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111.
1 INTsoDUcrIONTemperature is one of the most impoFtant essential factors of ocean, and its verticalstructure, especially the phenomenon ofthermocline, is concerned by military and manufacturepractices at all times. There are two classes of research methods for thermocIine, statisticmethod and numerical method. In recent years, more attention has been paid to the latterwhich becomes the primary development direction. Since Munk et al (1948) pot forward1-D model of thermocline at steady sta… 相似文献
112.
Observations of fluid mud were made in the lower North Passage of the Yangtze Estuary in February 2000, on 10 -11 August 2000, on 30 - 31 August 2000 (after two strong typhoons), on 21 - 24 August 2000 (neap tide) and on 3 -6 September 2000 (mean tide) respectively. In situ data show that the fluid mud in this area consists of fine cohesive sediment (median size 7.23 μm). The formation and movement of fluid mud varied during the neap-spring and flood-ebb tidal cycle. Observations suggest that fluid mud phenomena in this area may be categorised in a three-fold manner as slack water, storm and saltwedge features. The thickness of the fluid mud layer of slack water during the neap tide ranged from 0.2 to 0.96 m, whereas during the mean tide, the thickness ranged from 0.17 to 0.73 m, and the thickness of the fluid mud layer was larger during slack water than at the flood peak. Shoals cover an area of 800 km^2 with a water depth smaller than 5 m. Erosion of these extensive intertidal mudflats due to storm action provides an abundant sediment source. This is particularly significant in this estuary when the tidal level is lower than 5 m. The lower North Passage is a typical zone of saltwater wedging, so the saltwedge fluid mud has the most extensive spatial range in the estuary. 相似文献
113.
Long-term Sensor Drift Found in Recovered Argo Profiling Floats 总被引:5,自引:0,他引:5
We recovered three Argo profiling floats after 2 to 2.5 years of operation, and recalibrated their temperature, conductivity, and pressure sensors. The results demonstrate that these floats exhibited a significant drift in salinity of −0.0074 to −0.0125, primarily due to the conductivity sensor drift. Combined with the recalibration result for another previously recovered float, the indication is that the negative salinity drift increases nearly in proportion to the operating period of floats. The increasing rate is −0.0041 (±0.0015) year−1, which yields a salinity drift of −0.016 (±0.006) for the expected float lifetime of four years. The present result suggests that reducing the float surfacing time would improve the accuracy of the salinity measurements. 相似文献
114.
碳水化合物的组合合成是一项新兴技术,该技术可以在短时间内合成大量用于进行生物活性筛选的寡糖及拟糖物。液相与固相合成技术可以极大地加快药物研究与开发进程。作者针对该技术在碳水化合物合成方面的研究进展情况进行讨论。 相似文献
115.
Takushi?NikiEmail author Taiki?Fujinaga Mariyo?F.?Watanabe Junji?Kinoshita 《Journal of Oceanography》2004,60(5):913-917
Solid-phase microextraction (SPME) is a simple, sensitive and less destructive method for the determination of dimethylsulfide
(DMS) in seawater. Combined with detection by gas chromatography-mass spectrometry (GC-MS), the method had sufficient sensitivity
(minimum detectable concentration of DMS was 0.05 nM), and practical levels of reproducibility (relative standard deviation
≤7%) and linearity (r
2 > 0.995) over a wide concentration range (0.5 to 910 nM). The protocol developed was applied to a Sagami Bay water sample
to determine concentrations of DMS and DMSP, and in situ DMSP-lyase activity. 相似文献
116.
Eddy Shedding from the Kuroshio Bend at Luzon Strait 总被引:16,自引:1,他引:16
TOPEX/POSEDIENT-ERS satellite altimeter data along with the mean state from the Parallel Ocean Climate Model result have been used to investigate the variation of Kuroshio intrusion and eddy shedding at Luzon Strait during 1992–2001. The Kuroshio penetrates into the South China Sea and forms a bend. The Kuroshio bend varies with time, periodically shedding anticyclonic eddies. Criteria of eddy shedding are identified: 1) When the shedding event occurs, there are usually two centers of high Sea Surface Height (SSH) together with negative geostrophic vorticity in the Kuroshio Bend (KB) area. 2) Between the two centers of high SSH there usually exists positive geostrophic vorticity. These criteria have been used to determine the eddy shedding times and locations. The most frequent eddy shedding intervals are 70, 80 and 90 days. In both the winter and summer monsoon period, the most frequent locations are 119.5°E and 120°E, which means that the seasonal variation of eddy shedding location is unclear. 相似文献
117.
118.
The Effect of Internal Fluid on the Response of Vortex-Induced Vibration of Marine Risers 总被引:5,自引:1,他引:5
Based on Iwan‘s wake oseillator model developed with the classical van der Pol equalion, the differential equation for the response of the vortex-induced vihration (VIV) of the riser considering the effect of the internal flowing fluid and the external marine environmental condition is derived. The effect of the intermal flowing fluid on the response of VIV of the riser is studied by means of the Finite Element Method. The results show that the effect of the internal fluid velocity on the VIV of the riser is strong when the natural frequency of the riser is close to the vortex shedding frequency. In addition, the increase of the top tension can decrease the sensitivity of the riser to the internal fluid velocity. 相似文献
119.
In this paper we analyze seismic regime and earthquake depth distribution and correlation of seismicity and mud volcanism in the Azerbaijan and the Caspian Sea region. For the present region we have calculated accurate source locations, seismic activity, earthquake repetition and released earthquake energy parameters. It is shown that the active tectonic processes in the region are concentrated within the thick sedimentary cover that we consider as a general source of contemporary stress and a main structural element responsible for the origin of regional earthquakes. The correlation of seismicity and mud volcanism is of paragenetic character. 相似文献
120.
The floating oil storage system has been proposed as a new facility for Strategic Petroleum Reserve (SPR) in China. Mooring is one of the key technologies to ensure the safety, reliability, and performance of the oil storage system. This paper describes the concept, analysis, design and reliability of the mooring system. For mooring system design of these oil vessels, analysis is essential of the behavior of the vessel in connection with mooring facilities of nonlinear resilience. A nonlinear mathematical model for analyzing a moored vessel is established and solved. Some results of numerical simulations are presented. Assessment of the safety regarding the mooring system in terms of failure probability is carried out. Another simulation model for calculating the failure probability of the mooring system is proposed. The design parameters that have an influence on the characteristics of the failure probability have been identified. The simulation results show that the mooring system has an annual reliab 相似文献