To improve the energy resolution（？E） of Nb/Al superconducting tunnel junctions（STJs）, an ozone（O3） oxidation process has been developed to fabricate a thin defect-free tunnel barrier that simultaneously shows h...To improve the energy resolution（？E） of Nb/Al superconducting tunnel junctions（STJs）, an ozone（O3） oxidation process has been developed to fabricate a thin defect-free tunnel barrier that simultaneously shows high critical current JC〉 1000 A/cm^2 and high normalized dynamic resistance RDA 〉 100 MΩ·μm^2, where A is the size of the STJ. The 50-μm^2 STJs produced by O3 exposure of 0.26 Pa·min with an indirect spray of O3 gas, which is a much lower level of exposure than the O2 exposure used in a conventional O2 oxidation process, exhibit a maximum JC= 800 A/cm^2 and a high RDA = 372 MΩ ·μm^2. The 100-pixel array of the 100-μm^2STJs produced using the same O3 oxidation conditions exhibits a constant leak current I leak= 14.9 ± 3.2 n A at a bias point around △ /e（where e is half the energy gap of an STJ）,and a high fabrication yield of 87%. Although the I leak values are slightly larger than those of STJs produced using the conventional O2 oxidation process, the STJ produced using O3 oxidation shows a ？E = 10 eV for the C-Kα line, which is the best value of our Nb/Al STJ x-ray detectors.展开更多
Ti-Cu films with different Cu concentrations were fabricated by high-power pulsed magnetron sputtering（HPPMS） to release copper ions and catalyze NO to improve the blood compatibility. The Cu concentrations of films...Ti-Cu films with different Cu concentrations were fabricated by high-power pulsed magnetron sputtering（HPPMS） to release copper ions and catalyze NO to improve the blood compatibility. The Cu concentrations of films were 25.7 at% and 68.8 at%. Pure Ti films were also fabricated. Copper release, catalytic release of nitric oxide（NO）, and blood platelet adhesion of Ti-Cu films were studied. Ti-Cu films released copper ions in PBS solution and more Cu ions were released from films with 68.8 at% Cu. Ti-Cu films had excellent ability of catalytical decomposition of exogenous donor S-nitroso-N-acetyl-DL-penicillamine（SNAP） and as a result, nitric oxide（NO） was generated. The NO generation catalyzed by Ti-Cu films was significantly higher than that by pure Ti films. This was more eminent in the Ti-Cu films with 68.8 at% Cu. The platelet adhesion and activation of Ti-Cu films were significantly inhibited compared to that of pure Ti films in the presence of SNAP. The Ti-Cu film fabricated by HPPMS showed the ability of releasing Cu ions to catalyze SNAP to generate NO to inhibit platelet adhesion and activation.展开更多
The unsteady behavior of flow driven by a jet suddenly injected into a cell is numerically studied by solving the axisymmelric two-dimensional compressible Navier-Stokes equations. The system of the calculation is a m...The unsteady behavior of flow driven by a jet suddenly injected into a cell is numerically studied by solving the axisymmelric two-dimensional compressible Navier-Stokes equations. The system of the calculation is a model of the laser ablation of a certain duration followed by a discharging process through the exit hole at the down- stream end of the cell. In the calculations, the contour of the cell is changed while other parameters such as the Mach number of the jet, its duration, and the diameter of the cell exit are fixed. Monitoring the velocity at the exit hole is used to investigate the influence of the shape on the interaction between the shock wave and the jet. As the result, it was found that the velocity peak value and its arrival time at the downstream end of the cell exit are determined by the diameter of the cell.展开更多
文摘To improve the energy resolution（？E） of Nb/Al superconducting tunnel junctions（STJs）, an ozone（O3） oxidation process has been developed to fabricate a thin defect-free tunnel barrier that simultaneously shows high critical current JC〉 1000 A/cm^2 and high normalized dynamic resistance RDA 〉 100 MΩ·μm^2, where A is the size of the STJ. The 50-μm^2 STJs produced by O3 exposure of 0.26 Pa·min with an indirect spray of O3 gas, which is a much lower level of exposure than the O2 exposure used in a conventional O2 oxidation process, exhibit a maximum JC= 800 A/cm^2 and a high RDA = 372 MΩ ·μm^2. The 100-pixel array of the 100-μm^2STJs produced using the same O3 oxidation conditions exhibits a constant leak current I leak= 14.9 ± 3.2 n A at a bias point around △ /e（where e is half the energy gap of an STJ）,and a high fabrication yield of 87%. Although the I leak values are slightly larger than those of STJs produced using the conventional O2 oxidation process, the STJ produced using O3 oxidation shows a ？E = 10 eV for the C-Kα line, which is the best value of our Nb/Al STJ x-ray detectors.
基金Funded by the National Natural Science Foundation of China(No.31300787)the National Natural Science Foundation of China China Academy of Engineering Physics(NSAF No.U1330113)+1 种基金the Overseas Famous Teacher Program of Chinese Education Ministry(MS2010XNJT070)the Qingmiao Plan of SWJTU 2015(No.A0920502051517-6)
文摘Ti-Cu films with different Cu concentrations were fabricated by high-power pulsed magnetron sputtering（HPPMS） to release copper ions and catalyze NO to improve the blood compatibility. The Cu concentrations of films were 25.7 at% and 68.8 at%. Pure Ti films were also fabricated. Copper release, catalytic release of nitric oxide（NO）, and blood platelet adhesion of Ti-Cu films were studied. Ti-Cu films released copper ions in PBS solution and more Cu ions were released from films with 68.8 at% Cu. Ti-Cu films had excellent ability of catalytical decomposition of exogenous donor S-nitroso-N-acetyl-DL-penicillamine（SNAP） and as a result, nitric oxide（NO） was generated. The NO generation catalyzed by Ti-Cu films was significantly higher than that by pure Ti films. This was more eminent in the Ti-Cu films with 68.8 at% Cu. The platelet adhesion and activation of Ti-Cu films were significantly inhibited compared to that of pure Ti films in the presence of SNAP. The Ti-Cu film fabricated by HPPMS showed the ability of releasing Cu ions to catalyze SNAP to generate NO to inhibit platelet adhesion and activation.
基金the National Institute of Advanced Industrial Science and Technology(AIST)
文摘The unsteady behavior of flow driven by a jet suddenly injected into a cell is numerically studied by solving the axisymmelric two-dimensional compressible Navier-Stokes equations. The system of the calculation is a model of the laser ablation of a certain duration followed by a discharging process through the exit hole at the down- stream end of the cell. In the calculations, the contour of the cell is changed while other parameters such as the Mach number of the jet, its duration, and the diameter of the cell exit are fixed. Monitoring the velocity at the exit hole is used to investigate the influence of the shape on the interaction between the shock wave and the jet. As the result, it was found that the velocity peak value and its arrival time at the downstream end of the cell exit are determined by the diameter of the cell.
