任意曲线曲面上重磁位场转换的B样条函数法

提出用B样条函数求解曲线、曲面上重磁位场的向上延拓,水平、垂向导数计算,磁异常分量互换的方法。该方法的特点是:原理简明,程序通用性强,计算精度高。     

Detection of free gas and gas hydrate based on 3D seismic data and cone penetration testing: An example from the Nigerian Continental Slope

We present a new method to characterize free gas, gas hydrates and carbonate concretions occurrence which are considered as high-risk factors for sub-sea developments in the Niger delta. This method is based on the combination of 3D seismic data to the geotechnical site characterizations using piezocone CPTU tests (Cone Penetration Test with additional measurement of the pore water pressure). A special processing of the 3D seismic data has enabled the determination of the interval compressional velocity. Using the effective-medium theory, velocity anomalies (negative and positive) within the first 15 m were translated in gas hydrate and free gas distribution. The calibration of the P wave velocity anomalies was done thanks to in-situ geotechnical testing carried out during two oceanographic surveys (2003 and 2004). Comparison between in-situ testing, recovered cores and the prediction of the gas and the gas hydrate distribution based on the compressional wave velocity have shown that 3D seismic data is a valuable tool to identify heterogeneous areas but the use of the piezocone was essential to discriminate between gas hydrate occurrences and carbonate concretions' presence. Furthermore, in-situ compressional wave velocity (V_p) measurements have clearly demonstrated what it was suspected from the 3D seismic data, the co-existence in the study area between gas hydrate and free gas.     

南海大气低层风场的气候特征分析

分析１９８０－１９８７年欧洲中长期预报中心（ＥＣＭＷＦ）每日风场、温度场格点资料及同期南海区域测站和船舶资料，讨论南海低层风场的气候特征。南海为典型的季风活动区，冬季盛行东北季风，夏季盛行西南季风。流场的季节转换表现为季风系统的交替，相应不同的季风系统，南北温度梯度有一逆转过程，南海北部是温度梯度大且发生明显逆转的海区。１２°Ｎ以南海区气温全年变化极小，整个海区大气温度的季节变化不如流场变化快和显著。     

长江口三维潮流数值计算及动力分析

采用三维动力学数学模型对长江口潮流场进行了计算，对长江口潮流流态在一个潮周期内逐时进行了分析，并对长江口南支盐水倒灌从动力学角度进行了初步探讨。计算结果表明：文中模型较好地重演长江口潮流场，可以用于大型复杂河口工程实际中的潮流场的计算和分析。     

冲绳海槽天然气水合物BSR的地震研究

根据多道地震反射资料分析,在冲绳海槽南部和中部发现了拟海底反射层(BSR)现象。通过对海底异常反射层的振幅特征、速度异常和AVO属性分析,说明该BSR可能反映了天然气水合物的存在,并发现冲绳海槽断层与天然气水合物的形成有密切关系。     

南海北部海区上层水体平均声速场的变化

对所收集到的南海北部海区的温度、盐度和深度历史资料进行了声速的计算、统计与分析,结果表明该海区上层水体的平均声速场有较明显的年际变化:表层声速的平面分布显示出沿岸水与外海水强弱交替变化的特征,声速等值线的走向几乎与岸线平行,等声速线的值自近岸向外海增加,大陆架外缘海区声速的水平梯度较大;下层声速的分布以环流和水体共同作用的形式出现,50m层声速平面分布的趋势除冬季与表层稍为相似外,其余季节与表层有明显的差别,春、夏季节50m层声速自西向东增加,而秋季与其表层分布相反,自近岸向外海减小;声速的垂直分布受海水升温与降温的影响显著,春、夏季表层海水升温,海表声速最大,声速自海表随深度的增加而减小;秋、冬季表层附近水层降温,声速稍偏低,普遍出现正梯度现象,最大声速移至表层以下的水层,这个深度随季节的改变而改变,随海区的不同而不同.该海区的平均声速有年波动现象,表层波幅最大,随深度的增加波幅变小,至100m水层其波动的位相几乎与表层相反.     

能量分析在台风短期预报业务中的应用

本文以９４１４、９４１５号两个连续北上台风为例，证明能量场的分布与台风移向有着明显的对应关系。     

A Study on the Spectral Form of Nearshore Water Waves

- The spectral form of wind waves is investigated based on the ocean wave data observed at three nearshore stations of Taiwan. In this study, the generalized forms of Pierson-Moskowitz spectrum and JONSWAP spectrum are used to describe the local wave spectrum by selecting suitable spectral form parameters. It is shown that, at a specific site, the similarity of wave spectral form exists. Thus it is possible to use a representative spectral form for a given nearshore region to describe the wave spectrum at this nearshore. On the other hand, the effects of relative water depth on spectral form are examined. The feasibility of two spectral models in finite water depth is evaluated by using the same field wave data.     

LAS格式解析及其扩展域的应用

激光雷达是近年来兴起的一种快速获取地物目标三维信息的主动遥感技术。其采集的离散激光点具有数据量大,信息丰富等特点。目前常用的LIDAR数据存储格式,在存储LIDAR数据时存在种种不足,且数据交换和共享困难。LAS格式是ASPRS制定的标准LIDAR数据交换格式,能较好地解决多属性离散激光点数据的存储问题,具有结构严谨,便于扩展等优点。本文在对LAS格式进行解析的基础上,针对LAS变长记录的扩展域,介绍了一些实际的应用。