Study on General Performance of Jack-up Under Elevated Condition

Method of checking for jack-up elevated performance including leg structure strength, fixation system or jacking system bearing capacity, pre-load requirements, spud can bearing capacity and overturning stability is suggested in this paper. As an example, a jack-up with truss legs is analyzed by finite element analysis method. This paper may be helpful to the rig owners, operators and designers.     

西湖凹陷平北地区烃源岩特征及生排烃史

为了综合确定平北地区的主力烃源岩,深化其油气成藏动力学过程研究,在烃源岩分布特征及有机质丰度、类型和成熟度分析的基础上,应用舍油气盆地数值模拟技术,定量恢复了研究区主要烃源岩层系的生排烃历史。研究表明,平北地区主要发育始新统平湖组、渐新统花港组两套烃源岩系,其中平湖组暗色泥岩为主力烃源岩,具较高的有机质丰度、成熟度、生排烃强度与排烃效率;以平湖组为源岩的油气系统应是本区油气勘探的主要目标。     

Measurement of nuclides of uranium and thorium series of disequilibrium using γ-spectroscopy

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南海夏季风暴发过程的低频特征

应用1979～1996年共18a的NOAA卫星OLR资料及NCEP/NCAR再分析850hPa风场资料,分析了夏季南海地区及南海季风暴发过程的某些低频特征。认为北半球夏季南海地区的低频活动较活跃,并且具有明显的年际变化,这种年际变化同南海季风的暴发时间有联系。南海地区的低频振荡在南海季风暴发后增强。通过对18a 及K*的时段叠加合成图的分析,发现南海夏季风的暴发同赤道印度洋低频振荡的东传及西太平洋低频扰动西传有密切联系,南海夏季风暴发期间南海地区将印度洋与西太平洋之间的低频活动联系在一起。     

Clogging of saturated porous media by silt‐sized suspended solids under varying physical conditions during managed aquifer recharge

Managed aquifer recharge is an effective method for utilizing excess flood flows, but clogging of porous media is a limiting factor in the implementation of this water storage technique. In recent years, much research on the physical clogging of porous media during artificial recharge has been conducted. However, the understanding of clogging due to silt‐sized suspended solids (SS) is still inadequate, especially under varying physical conditions. Here, we subjected sand columns to controlled rates of flow and SS suspensions to investigate the influence of media size, SS size, SS concentration, and flow velocity on the clogging of porous media by silt‐sized SS. The results show that the diameter ratio of SS particles to sand grains is the dominant factor influencing the position of physical clogging. As pore velocity increased, the mobility of silt‐sized SS was enhanced and retention in the porous media decreased noticeably. The spatial retention profiles in the porous media were found to vary greatly at different flow velocities. The SS concentration of the infiltrating suspension also dramatically influenced the mobility and deposition of silt‐sized SS particles, such that high concentrations accelerated the clogging process. As the different physical factors changed, the breakthrough curves and retention profiles of silt‐sized SS particles changed obviously and the mechanisms of retention differed. On the whole, clogging position is mainly determined by particle size ratio, but clogging rate is dominated by a variety of factors including particle size ratio, SS concentration, and flow velocity.     

2006-2015年内蒙古呼伦湖富营养化趋势及分析

以内蒙古呼伦湖为研究对象,20062015年水质数据为基础,分析呼伦湖的富营养化变化趋势及其影响因素.结果表明,20062015年呼伦湖各水质指标都有不同程度的变幅,其中盐度变化范围为0.75~1.71 ng/L,均值为1.32 ng/L,2010年达到峰值1.71 ng/L,随后呈现逐年递减趋势;pH的变化范围为8.78~9.40,水体偏碱性;透明度的变化范围为0.17~0.26 m,近三年来透明度持续下降;溶解氧浓度变化范围为4.05~10.62 mg/L,均值为7.12 mg/L.总氮浓度的变化范围为1.16~3.53 mg/L,总磷浓度的变化范围为0.13~0.25 mg/L,叶绿素a浓度的变化范围为3.31~10.36 mg/m³,N/P比变化范围为4.92~15.35,水质已经达到地表水环境质量Ⅳ~Ⅴ类水体标准,是磷限制性湖泊.利用综合营养状态指数法对呼伦湖水体富营养化进行评价,2006-2015年呼伦湖水体表现出中度—重度—中度—轻度的变化趋势.通过分析呼伦湖富营养化的影响因素,结果表明,影响呼伦湖富营养化的可能因素为外源输入和入湖径流量,同时水深和水温也是呼伦湖发生富营养化的驱动因素,pH、透明度和溶解氧是呼伦湖富营养化影响水质的最主要表现指标.     

新丰江地区地壳P波三维速度结构及活动构造研究

利用震源位置和速度结构的联合反演得到2007年6月~2014年7月新丰江地区地震序列的震源位置及P波三维速度结构模型,并进一步对比区域活动构造的产状特征及震源机制解等。结果显示,自ES向WN新丰江库区断裂深度有逐渐增大的趋势,与重力场的研究结果一致。库区大坝至东源锡场之间的中-上地壳存在4个大小不等的高速体,其中,锡场下方的高速体Ⅰ体积最大(EW向截面约6km×7km),速度最大,中心速度达6.3km/s。库区大坝下方存在以人字石断裂(F2)、南山-坳头断裂(F4)、河源断裂(F1)、石角-新港-白田断裂(F5)等为中心的强烈构造变形区,1960年至今大坝下方高速体Ⅲ、Ⅳ边缘已发生包括1962年6.1级地震在内的7次ML≥5.0地震,能量释放较为彻底;锡场下方高速体Ⅰ的边缘自2012年以来中小地震活跃,且b值较低,不排除发展为中强震孕震凹凸体的可能。     

Improved preconditioned conjugate gradient algorithm and application in 3D inversion of gravity-gradiometry data

With the continuous development of full tensor gradiometer (FTG) measurement techniques, three-dimensional (3D) inversion of FTG data is becoming increasingly used in oil and gas exploration. In the fast processing and interpretation of large-scale high-precision data, the use of the graphics processing unit process unit (GPU) and preconditioning methods are very important in the data inversion. In this paper, an improved preconditioned conjugate gradient algorithm is proposed by combining the symmetric successive over-relaxation (SSOR) technique and the incomplete Choleksy decomposition conjugate gradient algorithm (ICCG). Since preparing the preconditioner requires extra time, a parallel implement based on GPU is proposed. The improved method is then applied in the inversion of noisecontaminated synthetic data to prove its adaptability in the inversion of 3D FTG data. Results show that the parallel SSOR-ICCG algorithm based on NVIDIA Tesla C2050 GPU achieves a speedup of approximately 25 times that of a serial program using a 2.0 GHz Central Processing Unit (CPU). Real airborne gravity-gradiometry data from Vinton salt dome (southwest Louisiana, USA) are also considered. Good results are obtained, which verifies the efficiency and feasibility of the proposed parallel method in fast inversion of 3D FTG data.     

根据余震资料求解2003年伽师MS6.8地震断层面的研究

大地震发生后,大量余震在断层面及其附近发生.余震震源位置的空间分布可以较为精确地勾画出断层面的形状和位置.假定地震发震断层可以用一个平面来模拟,且设大多数余震发生在这个断层面的附近,则可以通过余震震源位置参数来求解发震断层的走向、倾角及位置.本文首次采用2003年2月24日新疆伽师MS6.8地震后精确定位的小震资料反演了伽师地震断层面的走向和倾角,并以此为基础求得了该断层面上的滑动角.并根据小震丛集性原则,尝试用数学方法先对反演所采用的数据进行筛选再进行反演,所得的结果精确程度更高,验证了这种做法的有效性.     

基于多比例尺技术的南京市地震应急数据库建设

为实现不同比例尺地震应急数据的融合与集成,在分析城市地震应急数据库功能的基础上,设计了基于多比例尺空间数据库技术的南京市地震应急数据库框架。论述了其中不同尺度基础地理信息数据的处理、转换方法,以及多比例尺基础地理信息数据的融合建库方法。接着阐述了地震应急专题数据库的设计和与多尺度基础数据的联接。最后通过开发南京市地震突发事件救灾应急平台,展示了多比例尺应急数据库在地震应急平台中的应用。