Techniques for the detection of second sound shock pulses and induced quantum turbulence in He II
This paper discusses the design and operation of thin-film thermometers and heaters for the detection and generation of second sound shock (SSS) pulses and second sound resonance (SSR) waves. The detection of quantum turbulence at multiple points along a channel is also discussed. An instrumentation package to simultaneously detect SSS pulses and induced quantum turbulence in He II has been developed. This system is able to generate and detect SSS pulses in a channel of He II while monitoring for induced quantum turbulence at multiple points along the channel. The system monitors for quantum turbulence by the attenuation of SSR waves. The experiments using this instrumentation package offer the first opportunity to directly measure the quantum turbulence time and distance evolution of SSS pulses. These experiments have applications in transient heat transfer problems in He II, such as the cooling and stability of superconductors.
Two sections were investigated on the turbidity and fluorescence of suspended particulate matter(SPM) in waters around Taiwan Bank during July-August,2004.The study showed that the distribution of turbidity and fluorescence in Taiwan Bank in summer,combined with hydrology factors,was affected by the marine sediments re-suspension and sedimentary processes.The turbidity of SPM was influenced by the re-suspension of marine sediment in near shore and the outer fringe of continental shelf,but was not obvious in the shoal.The enrichment of phytoplankton had some effects on the turbidity in the outer fringe of continental shelf,but not evidence in near shore waters.