The bonding interface of 7B52 Al alloy laminated composite （ALC） fabricated by hot rolling was investigated using optical microscopy （OM）, transmission electron microscopy （TEM）, scanning electron microscopy （...The bonding interface of 7B52 Al alloy laminated composite （ALC） fabricated by hot rolling was investigated using optical microscopy （OM）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, ultrasonic flaw detection （UFD）, and bonding strength tests. The results show that metallurgical bonding is achieved at the interface after composite rolling. The TEM analysis and tensile tests indicate that the 7B52 ALC plate combines high strength of the hard individual layer and good toughness of the soft individual layer. However, UFD technology and SEM analysis prove that the defects （thick oxide films, acid washed residues, air, oil and coarse particles） existing in the bonding interface are harmful to the bonding strength. To sum up, the composite roiling process is suitable for 7B52 ALC plate, and the content and size of the defects should be controlled strictly. Advanced surface treatment of each individual layer would be beneficial to further improve the bonding quality.展开更多
This paper presents a three-stage hypothesis on the development of creative industrial clusters, which includes stages of agglomeration, interfacing, and network development. In the first stage, micro-entities concent...This paper presents a three-stage hypothesis on the development of creative industrial clusters, which includes stages of agglomeration, interfacing, and network development. In the first stage, micro-entities concentrate geographically in a creative industrial cluster in search of resources. The second stage reflects the need for building identity. Finally, the third stage is the outcome of multi-dimensional expansion. As a creative industrial cluster develops, its focus moves from geographic concentration to division of labor and the creation of novel systems. Using this three-stage framework, this paper conducts an empirical study on Beijing＇s 798 District （＂798＂）. Our study finds that the ＂self-destruction ＂phenomenon （which appeared after 798 had reached the stage of network development in a low-level capacity） is essentially the product of a squeezing effect of commercial prosperity on art production. Our study further examines four models of art-commerce integration and explains the ways in which creative industrial clusters are different from conventional industrial clusters： a creative cluster is a platform of integration for culture, commerce, and technology. Its course of development is characterized by novelty, emergence of identity through interfacing, and network cooperation.展开更多
基金Project(51312JQ08)supported by the Pre-Research Foundation of China General Equipment DepartmentProject(NBPJ2013-4)supported by the Postdoctoral Science Foundation of Ningbo Branch of China Academy of Ordnance Science+1 种基金Project(bsh1402073)supported by the Postdoctoral Science Foundation of Zhejiang Province,ChinaProject(2014A610051)supported by the Ningbo Natural Science Foundation of China
文摘The bonding interface of 7B52 Al alloy laminated composite （ALC） fabricated by hot rolling was investigated using optical microscopy （OM）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, ultrasonic flaw detection （UFD）, and bonding strength tests. The results show that metallurgical bonding is achieved at the interface after composite rolling. The TEM analysis and tensile tests indicate that the 7B52 ALC plate combines high strength of the hard individual layer and good toughness of the soft individual layer. However, UFD technology and SEM analysis prove that the defects （thick oxide films, acid washed residues, air, oil and coarse particles） existing in the bonding interface are harmful to the bonding strength. To sum up, the composite roiling process is suitable for 7B52 ALC plate, and the content and size of the defects should be controlled strictly. Advanced surface treatment of each individual layer would be beneficial to further improve the bonding quality.
基金Fertilization-independent formation of embryo,endospermand pericarpfor apomictic hybrid ricesupported by Australian Centre for International Agricultural Research(CIM/2002/106)
文摘This paper presents a three-stage hypothesis on the development of creative industrial clusters, which includes stages of agglomeration, interfacing, and network development. In the first stage, micro-entities concentrate geographically in a creative industrial cluster in search of resources. The second stage reflects the need for building identity. Finally, the third stage is the outcome of multi-dimensional expansion. As a creative industrial cluster develops, its focus moves from geographic concentration to division of labor and the creation of novel systems. Using this three-stage framework, this paper conducts an empirical study on Beijing＇s 798 District （＂798＂）. Our study finds that the ＂self-destruction ＂phenomenon （which appeared after 798 had reached the stage of network development in a low-level capacity） is essentially the product of a squeezing effect of commercial prosperity on art production. Our study further examines four models of art-commerce integration and explains the ways in which creative industrial clusters are different from conventional industrial clusters： a creative cluster is a platform of integration for culture, commerce, and technology. Its course of development is characterized by novelty, emergence of identity through interfacing, and network cooperation.
