2017年吉林宁江M 4.9地震前电磁变化

2017年7月23日吉林宁江M 4.9地震前,地震影响范围内电磁台站出现多种电磁异常,其中4项电磁手段异常明显,分别是：地磁垂直分量日变幅加卸载响应比异常、地磁场总场强度F₂₁每日一值空间相关异常、绥化地震台地电阻率EW向反向下降异常及林甸电阻率EW向整点值变化异常簇异常。本文对地磁异常进行统计、分析,为东北地区未来利用电磁方法分析预测地震提供经验。     

Using Geochemical Method to Distinguish Lateral Migration and Vertical Migration in Rifted Basin: A Case Study from Eastern Lujiapu Depression in the Kailu Basin, NE China

Migration fractionation diagnosis is complicated in rifted basins where migration distance is generally short and lateral migration in sandy beds and vertical migration along faults are co-existed. Quantitative data from GC-MS analysis makes it possible to distinguish lateral and vertical migration effects. Oils discovered from the Jiaolige oilfield, eastern Lujiapu Depression are derived from single source rock with similar maturity, which is an ideal case to study the migration fractionation effects. Compositional differences among oils are largely caused by the migration fractionation either laterally in sand beds or vertically along the faults. Subtle maturity differences are assessed by the classic saturated hydrocarbon parameters which have certain influence on nitrogen compounds. In a certain maturity range, the ratios of shield and semi-shield isomers to the exposed isomers of alkylcarbazoles change with maturity in an opposite direction with migration fractionation, which may conceal the migration influence. However, migration and maturation have the same effects on absolute concentrations of aikylated carbazoles and benzocarhazole [a]/([a] [c]) ratios, which provides an ideal tool for migration direction assessment. Continuous variations among different samples reflect increased migration distance in sandy beds, while abrupt changes may indicate the change of migration conduit systems. Integrated both geochemical interpretation and geological constrains, not only migration direction can be determined, but also the conduit systems through the sandy beds or the. faults can be recognized.     

气体交换速率和时间平均尺度对海-气碳通量估计的影响

基于卫星资料建立的CCMP风场、ECMWF波浪和最新CO₂分压数据, 分别用4种以风速为单参数和2种包含海况影响的双参数气体交换速率公式, 估算了全球海-气CO₂通量, 发现前者的结果比后者平均小30%左右, 从整体上看, 与单参数公式相比, 双参数公式使得海洋中CO₂源和汇的强度均明显增强。在此基础上, 讨论了时间平均尺度对海-气CO₂通量估计的影响, 结果表明, 标量平均法比矢量平均具有更好的稳定性, 但依然使得短时间平均比长时间平均得到的CO₂通量值要大, 月平均与6 h平均相比, 单参数公式和双参数公式分别使海洋的净吸收量减少33%和5%, 说明双参数公式具有较好的稳定性。研究还发现, 1988-2009年间, 全球平均风速有增大的趋势, 2006年前后出现一个极大值, 但相应的CO₂年净通量基本保持稳定, 甚至其绝对值有所减小、海洋的吸收能力减弱的倾向。     

论古岩溶洞穴型储层三维地质建模——以塔河油田四区奥陶系储层为例

古岩溶洞穴型储层是一种后期改造形成的特殊碳酸盐岩储层,储层发育复杂,非均质性很强.开展洞穴型储层建模研究对该类储层的三维定量表征以及数值模拟、储量计算等后续工作有重要意义.在古岩溶洞穴型储层成因特征分析的基础上,针对储层建模的几个关键环节开展了讨论,包括建模策略、模拟随机性控制方法以及数学方法等方面.并以塔河油田四区奥陶系储层为例进行了实践应用,在地貌分区、岩溶分带的地质框架下,以井孔数据为基础,优选能够反映洞穴发育概率的波阻抗反演信息及相干信息作为模拟的井间约束条件,选取具有趋势的同位协同序贯指示模拟方法整合多类信息建立了洞穴型储层三维地质模型,并提出了研究区分块设置局部变差函数的思路,取得了较好的效果.     

川东建南地区飞仙关组地震储层预测

利用三维地震资料,采用属性分析、波阻抗反演及厚度预测等技术对建南地区开展储层预测工作.建南地区下三叠统飞仙关组厚400～550m,划分为四个段,其中飞三段是主力产气层系,储层类型以孔隙型为主,局部发育孔隙-裂缝型,属于特低孔、(特)低渗储层.飞三段的沉积环境主要为开阔台地、台地边缘浅滩及台缘斜坡相带.研究区内普遍发育鲕...     

天津软土地区深基坑开挖对地下管线位移规律的数值模拟研究

以天津市某研发大楼深基坑工程为例,运用有限元模拟方法分析基坑开挖引起邻近管线位移的规律.模拟结果表明,基坑开挖顺序不同将导致管线位移不同,基坑从中间向两边开挖对管线的影响较从两边向中间开挖时要小,且基坑端部为管线曲率改变最大处.对土体的加固可有效减小基坑开挖引起的管线位移,加固土体的深度和宽度不同,对管线位移的限制作用也不相同,结合本工程实际情况,认为加固深度为7m、宽度为7m时,是在保证加固效果的前提下最经济的加固范围.     

“数字测图原理与应用”课程思政实施途径探讨

通过分析"数字测图原理与应用"课程的特点及内涵,深挖课程思政元素,分析了各章节专业知识目标和育人目标,提出了"知识回顾,创设情境;导入新课,讲授演示;突出重点,启发育人;升华认知,归纳总结"的教学设计。将思想政治与专业知识进行有效融合,以期为"数字测图原理与应用"课程思政改革提供参考和借鉴。     

Circular Polarization in a Solar Filament

Integrating 26 624 pairs of video frames, the authors have mapped the circular polarization in an active-region filament against the solar disk by using a traditional magnetograph working at the Hβ line. This filament, offset the disk center, appeared at the boundary of three decayed active regions. It was quiet and away from any strong enhanced network. The mapped circular polarization in the filament has an average polarization degree of 1.1×10⁻³ with a measurement precision of 4×10⁻⁴. The mapping of circular polarization in a filament may provide a supplementary diagnosis of the filament magnetic field, in addition to the mapping of linear polarization via the Hanle effect. However, the interpretation of the circular polarization requires treatment of the full quantum problem of Zeeman and non-Zeeman effects of Stokes line profiles.     

矩形截面桩在横向荷载作用下的极限承载力研究

本文根据极限分析法的基本原理，研究了粘土地基中矩形截面桩在横向荷载作用下的极限承载力问题，建立了矩形截面桩的极限承载力计算公式。