A self-normalized statistic the modified modal scintillation index MMSI is proposed and defined as the variance of the modulus of modal excitation normalized by the square of its expected value over some observation i...A self-normalized statistic the modified modal scintillation index MMSI is proposed and defined as the variance of the modulus of modal excitation normalized by the square of its expected value over some observation intervals.It is proved in an analytical form that the MMSI is a depth dependent signature and independent of the source level and the source range under the condition of the ideal waveguide while the classical modal scintillation index MSI depends on both the source level and the source range.The MSI and the MMSI in the Pekeris waveguide at 70 Hz are simulated with different source levels and source ranges by the Kraken normal mode model.The simulation results are consistent with the theoretical deduction.The MMSI probability density functions PDFs of different normal modes for surface and submerged sources are calculated using the mode filtering methods with the same variations of vertical motions.It is indicated that the PDFs can be used to separate the submerged and the surface sources except for the fourth mode.展开更多
为提高陶瓷微滤膜净化微污染水的效果,采用电絮凝预处理工艺提高陶瓷膜的出水水质。研究了电流密度、进水流量以及过滤模式对组合工艺出水水质的影响,得到了最佳运行参数:电流密度2.0 m A/cm2,进水流量4 L/min,过滤模式为错流过滤浓水...为提高陶瓷微滤膜净化微污染水的效果,采用电絮凝预处理工艺提高陶瓷膜的出水水质。研究了电流密度、进水流量以及过滤模式对组合工艺出水水质的影响,得到了最佳运行参数:电流密度2.0 m A/cm2,进水流量4 L/min,过滤模式为错流过滤浓水全排除。同时,对比了化学絮凝和电絮凝对陶瓷微滤膜出水水质的影响,结果表明:电絮凝对有机物的去除效果不及化学絮凝,两者的差距随着Al3+浓度的增加而增大。展开更多
基金The National Natural Science Foundation of China(No.11104029)
文摘A self-normalized statistic the modified modal scintillation index MMSI is proposed and defined as the variance of the modulus of modal excitation normalized by the square of its expected value over some observation intervals.It is proved in an analytical form that the MMSI is a depth dependent signature and independent of the source level and the source range under the condition of the ideal waveguide while the classical modal scintillation index MSI depends on both the source level and the source range.The MSI and the MMSI in the Pekeris waveguide at 70 Hz are simulated with different source levels and source ranges by the Kraken normal mode model.The simulation results are consistent with the theoretical deduction.The MMSI probability density functions PDFs of different normal modes for surface and submerged sources are calculated using the mode filtering methods with the same variations of vertical motions.It is indicated that the PDFs can be used to separate the submerged and the surface sources except for the fourth mode.
文摘为提高陶瓷微滤膜净化微污染水的效果,采用电絮凝预处理工艺提高陶瓷膜的出水水质。研究了电流密度、进水流量以及过滤模式对组合工艺出水水质的影响,得到了最佳运行参数:电流密度2.0 m A/cm2,进水流量4 L/min,过滤模式为错流过滤浓水全排除。同时,对比了化学絮凝和电絮凝对陶瓷微滤膜出水水质的影响,结果表明:电絮凝对有机物的去除效果不及化学絮凝,两者的差距随着Al3+浓度的增加而增大。
