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261.
Wanshan area has been chosen to be the specified field to calibrate and validate(Cal/Val) the HY-2 altimeter and its follow-on satellites. In March 2018, an experiment has been conducted to determine the sea surface height(SSH) under the HY-2 A ground track(Pass No. 203). A GPS towing-body(GPS-TB) was designed to measure the SSH covering an area of about 6 km×28 km wide centered on the HY-2 A altimeter satellite ground track. Three GPS reference stations, one tide gauge and a GPS buoy were placed in the research area, in order to process and resolve the kinematic solution and check the precision of the GPS-TB respectively. All the GPS data were calculated by the GAMIT/GLOBK software and TRACK module. The sea surface was determined by the GPS-TB solution and the tide gauge placed on Zhiwan Island. Then the sea surface of this area was interpolated by Arc GIS10.2 with ordinary Kriging method. The results showed that the precision of the GPS-TB is about 1.10 cm compared with the tide gauge placed nearby, which has an equivalent precision with the GPS buoy. The interpolated sea surface has a bias of –1.5–4.0 cm with standard deviation of 0.2–2.4 cm compared with the checking line. The gradient of the measured sea surface is about 1.62 cm/km along the HY-2 orbit which shows a good agreement compared with the CLS11 mean sea surface(MSS). In the Cal/Val of satellites, the sea surface between the tide gauge/GPS buoy and the footprint of altimeter can be improved by this work. 相似文献
262.
Rapid changes in the near-bottom water temperature are important environmental factors that can significantly affect the growth and development of species in the bottom culture. The object of this research is to investigate the mechanism causing these rapid changes within a bottom culture area near the Zhangzi Island. The hydrographic transects observations in the North Yellow Sea(NYS) suggest that our mooring station is very close to the tidal mixing front. The horizontal advection of the tidal front has induced the observed tidal change of bottom temperature at the mooring station. Analysis of the mooring near-bottom temperature and current measurements show that the angle between the tidal current horizontal advection and the swing of the tidal front is crucial in determining the variation trend of temperature. When the angle equals 90°, the horizontal tidal current advects along the isotherms so the temperature remains the same. When the angle is between 0° and 90°, the seawater moves from deep water to the warmer coastal zone and the temperature decreases. In contrast, the horizontal tidal advection moves the coastal warm water to the mooring station and the water temperature increases when the angle is between 90° and 180°. The amplitude of the temperature change is proportional to the magnitude of the horizontal temperature gradient and the tidal excursion in the direction of the temperature gradient. This study may facilitate the choice of culture area in order to have a good aquaculture production. 相似文献
263.
为了明确黄河调水调沙对河口海域大型底栖动物群落结构的影响,本研究于2012至2016年调水调沙后进行了大型底栖动物样品的采集工作。整个研究时期共鉴定出大型底栖动物7门138种,生物量和丰度2012年显著高于2016年,生物量年间无显著差异;研究时期内优势种以小型多毛类为主,鲜见软体动物、节肢动物和棘皮动物,其中2016年优势种全部为小个体多毛类;MDS显示,随时间的推移距河口不同距离梯度的大型底栖动物逐渐演变为相同的群落结构,且Shannon-Wiener多样性指数和Margalef丰富度指数呈下降趋势;CCA显示研究海域主要底栖动物种类的生态需求为高中值粒径、低溶解氧、pH、黏土和硫化物含量。本研究推测调水调沙工程一定程度上影响了底层生物群落结构,特别是研究海域的A断面。 相似文献
264.
In order to investigate the effect of internal friction of umbilical cable on its vortex-induced vibration(VIV)responses, the experimental study on VIV of bond umbilical cable(BUC) and un-bond umbilical cable(UBUC) was carried out in an experimental tank. A current generator in the laboratory simulated the uniform current, and the current velocities were observed in real time by using a Doppler Velocimeter. In addition, different sizes of top tension were applied to the umbilical cable model. The VIV responses of the umbilical cable model were measured by using Fiber Bragg grating(FBG) strain sensors. The displacement responses of umbilical cable model were reconstructed based on the experimental strain data processed by modal superposition method. In this paper, the traveling wave characteristics, the spatial-temporal distribution characteristics of frequency and fatigue damage of the BUC and UBUC under VIV are studied. The experimental results show that there are obvious differences between BUC and UBUC in the response characteristics of VIV. The UBUC appears the traveling wave sooner than BUC, but its standing wave characteristics are more obvious than those of BUC at high velocities. Compared with BUC, the spatial-temporal distribution of UBUC frequencies appears wide-band distribution sooner, but has narrower bandwidth in the "lock-in" state. The level of fatigue damage of BUC was approximately the same as that of UBUC. 相似文献
265.
“天擎”是数算一体的气象大数据云平台,具备海量数据存储、全业务贯通、数据应用高效的能力,支持各类气象应用的“云”化融入,全面支撑“云+端”的气象业务模式。该研究以云南省降水量告警系统为例,分析了应用系统融入“天擎”的全套流程。首先从系统技术架构的设计着手,对照融入要求,确定需要融入的切入点;然后从数据采集、数据存储、产品加工、业务监控、业务应用等5个方面对系统融入流程进行具体研究;最后,针对开发过程中需要注意的关键问题进行技术总结,可为后续融入工作提供参考。研究结果表明,基于“天擎”的系统融入开发流程较为简洁快速,普通开发人员较易上手,整个融入过程能从系统技术架构的多个层面减少不必要的开发步骤,缩短开发周期。 相似文献
266.
267.
268.
辽东湾北部地区走滑构造特征与油气富集规律 总被引:4,自引:2,他引:2
辽东湾北部地区右行走滑构造特征较为典型,主要表现为:沿走滑断裂带发育雁行式伸展断裂;剖面上发育花状构造;走滑断裂沿走向呈“S”型或反“S”型波状弯曲;沿走滑断裂带断槽与断鼻构造相间分布。分析认为,渐新世晚期,辽东湾北部地区南北向拉张、东西向挤压的区域应力场控制了右行走滑构造的形成,断槽与断鼻构造相间分布是由于沿走滑断裂带局部应力场性质发生改变所致。右行走滑断裂的“S”型弯曲部位为增压弯部位,走滑断裂两侧断块在此汇聚,地层因应力集中而形成断鼻构造;右行走滑断裂的反“S”型弯曲部位为释拉张部位,走滑断裂两侧断块在此离散,地层因拉张而发生断陷形成断槽。受走滑构造所控制,油气沿走滑断层自断槽向断鼻方向运移、聚集而成藏。研究走滑构造发育特征,对于预测圈闭分布以和研究油气富集规律具有重要意义。 相似文献
269.
干旱半干旱区水资源承载力评价及空间规划指引——以宁夏西海固地区为例 总被引:4,自引:1,他引:3
以宁夏西海固地区为例,在区域尺度水资源超载状态分析基础上,构建了栅格尺度水资源承载力评价指标体系和计算方法,阐释了水资源承载力空间格局、特征及其与人口经济要素的空间关系,并提出空间规划与发展路径指引。干旱半干旱区栅格尺度的水资源承载力评估指标体系包括5项一级指标和12项二级指标,案例实证研究与校验表明:指标体系与评估模型具有可操作性,可为空间规划与管制提供更有效的决策支撑;西海固地区栅格尺度的水资源承载力划分为强、较强、中等、较弱以及弱5个等级,强和较强等级区主要位于清水河河谷平原,是黄河扬水灌区与地下水资源富集区的叠加区域,较弱和弱等级区集中分布于黄土丘陵区、六盘山及其余脉山地区。在水资源承载力空间差异分析的基础上,因地制宜地制定空间开发指引,建立“节流为主、开源为辅”的水资源保障体系,有助于构建与区域水资源条件相适应的人口产业布局模式。 相似文献
270.
Mariculture has rapidly grown worldwide, which might greatly influence the biogeochemical cycle of organic carbon in coastal seas. In this study, several geochemical parameters, including grain size composition, sedimentary total organic carbon(TOC), total nitrogen(TN), stable carbon(δ13 C) and nitrogen(δ15 N) isotopic compositions, were analyzed for surface sediments collected from different mariculture zones of Sanggou Bay and in different seasons. We investigated the composition and distribution of organic matter in surface sediments and further evaluated the contribution of mariculture activities to TOC sources. The TOC and TN contents(mass percentage) in the bay were in the range of 0.14% to 1.45% and 0.03% to 0.20%, respectively. The spatial distribution indicated that sedimentary TOC and TN contents in shellfish monoculture and shellfish-kelp polyculture zones were higher than in other mariculture zones, which might be related to grain size composition and mariculture organisms. Seasonal variations of TOC contents were observed in different mariculture zones. The TOC/TN atomic ratio(C/N), δ13 C and δ15 N were in the ranges of 5.97 to 10.97,-21.76‰ to-13.14‰ and 2.13‰ to 8.08‰, respectively, implying that sedimentary organic matter in Sanggou Bay was the mixture of marine phytoplankton, terrestrial and maricultural sources. A simple mixing model based on δ13 C was applied and the results indicated that the relative contributions of organic carbon sources in Sanggou Bay followed the order kelp(36.6%) ? marine phytoplankton(28.7%) ? shellfish bio-deposition(23.8%) ? terrestrial input(10.9%). Surface sediments in Sanggou Bay were dominated by mariculture-derived organic carbon, which on average accounted for 60.4% of TOC. 相似文献