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41.
针对以往噪声信号发射换能器在实际工作中,存在着诸多影响正常科研试验的问题,并根据噪声信号的技术要求,以及探测方式的技术特征,我们对噪声发射换能器进行了重新设计,从选用超磁致伸缩材料作为换能器的材料入手,结合国内外一些新的设计理念,从材料性能分析,到理论设计,最后到可靠性实施方法,都进行了周密细致的研究,并完成了设计全过程。测试结果和使用性能表明,达到了预期的目的,这也是该材料在国内首次应用于单只宽频水声换能器中,开创了稀土超磁致伸缩材料应用的又一个先列。 相似文献
42.
Shigenao Maruyama Koutaro Tsubaki Keisuke Taira Seigo Sakai 《Journal of Oceanography》2004,60(3):563-568
Deep seawater in the ocean contains a great deal of nutrients. Stommel et al. have proposed the notion of a “perpetual salt fountain” (Stommel et al., 1956). They noted the possibility of a permanent upwelling of deep seawater with no additional external energy source. If
we can cause deep seawater to upwell extensively, we can achieve an ocean farm. We have succeeded in measuring the upwelling
velocity by an experiment in the Mariana Trench area using a special measurement system. A 0.3 m diameter, 280 m long soft
pipe made of PVC sheet was used in the experiment. The measured data, a verification experiment, and numerical simulation
results, gave an estimate of upwelling velocity of 212 m/day.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
43.
Toshiro Saino Alexander Bychkov Chen-Tung Arthur Chen Paul J. Harrison 《Journal of Oceanography》2004,60(1):1-4
This special issue is comprised of 13 papers, including this overview, and focuses on the synthesis of the Joint Global Ocean
Flux Study (JGOFS) in the North Pacific which took place from 1997 through 2003. The effort was led by the JGOFS North Pacific
Synthesis Group, with the aim of quantifying CO2 drawdown by physical and biological pumps in the North Pacific by identifying and studying the regional, seasonal to inter-annual
variations in the key processes, and understanding their regulating mechanisms. Emphasis was placed on the similarities and
differences of the biogeochemical regimes in the eastern and western subarctic Pacific. Effort was also made to address the
future research directions which arose from the scientific findings during the North Pacific JGOFS process study. A brief
overview of the papers from view points of CO2 drawdown by physical and biological pumps, spatial variability, and temporal variability from seasonal to decadal scales
is made, followed by suggestions for the directions of future research.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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47.
本文采用1985年12月12日至1986年2月8日“向阳红14”号调查船在太平洋调查所获海洋水文气象资料,计算了四种热交换量。结果表明:海-气热输送与天气系统和海洋水文条件关系密切。冬季,在各种天气系统条件下西太平洋及中太平洋的大气主要是从海洋得到热量,其中以黑潮流经的海域最为明显,而热交换的方式主要是海洋以潜热的形式把热量输送给大气。 相似文献
48.
In this study, the impact of oceanic processes on the sensitivity of transient climate change is investigated using two sets of coupled experiments with and without tidal forcing, which are termed Exp_Tide and Exp_Control,respectively. After introducing tidal forcing, the transient climate response(TCR) decreases from 2.32 K to 1.90 K,and the surface air temperature warming at high latitudes decreases by 29%. Large ocean heat uptake efficiency and heat storage can explain the low TCR in Exp_Tide. Approximately 21% more heat is stored in the ocean in Exp_Tide(1.10×10~(24) J) than in Exp_Control(0.91×10~(24) J). Most of the large ocean warming occurs in the upper 1 000 m between 60°S and 60°N, primarily in the Atlantic and Southern Oceans. This ocean warming is closely related to the Atlantic Meridional Overturning Circulation(AMOC). The initial transport at mid-and high latitudes and the decline in the AMOC observed in Exp_Tide are both larger than those observed in Exp_Control. The spatial structures of AMOC are also different with and without tidal forcing in present experiments. The AMOC in Exp_Tide has a large northward extension. We also investigated the relationship between AMOC and TCR suggested by previous studies using the present experiments. 相似文献
49.
Seasonal Variability of Near-Surface Heat Budget of Selected Oceanic Areas in the North Tropical Indian Ocean 总被引:1,自引:0,他引:1
The results obtained from an Ocean General Circulation Model (OGCM), the Modular Ocean Model 2.2, forced with the National
Center for Environmental Prediction/National Center for Atmospheric Research reanalysis data, and observational data have
been utilized to document the climatological seasonal cycle of the upper ocean response in the Tropical Indian Ocean. We address
the various roles played by the net surface heat flux and the local and remote ocean dynamics for the seasonal variation of
near-surface heat budget in the Tropical Indian Ocean. The investigation is based in seven selected boxes in the Arabian Sea,
Bay of Bengal and the Equatorial Indian Ocean. The changes of basin-wide heat budget of ocean process in the Arabian Sea and
the Western Equatorial Indian Ocean show an annual cycle, whereas those in the Bay of Bengal and the Eastern Equatorial Indian
Ocean show a semi-annual cycle. The time tendency of heat budget in the Arabian Sea depends on both the net surface heat flux
and ocean dynamics while on the other hand, that in the Bay of Bengal depends mainly on the net surface flux. However, it
has been found that the changes of heat budget are very different between western and eastern regional sea areas in the Arabian
Sea and the Bay of Bengal, respectively. This difference depends on seasonal variations of the different local wind forcing
and the different ocean dynamics associated with ocean eddies and Kelvin and Rossby waves in each regional sea areas. We also
discuss the comparison and the connection for the seasonal variation of near-surface heat budget among their regional sea
areas.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
50.
A numerical procedure is described for predicting the motion and structural responses of tension leg platforms (TLPs) in waves. The developed numerical approach, in a TLP is assumed to be flexible instead of rigid, is based on a combination of the three dimensional source distribution method and the finite-element method. The hydrodynamic interactions among TLP members, such as columns and pontoons, are included in the motion and structural response analysis. Numerical results are compared with the experimental and numerical ones. The results of comparison confirmed the validity of the proposed approach. 相似文献