This paper investigates the magnetic field component impact on cathode spots motion trajectory and the mechanism of periodic contraction.Electromagnetic coils and permanent magnets were installed at the different side...This paper investigates the magnetic field component impact on cathode spots motion trajectory and the mechanism of periodic contraction.Electromagnetic coils and permanent magnets were installed at the different sides of cathode surface,the photographs of cathode spots motion trajectory were captured by a camera.Increasing the number of magnets and decreasing the distance between magnets and cathode both lead to enhancing cathode spots motion velocity.Radii of cathode spots trajectory decrease gradually with the increasing of electromagnetic coil＇s current,from 40 mm at 0 A to 10 mm at 2.7 A.Parallel magnetic field component intensity influence the speed of cathode spots rotate motion,and perpendicular magnetic field component drives spots drift in the radial direction.Cathode spot＇s radial drift is controlled by changing the location of the ‘zero line＇ where perpendicular magnetic component shifts direction and the radius of cathode spots trajectory almost equal to ‘zero line＇.展开更多
Identifying the optimal intensity measures(IMs)of ground motion is a critical step in the seismic fragility analysis of slopes using probabilistic seismic demand models.In this study,we investigated various IMs of ear...Identifying the optimal intensity measures(IMs)of ground motion is a critical step in the seismic fragility analysis of slopes using probabilistic seismic demand models.In this study,we investigated various IMs of earthquake ground motions,considering both vertical and horizontal components that can trigger landslides,through numerical simulations.A set of 19 IMs was examined for three heights of slopes.The optimal IMs were assessed using the maximum permanent displacement as an engineering demand parameter.The findings reveal that acceleration-related parameters specifically sustained maximum acceleration(SMA)and root-mean-square of acceleration,and velocity-related parameters namely sustained maximum velocity(SMV)and peak ground velocity,are the most effective IMs for slopes subjected to both vertical and horizontal ground motions.For slopes subjected exclusively to horizontal ground motion,SMA is recommended as the optimal IM for lower-height slopes,while SMV is more suitable for the taller slope.In contrast,for models subjected to combined horizontal and vertical ground motions,SMA is consistently identified as the optimal IM for slope across all heights.Notably,the study concludes that peak ground acceleration,a commonly used parameter in seismic analysis,is unsuitable for the considered slopes.展开更多
This paper deals with the components of pcriod of 29.8 yr in polar motion and △ I. o. d. The oscillation of inner core (OIC), as a most possible cause of them, is proposed. Parameters of oscillation are found and its...This paper deals with the components of pcriod of 29.8 yr in polar motion and △ I. o. d. The oscillation of inner core (OIC), as a most possible cause of them, is proposed. Parameters of oscillation are found and its effects on Earth’s mass center (EMC), distance of observatories to EMC, gravity and latitude are estimated.展开更多
文摘This paper investigates the magnetic field component impact on cathode spots motion trajectory and the mechanism of periodic contraction.Electromagnetic coils and permanent magnets were installed at the different sides of cathode surface,the photographs of cathode spots motion trajectory were captured by a camera.Increasing the number of magnets and decreasing the distance between magnets and cathode both lead to enhancing cathode spots motion velocity.Radii of cathode spots trajectory decrease gradually with the increasing of electromagnetic coil＇s current,from 40 mm at 0 A to 10 mm at 2.7 A.Parallel magnetic field component intensity influence the speed of cathode spots rotate motion,and perpendicular magnetic field component drives spots drift in the radial direction.Cathode spot＇s radial drift is controlled by changing the location of the ‘zero line＇ where perpendicular magnetic component shifts direction and the radius of cathode spots trajectory almost equal to ‘zero line＇.
基金funded by the National Natural Science Foundation of China(Grant No.52422807).
文摘Identifying the optimal intensity measures(IMs)of ground motion is a critical step in the seismic fragility analysis of slopes using probabilistic seismic demand models.In this study,we investigated various IMs of earthquake ground motions,considering both vertical and horizontal components that can trigger landslides,through numerical simulations.A set of 19 IMs was examined for three heights of slopes.The optimal IMs were assessed using the maximum permanent displacement as an engineering demand parameter.The findings reveal that acceleration-related parameters specifically sustained maximum acceleration(SMA)and root-mean-square of acceleration,and velocity-related parameters namely sustained maximum velocity(SMV)and peak ground velocity,are the most effective IMs for slopes subjected to both vertical and horizontal ground motions.For slopes subjected exclusively to horizontal ground motion,SMA is recommended as the optimal IM for lower-height slopes,while SMV is more suitable for the taller slope.In contrast,for models subjected to combined horizontal and vertical ground motions,SMA is consistently identified as the optimal IM for slope across all heights.Notably,the study concludes that peak ground acceleration,a commonly used parameter in seismic analysis,is unsuitable for the considered slopes.
文摘This paper deals with the components of pcriod of 29.8 yr in polar motion and △ I. o. d. The oscillation of inner core (OIC), as a most possible cause of them, is proposed. Parameters of oscillation are found and its effects on Earth’s mass center (EMC), distance of observatories to EMC, gravity and latitude are estimated.
