Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of normal metal/dx2-y2 ＋ idxy mixed wave superconductor graphene junctions. It is found that the conductance spectra vary ...Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of normal metal/dx2-y2 ＋ idxy mixed wave superconductor graphene junctions. It is found that the conductance spectra vary strongly with the orientation of the gap and the amplitude ratio （Δ1/Δ0） of two components for dx2-y2 ＋ idxy mixed wave. The zero bias conductance is nearly 2 and the conductance peak vanishes in doped graphene for a = 0 and Δ1/Δ0 = 1. The conductance increases with increasing the amplitude ratio of two components for α =π/4 and Δ1/Δ0 -- 1. The ZBCP becomes observable wide with 1 〈 EF/Δ0 〈 100 for α= π/4 and Δ1/Δ0 = 1. This property is different from that in normal metal/dx2-y2 wave superconductor graphene junctions.展开更多
Second lining stability, which is the last protection in tunnel engineering, is critically important. The theological properties of the surrounding rock heavily affect second lining stability. In this work, we used la...Second lining stability, which is the last protection in tunnel engineering, is critically important. The theological properties of the surrounding rock heavily affect second lining stability. In this work, we used laboratory triaxial compressive rheological limestone tests to study nonlinear creep damage characteristics of surrounding rock mass in construction projects. We established a nonlinear creep damage constitutive model for the rock mass, as well as a constitutive model numerical implementation made by programming. Second, we introduced a new foam concrete with higher compression performance and good ductility and studied its mechanical properties through uniaxial and triaxial tests. This concrete was used as the filling material for the reserved deformation layer between the primary support and second lining. Finally, we proposed a high efficiency and accuracy staged optimization method. The minimum reserved deformation layer thickness was established as the optimization goal, and the presence of plastic strain in the second lining after 100 years of surrounding rock creep was used as an evaluation index. Reserved deformation layer thickness optimization analysis reveals no plastic strain in the second lining when the reserved deformation minimum thickness layer is 28.50 cm. The results show that the new foam concrete used as a reserved deformation layer filling material can absorb creep deformation of surrounding rock mass, reduce second lining deformation that leads to plastic strain, and ensure long-term second lining stability.展开更多
After a long subway tunnel operators will produce cross-sectional deformation. Articles designed vehicle laser ranging device tbr continuous measurement of tunnel wall to test their defomaed state. The paper also desc...After a long subway tunnel operators will produce cross-sectional deformation. Articles designed vehicle laser ranging device tbr continuous measurement of tunnel wall to test their defomaed state. The paper also describes the tunnel cross-section deltbrmation measurement method, contour titting principles and error analysis and networking technology for wireless data transmission methods. The detection system is designed to achieve a tunnel section of the structural safety testing and deformation that may occur timely disaster warning, the safe operation of the subway tunnel to provide effective protection.展开更多
Central venous catheterization is widely used in the emergency setting. This review aims to assess central venous catheterization from the perspectives of types of catheters, sites of insertion, and tech- niques. In e...Central venous catheterization is widely used in the emergency setting. This review aims to assess central venous catheterization from the perspectives of types of catheters, sites of insertion, and tech- niques. In emergency conditions, non-tunneled catheters are preferred because the technique for its insertion is not complicated and less time-consuming. The size of catheter depends on the purpose of catheterization. For example, a large bore catheter is needed for rapid infusion. The ideal catheterization site should bear fewer thromboses, lower infectious rate, and fewer mechanical complications. Thus the femoral vein should be avoided due to a high rate of colonization and thrombosis while the subclavian vein seems to exhibit fewer infectious complications compared with other sites. The ultrasound-guided technique increases the success rate of insertion while decreases the mechanical complications rate,展开更多
Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of graphene ferromagnet/p wave superconductor junctions. It is found that the conductance spectra are affected by the p wav...Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of graphene ferromagnet/p wave superconductor junctions. It is found that the conductance spectra are affected by the p wave pairing symmetry. The ferromagnetic exchange energy in the ferromagnet can suppress Andreev retroreflection but enhance the specular Andreev reflection in graphene ferromagnet/p wave superconductor junctions. The conductance decreases with increasing exchange energy Eh for Eh〈Er （the Fermi energy in the ferromagnet region）, but the conductance increases with increasing exchange energy Eh for Eh〉EF.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No. 11074088
文摘Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of normal metal/dx2-y2 ＋ idxy mixed wave superconductor graphene junctions. It is found that the conductance spectra vary strongly with the orientation of the gap and the amplitude ratio （Δ1/Δ0） of two components for dx2-y2 ＋ idxy mixed wave. The zero bias conductance is nearly 2 and the conductance peak vanishes in doped graphene for a = 0 and Δ1/Δ0 = 1. The conductance increases with increasing the amplitude ratio of two components for α =π/4 and Δ1/Δ0 -- 1. The ZBCP becomes observable wide with 1 〈 EF/Δ0 〈 100 for α= π/4 and Δ1/Δ0 = 1. This property is different from that in normal metal/dx2-y2 wave superconductor graphene junctions.
基金Projects(51409154,41372289)supported by the National Natural Science Foundation of ChinaProjects(2015JQJH106,2014TDJH103)supported by Research Fund of Shandong University of Science and Technology,China
文摘Second lining stability, which is the last protection in tunnel engineering, is critically important. The theological properties of the surrounding rock heavily affect second lining stability. In this work, we used laboratory triaxial compressive rheological limestone tests to study nonlinear creep damage characteristics of surrounding rock mass in construction projects. We established a nonlinear creep damage constitutive model for the rock mass, as well as a constitutive model numerical implementation made by programming. Second, we introduced a new foam concrete with higher compression performance and good ductility and studied its mechanical properties through uniaxial and triaxial tests. This concrete was used as the filling material for the reserved deformation layer between the primary support and second lining. Finally, we proposed a high efficiency and accuracy staged optimization method. The minimum reserved deformation layer thickness was established as the optimization goal, and the presence of plastic strain in the second lining after 100 years of surrounding rock creep was used as an evaluation index. Reserved deformation layer thickness optimization analysis reveals no plastic strain in the second lining when the reserved deformation minimum thickness layer is 28.50 cm. The results show that the new foam concrete used as a reserved deformation layer filling material can absorb creep deformation of surrounding rock mass, reduce second lining deformation that leads to plastic strain, and ensure long-term second lining stability.
文摘After a long subway tunnel operators will produce cross-sectional deformation. Articles designed vehicle laser ranging device tbr continuous measurement of tunnel wall to test their defomaed state. The paper also describes the tunnel cross-section deltbrmation measurement method, contour titting principles and error analysis and networking technology for wireless data transmission methods. The detection system is designed to achieve a tunnel section of the structural safety testing and deformation that may occur timely disaster warning, the safe operation of the subway tunnel to provide effective protection.
文摘Central venous catheterization is widely used in the emergency setting. This review aims to assess central venous catheterization from the perspectives of types of catheters, sites of insertion, and tech- niques. In emergency conditions, non-tunneled catheters are preferred because the technique for its insertion is not complicated and less time-consuming. The size of catheter depends on the purpose of catheterization. For example, a large bore catheter is needed for rapid infusion. The ideal catheterization site should bear fewer thromboses, lower infectious rate, and fewer mechanical complications. Thus the femoral vein should be avoided due to a high rate of colonization and thrombosis while the subclavian vein seems to exhibit fewer infectious complications compared with other sites. The ultrasound-guided technique increases the success rate of insertion while decreases the mechanical complications rate,
基金supported by the National Natural Science Foundation of China (Grant No. 11074088)
文摘Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of graphene ferromagnet/p wave superconductor junctions. It is found that the conductance spectra are affected by the p wave pairing symmetry. The ferromagnetic exchange energy in the ferromagnet can suppress Andreev retroreflection but enhance the specular Andreev reflection in graphene ferromagnet/p wave superconductor junctions. The conductance decreases with increasing exchange energy Eh for Eh〈Er （the Fermi energy in the ferromagnet region）, but the conductance increases with increasing exchange energy Eh for Eh〉EF.
