基于变分贝叶斯Cubature KF的SINS海上对准方法

针对SINS海上对准中速度等量测值的先验统计特性未知导致Cubature滤波(Cubature KF)的失准角估计值出现严重振荡的问题,提出变分贝叶斯Cubature滤波.该滤波方法通过近似计算状态变量和量测噪声方差的联合条件后验概率密度,在估计状态变量的同时,实时调整变分贝叶斯参数,估计和修正时变的量测噪声方差,减弱量测噪声方差统计特性对状态变量估计值的影响.半实物仿真结果表明,该方法能够减小Cubature KF海上对准失准角估计值的振荡性,提高海上对准的精度.     

海上风电施工

<正>风电作为绿色可再生能源,取之不尽、用之不竭,是一种极为重要、有效的替代能源,有助于缓解我国目前优质能源供应不足的现状,减轻能源进口的压力。相比于陆上风电,海上风力发电具有广阔的空间,占地资源少,且风力和风能密度更大,风机单机容量也显著提高,并靠近电力负荷中心,免去了长距离输送的麻烦,更具发展潜力。我公司参加了2010年国内首批海上风电特许权招投标,并长期跟踪国内某电力集团位于沿海某省的150MW海上风电示范场工程。依据工程现场以及我公司自有资源情况,总结研究出了一套完整的海     

中国经略海洋的思维，目标与手段——评《中国海权策：外交、海洋经济及海上力量》

中国是陆海兼备的国家,拥有漫长的海岸线、广袤的海域和丰富的海洋资源。按照《联合国海洋法公约》,沿海国家主权范围的海洋区域主要包括内水、内海、领海、毗连区、专属经济区、大陆架等。     

Experimental study on spectral responses of offshore oil slick

Using the seawater taken from Liaodong Bay and crude oil taken from Liaohe Oilfield, a laboratory experiment was designed to study the change of reflectance spectrum of artificial offshore oil slick with its thickness and to identify the spectrum ranges suitable for quantifying the thickness of the oil slick. During the experiment, crude oil was continuously dropped into the seawater to generate artificial oil slick with different thicknesses. After every drop of crude oil was added, reflectance spectrum of the oil slick was measured with a high resolution spectroradiometer （ASD FieldSpec Pro FR）. The influence of oil slick thickness on its reflectance spectrum was explored through statistical analysis. The results show that the reflectance of oil slick changes marginally with oil slick thickness and higher than that of seawater in infrared band from 1150 to 2500 nm. This spectrum range can be practically used to distinguish oil slick from seawater. In the spectrum range from 400 to 1150 nm, the reflectance of oil slick decreases with its thickness. The negative power function is the best-fit function expressing the relationship between the reflectance and thickness. The spectral characteristics of oil slick are very distinct at 550 and 645 nm. They are the best wavelengths for monitoring the existence of offshore oil slick and estimating its thickness.     

石油时代真的将要终结吗?

地球的石油埋藏量是有限的。这一点毫无疑问。由于人类大量地消耗了石油,贪婪地攫取着石油,石油资源的短缺在所难免。根据经济学供求原理推论,既然石油资源不是取之不尽、用之不竭的,那么它必然会随着需求的     

中海油在海上油田开发中的钻完井技术现状和展望

本文总结中国海洋石油总公司在海上油田勘探、开发和生产中,结合海上油田开发的需要和特点,通过不断的探索和实践,逐步的掌握了在中国近海开发油田的关键技术及其特点。同时根据目前国外的开发技术发展现状,结合中海油自身的特点,针对海上油田开发的具体不同的需求。经过改革开放20多年来的不断努力,中海油已经掌握并形成了一整套的海上油气田开发的钻完井工程技术。并且形成了以海上油田开发为目标的优快钻完井技术体系;大位移钻井技术体系;     

深度挖掘水平井资料预测地层倾角新方法

针对海上油田水平井较多的特征,深挖水平井资料预测地层倾角.根据水平井与储层相对位置及水平段轨迹形态,将水平井厘定为3类,分别为:"一"字型水平井、"V"字型水平井和小井斜水平井,阐述不同类型水平井资料挖掘过程中的优势与劣势,并结合不同类型水平井的资料特点,利用多类型电阻率测井协同、水平段拆分对比、真厚度方向校正对比等方...     

改进的海上稠油黏弹性聚合物驱分流量方程

现有的聚合物驱分流量方程多针对陆上油田建立,且对聚合物流动过程中涉及的物化现象考虑不足,对渤海稠油油藏的适应性较差。为更好的描述海上油田注聚油藏动态,结合现有的分流量方程,考虑了聚合物黏弹性、聚合物老化降解以及原油张弛特性等关键因素的影响,建立了改进的聚合物驱分流量方程,为海上聚合物驱快速评价提供一种有效的预测方法。计算分析表明:聚合物黏弹性、降解效应、原油黏度特性以及不可及孔隙体积等均会对聚驱分流曲线形态产生明显影响;改进后的分流量方程能较准确预测海上聚合物驱动态。     

Changes in sea surface temperature in western South China Sea over the past 450 ka

Sea surface temperature over the past 450 ka was obtained by the unsaturation of molecular fossil-long chain alkenone with a resolution of about 1 ka from the western South China Sea. This is the longest temperature profile in the South China Sea at such high resolution. The U37^κ-SST results revealed similar glacial-interglacial cycles as the δ^18O profile of planktonic foraminifera, with SST variability of 23-25.5℃ for glacial and 25-28℃ for interglacial periods. The highest SST （28.4℃） was recorded at MIS5.5 and lowest SST （22.6℃） during MIS2. The SST record preceded the planktonic foraminiferal δ^18O on five glacial-interglacial transitions. Comparison of temperature records from the Southern and Northern Hemispheres indicated a more Southern Hemisphere-like pattern for the temperature variation in the SCS. Strong precession and semiprecession signals in the spectra of our SST record manifest the tropical phenomena.     

Tribological behaviors of some polymeric materials in sea water

Ocean tribology, a new research field of tribology, is being established and developing. The investigation on the tribology in sea water has important significance to ocean exploitation. In this paper, the tribological behaviors of UHMWPE, PTFE as well as Ekonol/PTFE, graphite/PTFE and CF/PTFE sliding against GCr15 steel and Ni-Cr-WC alloy in sea water were investigated, and compared with those in pure water. Results show that the main factors that affect the tribological behaviors of five polymeric materials in sea water are the corrosive effect and lubricating effect of sea water. When polymeric materials sliding against GCr15 in sea water, owing to serious corrosion of counterface by sea water, the surface roughness of the counterface increases largely. As a result, the lubricating effect of medium decreases sharply and the plowing effect of counterface increases greatly. So the friction coefficients and wear rates of five materials sliding against GCr15 in sea water are much larger than those under other conditions. Such wear model, depending on the corrosion of counterface by medium, can be called indirect corrosive wear. Under other three conditions, owing to the more superior lubricating effect of sea water than pure water and the better wettability of Ni-Cr-WC than GCr15, the friction coefficients and wear rates of five materials increase in the following order： sliding against Ni-Cr-WC in sea water 〈 sliding against Ni-Cr-WC in pure water 〈 sliding against GCr15 in pure water. Moreover, compared with other materials, CF/PTFE is the one with more superior plowing and wear resistance in pure and sea water, which is a potential frictional material well suitable for pure and sea water lubrication.