The typical morphology of alloy lead（Pb） in ancient bronzes made in the Spring-Autumn Warring States Period（770 B.C.-221 B.C.）,China,was examined by using electron microscopic techniques.We propose that the main p...The typical morphology of alloy lead（Pb） in ancient bronzes made in the Spring-Autumn Warring States Period（770 B.C.-221 B.C.）,China,was examined by using electron microscopic techniques.We propose that the main purposes for adding metallic Pb in a large quantity into ancient bronzes,such as arrows and ritual vessel-Ding,were for increasing weight and economical reasons.In order to promote adding efficiency and improve casting quality for getting homogenously distributed Pb particles in the bronzes,a process through inserting Pb rod into the mold is supposed to be used during casting,which provided a process for preventing Pb sinkage.Scanning electron microscope（SEM） observations from the fracture surface of the bronzes revealed that the Pb particle possessed a ＂hollow-cored bubble＂ structure,which was formed due to absorbing casting gases during solidification and therefore indirectly eliminated the casting porosity and loosen.展开更多
Chloride ion critical content was studied under soaking and cycle of dry and wet conditions, with three electrochemical nondestructive measuring techniques, i e, half-cell potential, A C impedance, and time potential....Chloride ion critical content was studied under soaking and cycle of dry and wet conditions, with three electrochemical nondestructive measuring techniques, i e, half-cell potential, A C impedance, and time potential. The experimental results show that chloride ion critical content is primarily determined by the water cement ratio, while for the same concrete mixture the chloride ion critical content in soaking conditions is larger than that in a cycle of dry and wet conditions.展开更多
基金Supported by the National Natural Science Foundation of China(J1210061)
文摘The typical morphology of alloy lead（Pb） in ancient bronzes made in the Spring-Autumn Warring States Period（770 B.C.-221 B.C.）,China,was examined by using electron microscopic techniques.We propose that the main purposes for adding metallic Pb in a large quantity into ancient bronzes,such as arrows and ritual vessel-Ding,were for increasing weight and economical reasons.In order to promote adding efficiency and improve casting quality for getting homogenously distributed Pb particles in the bronzes,a process through inserting Pb rod into the mold is supposed to be used during casting,which provided a process for preventing Pb sinkage.Scanning electron microscope（SEM） observations from the fracture surface of the bronzes revealed that the Pb particle possessed a ＂hollow-cored bubble＂ structure,which was formed due to absorbing casting gases during solidification and therefore indirectly eliminated the casting porosity and loosen.
文摘Chloride ion critical content was studied under soaking and cycle of dry and wet conditions, with three electrochemical nondestructive measuring techniques, i e, half-cell potential, A C impedance, and time potential. The experimental results show that chloride ion critical content is primarily determined by the water cement ratio, while for the same concrete mixture the chloride ion critical content in soaking conditions is larger than that in a cycle of dry and wet conditions.
