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91.
上海吴淞站是我国沿海地区记录最长的验潮站之一。通过对吴淞站和黄浦公园站的潮位数据的对比分析,揭示出1952年之前数据存在着系统偏差。并通过小波分析方法获得了序列变化的突变点在1929年和1951年,进而对吴淞月均潮位数据分3个时段进行了调整。在此基础上,对吴淞站1937年9月~1943年12月间缺失数据采用回归模型进行了插补。这一检验定位和调整的思路可供吴淞站和其他存在数据瑕疵的长序列潮位数据分析利用研究借鉴。  相似文献   
92.
The correlation between the Kuroshio and coastal sea level south of Japan has been examined using the altimetry and tide gauge data during the period 1992–2000. The sea level varies uniformly in a region bounded by the coast and the mean Kuroshio axis, which stretches for several hundred kilometers along the coast. These variations are related with the Kuroshio velocity, as coastal sea level decreases (or increases) when the Kuroshio is faster (or slower). To the east of the Kii Peninsula, where sea level variations are different from these to the west, movement of the Kuroshio axis additionally affects coastal sea level variations.  相似文献   
93.
The coastal sea level propagating westward along the south coast of Japan and the impact of the disturbance on the generation of the Kuroshio small meander have been examined. The propagation occurs in sea level variations for periods shorter than 10 days and is remarkable for periods of 4–6 days. Characteristics of the 4–6 day component have been studied using the extended empirical orthogonal function (EEOF). The first and second modes of EEOF are almost in-phase throughout the south coast of Japan. The higher four modes of EEOF are significantly excited when the Kuroshio takes the non-large-meander path, and propagate westward with phase speeds of 2.8 m s−1 (third and fourth modes) and 1.6 m s−1 (fifth and sixth modes) in the Kuroshio region west of Mera in the Boso Peninsula. The analysis shows that more than 70% of the small meanders generate in two months after a significant propagating disturbance reaches south of Kyushu when the velocity of the Kuroshio is high. This effect of coastal disturbance is examined by numerical experiments with a 2.5-layer model in which coastal disturbance is excited by vertical displacement of the upper interface. The result is that offshore displacement of the Kuroshio occurs southeast of Kyushu only in the case of significant upward displacement of the interface under the influence of a high Kuroshio velocity. The significant coastal disturbance, which is associated with upward displacement of the density interface, and a high Kuroshio velocity can therefore be important factors in generating small meanders.  相似文献   
94.
海上桶基平台桶形基础渗流场的模型试验研究   总被引:1,自引:0,他引:1  
海上桶形基础平台是一种新型平台,为研究其负压沉贯机理,了解沉贯过程中渗流场的基本特点,我们在室内进行了桶形基础渗流场模型试验。得到了渗流场的变化规律,验证了理论分析的结果,并得到一些有益的结论。  相似文献   
95.
在阅读、分析以往的有关资料的基础上 ,结合实际的试验条件 ,对桶形基础及其作用下的粉质土海床失稳机制研究的试验作出了专门设计。该设计通过配土、设计模型桶基和负压沉贯的操作过程、设置孔压传感器等实验手段 ,努力从土体破坏的角度 ,寻求负压沉贯过程中沉贯负压、沉贯阻力及孔隙水压力之间的变化关系和确定桶基的上拔力。并且指出了数据处理的基本思路 ,以利于课题的深入研究。  相似文献   
96.
Accurate precipitation measurements are essential for many hydrological and hydrogeological management strategies. Precipitation at the Hilton Experimental Site has been regularly measured since 1982. This paper summarises 157 rain gauge years of precipitation data, recorded between 1982 and 2006, using 11 rain gauges on the 0·5 hectare site. Precipitation varied markedly within the site. Precipitation totals were notably different between two adjacent rain gauges, the mean difference being 0·3% of the total. Variations in mean annual precipitation within the site were ?8%. Spatial variations in wind turbulence appeared to be the main factor influencing intra‐site variability. Precipitation totals varied with gauge exposure, with surface level gauges receiving ?5·9% more precipitation than standard rain gauges, the difference being less lower down the slope. On a steep (~15° ) slope, basal sections had 2·5–7·9% more precipitation. Upper gauges received less, probably due to turbulence as increased exposure on the top of the slope resulted in precipitation being carried over the gauge orifice. Results confirm that due attention must be given to the inherent variability of precipitation amounts when calculating precipitation inputs. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
97.
GPS浮标天线高的动态标定方法   总被引:2,自引:0,他引:2  
针对组装式全球定位系统浮标因每次加载设备不同,浮标体质心与吃水存在变化的问题,该文提出一种借助全球定位系统动态后处理和验潮仪的浮标全球定位系统天线高的动态标定方法。实验表明,该方法能有效测定全球定位系统浮标天线相位中心至吃水面距离,标定精度优于1cm,并可应用于所有类型全球定位系统浮标的天线高标定和校核。  相似文献   
98.
雨量计是地震监测中的辅助仪器,用于测量大气降水量。北方冬季严寒,固态降水不能被及时有效记录,且在融化过程中可能会凝结在雨量计传感器中,造成传感器不能记录甚至被冻坏。为此设计一种加热装置,通过加装智能识别、桶内加热器、延时等装置,对现有非融雪式雨量计进行改造,将固态降水有效转化为液态降水,从而得到降水量的真实记录。  相似文献   
99.
Reconstruction of Mediterranean sea level fields for the period 1945–2000   总被引:1,自引:1,他引:0  
The distribution of sea level in the Mediterranean Sea is recovered for the period 1945–2000 by using a reduced space optimal interpolation analysis. The method involves estimating empirical orthogonal functions from satellite altimeter data spanning the period 1993–2005 that are then combined with tide gauge data to recover sea level fields over the period 1945–2000. The reconstruction technique is discussed and its robustness is checked through different tests. For the altimetric period (1993–2000) the prediction skill is quantified over the whole domain by comparing the reconstructed fields with satellite altimeter observations. For past times the skill can only be tested locally, by validating the reconstruction against independent tide gauge records. The reconstructed distribution of sea level trends for the period 1945–2000 shows a positive peak in the Ionian Sea (up to 1.5 mm yr− 1) and a negative peak of − 0.5 mm yr− 1 in a small area to the south-east of Crete. Positive trends are found nearly everywhere, being larger in the western Mediterranean (between 0.5 and 1 mm yr− 1) than in the eastern Mediterranean (between 0 and 0.5 mm yr− 1). The estimated rate of mean sea level rise for the period 1945–2000 is 0.7 ± 0.2 mm yr− 1, i.e. about a half of the rate estimated for global mean sea level. These overall results do not appear to be very sensitive to the distribution of tide gauges. The poorest results are obtained in open-sea regions with intense mesoscale variability not correlated with any tide gauge station, such as the Algerian Basin.  相似文献   
100.
何龙飞  林坚  孙亚军  王宇清 《探矿工程》2010,37(8):41-43,46
根据京沪高速铁路徐州东站大口径嵌岩灌注桩工程,试制SH25H型液压风动冲击钻机?采用气动潜孔锤空气正循环组合钻进工艺,结合捞砂桶排渣,摸索总结出一套针对硬岩地层的干式成孔新方法,钻进效率及钻孔质量显著提高,为大直径成孔施工增添了一种新的方法。  相似文献   
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