The effect of yttrium and mischmetal(MMs) on the as-cast and solid solution treated structures of Mg-Al alloys with different Al-contents was investigated. The results show that the MMs in Mg-Al alloy existed in rod A...The effect of yttrium and mischmetal(MMs) on the as-cast and solid solution treated structures of Mg-Al alloys with different Al-contents was investigated. The results show that the MMs in Mg-Al alloy existed in rod Al 4(Ce, La)compound while Y in Mg-Al alloy in polygonal Al 2Y compound. The amount of Mg 17Al 12 in Mg-Al alloy is decreased with increasing Y or MMs addition, and Mg 17Al 12 intermetallic compound is changed from continuous network to discontinuous one. The Al 4(Ce, La) and Al 2Y compounds are not dissolved into Mg-Al alloy matrix during solid solution treatment so that their high heat stability can be exhibited. The experiment of mechanical properties indicate that elongation and impact toughness of the Mg-Al-Y alloy with polygonal Al 2Y compound are higher than those of Mg-Al-MMs alloy with rod Al 4(Ce, La) compound.展开更多
The determination of five aromatic amines was studied using capillary electrophoresis with pulse voltammetric detector. The D/A converter at an EVOC PLC-711B Card was used to generate the pulse electrode potential wav...The determination of five aromatic amines was studied using capillary electrophoresis with pulse voltammetric detector. The D/A converter at an EVOC PLC-711B Card was used to generate the pulse electrode potential waveform. The A/D converter acquired the electrode current at the last one millisecond of every pulse. Good reproducibility and low limit were obtained. The results shown that pulse voltammetric detection has the advantages of elimination of charge current and direct identification of unknown chemicals.展开更多
文摘The effect of yttrium and mischmetal(MMs) on the as-cast and solid solution treated structures of Mg-Al alloys with different Al-contents was investigated. The results show that the MMs in Mg-Al alloy existed in rod Al 4(Ce, La)compound while Y in Mg-Al alloy in polygonal Al 2Y compound. The amount of Mg 17Al 12 in Mg-Al alloy is decreased with increasing Y or MMs addition, and Mg 17Al 12 intermetallic compound is changed from continuous network to discontinuous one. The Al 4(Ce, La) and Al 2Y compounds are not dissolved into Mg-Al alloy matrix during solid solution treatment so that their high heat stability can be exhibited. The experiment of mechanical properties indicate that elongation and impact toughness of the Mg-Al-Y alloy with polygonal Al 2Y compound are higher than those of Mg-Al-MMs alloy with rod Al 4(Ce, La) compound.
文摘The determination of five aromatic amines was studied using capillary electrophoresis with pulse voltammetric detector. The D/A converter at an EVOC PLC-711B Card was used to generate the pulse electrode potential waveform. The A/D converter acquired the electrode current at the last one millisecond of every pulse. Good reproducibility and low limit were obtained. The results shown that pulse voltammetric detection has the advantages of elimination of charge current and direct identification of unknown chemicals.
