排序方式: 共有13条查询结果,搜索用时 46 毫秒
11.
Using high sampling-rate ADCP for observing vigorous processes above sloping [deep] ocean bottoms 总被引:1,自引:0,他引:1
Above sloping bottoms in the ocean mixing processes are not predominantly generated by shear-induced turbulence via bottom friction. Instead, the restratifying buoyancy forces and internal waves create a highly non-linearly varying environment including ‘stratified turbulence’. Most of the resulting vigorous mixing processes that dominate sediment resuspension occur during the passage of frontal bores or solitary boluses, ‘solibores’. Here, the observed evolution of different forms of highly non-linear strictly upslope moving ‘waves’, bores or boluses are reviewed from various NIOZ projects at deep sloping bottom sites ranging from 500 to 3000 m.Such fronts pass a fixed site within a few minutes, extending some 60 ± 30 m above the bottom and occurring over much larger periods at once per subinertial or meso-scale period or approximately, but not exactly, once per tidal harmonic period. In order to observe the details of such solibore one needs specific, high-sampling rate equipment. A suitable piece of equipment is a bottom-mounted 4-beam 300 kHz acoustic Doppler current profiler (ADCP), provided it samples at a rate of about once per second over a period of at least several weeks. Not just the three components of current velocity [u,v,w] are monitored over a range of some 80 m at 1 m intervals, but also the relative ‘echo intensity’ dI, which is a measure for suspended matter and stratified turbulence. Such ADCP-observations are combined and compared with high-resolution temperature measurements. Fine details show a turbulent inner core with more or less laminar streamlines outside it. Whether a front or a bolus, the bore is never observed as a completely closed contour, as swept up turbulent material is sucked into the core at the rear end. 相似文献
12.
李隽业 《交通运输系统工程与信息》2002,2(2):14-18
新亚欧大陆桥经济带的开发时至今日虽已取得了较大的进展,但是由于资源禀赋、区位条件、资源配置效率、产业结构等方面的原因,经济带各地区的发展极为不均衡.论文从实证的角度对此问题进行了研究,并就新亚欧大陆桥经济带协调发展提出一些相应的对策及建议. 相似文献
13.
BOSTON Celtics在22年之后,终于又尝到了NBA总冠军的滋味,三巨头感慨万分地拿到了联盟中最为珍贵的总冠军戒指,而对于BOSTON,这已经是第17次夺冠!本文主角的东家,也干最近将美国总部迁址到了Boston,可见这座城市的魅力决不仅限于运动赛场上,除了Bentley高层存在忠实球迷的可能性之外,两个名词的首字母均为“B”也许更是天意! 相似文献