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991.
???????????????????????淶???й?????GPS????????涨????????GPS???????????顣???????????????????仯???α????????涨???????????????仯??α???????????????????????????26.98 mm?????????????涨????10???????????????????????£??????????????????????????????GPS???????????????????????? 相似文献
992.
建立了天然气水合物钻探取样过程中“桩效应”的数学模型,通过解析分析,提出了取样高度的隐式解。分析了取样筒内径和样品与取样筒之间摩擦系数对取样高度的影响。参数分析表明,岩层的内摩擦角和粘聚力对取样高度也有很大的影响。取样深度对取样率的影响较小。 相似文献
993.
Observations of the Alaskan Stream near Samalga Pass and its connection to the Bering Sea: 2001–2004
Year-long moorings were deployed across the Alaskan Stream near Samalga Pass (169°W) on two occasions, first in 2001–2002 (5 moorings) and again in 2003–2004 (3 moorings). Currents were measured throughout the water column, and temperature and salinity were measured at selected depths. Satellite altimetry and satellite-tracked drifters revealed a well defined Alaskan Stream, with the largest near-surface average speeds (>60 cm s−1) and highest eddy kinetic energy just upstream from the mooring sites. Excluding periods when large eddies disrupted the flow, transport in the Alaskan Stream ranged from 10 to 30×106 m3 s−1. The estimated mean transport in 2001–2002 was 19×106 m3 s−1, and in 2003–2004 was 21×106 m3 s−1. Large (diameter>200 km), anti-cyclonic eddies were not uncommon in the vicinity of Samalga Pass (14 times in 20 year period, 1992–2012). Although there were no such eddies observed during the period 2000–2003, one of the largest ever recorded eddies occurred in spring 2004. In addition, smaller eddies occurred on several occasions. Eddies disrupted the flow, shifting the Alaskan Stream farther off shore and were clearly evident in both the satellite imagery and the mooring data. Other energetic events, which were less evident in the satellite records, but clearly evident in the mooring measurements, also disrupted the flow. In addition to the moorings in the Alaskan Stream, pressure gauges were placed in Samalga Pass and a single mooring measuring currents was placed in the Aleutian North Slope Current (ANSC) in the Bering Sea. The alongshore, near-surface flow measured at the moorings deployed on the 1000-m isobaths in the Alaskan Stream and the ANSC were significantly correlated with the bottom pressure time series. In addition, at periods longer than 14 days, the bottom pressure measured at the mooring sites in Samalga Pass was significantly correlated with the sea surface height measured by the satellites. The eddy kinetic energies measured from the satellites and from moorings were also significantly correlated. 相似文献
994.
Using the wave model WAVEWATCH III(WW3), we simulated the generation and propagation of typhoon waves in the South China Sea and adjacent areas during the passage of typhoon Nesat(2011). In the domain 100°–145°E and 0°–35°N, the model was forced by the cross-calibrated multi-platform(CCMP) wind fi elds of September 15 to October 5, 2011. We then validated the simulation results against wave radar data observed from an oil platform and altimeter data from the Jason-2 satellite. The simulated waves were characterized by fi ve points along track using the Spectrum Integration Method(SIM) and the Spectrum Partitioning Method(SPM), by which wind sea and swell components of the 1D and 2D wave spectra are separated. There was reasonable agreement between the model results and observations, although the WW3 wave model may underestimate swell wave height. Signifi cant wave heights are large along the typhoon track and are noticeably greater on the right of the track than on the left. Swells from the east are largely unable to enter the South China Sea because of the obstruction due to the Philippine Islands. During the initial stage and later period of the typhoon, swells at the fi ve points were generated by the propagation of waves that were created by typhoons Haitang and Nalgae. Of the two methods, the 2D SPM method is more accurate than the 1D SIM which overestimates the separation frequency under low winds, but the SIM method is more convenient because it does not require wind speed and wave direction. When the typhoon left the area, the wind sea fractions decreased rapidly. Under similar wind conditions, the points located in the South China Sea are affected less than those points situated in the open sea because of the infl uence of the complex internal topography of the South China Sea. The results reveal the characteristic wind sea and swell features of the South China Sea and adjacent areas in response to typhoon Nesat, and provide a reference for swell forecasting and offshore structural designs. 相似文献
995.
996.
?????????EEMD??GPS???????????????????????????????????????徭??????????????????????????????????????????????????????????????????????й?????CORS??????????????????????????飬?????????????????????????????????????????????????????????????????????????? 相似文献
997.
??????Leica 1200???????????????156 m?????1.2 km???????????
20 h????????GAMIT10.4?????????3????????????????????????????????????????????????????????????ж???????????????????????????????????????????????? 相似文献
998.
??????е??????????????淶????DZ/T 0082??2006????????????????±??????γ?????????????????????????????????Li??Gotze??1996????????????????????????????????????????????????????????????????3????????ж????????????????й?????????????????????????????????й?????????????淶?е???????????????????????????????????н???????????0.24×10-5 m/s2??????????????????????????????? 相似文献
999.
????????λ???????????????????????й???????????GPS/??????????EIGEN-6c2??EGM08?????????????????EIGEN-6c2?????????????EGM08????????2~3 cm??????????????????????????18 cm?????????1985?????????????????(W 0???????26 cm?? 相似文献
1000.
???????????????????з????????????????????????“??????????”????????????????????????????????????????????????з?????????????????????????????????????????????? 相似文献