By considering higher order approximation to the interaural phase difference, a more general localization equation for stereo sound image with interchannel phase difference is derived. At very low frequency or low int...By considering higher order approximation to the interaural phase difference, a more general localization equation for stereo sound image with interchannel phase difference is derived. At very low frequency or low interchannel phase difference, the equation can be simplified to Makita theory. In general, image position is obviously affected by frequency.It is shown that image position varying with freqllency is the main reason for image width broadening in stereo reproduction with interchannel phase difference. And an extra interaural sound level difference caused by interchannel phase difference is the main reason for image naturalness degrading. In practice, it is necessary to reduce the interchannel phase difference,at least, to less than 60°.展开更多
Both interchannel wetlands and multi-channels are crucial geomorphologic units in an anastomosing river system.Planform characteristics and development of interchannel wetlands and multi-channels control the character...Both interchannel wetlands and multi-channels are crucial geomorphologic units in an anastomosing river system.Planform characteristics and development of interchannel wetlands and multi-channels control the characteristics of anastomosing rivers.To under-stand the role that interchannel wetlands play in the development of anastomosing rivers,a study was conducted on the Maqu Reach of the Upper Yellow River(MRUYR),a gravel-bed anastomosing river characterized by highly developed interchannel wetlands and ana-branches.Geomorphologic units in the studied reach were extracted from high resolution satellite imagery in Google Earth.The size distributions of interchannel wetlands and inter-channel wetland clusters(IWCs),a special combination of interchannel wetlands and ana-branches,were investigated.Geomorphologic parameters,including the ratio of interchannel wetland area to IWC area(P),shoreline density(DL),and node density(Dn)were used to analyze planform characteristics of IWCs and the development of multi-channels in the stud-ied reach.The results suggest that small or middle sized interchannel wetlands and large or mega sized IWCs are more common at the study site.The area of IWC(Su)is highly cor-related with other geomorphologic parameters.P increases with increasing Su,and the upper limit is about 80%,which indicates that the development of interchannel wetlands and ana-branches in the IWC is in the equilibrium stage.In contrast,D~and D,show a tendency to decrease with increasing Su due to diverse evolution processes in IWCs with different sizes.There are three main reasons leading to the formation of IWCs:varying stream power due to the meandering principal channel;development of the river corridor due to the weakening of geologic structure control;and high stability of interchannel wetlands due to conservation by shoreline vegetation.展开更多
文摘By considering higher order approximation to the interaural phase difference, a more general localization equation for stereo sound image with interchannel phase difference is derived. At very low frequency or low interchannel phase difference, the equation can be simplified to Makita theory. In general, image position is obviously affected by frequency.It is shown that image position varying with freqllency is the main reason for image width broadening in stereo reproduction with interchannel phase difference. And an extra interaural sound level difference caused by interchannel phase difference is the main reason for image naturalness degrading. In practice, it is necessary to reduce the interchannel phase difference,at least, to less than 60°.
基金National Natural Science Foundation of China,No.41571005,No.41271027
文摘Both interchannel wetlands and multi-channels are crucial geomorphologic units in an anastomosing river system.Planform characteristics and development of interchannel wetlands and multi-channels control the characteristics of anastomosing rivers.To under-stand the role that interchannel wetlands play in the development of anastomosing rivers,a study was conducted on the Maqu Reach of the Upper Yellow River(MRUYR),a gravel-bed anastomosing river characterized by highly developed interchannel wetlands and ana-branches.Geomorphologic units in the studied reach were extracted from high resolution satellite imagery in Google Earth.The size distributions of interchannel wetlands and inter-channel wetland clusters(IWCs),a special combination of interchannel wetlands and ana-branches,were investigated.Geomorphologic parameters,including the ratio of interchannel wetland area to IWC area(P),shoreline density(DL),and node density(Dn)were used to analyze planform characteristics of IWCs and the development of multi-channels in the stud-ied reach.The results suggest that small or middle sized interchannel wetlands and large or mega sized IWCs are more common at the study site.The area of IWC(Su)is highly cor-related with other geomorphologic parameters.P increases with increasing Su,and the upper limit is about 80%,which indicates that the development of interchannel wetlands and ana-branches in the IWC is in the equilibrium stage.In contrast,D~and D,show a tendency to decrease with increasing Su due to diverse evolution processes in IWCs with different sizes.There are three main reasons leading to the formation of IWCs:varying stream power due to the meandering principal channel;development of the river corridor due to the weakening of geologic structure control;and high stability of interchannel wetlands due to conservation by shoreline vegetation.
