阿尔及利亚Chelif盆地中—新生界烃源岩研究   总被引：1，自引：0，他引：1  

张春书  王玥  张元福  郭岭  陆裕 《现代地质》2009,23(5)

Chelif盆地的勘探在近半个世纪一直没有突破,是否存在有效烃源岩成为制约勘探决策的主要因素。在分析Chelif盆地地表和钻井样品地球化学特征的基础上,研究和预测了中—新生界烃源岩性质与分布,并且采用ΔlogR技术计算TOC含量以弥补露头采样的不足。研究显示,Chelif盆地是阿尔及利亚西北部的中—新生界叠合盆地。在白垩纪Chelif盆地处于被动大陆边缘的拉张构造环境,属于海相盆地;到新生代盆地演变为山间盆地,经历断坳演化过程,形成了快速充填的沉积特征。盆地发育上白垩统、下中新统和上中新统3套烃源岩,有机质丰度显示,该烃源岩为中等—好烃源岩,含Ⅱ型干酪根,有机质热演化处于低成熟—成熟阶段。上白垩统泥灰岩为盆地的主力烃源岩,盆地油气源较丰富,具有较好的勘探前景。  相似文献   

南北地震带北部5次（1561~1920年）M≥7级地震触发关系研究   总被引：7，自引：1，他引：6       下载免费PDF全文

韩竹军  董绍鹏  谢富仁  安艳芬 《地球物理学报》2008,51(6):1776-1784

以南北地震带北部的青藏高原东北边缘与华北构造区过渡部位为例,通过建立地震构造模型,计算静态库仑破裂应力改变量（ΔCFS）,研究了该区1561~1920年360年间5次M≥7级地震之间的触发过程.结果表明,在1561年罗山东麓7¹/₄级地震之后,下一次地震无一例外地发生在前面地震产生的应力触发区（ΔCFS>0）.在4条被触发的发震断裂中,有3条发震断裂的平均ΔCFS>0.2×10⁵ Pa,最大可达0.62×10⁵ Pa,超出目前普遍认为触发应力阀值（0.1×10⁵ Pa）.根据断裂库仑破裂应力变化量（ΔCFS）和构造应力累计率（δτ）,计算获得了下一次地震发生的提前量（ΔT）,地震活动提前量最大可以达到160a.在一条重要活动构造带或地区上,一次地震发生对下一次地震的触发缩短了地震重复发生所需要的累积时间,使得地震可以提前发生,这一方面使得某一特定的发震断裂在时间尺度表现出准周期性,另一方面使得空间上不同发震断裂的地震活动表现出丛集发生的现象.此项研究有助于认识断裂间相互作用特点、揭示地震丛集发生规律以及预测未来地震危险区.  相似文献   

三角褐指藻Δ5去饱和酶基因的原核表达     

刘冬梅  马晓磊  朱葆华  李斯  于文功  杨官品  潘克厚 《海洋湖沼通报》2012,(1):116-122

Δ5脂肪酸去饱和酶(Δ5fatty acid desaturase)是合成花生四烯酸(AA)和EPA的关键酶。为了构建三角褐指藻Δ5脂肪酸去饱和酶基因(简称D5)的原核表达重组质粒,并实现在E.coli BL21(DE3)中的表达。本研究根据GenBank中三角褐指藻Δ5脂肪酸去饱和酶基因序列,设计引物,扩增该基因并插入到pET28a中,测序鉴定后,转化E.coli BL21(DE3)感受态细胞,IPTG诱导表达,SDS-PAGE分析表达产物。结果表明pET28a-D5构建成功,IPTG能诱导D5特异性表达。  相似文献   

VISCOELASTIC STRESS TRANSFER BETWEEN 2008 AND 2014 YUTIAN M7 EARTHQUAKES,XINJIANG          下载免费PDF全文

WANG Hui  CAO Jian-ling  HONG Shun-ying  XU Yue-ren  JING Feng 《地震地质》2016,38(3):646-659

Two earthquakes with magnitude larger than 7.0 occurred in 2008 and 2014 on the southwestern end of the Altyn Tagh Fault, which is located in the northwestern borderland of Tibetan plateau. Occurrences of these two earthquakes provide important insights into regional geodynamics and potential seismic risk. Layered viscoelastic model is employed in the paper to study the interaction between these two events. We find that most of aftershocks were triggered by coseismic stress produced by the 2008 Yutian earthquake, and the effect of this earthquake is insignificant on the occurrence of the 2014 Yutian earthquake. However, stress transfer by viscoelastic relaxation of postseismic deformation is in favor of occurrence of the 2014 Yutian earthquake. The coseismic and postseismic stress transfer produced by the 2014 Yutian earthquake leads to stress increasing on the western segment of the Altyn Tagh Fault. Since the occurrence time of the last major earthquake on the western segment of the Altyn Tagh Fault is tens of years ago, it should have accumulated large moment deficit on the fault segment. The Altyn Tagh Fault should be considered as a fault with high potential seismic risk.  相似文献   

南京信息工程大学气候预测系统1.0版简介          下载免费PDF全文

贺嘉樱  伍继业  罗京佳 《大气科学学报》2020,43(1):128-143

南京信息工程大学气候预测系统1.0版(NUIST CFS1.0)是基于日本海洋科学技术开发机构(JAMSTEC)的SINTEX-F模式发展而来,可以实现对全球气候异常的季节-年际预测。对过去近40 a的集合历史回报预测试验结果的评估发现,该预测系统对热带太平洋和印度洋海温异常具有良好的预测技巧,并且该系统能提前1.5~2 a对ENSO(Nino3.4指数)做出有技巧的预测(即相关系数达0.5),同时也可以提前1~2个季节对印度洋偶极子(IOD)做出有较高技巧的预测,展现了对主要热带气候信号的良好预测技巧。但是与国内外所有动力模式预测系统类似,该系统对东亚地区的气候异常预测还存在较大的不足。考虑到ENSO对东亚地区气候异常的强烈影响,本文尝试去除与ENSO预测相关的系统偏差来初步订正东亚地区夏季温度异常和降水距平百分率的预测结果。对比订正前后的结果表明,这一简单的订正方法有助于提高我国气候异常的预测准确率。同时选取2019年夏季气温异常和降水距平百分率的实时预测结果作为个例进行分析,发现订正能够提供一定的技巧改善,但与观测结果相比仍存在较大偏差,需要在今后的工作中不断改进完善。此外,本文也初步评估了NUIST CFS1.0对我国冬春季的气候预测技巧,并提供了经简单订正后的2019/2020年冬季和2020年春季的实时预测结果。  相似文献   

Co-seismic Coulomb stress changes on the northern Tanlu fault zone caused by the Tohoku-Oki MW9.0 earthquake*          下载免费PDF全文

Fei Chen  Tai Liu  Yawen She  Xing Huang  Guangyu Fu 《地震科学（英文版）》2020,33(1):11-22

Based on the spherical earth dislocation theory and a fault slip model of the Tohoku-Oki M_W9.0 earthquake, the co-seismic Coulomb failure stress changes (ΔCFS) on the northern Tanlu fault zone at depths of 0–40 km are calculated. By comparing two sets of results from the spherical earth dislocation theory and the semi-infinite space one, the effect of earth curvature on the calculation results is analyzed quantitatively. First, we systematically summarize previous researches related to the northern Tanlu fault zone, divide the fault zone as detailed as possible, give the geometric parameters of each segment, and establish a segmented structural model of the northern Tanlu fault zone. Second, we calculate the Coulomb stress changes on the northern Tanlu fault zone by using the spherical earth dislocation theory. The result shows the Coulomb stress changes are no more than 0.003 MPa, which proves the great earthquake did not significantly change the stress state of the fault zone. Finally, we quantitatively analyze the disparities between the results of semi-infinite space dislocation theory and the spherical earth one. The average disparity between them is about 7.7% on the northern Tanlu fault zone and is 16.8% on the Fangzheng graben, the maximum disparity on this graben reaches up to 25.5%. It indicates that the effect of earth curvature can not be ignored. So it’s necessary to use the spherical earth dislocation theory instead of the semi-infinite space one to study the Coulomb stress change in the far field.  相似文献