duration,Si-Y2O3 infiltration coating was compared with single Si infiltration coating. The results show that the upper part of the outer coating layer is composed of （Nb, M）Si2 columnar grains, and the lower part composed of （Nb, M）Si2 equiaxed grains. The coating microstructure can be refined obviously by adding 0.75% （mass fraction） Y2O3 to the pack mixture. The total length of either vertical cracks or horizontal cracks is relatively small when the Y2O3 amount in pack mixture is in the range from 0.5% to 0.75%.

The laser sint alloy and TiH2. The mi formation mechanisms cussed. In the sintered ering experiment was carried out on the powder mixture of self-melting nickel-based crostructure of sintered samples was characterized by XRD,SEM and EDX. And the of porous structure and precipitated phase in sintered samples were simply dis samples, the reinforcing phases TiC and TiBz are in-situ synthesized and structure is also formed. A large number of micron-sized pores are uniformly dispersed in the matrix as the high-temperature strengthening phase CrB with a radial or acicular-lobate shape. porous as well

High-purity Er2O3 ceramic target material of about 90% relative density was prepared by lowtemperature nonpressurized sintering at 1 450℃ and with Er2O3 nanopowders as its raw material. The target materials prepared with Er2O3 nanopowders of various shape were analyzed from their fracture appearance and density. The results show that the target material prepared by low-temperature nonpressurized sintering and with three-dimensionally subsphaeroidal Er2O3 nanopowders as its raw material has the optimal performance.

The compound carbide （W-Ti-Ta-Nb）C was prepared by direct reduction. The influences of different calcination temperature and duration and mixing time on the contents of solid solution phase,combined carbon and free carbon in the prepared （W-Ti-Ta-Nb）C were investigated. By orthogonal experiments, the optimal carbonization parameters are obtained as follows：calcination temperature 2 100℃ ,calcination duration 50min and mixing duration 3 h. The final product is completely in the state of solid solution phase,where the content of combined carbon is 10.67% and free carbon is 0.15%.

A （Ti,V）C steel bonded carbide was prepared by in-situ sintering with the powders of titanium, ferrovanadium, carbon, ferrochromium, ferromolybdenum and iron as its raw materials. The phase composition,microstructure and micro-area composition of the carbide were studied by XRD, SEM and EDS. And the bending strength of the carbide sample was also measured. The results show that the morphology of （Ti,V）C reinforcing phase in the carbide is more regular and rounding than TiC particles. The bending strength is high. Furthermore, cleavage of reinforcing phase, quasi-cleavage of matrix and dimple are presented in the fractographic appearance of the carbide sample.