Changes in electroretinographic b-wave in the presence of background lights of increas-ing intensity were examined in isolated, superfused carp retinas. Within a certain range ofambient illumination b-waves elicited b...Changes in electroretinographic b-wave in the presence of background lights of increas-ing intensity were examined in isolated, superfused carp retinas. Within a certain range ofambient illumination b-waves elicited by red (695 nm) test flashes against dimmer backgroundlights were smaller in size than against brighter ones. Accordingly, incremental thresholdsfor red flashes decreased as the intensity of background lights increased within this intensityrange. The results suggest that cone pathways may be suppressed by rods in darkness anddim illumination. The phenomenon was absent for photoreceptor potentials(PⅢ components),indicating that the rod-cone interaction occurs in second-order retinal neurons.展开更多
Frequency-invariant beamformer （FIB） design is a key issue in wideband array signal processing. To use commonly wideband linear array with tapped delay line （TDL） structure and complex weights, the FIB design is p...Frequency-invariant beamformer （FIB） design is a key issue in wideband array signal processing. To use commonly wideband linear array with tapped delay line （TDL） structure and complex weights, the FIB design is provided according to the rule of minimizing the sidelobe level of the beampattern at the reference frequency while keeping the distortionless response constraint in the mainlobe direction at the reference frequency, the norm constraint of the weight vector and the amplitude constraint of the averaged spatial response variation （SRV）. This kind of beamformer design problem can be solved with the interior-point method after being converted to the form of standard second order cone programming （SOCP）. The computer simulations are presented which illustrate the effectiveness of our FIB design method for the wideband linear array with TDL structure and complex weights.展开更多
以适用于南海海域作业的圆筒型浮式钻井生产储卸油系统(Floating Drilling Production Storage and Offloading System,FDPSO)为对象,研究不同阻尼板锥角下FDPSO垂荡和纵摇幅值变化规律。基于三维势流理论计算FDPSO所受波浪载荷,施加由...以适用于南海海域作业的圆筒型浮式钻井生产储卸油系统(Floating Drilling Production Storage and Offloading System,FDPSO)为对象,研究不同阻尼板锥角下FDPSO垂荡和纵摇幅值变化规律。基于三维势流理论计算FDPSO所受波浪载荷,施加由不同方法计算得到的黏性阻尼,计算FDPSO的运动响应传递函数,采用谱分析方法预报垂荡、纵摇运动,计算不同锥角下二阶波浪载荷引起的纵摇运动响应。计算结果表明:圆筒型FDPSO垂荡运动相对较强,不过抗摇性能良好;阻尼板锥角的增大不利于FDPSO垂荡和纵摇运动响应的控制,二阶波浪载荷对圆筒型FDPSO纵摇运动响应具有较大的影响,应给予关注。展开更多
基金Project supported by grants from the National Natural Science Foundation of China (3870203) and from the National Institutes of Health (EY08338) to X. L. Yang.
文摘Changes in electroretinographic b-wave in the presence of background lights of increas-ing intensity were examined in isolated, superfused carp retinas. Within a certain range ofambient illumination b-waves elicited by red (695 nm) test flashes against dimmer backgroundlights were smaller in size than against brighter ones. Accordingly, incremental thresholdsfor red flashes decreased as the intensity of background lights increased within this intensityrange. The results suggest that cone pathways may be suppressed by rods in darkness anddim illumination. The phenomenon was absent for photoreceptor potentials(PⅢ components),indicating that the rod-cone interaction occurs in second-order retinal neurons.
基金supported by the President Award of Chinese Academy of Sciences (O729031511)
文摘Frequency-invariant beamformer （FIB） design is a key issue in wideband array signal processing. To use commonly wideband linear array with tapped delay line （TDL） structure and complex weights, the FIB design is provided according to the rule of minimizing the sidelobe level of the beampattern at the reference frequency while keeping the distortionless response constraint in the mainlobe direction at the reference frequency, the norm constraint of the weight vector and the amplitude constraint of the averaged spatial response variation （SRV）. This kind of beamformer design problem can be solved with the interior-point method after being converted to the form of standard second order cone programming （SOCP）. The computer simulations are presented which illustrate the effectiveness of our FIB design method for the wideband linear array with TDL structure and complex weights.
文摘以适用于南海海域作业的圆筒型浮式钻井生产储卸油系统(Floating Drilling Production Storage and Offloading System,FDPSO)为对象,研究不同阻尼板锥角下FDPSO垂荡和纵摇幅值变化规律。基于三维势流理论计算FDPSO所受波浪载荷,施加由不同方法计算得到的黏性阻尼,计算FDPSO的运动响应传递函数,采用谱分析方法预报垂荡、纵摇运动,计算不同锥角下二阶波浪载荷引起的纵摇运动响应。计算结果表明:圆筒型FDPSO垂荡运动相对较强,不过抗摇性能良好;阻尼板锥角的增大不利于FDPSO垂荡和纵摇运动响应的控制,二阶波浪载荷对圆筒型FDPSO纵摇运动响应具有较大的影响,应给予关注。
