Application of in-seam directional drilling technology for gas drainage with benefits to gas outburst control and greenhouse gas reductions in Daning coal mine,China

Gas outburst disasters are becoming more serious as the underground coal mines become deeper in China, and a thick zone of deformed coal provides conditions favorable to coal and gas outbursts. The Daning coal mine’s main mining seam is the No. 3 coal seam with coal and gas outburst hazard, which often contains two normal coal sub-layers and one deformed sub-layer. Considering both the geological conditions of the coal seam and applications of the in-seam directional longhole drilling technology, a new schematic diagram of in-seam directional longholes for gas drainage is developed. The two borehole layout models of longwall panel and main entries for gas outburst disasters control have been successfully applied. The gas drainage rates of both models are >70 %, and the residual gas contents are both <8 m³/t, which can be considered that the gas outburst disasters were effectively controlled. To better guide gas drainage, gas drainage normal and failure modes have been obtained. Although in-seam directional longhole technology has been successfully applied for regional gas drainage with benefits to gas outburst control, there are also some problems that are detrimental to greenhouse gas reductions in gas drainage and gas utilization. The three main problems are air leakage failure in gas drainage, decreasing gas concentration and a low gas utilization ratio. To address the problems mentioned above, five improvements are suggested.     

喜马拉雅造山带东构造结拉布拉多期和格林威尔期造山作用的记录

位于喜马拉雅东构造结西北部的南迦巴瓦复合体,是构造应力最强、隆升和剥蚀最快、新生代变质和深熔作用最强的地区。为厘定该地区早期的变质岩浆作用,本文对南迦巴瓦复合体北部的花岗片麻岩和混合岩进行了岩石学和年代学研究。花岗片麻岩原岩为富钾的偏铝质花岗岩,具有岩浆弧花岗岩的成分特征。花岗片麻岩中的锆石具有岩浆锆石的环带结构,记录了487.9±1.6Ma的一期构造岩浆事件;混合岩的锆石具有明显的核-边结构,核部和边部的不协和线交点年龄分别为1559±13Ma、1154±12Ma。对比印度大陆东部的西隆高原、东高止造山带,发现三者都经历了拉布拉多期、格林威尔期以及泛非期的造山作用。因此,我们认为喜马拉雅东构造结与这两个地区密切相关,可能是他们向北的延伸,这三者可能组成统一的印度大陆东部造山带,一起经历了哥伦比亚超大陆、Rodinia和冈瓦纳超大陆的聚合与裂解过程。     

大兴安岭地区扎兰屯变质杂岩的碎屑锆石U-Pb年龄及其大地构造意义

兴安地块位于额尔古纳和松辽地块之间,长期存在着是稳定陆块和造山带等不同的认识。本文针对兴安地块南部扎兰屯地区出露的原兴华渡口群进行了专项研究,结合前人的研究成果,对该变质杂岩的形成时代、碎屑锆石年龄谱进行了研究,研究成果对该地块的大地构造属性具有重要的制约作用。(1)扎兰屯地区变质杂岩主要为绿片岩-低角闪岩相变质的碎屑岩-火山碎屑岩系,其形成时代晚于481Ma,为早古生代晚期。岩石组合、变质程度与年代学研究表明其与北部的典型兴华渡口群不同,两者不能作为同一地层单元,应该予以解体。(2)扎兰屯变质杂岩碎屑锆石年龄谱主要分为三期:481~580Ma,峰期年龄为529Ma;699~998Ma,峰期年龄为833Ma和1213~3200Ma峰期年龄为2000Ma,分别记录了泛非期Gondwana、新元古Rodinia两期重大地质事件和变质基底的年龄信息。(3)兴安地块以发育兴华渡口群为标志,存在时代为新元古代甚至为太古代的变质结晶基底,因此兴安地块应为一稳定的微陆块,而非夹持于额尔古纳和松辽地块之间的造山带。     

新疆雅满苏铁矿床矽卡岩和磁铁矿矿物学特征及其地质意义

雅满苏铁矿床位于东天山中段,矿体赋存于下石炭统雅满苏组安山质火山碎屑岩中,受近EW向断裂及环形断裂构造控制。矿体主要呈层状、似层状、透镜状,近矿围岩蚀变强烈,形成石榴石矽卡岩及复杂矽卡岩。电子探针分析结果表明,石榴石为钙铁榴石-钙铝榴石系列,其化学组成可表示为And45.68~100Gro0.67~57.95(A1m+Sps)11~29.03,与典型的矽卡岩型铁矿中石榴石端员组分相似。在磁铁矿Ca+Al+Mn-Ti+V图解中,大部分样品落入矽卡岩型铁矿区;TiO2-Al2O3-MgO图解中,大多数的样品落入沉积变质接触交代磁铁矿趋势区,部分早期磁铁矿落在岩浆趋势区内。结合矿床地质特征和矿物学研究,认为大多数样品经过了一个热液交代作用过程,表明雅满苏铁矿的形成与岩浆热液交代作用有关。     

Market risk in carbon market: an empirical analysis of the EUA and sCER

The paper uses a capital asset pricing model to analyze the market risk in the European Union Emission Trading System (EU ETS) and clean development mechanisms (CDM) and Zipf analysis technology to analyze the carbon price volatility in different expectations of returns in the two markets. The results show that the systematic risk of the EU ETS market is around 0.07 %, but the CDM market is clearly divided into two stages; the systematic risk of the futures contracts in the first stage (DEC09–DEC12) is less than the EU ETS market, but the systematic risk of the futures contracts that enter the market is greater than the EU ETS market and has a higher market sensitivity, although on the unsystematic risk. The CDM market is always greater than the EU ETS market. Abnormal returns in the two carbon markets are both lower than 0.02 %, but CDM is higher. The probability of price down is greater than that of price up. The carbon price is affected by market mechanisms and external factors (economic crisis and environmental policies) in the low expectations of returns. However, in the high expectations of returns, compared with the CDM market, the carbon price change in the EU ETS market is less stable and has higher risks.

     

The Metastable Phase Equilibria of the MeX-MgCl_2-H_2O Systems

正1 Introduction The Pingluoba brine,which characterized as high concentration with sodium,potassium,boron,lithium,and rubidium,possess great development value.The main composition of the brine can be summarized to the     

西藏冈底斯南缘中新世含矿斑岩源区组成与成因

青藏高原南部中新世下地壳流动是当前大陆动力学研究的热点,关键科学问题是下地壳的流动方向。LA-ICP-MS定年结果表明冲江斑状黑云母二长花岗岩的形成时代为14.9~14.8 Ma,朱诺斑状花岗岩的形成时代为15.3~14.9 Ma。含矿埃达克质斑岩的特征如下:Si O2含量67.72%~74.49%,K2O含量2.85%~5.98%,Sr含量93~804μg/g,高Sr/Y(16~139)、(La/Yb)N(21~43)比值,Eu/Eu*值为0.6~0.91。冲江岩体锆石εHf(t)值为1.2~5.1,朱诺岩体锆石εHf(t)值为–6.9~–0.1,他们与徐旺春等报道的镁铁质麻粒岩的锆石Hf值(–2.5~4.8)具有很好的叠合性,暗示镁铁质麻粒岩(印度镁铁质下地壳)可以作为他们的岩浆源区。此外,Sr-Nd同位素表现出雅鲁藏布江蛇绿岩和拉萨地块两个端元混合的特征,Pb同位素表现出雅鲁藏布江蛇绿岩和喜马拉雅富集陆壳端元的特征。上述同位素地球化学特征表明,冈底斯中新世埃达克质斑岩的岩浆源区物质组成包括:拉萨陆壳、印度陆壳、雅鲁藏布江蛇绿岩(地幔成分),表现出加厚下地壳部分熔融特征,暗示青藏高原南部由南向北的下地壳流动方向。     

伪随机激电法的有限单元法数值模拟研究

利用有限单元法和Cole-Cole模型对伪随机激电法进行数值模拟研究。首先简要介绍了伪随机激电法的基本原理,然后在忽略电磁效应的情况下,给出电场的边值问题和变分方程,将模型中大地和极化异常体的电阻率用Cole-Cole模型的参数替换,通过解方程最后得到模型节点上的复电位值。通过改变地电模型的参数,得到了不同参数下幅频率的模型相应曲线。模拟结果与实际情况符合,表明运用有限单元法模拟伪随机激电法中的参数是正确和适用的。     

西藏尼木县岗讲铜钼矿找矿方向研究

通过对岗讲矿区100多个钻孔资料的对比研究,三维模拟和区域矿床(点)对比分析,提出了岗讲铜钼矿床的成矿模型为,四周以"井字型"断裂环绕,平面以"似环状"形态分布,核部主体为不含矿英云闪长玢岩,并以30°~50°夹角从"柱状"体向四周以岩枝形态侵入,上部呈"蘑菇状"覆盖含矿二长花岗斑岩,在英云闪长玢岩与二长花岗斑岩接触带常伴随强烈的断裂破碎和泥化现象,二长花岗斑岩体内常形成一定规模的斑岩铜钼矿体。根据其成矿模型,寻找闪长玢岩(或者英云闪长玢岩)与二长花岗斑岩接触带及断裂构造交汇部位是今后找矿勘查工作的关键所在。     

长三角创新产学合作与企业创新绩效:尺度与效应北大核心CSCDCSSCI

产学合作网络是长三角创新共同体建设的重要方面,而当前经济地理学相关研究集中在“本地/全球”二元尺度讨论上,缺乏多尺度产学合作效应的比较分析。基于IncoPat专利数据,本文从尺度和效应视角探讨了长三角创新产学合作与企业创新绩效的关系,得到以下结论:①长三角创新产学合作的空间格局呈现以省会城市为中心的星芒状结构,核心城市占据的网络优势地位能够助力其在网络中获取创新资源,并且高校资源的不均衡分布特征进一步巩固了省会城市的优势地位,使得长三角创新产学合作格局具有明显的路径依赖特征。②本省与长三角区域尺度创新产学合作对企业创新绩效的影响要显著高于其他尺度。从区域尺度客观看待高校在空间创新进程中的作用尤为重要。③长三角创新产学合作的平均距离与企业创新绩效间呈现显著的倒“U”型关系,并且工科院校产学合作的作用和极值点均要大于综合院校和其他院校。由此,本文提出以下建议:一方面应该加快推进以区域尺度创新产学合作为重点的产学合作体系建设;另一方面应当强化薄弱地区产学合作的多尺度耦合网络建设,着力提升薄弱地区的网络地位。