In our previous studies, the influence of L1 2 modified Al 2.5 Cu 0.5 Ti and Al 2.7 Fe 0.3 Ti particles on the grain refining performance of an Al cast was studied. It has been shown that the L1 2 modified intermetallic compound particles act as heterogeneous nucleation sites of α-Al solidification. Since nuclei are formed on the surface of the heterogeneous nucleation site particles, only the surface region of the Al 3 Ti particles must be modified into an L1 2 structure. In this study, therefore, the formation of the Al 2.5 Cu 0.5 Ti phase by the reaction between Al 3 Ti and Cu is studied. For this purpose, Cu/Al 3 Ti diffusion couple specimens and specimens of Al 3 Ti particles dispersed in a Cu matrix are fabricated by a spark plasma sintering (SPS) method, and the reaction between Cu and Al 3 Ti during heat treatment of these specimens is studied. It is found that the L1 2 modified Al 2.5 Cu 0.

The expression on dark-field micrographs using RI-labeled probe was estimated with Scion ImagePC software. Step 11 spermatids expressed more than twice as much PHGPx mRNA as step 4 spermatids. These results suggest that PHGPx may play an essential role in spermatogenes is.

Strength evaluation ofsilicon based on fracture mechanics and characterization ofdamage

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