Gas accumulation from oil cracking in the eastern Tarim Basin: A case study of the YN2 gas field

Oil and gas exploration in eastern Tarim Basin, NW China has been successful in recent years, with several commercial gas accumulations being discovered in a thermally mature to over-mature region. The Yingnan2 (YN2) gas field, situated in the Yingnan structure of the Yingjisu Depression, produces gases that are relatively enriched in nitrogen and C₂₊ alkanes. The δ¹³C₁ (−38.6‰ to −36.2‰) and δ¹³C₂ values (−30.9‰ to −34.7‰) of these gases are characteristic of marine sourced gases with relatively high maturity levels. The distributions of biomarkers in the associated condensates suggest close affinities with the Cambrian–Lower Ordovician source rocks which, in the Yingjisu Sag, are currently over-mature (with 3–4%Ro). Burial and thermal maturity modeling results indicate that paleo-temperatures of the Cambrian–Lower Ordovician source rocks had increased from 90 to 210 °C during the late Caledonian orogeny (458–438 Ma), due to rapid subsidence and sediment loading. By the end of Ordovician, hydrocarbon potential in these source rocks had been largely exhausted. The homogenization temperatures of hydrocarbon fluid inclusions identified from the Jurassic reservoirs of the YN2 gas field suggest a hydrocarbon emplacement time as recent as about 10 Ma, when the maturity levels of Middle–Lower Jurassic source rocks in the study area were too low (<0.7%Ro) to form a large quantity of oil and gas. The presence of abundant diamondoid hydrocarbons in the associated condensates and the relatively heavy isotopic values of the oils indicate that the gases were derived from thermal cracking of early-formed oils. Estimation from the stable carbon isotope ratios of gaseous alkanes suggests that the gases may have been formed at temperatures well above 190 °C. Thus, the oil and gas accumulation history in the study area can be reconstructed as follows: (1) during the late Caledonian orogeny, the Cambrian–Lower Ordovician marine source rocks had gone through the peak oil, wet gas and dry gas generation stages, with the generated oil and gas migrating upwards along faults and fractures to form early oil and gas accumulations in the Middle–Upper Ordovician and Silurian sandstone reservoirs; (2) since the late Yanshanian orogeny, the early oil accumulations have been buried deeper and oil has undergone thermal cracking to form gas; (3) during the late Himalayan orogeny, the seals for the deep reservoirs were breached; and the gas and condensates migrated upward and eventually accumulating in the relatively shallow Jurassic reservoirs.     

钢-混凝土组合剪力墙抗震性能研究简述

钢-混凝土组合剪力墙可以充分发挥钢和混凝土2种材料的优势,改善传统钢筋混凝土剪力墙延性和耗能能力较差的缺点,在钢-混凝土混合结构中具有应用优势。本文简要介绍了国内外一些新型的钢-混凝土组合剪力墙,并简述了其抗震性能的研究现状,最后对一些关键问题进行了初步探讨。     

Application of flocculation combined with vacuum preloading to reduce river-dredged sludge

Abstract

To achieve the rapid dewatering of dredged sludge, the flocculation–vacuum-preloading method was tested indoors. In this study, the optimal mixing ratio of six flocculants was determined through the settling column test, and then the proposed method was tested. The water drainage and settlement were monitored during the test, while the soil moisture content and shear strength were measured after the test. The results show that all the flocculants had an optimal mixing ratio, and the addition of 0.8% FeCl₃ or 0.08% anionic polyacrylamide (APAM) in the sludge can better accelerate solid–liquid separation of the sludge. After the test, the water content in the sludge decreased from 140% to 60%. Compared with general vacuum preloading, the use of the proposed method increased the water drainage by 46.5% and 56.8% and decreased the soil volumes by 60.5% and 82.4% for FeCl₃ and APAM, respectively. Moreover, the corresponding shear strength was increased from 10 to 14 and 17?kPa. In addition, the use of APAM increased the solidification rate of heavy metals in the sludge to more than 80%, effectively inhibiting the migration of heavy metals.     

腐植煤中的超细纹层

利用超薄切片透射电镜分析技术，在华北东部太原组和山西组、吐─哈盆地侏罗系腐植煤中检出了超细纹层。超细纹层在腐植煤中呈分散状、间隔状和密集状，前二者主要存在于无结构镜质体中，后者则存在于沥青质体或层状藻类体条带中。超细纹层来源于微藻类细胞的抗分解外壁，是藻类在超微层次的重要表现形式。腐植煤形成过程中藻类的贡献较藻类体数量所反映的要高。     

长江经济带文旅产业融合发展水平测度及 空间演化研究

加快文旅产业融合发展利于增强国家软实力和满足人民日益增长的物质文化需要。采用2002—2017年长江经济带11省市和三大城市群的73个地级及以上城市截面数据,运用双产业系统的耦合测度模型、相对发展度模型和探索性空间数据分析法,实证分析长江经济带文旅产业融合发展水平及其空间演化特征。研究发现：（1）文旅产业融合发展水平整体趋于上升,但仍属初级融合阶段。文旅产业融合发展水平从下游到中游及上游呈逐步递减趋势。（2）文旅产业融合发展水平及其增速出现空间异质性。中上游地区文旅产业融合发展水平增速较快,并与下游地区的差距有所减小。（3）文旅产业融合发展的空间集聚差异显著。下游地区属于“高-高”集聚区,成为文旅产业融合发展的重要增长极,具有明显的空间扩散效应;中游地区及核心城市属于“高-低”集聚区,正在成为文旅产业融合发展的新增长极;上游地区则需加快打破二者融合发展的 “低-低”集聚区困局。（4）三大城市群间的文旅产业融合发展不平衡。长三角城市群文旅产业的相应综合发展指数明显领先、二者融合发展的“高-高”集聚空间趋于扩大。     

长三角城市群工业韧性的时空演变及影响因素研究

在世界经济不确定性日益增加的背景下,推进优化我国区域工业韧性演变格局和厘清工业韧性影响机制具有重要现实意义。本文以长三角城市群为例,在突变级数模型对工业韧性评价的基础上,利用核密度估计、泰尔熵指数和Tobit空间滞后面板模型,对长三角城市群工业韧性的时空演变特征及其影响因素进行探讨。研究发现：（1）长三角城市群工业韧性提升显著,总体上达到了中高韧性水平。长三角城市群工业韧性的内部差距不断缩小,但仍然存在不同空间尺度的“核心-边缘”分异格局。（2）综合实力较强的中心城市工业韧性具有显著的空间溢出效应。上海、杭州、南京、合肥及宁波等城市周边形成高水平工业韧性的集聚区。（3）工业结构是影响长三角城市群工业韧性的最主要因素。区域金融环境、政府公共服务以及区域外贸依存度均不同程度对工业韧性产生显著影响。     

西昆仑穆呼锰矿床地质特征、控矿因素及成矿模式

穆呼锰矿床位于西昆仑造山带玛尔坎苏锰矿带东段,研究程度相对薄弱。穆呼锰矿床的含矿地层为上石炭统喀拉阿特河组,自下而上可分为角砾灰岩、钙质杂砂岩和含炭质泥灰岩3个岩性段,具有完整的海侵层序特征,反映了由逐步断陷到稳定沉积的盆地演化过程。锰矿层赋存于第三岩性段炭质泥灰岩中,矿石矿物主要为化学组分纯净的泥晶菱锰矿。根据详细的矿相学观察并综合前人研究成果,笔者认为菱锰矿是初始沉淀的锰（氢）氧化物与有机质通过成岩反应形成的。这种成矿机制需要3个基本条件：丰富的锰质来源、氧化还原分层的海水和有机质的大量埋藏。在穆呼一带,有利于满足以上条件的主要控矿因素包括：伸展拉张的构造背景、强烈的海底热液活动、海侵事件和温暖潮湿的古气候。笔者根据w（Ba）-w（P₂O₅）图解并结合区域对比分析,初步认为穆呼锰矿床的成矿模式可能属于最小含氧量带扩张型。     

峡江-广丰和三南-寻乌火山岩带晚中生代粗面岩SHRIMP锆石U-Pb年龄

江西及广东北缘呈近EW向展布的峡江-广丰火山岩带和三南(全南、定南、龙南)-寻乌火山岩带,是我国东南部中生代以高钾钙碱性长英质火山岩为主体的火山岩带的组成部分.峡江-广丰火山岩带的石溪盆地、三南-寻乌火山岩带的三百山盆地和大长沙盆地出露少量粗面岩,粗面岩所含锆石具有明显的振荡环带,Th/U比值高,属典型的岩浆成因锆石....     

Emergency Seismic Damage Assessment of the M_S8.0 Great Wenchuan Earthquake Based on Remote Sensing Imagery

The fast processing, seismic damage data extraction and loss evaluation from RS imagery acquired immediately after a destructive earthquake occurs, are important means for compen-sating the insufficiency of seismic damage information from ground-based investigations and provide an important basis for emergency command and rescue. The paper introduces the method of emergency seismic damage assessment using remote sensing data and its application to the great Wenchuan earthquake of magnitude 8.0 occurring in southwest Sichuan Province on May 12, 2008. The practical effectiveness of the method is also evaluated in the paper.     

吐哈盆地侏罗系煤中超微类脂体特征和演化

利用共聚焦激光显微镜和透射电镜对吐哈盆地侏罗系煤进行超微层次有机岩石学分析，发现微米级以下超微类脂体普遍存在于无结构镜质体和一些粗粒体之中。常规光学显微镜下难以分辨超微类脂体，在镜质体反射率Ｒｏ０．５０％￣０．７０％时，煤中超微类脂体数量一般为８％￣１２％。超微类脂体的光性演化明显领先于壳质组形态组分孢子体和角质体，它是吐哈侏罗系煤中重要的生油组分。