Significant grain refinement was achieved in rare earth (RE) containing aeronautic magnesium alloy ZE41A through equal-channel angular pressing (ECAP) using rotary die at 603 K. Influence of ECAP pass number on its mi...Significant grain refinement was achieved in rare earth (RE) containing aeronautic magnesium alloy ZE41A through equal-channel angular pressing (ECAP) using rotary die at 603 K. Influence of ECAP pass number on its microstructure change and corrosion behavior was investigated by optical microscope (OM)/scanning electron microscope (SEM) observation and potentiostatic polarization tests in aqueous solution of NaCl, respectively. The results showed that ultrafine equiaxial grains (about 2.5 μm) were obtained over 16 passes due to plastic-induced grain refinement accommodated by dynamic recrystallization. The lower corrosion current density and nobler corrosion potential correlated with large number of pressing passes were attributed to the low tendency toward localized corrosion with broken secondary phase after homogenization on ultrafine-grained Mg matrix. The multi-pass ECAP method made the ZE41A aeronautic magnesium alloy more attractive since severe plastic deformation may significantly improve its corrosion resistance besides superior mechanical properties.展开更多
In this paper, we report a multiple sequence alignment result on the basis of 10 amino acid sequences of the M protein, which come from different coronaviruses (4 SARS associated and 6 others known). The alignment mo...In this paper, we report a multiple sequence alignment result on the basis of 10 amino acid sequences of the M protein, which come from different coronaviruses (4 SARS associated and 6 others known). The alignment model was based on the profile HMM (Hidden Markov Model), and the model training was implemented through the SAHMM (Self Adapting Hidden Markov Model) software developed by the authors.展开更多
基金Project supported by the Japan Society for the Promotion of Science (JSPS) for UFG ZE41A FabricationQing Lan Project (Jiangsu,China)
文摘Significant grain refinement was achieved in rare earth (RE) containing aeronautic magnesium alloy ZE41A through equal-channel angular pressing (ECAP) using rotary die at 603 K. Influence of ECAP pass number on its microstructure change and corrosion behavior was investigated by optical microscope (OM)/scanning electron microscope (SEM) observation and potentiostatic polarization tests in aqueous solution of NaCl, respectively. The results showed that ultrafine equiaxial grains (about 2.5 μm) were obtained over 16 passes due to plastic-induced grain refinement accommodated by dynamic recrystallization. The lower corrosion current density and nobler corrosion potential correlated with large number of pressing passes were attributed to the low tendency toward localized corrosion with broken secondary phase after homogenization on ultrafine-grained Mg matrix. The multi-pass ECAP method made the ZE41A aeronautic magnesium alloy more attractive since severe plastic deformation may significantly improve its corrosion resistance besides superior mechanical properties.
文摘In this paper, we report a multiple sequence alignment result on the basis of 10 amino acid sequences of the M protein, which come from different coronaviruses (4 SARS associated and 6 others known). The alignment model was based on the profile HMM (Hidden Markov Model), and the model training was implemented through the SAHMM (Self Adapting Hidden Markov Model) software developed by the authors.
