Cables composed of rare-earth barium copper oxide(REBCO)tapes have been extensively used in various superconducting devices.In recent years,conductor on round core(CORC)cable has drawn the attention of researchers wit...Cables composed of rare-earth barium copper oxide(REBCO)tapes have been extensively used in various superconducting devices.In recent years,conductor on round core(CORC)cable has drawn the attention of researchers with its outstanding current-carrying capacity and mechanical properties.The REBCO tapes are wound spirally on the surface of CORC cable.Under extreme loadings,the REBCO tapes with layered composite structures are vulnerable,which can lead to degradation of critical current and even quenching of superconducting devices.In this paper,we simulate the deformation of CORC cable under external loads,and analyze the damage inside the tape with the cohesive zone model(CZM).Firstly,the fabrication and cabling of CORC are simulated,and the stresses and strains generated in the tape are extracted as the initial condition of the next step.Then,the tension and bending loads are applied to CORC cable,and the damage distribution inside the tape is presented.In addition,the effects of some parameters on the damage are discussed during the bending simulations.展开更多
Before 1986, people were hesitant to believe that superconductors could operate at such high temperatures, well above the readily liquid nitrogen regime. It was a dream! Shortly after the discovery of
Ag-sheathed(Bi,Pb)_2Sr_2Ca_2Cu_3O_x tapes were fabricated by a powder-in-tube method.A high critical current density of 2.8×10~4 A/cm^2 at 77K,0T and 4×10~4 A/cm^2 at 4.2K,5T(H⊥ab),6.3× 10~4 A/cm^2 at ...Ag-sheathed(Bi,Pb)_2Sr_2Ca_2Cu_3O_x tapes were fabricated by a powder-in-tube method.A high critical current density of 2.8×10~4 A/cm^2 at 77K,0T and 4×10~4 A/cm^2 at 4.2K,5T(H⊥ab),6.3× 10~4 A/cm^2 at 4.2K,7T(H∥ab)is obtained.The microstructure of the tapes with high J_c values was in- vestigated by transmission electron microscope(TEM)and X-ray energy dispersive spectrum system(EDS). For comparison,a tape fabricated by a different procedure with a low J_c of about 1×10~4 A/cm^2 at 77K,0T was also studied.The relationship between J_c and microstructure of the tapes and the effect of the processing on the microstructure and J_c were elucidated.展开更多
No sooner had the high T_c superconducting oxides been discovered than the wide interest was exhibited in the research of the electronic structure and ionic valence state of these kinds of materials. Based on theoreti...No sooner had the high T_c superconducting oxides been discovered than the wide interest was exhibited in the research of the electronic structure and ionic valence state of these kinds of materials. Based on theoretic calculations and experimental results of the X-ray photoelectron spectroscopy (XPS)and the electron-energy-loss spectroscopy (EELS), it展开更多
INTRODUCTIONIn order to improve the efficiency of the electrically small antenna, which has the physical extension smaller than the maximum free space wavelength transmitted or received, superconducting materials bega...INTRODUCTIONIn order to improve the efficiency of the electrically small antenna, which has the physical extension smaller than the maximum free space wavelength transmitted or received, superconducting materials began to be utilized in fabricating antennas since 1960s. In 1988, the Birmingham group of UK made for the first time the small dipole antennas展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.U2241267,1217215511872195)。
文摘Cables composed of rare-earth barium copper oxide(REBCO)tapes have been extensively used in various superconducting devices.In recent years,conductor on round core(CORC)cable has drawn the attention of researchers with its outstanding current-carrying capacity and mechanical properties.The REBCO tapes are wound spirally on the surface of CORC cable.Under extreme loadings,the REBCO tapes with layered composite structures are vulnerable,which can lead to degradation of critical current and even quenching of superconducting devices.In this paper,we simulate the deformation of CORC cable under external loads,and analyze the damage inside the tape with the cohesive zone model(CZM).Firstly,the fabrication and cabling of CORC are simulated,and the stresses and strains generated in the tape are extracted as the initial condition of the next step.Then,the tension and bending loads are applied to CORC cable,and the damage distribution inside the tape is presented.In addition,the effects of some parameters on the damage are discussed during the bending simulations.
文摘Before 1986, people were hesitant to believe that superconductors could operate at such high temperatures, well above the readily liquid nitrogen regime. It was a dream! Shortly after the discovery of
文摘Ag-sheathed(Bi,Pb)_2Sr_2Ca_2Cu_3O_x tapes were fabricated by a powder-in-tube method.A high critical current density of 2.8×10~4 A/cm^2 at 77K,0T and 4×10~4 A/cm^2 at 4.2K,5T(H⊥ab),6.3× 10~4 A/cm^2 at 4.2K,7T(H∥ab)is obtained.The microstructure of the tapes with high J_c values was in- vestigated by transmission electron microscope(TEM)and X-ray energy dispersive spectrum system(EDS). For comparison,a tape fabricated by a different procedure with a low J_c of about 1×10~4 A/cm^2 at 77K,0T was also studied.The relationship between J_c and microstructure of the tapes and the effect of the processing on the microstructure and J_c were elucidated.
基金Project supported by the National Center for Research and Development on Superconductivity.
文摘No sooner had the high T_c superconducting oxides been discovered than the wide interest was exhibited in the research of the electronic structure and ionic valence state of these kinds of materials. Based on theoretic calculations and experimental results of the X-ray photoelectron spectroscopy (XPS)and the electron-energy-loss spectroscopy (EELS), it
文摘INTRODUCTIONIn order to improve the efficiency of the electrically small antenna, which has the physical extension smaller than the maximum free space wavelength transmitted or received, superconducting materials began to be utilized in fabricating antennas since 1960s. In 1988, the Birmingham group of UK made for the first time the small dipole antennas
