Assessment of Fatigue Strength of An Offshore Floating Production and Storage Unit

The procedure of assessment of structural fatigue strength of an offshore floating production and storage and offloading unit(FPSO) in this paper. The emphasis is placed on the long-term prediction of wave induced loading, the refined finite element model for hot spot stress calculation, the combination of stress components, and fatigue damage assessment based on S-N curve.     

卤虫(Artemia salina)卵孵化条件、网箱孵化和幼体收集时机的研究

本文研究了温度、盐度、pH和光刺激对卤虫卵孵化的影响,提出了本品系卤卵大量孵化的最适孵化温度、盐度和pH控制范围,并就孵化时对卤虫卵进 行室内自然光刺激持续的时间和阶段进行了试验,发现光刺激也可在孵化前进行。本试验首次应用23cm×23cm×40cm的网箱进行卤虫卵的孵化,其效果比相同水体的水泥池约提高一倍。本文还从无节幼体的活力、孵化水质的变化和孵化高蜂期等方面,探讨了卤虫卵大量孵化时无节幼体的收集最有利时机。     

利用Jason-1数据监测呼伦湖水位变化

卫星测高为内陆水域水位变化的实时和连续监测提供了一种高效的技术工具．但是这种应用受到数据点覆盖稀疏的限制。利用Jason-13年（2002-2004）GDRs测高数据作简单的数据编辑,并进行必要的地球物理改正．最后得到内蒙古地区呼伦湖水位变化的时间序列。呼伦湖地区由于近年来持续干旱,水位呈现明显的下降趋势．年平均下降约0．3～0．5m。在一般的内陆水域．水位变化主要取决于降雨量和蒸发量,所以,根据卫星测高所得的水位变化信息．可以为区域气候变化的研究提供一种全新的技术与方法。     

冰雪圈研究的新动态--参加2004年AGU秋季年会情况报告

2004年美国地球物理联合会(AGU)秋季年会于12月在美国旧金山市召开,这是地球科学界的一次盛会。本文介绍了会议的情况,综述了其中冰冻圈科学研究方面的部分最新动态。     

Research on the Probability of Earthquake Occurrence in the Daduhe Drainage Area

This paper applies the Seismic Hazard Analysis method for the cities of China to research on the probability of earthquake occurrence in the Daduhe drainage area, where the cascade dam system is located. This research is based on the potential seismic source scheme of the Seismic Ground Motion Parameter Zonation Map of China （2001）, and uses Poisson distribution as an earthquake occurrence model. Earthquake magnitude obeys truncated exponential distribution. The spatial distribution function of the potential seismic source zone is taken as the first-class spatial probability distribution, and the homogeneous probability distribution in the potential seismic source zone as the second-class spatial probability distribution. Considering the seismic intensity attenuation relationship of western China, we compute the occurrence probability of an earthquake around magnitude 6.0 （5.5 - 6.5）, 7.0 （6.5 - 7.5） and over 7.5 in the Daduhe drainage area, where 22 series cascade dams will be built. The results can be used for hydropower plant planning, hydropower dam site selection and seismic fortification.     

利用地球重力场模型确定南极大地水准面

利用我国最新地球重力场模型 WDM94,给出了南极 (纬度范围为 - 60°～ - 90°)大地水准面高和平均空间重力异常。为了全面总结分析南极大地水准面特征 ,收集了国外最新地球重力场模型 OSU91 ( 360阶次 )和 JGMOSU( 360阶次 ) ,计算了相应的大地水准面高和平均重力异常。其结果分别与 WDM94的结果作了比较 ,WDM94与 OSU91和 JGMOSU的大地水准面高标准差分别为± 1 .90 m和± 2 .0 9m,平均空间重力异常标准差分别为± 8.97mgal和± 9.32 mgal     

利用微波辐射计AMSR-E的京津冀地区大气水汽反演

目的 发展了微波遥感水汽反演算法,对于裸露地表,通过极化差比值形式消除地表信息对大气水汽反演的干扰;针对非裸露地表,首先反演了地表发射率并对不同波段地表发射率之间的关系进行分析,进而建立了非裸露地表上空大气水汽的反演算法。本文算法的反演结果与GPS探测结果的对比显示均方根误差为7.4mm,与MODIS大气水汽产品空间分布特征的对比也显示了两者较高的区域一致性。最后对京津冀平原地区和山地地区的水汽进行了时间序列的分析。     

地理时空大数据协同计算技术

大数据时代,地理时空数据的迅猛增长给应用理念、技术框架和服务形式带来挑战。本文在阐述地理时空大数据概念的基础上,首先分析了地理时空大数据计算面临的挑战,从数据协同、技术协同、服务协同和生产协同4个层次阐述了地理时空大数据协同计算方法;然后,根据平台化服务的需求设计了地理时空大数据协同计算框架,从遥感数据综合预处理、地理时空数据的组织与管理、地理时空大数据高效计算、地理时空大数据可视化4个方面论述了地理时空大数据协同计算实现的关键技术;最后,以遥感大数据综合处理系统作为案例说明了地理时空大数据协同计算与服务的实现方法,并对地理时空大数据的应用模式进行了展望。     

四川及邻区不同风险水平下地震动峰值加速度的比值特征

基于四川及邻区8181个控制点的地震危险性分析结果,统计得出了不同风险水平下中硬场地地震动峰值加速度的比值特征.文中重点分析了大震与中震地震作用的比值(K2值)的统计特征和空间分布特征,初步分析了影响K2值的因素.本文研究结果不仅可为抗倒塌地震区划图编图原则和编图方法的确定提供重要依据,还可为不同行业、不同工程的抗震设计和验算提供参考.     

Temperature variation and its driving forces over the Antarctic coastal regions in the past 250 years

By comparing the oxygen isotopic temperatures recorded by many shallow ice cores from the coastal regions of Antarctica, this paper presents the special characteristics of the temperature variations over the Antarctic coastal regions in the past 50 years, 150 years and 250 years. In the past 50 years, the isotopic temperatures recorded in the ice cores over different sites on the Antarctic coastal regions differ greatly. For instance, although increasing isotopic temperatures have been reported for many sites studied, many sites show decreasing trends, the regional regularity in temperature variations is still insignificant. In the past 150 years, the isotopic temperature trends in the coastal regions of Antarctica show an alternate-distributing pattern. In the past 250 years, all the ice cores from the coastal regions of Antarctica have recorded the so-called Little Ice Age (LIA). The above-mentioned spatial characteristics of the temperature variations over the Antarctic coastal regions are likely to reflect the impacts of the unique Southern Hemisphere atmospheric circulation, the Antarctic Circumpolar Wave (ACW) and the special terrain (such as the large drainage basins) on the coastal regions of Antarctica. Furthermore, the impacting intensity of the unique Southern Hemisphere atmospheric circulation, the Antarctic Circumpolar Wave and the special terrain differs in terms of the temporal scale of the temperature change.