One of the critical aspects in mine design is slope stability analysis and the determination of stable slopes. In the Chador- Malu iron ore mine, one of the most important iron ore mines in central Iran, it was consid...One of the critical aspects in mine design is slope stability analysis and the determination of stable slopes. In the Chador- Malu iron ore mine, one of the most important iron ore mines in central Iran, it was considered vital to perform a comprehensive slope stability analysis. At first, we divided the existing rock hosting pit into six zones and a geotechnical map was prepared. Then, the value of MRMR （Mining Rock Mass Rating） was determined for each zone. Owing to the fact that the Chador-Malu iron ore mine is located in a highly tectonic area and the rock mass completely crushed, the Hoek-Brown failure criterion was found suitable to estimate geo-mechanical parameters. After that, the value of cohesion （c） and friction angle （tp） were calculated for different geotechnical zones and relative graphs and equations were derived as a function of slope height. The stability analyses using numerical and limit equilibrium methods showed that some instability problems might occur by increasing the slope height. Therefore, stable slopes for each geotechnical zone and prepared sections were calculated and presented as a function of slope height.展开更多
The elimination of zig-zag defects in polyimide-coated surface-stabilized ferroelectric liquid crystal(SSFLC) cells is carried out by applying a low-frequency electric field. It has been achieved when the thickness of...The elimination of zig-zag defects in polyimide-coated surface-stabilized ferroelectric liquid crystal(SSFLC) cells is carried out by applying a low-frequency electric field. It has been achieved when the thickness of SSFLC cell is 3 μm. The optical spectral transmittance measurement confirmed that there is no change of layer structure, and the memory capability was not improved. The different effects of low-frequency electric field applied on the different thickness FLC cells have been observed, and experimental results were presented.展开更多
In order to study the unsteady aerodynamics effects in railway tunnels,the 3D Reynolds average Navier-Stokes equations of a viscous compressible fluid are solved,and the two-equation k-ε model is used in the simulati...In order to study the unsteady aerodynamics effects in railway tunnels,the 3D Reynolds average Navier-Stokes equations of a viscous compressible fluid are solved,and the two-equation k-ε model is used in the simulation of turbulence,while the dynamic grid technique is employed for moving bodies.We focus on obtaining the changing tendencies of the aerodynamic force of the train and the aerodynamic pressures on the tunnel wall and train surface,and discovering the relationship between the velocity of the train and the intensity of the micro pressure wave at the tunnel exit.It is shown that the amplitudes of the pressure changes in the tunnel and on the train surface are both approximately proportional to the square of the train speed,so are the microwave and the drag of the train.展开更多
A compression wave discharged from an open end of a tube causes positive impulsive noise. Active noise cancellation which is the canceling of the noise by the addition of an inverse wave is a useful technique for redu...A compression wave discharged from an open end of a tube causes positive impulsive noise. Active noise cancellation which is the canceling of the noise by the addition of an inverse wave is a useful technique for reducing impulsive noise. The main objective of this study is to present the design for a negative impulsive wave generator utilizing unsteady mass influx. In this paper, in order to clarify the relationship between the unsteady mass influx and the negative impulsive wave! numerical and aeroacoustic analyses have been carried out using an unsteady expansion wave discharged from an open end of a shock tube. As a result, the effect of an unsteady expansion wave on a negative impulsive wave was clarified.展开更多
文摘One of the critical aspects in mine design is slope stability analysis and the determination of stable slopes. In the Chador- Malu iron ore mine, one of the most important iron ore mines in central Iran, it was considered vital to perform a comprehensive slope stability analysis. At first, we divided the existing rock hosting pit into six zones and a geotechnical map was prepared. Then, the value of MRMR （Mining Rock Mass Rating） was determined for each zone. Owing to the fact that the Chador-Malu iron ore mine is located in a highly tectonic area and the rock mass completely crushed, the Hoek-Brown failure criterion was found suitable to estimate geo-mechanical parameters. After that, the value of cohesion （c） and friction angle （tp） were calculated for different geotechnical zones and relative graphs and equations were derived as a function of slope height. The stability analyses using numerical and limit equilibrium methods showed that some instability problems might occur by increasing the slope height. Therefore, stable slopes for each geotechnical zone and prepared sections were calculated and presented as a function of slope height.
文摘The elimination of zig-zag defects in polyimide-coated surface-stabilized ferroelectric liquid crystal(SSFLC) cells is carried out by applying a low-frequency electric field. It has been achieved when the thickness of SSFLC cell is 3 μm. The optical spectral transmittance measurement confirmed that there is no change of layer structure, and the memory capability was not improved. The different effects of low-frequency electric field applied on the different thickness FLC cells have been observed, and experimental results were presented.
基金Project(No.2009BAG12A01) supported by the National Key Technology R&D Program of China
文摘In order to study the unsteady aerodynamics effects in railway tunnels,the 3D Reynolds average Navier-Stokes equations of a viscous compressible fluid are solved,and the two-equation k-ε model is used in the simulation of turbulence,while the dynamic grid technique is employed for moving bodies.We focus on obtaining the changing tendencies of the aerodynamic force of the train and the aerodynamic pressures on the tunnel wall and train surface,and discovering the relationship between the velocity of the train and the intensity of the micro pressure wave at the tunnel exit.It is shown that the amplitudes of the pressure changes in the tunnel and on the train surface are both approximately proportional to the square of the train speed,so are the microwave and the drag of the train.
文摘A compression wave discharged from an open end of a tube causes positive impulsive noise. Active noise cancellation which is the canceling of the noise by the addition of an inverse wave is a useful technique for reducing impulsive noise. The main objective of this study is to present the design for a negative impulsive wave generator utilizing unsteady mass influx. In this paper, in order to clarify the relationship between the unsteady mass influx and the negative impulsive wave! numerical and aeroacoustic analyses have been carried out using an unsteady expansion wave discharged from an open end of a shock tube. As a result, the effect of an unsteady expansion wave on a negative impulsive wave was clarified.
