Receiver ghost reflections adversely affect variable-depth streamer （VDS） data acquisition. In addition, the frequency notches caused by the interference between receiver ghosts and primary waves strongly affect sei...Receiver ghost reflections adversely affect variable-depth streamer （VDS） data acquisition. In addition, the frequency notches caused by the interference between receiver ghosts and primary waves strongly affect seismic data processing and imaging. We developed a high-resolution Radon transform algorithm and used it to predict receiver ghosts from VDS data. The receiver ghost reflections are subtracted and removed from the raw data. We propose a forward Radon transform operator of VDS data in the frequency domain and, based on the ray paths of the receiver ghosts, we propose an inverse Radon transform operator. We apply the proposed methodology to model and field data with good results. We use matching and subtracting modules of commercially available seismic data processing software to remove the receiver ghosts. The frequency notches are compensated and the effective frequency bandwidth of the seismic data broadens.展开更多
The AR coatings for GaInP/GaAs tandem solar cell are simulated.Results show that,under the condition of the lack of suitable encapsulation, a very low energy loss could be reached on MgF2/ZnS system; in the case of gl...The AR coatings for GaInP/GaAs tandem solar cell are simulated.Results show that,under the condition of the lack of suitable encapsulation, a very low energy loss could be reached on MgF2/ZnS system; in the case of glass encapsulation,the Al2O3/ZrO2 and Al2O3/TiO2 systems are appropriate choice; for AlInP window layer,the thickness of 30 nm is suitable.展开更多
Lidar has been used extensively in the area of atmospheric aerosol measurement.Two unknowns at the reference altitude,the lidar ratio and the backscatter coefficient,need to be resolved from the lidar equation.In the ...Lidar has been used extensively in the area of atmospheric aerosol measurement.Two unknowns at the reference altitude,the lidar ratio and the backscatter coefficient,need to be resolved from the lidar equation.In the actual application,these two values are difficult to obtain,particularly the backscatter coefficient.To better characterize the optical properties of aerosols,optical thickness,and attenuated backscatter obtained by other instruments are usually used as the input for joint inversion.However,this method is limited by location and time.In this study,the authors propose a new method for aerosol retrieval by using Mie scattering lidar data to solve this problem.The authors take the horizontal aerosol extinction coefficient as the constraint to begin the iteration until a self-consistent aerosol vertical profile was obtained.By comparing their results with Aerosol Robotic Network(AERONET) data,the authours determine that the aerosol extinction coefficient obtained by combining horizontal and vertical lidar observations is more precise than that obtained by using the traditional Fernald method.This new method has been adopted for retrieving the extinction coefficient of aerosols during the observation days.展开更多
The principle and method for measuring the wall thickness of transparent tube are presented.The measurement is based on total-refection vanishing light. The transmittance of transparent tube in the parallel light is s...The principle and method for measuring the wall thickness of transparent tube are presented.The measurement is based on total-refection vanishing light. The transmittance of transparent tube in the parallel light is studied. The critical conditions of total--reflection are discussed.展开更多
文摘Receiver ghost reflections adversely affect variable-depth streamer （VDS） data acquisition. In addition, the frequency notches caused by the interference between receiver ghosts and primary waves strongly affect seismic data processing and imaging. We developed a high-resolution Radon transform algorithm and used it to predict receiver ghosts from VDS data. The receiver ghost reflections are subtracted and removed from the raw data. We propose a forward Radon transform operator of VDS data in the frequency domain and, based on the ray paths of the receiver ghosts, we propose an inverse Radon transform operator. We apply the proposed methodology to model and field data with good results. We use matching and subtracting modules of commercially available seismic data processing software to remove the receiver ghosts. The frequency notches are compensated and the effective frequency bandwidth of the seismic data broadens.
文摘The AR coatings for GaInP/GaAs tandem solar cell are simulated.Results show that,under the condition of the lack of suitable encapsulation, a very low energy loss could be reached on MgF2/ZnS system; in the case of glass encapsulation,the Al2O3/ZrO2 and Al2O3/TiO2 systems are appropriate choice; for AlInP window layer,the thickness of 30 nm is suitable.
基金supported by the National Natural Science Foundation of China (Grant No.41127901)
文摘Lidar has been used extensively in the area of atmospheric aerosol measurement.Two unknowns at the reference altitude,the lidar ratio and the backscatter coefficient,need to be resolved from the lidar equation.In the actual application,these two values are difficult to obtain,particularly the backscatter coefficient.To better characterize the optical properties of aerosols,optical thickness,and attenuated backscatter obtained by other instruments are usually used as the input for joint inversion.However,this method is limited by location and time.In this study,the authors propose a new method for aerosol retrieval by using Mie scattering lidar data to solve this problem.The authors take the horizontal aerosol extinction coefficient as the constraint to begin the iteration until a self-consistent aerosol vertical profile was obtained.By comparing their results with Aerosol Robotic Network(AERONET) data,the authours determine that the aerosol extinction coefficient obtained by combining horizontal and vertical lidar observations is more precise than that obtained by using the traditional Fernald method.This new method has been adopted for retrieving the extinction coefficient of aerosols during the observation days.
文摘The principle and method for measuring the wall thickness of transparent tube are presented.The measurement is based on total-refection vanishing light. The transmittance of transparent tube in the parallel light is studied. The critical conditions of total--reflection are discussed.
