2013年岷县—漳县6.6级地震地磁垂直分量日变化低点时间空间分布特征

2013年6月16日, 中国大陆西部出现地磁低点位移。 异常出现后一个月内, 位于低点位移分界线附近发生7月22日岷县、 漳县交界6.6级地震。 本文通过采用实测低点时间减去理论低点时间的方法剔除低点时间经度效应, 并以剔除经度效应后低点时间为0 h的等值线作为低点位移分界线, 2013年岷县—漳县6.6级地震震中处于6月16日地磁低点位移分界线上。 对异常期间的中国大陆地区地磁垂直分量日变形态进行统计, 发现其存在显著的分区特征, 低点时间为正的区域内日变化形态基本呈现W型, 低点时间为负的区域内日变化形态主要呈现V字型特征。 低点位移异常日期间, 中国大陆存在显著的高梯度带, 本文采用梯度值定量描述低点时间空间变化程度。 在6月13日正常日期间, 中国大陆地区未出现梯度值大于1.5 h/(°)的区域, 在6月16日异常日期间, 出现梯度值大于1.5 h/(°)的区域, 2013年岷县—漳县6.6级地震位于高梯度区边缘。     

Numerical Simulation of Bed Separation Development and Grout Injecting into Separations

In this paper, the Cosserat theory that has been incorporated into a three dimensional finite element code COSFLOW, is applied to analyze the development of bed separations in the layered overburden and grout injection into the bed separations. The mechanism of bed separation development during the longwall mining is investigated. A parametric study is carried out to investigate the effect of major factors including hard rock grade, panel height and panel weight on bed separation development. Based on the modeling, a conceptual model to describe the development process of bed separation is proposed. The effect of grout injecting into the bed separations on subsidence reduction is also studied and the conclusion agrees well with the common realization.     

关于Win猜想的两个结果

设G是2n个顶点的简单图,k为不小于-1的整数,若G中每一对不相邻的顶点u和v,都有d(u)+d(v)≥2n+k,则称G为Ore k—型图。S.Win给出下面的猜想: 若G是Ore k—型图,则G有k+2个边不相交的1—因子。其中k≤2n-4。 本文证明了k=2n-4和k=2n-5时Win猜想是成立的。     

Expression pattern of peptide and amino acid genes in digestive tract of transporter juvenile turbot (<Emphasis Type="Italic">Scophthalmus maximus</Emphasis> L.)

Turbot (Scophthalmus maximus L.), a carnivorous fish species with high dietary protein requirement, was chosen to examine the expression pattern of peptide and amino acid transporter genes along its digestive tract which was divided into six segments including stomach, pyloric caeca, rectum, and three equal parts of the remainder of the intestine. The results showed that the expression of two peptide and eleven amino acid transporters genes exhibited distinct patterns. Peptide transporter 1 (PepT1) was rich in proximal intestine while peptide transporter 2 (PepT2) was abundant in distal intestine. A number of neutral and cationic amino acid transporters expressed richly in whole intestine including B⁰-type amino acid transporter 1 (B⁰AT1), L-type amino acid transporter 2 (LAT2), T-type amino acid transporter 1 (TAT1), proton-coupled amino acid transporter 1 (PAT1), y⁺L-type amino acid transporter 1 (y⁺LAT1), and cationic amino acid transporter 2 (CAT2) while ASC amino acid transporter 2 (ASCT2), sodium-coupled neutral amino acid transporter 2 (SNAT2), and y⁺L-type amino acid transporter 2 (y⁺LAT2) abundantly expressed in stomach. In addition, system b^0,+ transporters (rBAT and b^0,+AT) existed richly in distal intestine. These findings comprehensively characterized the distribution of solute carrier family proteins, which revealed the relative importance of peptide and amino acid absorption through luminal membrane. Our findings are helpful to understand the mechanism of the utilization of dietary protein in fish with a short digestive tract.     

辽河盆地大民屯凹陷古近系沙河街组页岩气成藏地质条件研究

辽河盆地大民屯凹陷厚层暗色富有机质泥页岩的沉积特征研究和地球化学数据分析结果表明,大民屯古近系凹陷古近系沙河街组发育湖泊和扇三角洲沉积。在扇三角洲中的沼泽地带,发育富有机质的碳质泥岩。暗色泥岩主要产生于半深湖-深湖环境中,具有厚度大、连续性强、分布广的特点。泥岩中的干酪根类型主要以腐泥腐殖质型(II2)和腐殖型(III)为主,利于产气。有机质成熟度(Ro)平均为0.8%~1.3%,有机质处于低熟-成熟阶段。TOC平均为3%~8.46%,有机质丰度较高。脆性矿物总量达到29.0%~51.7%,有利于页岩气的开采。页岩气类型主要为热成因页岩气和生物化学成因页岩气。在页岩气成藏的地质因素分析基础上,综合研究认为,荣胜堡洼陷和三台子洼陷是沙河街组页岩气富集的有利区域。     

The Southwest Indian Ocean thermocline dome in CMIP5 models: Historical simulation and future projection

Using 20 models of the Coupled Model Intercomparison Project Phase 5 (CMIP5), the simulation of the Southwest Indian Ocean (SWIO) thermocline dome is evaluated and its role in shaping the Indian Ocean Basin (IOB) mode following El Niño investigated. In most of the CMIP5 models, due to an easterly wind bias along the equator, the simulated SWIO thermocline is too deep, which could further influence the amplitude of the interannual IOB mode. A model with a shallow (deep) thermocline dome tends to simulate a strong (weak) IOB mode, including key attributes such as the SWIO SST warming, antisymmetric pattern during boreal spring, and second North Indian Ocean warming during boreal summer. Under global warming, the thermocline dome deepens with the easterly wind trend along the equator in most of the models. However, the IOB amplitude does not follow such a change of the SWIO thermocline among the models; rather, it follows future changes in both ENSO forcing and local convection feedback, suggesting a decreasing effect of the deepening SWIO thermocline dome on the change in the IOB mode in the future.     

勘探线剖面图从二维转化为三维算法

用勘探线剖面图结合钻井与其他资料进行地质模型三维重建是三维地质建模的重要方法。其中勘探线剖面图从二维坐标系向三维坐标系的转换是三维建模的一个重要环节。针对当前勘探线剖面坐标转换过程中勘探线上钻孔并不总是布置在一条直线上(弯折勘探线)的特点,该文提出了一种构建弯折三维剖面的方法。该方法首先由剖面线的起点、终点以及勘探线上钻孔孔口点作为转折点构建三维折勘探线剖面框架;然后将二维剖面图上分段转换剖面上要素点的二维坐标到三维空间,并对跨越剖面转折点的长边添加转折控制点;最后以青海某煤田勘探区的二维勘探线剖面图数据为例,利用该勘探线剖面坐标转换算法,实现了二维勘探线剖面图到三维勘探线剖面图的转化,结果表明三维剖面上保持了原二维剖面所表达的地质模型的几何形态。     

长江河口浮泥形成机理及变化过程

1976年以来，在长江河口盐水楔和最大浑浊带活动的河道进行了20余次现场观测，本文在现场观测资料基础上，确认长江河口浮泥由细颗粒泥沙组成，中值粒径在8－11.5um,小于2um的粘土占28.18%-36.39%,长江河口浮泥是悬沙在盐水混合环境中絮凝沉降于近义廾风暴潮再悬浮泥沙形成的高浓度浑水层，在成因类型上分为憩流浮泥，盐水楔浮泥和风暴潮浮泥，第1种在涨或落潮转流期低流时形成，规模大，厚度薄，第2种在盐水楔发育时形成，规模较小，厚度较大，第3种在大风后形成，规模大，厚度薄，第2种在盐水楔发育时形成，规模较小，厚度较大，第3种在大风后形成，规模大，范围广，若三者相遇，则浮泥厚度和范围最大，浮泥具有枯季，大小潮秽暴周期变化规律，长江河口河道多的浮泥层，浮泥层的变化与河口拦门沙的冲淤有良好的正相关。     

Distribution of n-alkan-2-ones in Qionghai Lake sediments,southwest China,and its potential for late Quaternary paleoclimate reconstruction

Studies on long-chain n-alkan-2-ones from lake sediments remain sparse. In this study, we present an n-alkan-2-one record from Qionghai Lake, southwest China, to assess the paleoclimate significance of variations in their compositions. A homologous series of n-alkan-2-ones ranging from C₂₁ to C₃₅ were identified, with maximum concentrations of the C₂₉ or C₃₁ chain lengths and a strong odd-over-even predominance. This type of n-alkan-2-one is considered to derive mainly from microbial oxidation of the corresponding n-alkanes, and partial inputs from plants. The n-alkan-2-one-derived average chain length (ACL) and carbon preference index (CPI) values changed significantly over the past 28k cal a bp , consistent with the sediment grain size and n-alkane proxies from the same core. Generally, the high CPI_27-33-ket and low ACL_27-33-ket values indicated cold and dry climates such as for the Last Glacial Maximum (23.2–19.7k cal a bp ), Heinrich 1 event (17.6–15.6k cal a bp ) and Younger Dryas (12.8–11.6k cal a bp ), but low CPI_27-33-ket and high ACL_27-33-ket values denoted a warm and humid Holocene Climatic Optimum (7.0–4.3k cal a bp ). Therefore, n-alkan-2-ones have great paleoclimatic potential and can be applied together with other biomarkers to reconstruct a reliable paleoclimate record in lake sediments.     

西藏林周地区始新世托龙I型花岗岩对印度-欧亚板块碰撞时限的制约

目前已有研究对印度-欧亚板块碰撞时限的认识存在诸多分歧。本文对西藏林周县中部出露的托龙岩体开展了锆石U-Pb年代学、全岩地球化学和锆石Hf同位素分析,以期进一步约束印度-欧亚板块的碰撞时间。托龙岩体内出露的石英二长斑岩呈岩株状侵入到帕那组中,锆石U-Pb定年结果显示该石英二长斑岩形成于始新世(50.5±0.6 Ma),锆石εHf (t)值为-0.6~-0.5。石英二长斑岩具有较低的A/CNK值、较高的K₂O含量和K₂O/Na₂O值,属于准铝质和钾玄岩系列。岩石普遍亏损高场强元素Nb、Ta、Ti和P,富集大离子亲石元素Th、U和Pb,轻、重稀土元素分异明显,(La /Yb)_N =15.3~16.3,Eu负异常较弱,δEu=0.56~0.69。托龙岩体较低的A/CNK值、P₂O₅与SiO₂的负相关性以及Y含量与Rb含量之间的正相关性,表明托龙石英二长斑岩为I型花岗岩。综合岩体的地球化学特征、同位素特征和前人研究成果,认为托龙石英二长斑岩可能是相对古老的变质中基性岩部分熔融的产物,形成于印度-欧亚板块碰撞引起的俯冲板片断离环境,指示了印度-亚洲大陆的碰撞应发生于50 Ma之前。