An original reinforced concrete(RC) column and four strengthened specimens, two with RC jackets and two with wing walls, were tested in this study. The original column specimen was designed to comply with older(pre-19...An original reinforced concrete(RC) column and four strengthened specimens, two with RC jackets and two with wing walls, were tested in this study. The original column specimen was designed to comply with older(pre-1999) design standards so that the usual detailing defi ciencies in existing school buildings in Taiwan could be simulated. Two different structural details were chosen to fabricate the full-scale specimens for each retrofi tting technique. The study confi rmed that either RC jacketing or the installation of wing walls with two different structural details can effectively improve the stiffness and strength of an existing column. RC jacketing shows a better improvement in energy dissipation and ductility when compared to the columns with wing walls installed. This is because the two RC jacketed columns experienced a fl exural failure, while a shear failure was found in the two columns with the wing walls installed, and thus led to a drastic decrease of the maximum lateral strengths and ductility. Since many factors may affect the installation of a post-installed anchor, it is better to use standard hooks to replace post-installed anchors in some specifi c points when using RC jacketing or installing wing walls.展开更多
We prepared 300-nm GeTe thin films on(111)-oriented and piezoelectrically active 0.71 Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.29PbTiO_(3)(PMN-0.29 PT)single-crystal substrates by the pulsed laser deposition and investigated the e...We prepared 300-nm GeTe thin films on(111)-oriented and piezoelectrically active 0.71 Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.29PbTiO_(3)(PMN-0.29 PT)single-crystal substrates by the pulsed laser deposition and investigated the effects of in situ electric-field-controllable non-180ferroelastic domain switching of the PMN-0.29 PT on the electronic properties of the GeTe films.The in-plane strain of the PMN-0.29 PT could be modulated continuously and reversibly by electric fields in a nonvolatile manner and could be effectively transferred to the GeTe films.Based on this,we realized reversible and nonvolatile resistance switching and obtained multilevel stable nonvolatile resistance states with good stability and endurance at T=300 K by applying appropriate asymmetrical bipolar electric fields to the PMN-0.29 PT(111)substrates along the thickness direction.Such heterostructures may be used for multilevel data storage that allows each unit to store multiple bits of information and thus improve the memory density.Our investigation would be beneficial for the fabrication of nonvolatile memory devices using PMN-xPT-based heterostructures.展开更多
基金the fi nancial support for this study from the Architecture and Building Research Institute,Chinese Taipei,under Grant No.099301070000G1005
文摘An original reinforced concrete(RC) column and four strengthened specimens, two with RC jackets and two with wing walls, were tested in this study. The original column specimen was designed to comply with older(pre-1999) design standards so that the usual detailing defi ciencies in existing school buildings in Taiwan could be simulated. Two different structural details were chosen to fabricate the full-scale specimens for each retrofi tting technique. The study confi rmed that either RC jacketing or the installation of wing walls with two different structural details can effectively improve the stiffness and strength of an existing column. RC jacketing shows a better improvement in energy dissipation and ductility when compared to the columns with wing walls installed. This is because the two RC jacketed columns experienced a fl exural failure, while a shear failure was found in the two columns with the wing walls installed, and thus led to a drastic decrease of the maximum lateral strengths and ductility. Since many factors may affect the installation of a post-installed anchor, it is better to use standard hooks to replace post-installed anchors in some specifi c points when using RC jacketing or installing wing walls.
基金Project supported by the Natural Science Foundation of Zhejiang Province(No.LQ18E050004)the Initial Foundation of Ningbo University(No.421610040)the K.C.Wong Magna Fund in Ningbo University,China
基金the National Natural Science Foundation of China(Grant Nos.51572278,51790491,11574126,51872278)the National Basic Research Programof China(Grant Nos.2016YFA0300103 and 2015CB921201)Support from Jiangxi Key Laboratory for Two-Dimensional Materials and Jiangxi Engineering Laboratory for Thin Films and Devices is also acknowledged.
文摘We prepared 300-nm GeTe thin films on(111)-oriented and piezoelectrically active 0.71 Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.29PbTiO_(3)(PMN-0.29 PT)single-crystal substrates by the pulsed laser deposition and investigated the effects of in situ electric-field-controllable non-180ferroelastic domain switching of the PMN-0.29 PT on the electronic properties of the GeTe films.The in-plane strain of the PMN-0.29 PT could be modulated continuously and reversibly by electric fields in a nonvolatile manner and could be effectively transferred to the GeTe films.Based on this,we realized reversible and nonvolatile resistance switching and obtained multilevel stable nonvolatile resistance states with good stability and endurance at T=300 K by applying appropriate asymmetrical bipolar electric fields to the PMN-0.29 PT(111)substrates along the thickness direction.Such heterostructures may be used for multilevel data storage that allows each unit to store multiple bits of information and thus improve the memory density.Our investigation would be beneficial for the fabrication of nonvolatile memory devices using PMN-xPT-based heterostructures.
