Carbon fibers（CFs） were coated with a nickel-phosphorus（Ni-P） film using an electroless plating process. The morphology, elemental composition and phases in the coating layer of the CFs were investigated by scanni...Carbon fibers（CFs） were coated with a nickel-phosphorus（Ni-P） film using an electroless plating process. The morphology, elemental composition and phases in the coating layer of the CFs were investigated by scanning electron microscopy（SEM）, energy dispersive spectroscopy（EDS） and X-ray diffraction（XRD）, respectively. Wet paper-making method was used to prepare nickle coated carbon fiber paper（NCFP）. Vacuum assisted infusion molding process（VAIMP） was employed to manufacture the NCFP reinforced epoxy composites, and carbon fiber paper（CFP） reinforced epoxy composites were also produced as a comparison. Electromagnetic interference（EMI） shielding properties of the composites were measured in the 3.22-4.9 GHz frequency range using waveguide method. Both NCFP and CFP reinforced epoxy composites of 0.5 mm thickness exhibited high EMI shielding effectiveness（SE） at 8wt% fiber content, 35 d B and 30 d B, respectively, and reflection was the dominant shielding mechanism.展开更多
A three-dimensional viscoelastic LDDA method is put forward on the basis of the two-dimensional elastic LDDA method and a corresponding computer program is developed. Both the method and the program, verified by a num...A three-dimensional viscoelastic LDDA method is put forward on the basis of the two-dimensional elastic LDDA method and a corresponding computer program is developed. Both the method and the program, verified by a numerical frictional experiment composed of two blocks, are correct and reliable. Simultaneously, using this program, the present velocity field of the eastern Asia area, which is induced by the collision of the Indian shield against the Asian plate, is investigated. The primary result shows that the velocity field in magnitude is largest near the colliding boundary and attenuates fast away from it. The Tibet plateau moves northeast, the North China plain and the southeastern Asia moves eastward and southeastward, respectively. The attenuation of the velocity field across Qilianshan is nonlinear, its direction changes from the northeast nearly to the east, its gradient is 0.05 mma-1km-1 and 0.007 mma-1km-1 to the southwest and the northeast of Qilianshan, respectively. The attenuation of the velocity field is almost linear across the Longmenshan fault, its gradient is 0.01 mma-1km-1 and its direction is toward the southeast. The remarkable deformation caused by collision extends to the east longitude 115 and to the north latitude 45. The velocity field obtained by the method is basically consistent with the data from the Global Positioning System. The relative slip rate along the Bangong-Nujiang-Lancangjiang fault is 0.5 mm/a, the Jinshajiang fault, 0.8 mm/a, while the Tanlu fault hardly moves. It is shown that the method proposed in this paper could be employed to study the geodynamic problems with faults.展开更多
The aim of this investigation was to improve power performance of Savonius hydraulic turbine utilizing small stream for electric generation.An attempt was made to increase the power coefficient of runner by the use of...The aim of this investigation was to improve power performance of Savonius hydraulic turbine utilizing small stream for electric generation.An attempt was made to increase the power coefficient of runner by the use of flat shield plate placed upstream of the runner.The difference of the power coefficient is discussed in relation to clearance between the runner and the bottom wall and the rotation direction of the runner.The flow field around the runner was also examined visually to clarify influences of setting conditions on the power performance.From this study it was found that the power coefficient is achieved for 0.47 by only using a flat shield plate,the increase is up to 80% over the runner without the plate.Moreover,it is the proper condition that clearance ratio is 0.73 in this study.展开更多
基金Funded by the National Natural Science Foundation of China(No.51373129)
文摘Carbon fibers（CFs） were coated with a nickel-phosphorus（Ni-P） film using an electroless plating process. The morphology, elemental composition and phases in the coating layer of the CFs were investigated by scanning electron microscopy（SEM）, energy dispersive spectroscopy（EDS） and X-ray diffraction（XRD）, respectively. Wet paper-making method was used to prepare nickle coated carbon fiber paper（NCFP）. Vacuum assisted infusion molding process（VAIMP） was employed to manufacture the NCFP reinforced epoxy composites, and carbon fiber paper（CFP） reinforced epoxy composites were also produced as a comparison. Electromagnetic interference（EMI） shielding properties of the composites were measured in the 3.22-4.9 GHz frequency range using waveguide method. Both NCFP and CFP reinforced epoxy composites of 0.5 mm thickness exhibited high EMI shielding effectiveness（SE） at 8wt% fiber content, 35 d B and 30 d B, respectively, and reflection was the dominant shielding mechanism.
文摘A three-dimensional viscoelastic LDDA method is put forward on the basis of the two-dimensional elastic LDDA method and a corresponding computer program is developed. Both the method and the program, verified by a numerical frictional experiment composed of two blocks, are correct and reliable. Simultaneously, using this program, the present velocity field of the eastern Asia area, which is induced by the collision of the Indian shield against the Asian plate, is investigated. The primary result shows that the velocity field in magnitude is largest near the colliding boundary and attenuates fast away from it. The Tibet plateau moves northeast, the North China plain and the southeastern Asia moves eastward and southeastward, respectively. The attenuation of the velocity field across Qilianshan is nonlinear, its direction changes from the northeast nearly to the east, its gradient is 0.05 mma-1km-1 and 0.007 mma-1km-1 to the southwest and the northeast of Qilianshan, respectively. The attenuation of the velocity field is almost linear across the Longmenshan fault, its gradient is 0.01 mma-1km-1 and its direction is toward the southeast. The remarkable deformation caused by collision extends to the east longitude 115 and to the north latitude 45. The velocity field obtained by the method is basically consistent with the data from the Global Positioning System. The relative slip rate along the Bangong-Nujiang-Lancangjiang fault is 0.5 mm/a, the Jinshajiang fault, 0.8 mm/a, while the Tanlu fault hardly moves. It is shown that the method proposed in this paper could be employed to study the geodynamic problems with faults.
基金supported by KAKENHI No.2231004 and Ministry of Environment
文摘The aim of this investigation was to improve power performance of Savonius hydraulic turbine utilizing small stream for electric generation.An attempt was made to increase the power coefficient of runner by the use of flat shield plate placed upstream of the runner.The difference of the power coefficient is discussed in relation to clearance between the runner and the bottom wall and the rotation direction of the runner.The flow field around the runner was also examined visually to clarify influences of setting conditions on the power performance.From this study it was found that the power coefficient is achieved for 0.47 by only using a flat shield plate,the increase is up to 80% over the runner without the plate.Moreover,it is the proper condition that clearance ratio is 0.73 in this study.
