云南元阳大坪金矿铅同位素化探评价

通过对云南元阳大坪金矿某切穿矿脉剖面、不同海拔高程矿脉的矿石和围岩的铅同位素组成分析，采用铅同位素系统剖面化探方法对大坪金矿进行了化探评价和隐伏矿的预测分析，指出大坪金矿已进入主矿体的中心部位，深部隐伏矿潜力不大，找矿战略应以扩大横向为主。金矿化与闪长岩铅同位素组成的一致性，表明金矿化受闪长岩的控制。     

青海省纳日贡玛斑岩型铜钼矿床成矿岩体的物质来源及成矿背景分析

纳日贡玛斑岩型铜钼矿床是西南三江地区继玉龙特大型斑岩铜矿之后发现的又一大型矿床。在总结矿床地质特征的基础上,对该矿床的含矿斑岩体开展了详细的岩石学,地球化学及S、O、Pb、Sr同位素等特征的研究,并探讨了成矿意义。结果表明:纳日贡玛成矿斑岩体大部分为高钾钙碱性花岗岩,部分为钾玄岩系花岗岩,Ti、Ta、Yb、Ba等元素亏损,富集Zr,Hf、Rb和轻稀土元素,中低初始锶比值结合铅同位素分析结果表明它们主要来源于青藏高原加厚的下部地壳熔融,具有幔源成分的混染。     

河南省专业村销售市场的时空变化——以50个专业村为例北大核心CSCDCSSCI

专业村是农区经济发展的重要形式,销售市场作为影响专业村发展的关键因素,其时空变化是一个值得探究的问题。文章以河南省50个专业村2008年和2017年两次追踪调查数据为基础,运用标准差椭圆、社会网络分析和地理探测器等方法,梳理了河南省50个专业村销售市场的时空变化特征。研究结果表明:①专业村销售市场在时空分布上具有差异性、扩张性、波动性和扁平化的分异特征。其中心迁移变动方向不一,空间分布范围不断扩张,市场波动性比较明显,呈现出扁平化的发展趋势。②在网络结构上表现为“省内紧缩、省外拓展”的演化格局。国内一线城市的个体中心性在增强,省内部分城市的个体中心性在减弱。③在市场开拓上呈显著扩张态势,但受产品特性和交通条件等限制,不同类型专业村销售市场的扩散特征存在一定差异。从扩散距离来看,服务业型最远,农业型最近;从扩散增量大小来看,服务业型最大,工业型较小;从扩散速率快慢来看,农业型最快,工业型偏慢。④测算结果表明,不同因素对专业村销售市场扩散距离的解释力存在显著差异。整体来看,资源禀赋优势有所减弱,交通条件、产业水平和销售方式等影响明显增强。专业村销售市场的变化机制较为复杂,必要的村庄基础与产业组织为专业村产品的生产销售提供了空间载体与经济载体,销售市场则通过反馈机制,不断规范生产,促进产业升级。     

砂岩和大理岩纵波速度及Q值实验研究

利用新近完成的弹性波参数测量系统,我们在静水压力(常压—32MPa)范围内,对不同饱和度砂岩和大理岩的纵波速度和Q 值进行了测试.结果表明,随着静水压力和饱和度的增加,砂岩和大理岩的纵波速度均增加;砂岩的Q 值随静水压力增加,但随饱和度减小.有关静水压力、孔隙流体对岩石纵波和Q 值的影响机理也作了简要论述.     

Catastrophic debris flows triggered by the 20 August 2019 rainfall,a decade since the Wenchuan earthquake,China

Landslides - Enhanced debris flow activity observed after the 2008 Wenchuan earthquake, Sichuan Province, SW China, is still intense more than a decade since the earthquake. A heavy rainstorm on 20...     

寒区桩基热稳定性研究进展

桩基础锚固长度大、埋置深,对地温场的扰动小、回冻快,在青藏高原多年冻土区被广泛使用。寒区桩基热稳定性研究是一个交叉面广、综合性较强的问题,它涉及到传热学、冻土学、桩基础的设计、桩-土相互作用等多方面的内容。在大量文献基础上,从现场试验、模型试验、理论计算等角度,对寒区桩基热稳定研究现状进行了总结和分析,文献研究表明：土体回冻过程受众多因素影响,而影响程度最大的是混凝土浇筑时的水化热释放;在全球变暖的情形下,未来50年青藏高原冻土退化严重,对桩基热稳定性构成威胁,需要采取相应的保护措施。     

Pricing of uncertain certified emission reductions in a Chinese coal mine methane project with an extended Rubinstein-Ståhl model

The development of coal mine methane (CMM) projects is subject to various kinds of risk, one of these being their highly variable methane content. In this study, a new methodology is proposed to reflect the impact of this uncertainty on a negotiated Certified Emission Reduction (CER) price, which is based on the available information. To simulate a process of price negotiation the Rubinstein-Ståhl bargaining game is utilized, where a buyer’s discount factor is unknown. It is assumed that a buyer’s willingness to accomplish price negotiations depends on the CER uncertainty. The bargaining model has been extended by introducing dependence of its three parameters on the probability of a failure to fulfil the contracted CER amount. To quantify this probability, we develop a conditional distribution given information on the point estimate of methane amount for the project under consideration, and on the distribution of available estimates from coal mines having similar characteristics. The proposed approach is applied to a particular CMM capture and utilization project in Anhui province, China. The results indicate that the uncertainty influence is significant, particularly when the credibility of a seller increases, i.e. the probability of a failure to fulfil the project decreases. The analysis can be of use to both negotiating parties at an early stage of a comprehensive CMM project planning.     

Mineral occurrence for Dachang gold deposit and its impact on gold recovery rate in Qumarleb County,Qinghai

Based on X-ray diffraction,optical microscopy and scanning electron microscopy analysis of the Dachang gold ore,it is showed that the sulfide of ore is the main carrier minerals of gold. A majority of gold is embedded in pyrite and tetrahedrite as the form of inclusion and a small amount intergrowth with pyrite and gangue mineral,occasionally the presence is in form of monomer natural gold. The main factors which influence the recovery rate are sulfide mineral particle size,and the fine grained sulfide is beneficial for the dissociation and flotation of gold bearing minerals. The monomer dissociation degree of gold bearing minerals can reach91. 3%,when the grinding fineness is less than 0. 074 mm and grain level accounts as 80%. It is not conducive to the flotation of sulfide if the grinding fineness is low or high. It is difficult to completely dissociate the monomer if there is a small amount of pyrite and arsenopyrite in the ore. Therefore,before leaching the gold,it must conduct pretreatment to reach the ideal recovery rate of the gold,like roasting oxidation,pressure oxidation and biological oxidation. The fine microscopic gold has little influence on the gold recovery rate.     

邯郸市地热资源评价

通过对邯郸市的地热地质条件、热储赋存条件的分析与研究，阐述了该区具有经济价值的上第三系热储层的地热赋存特征，并对发育良好、遍布全区、水量丰富、水质好、埋深适中、具有开发利用价值的上第三系明化镇和馆陶组两个热储层其地热资源量进行了计算，就本区地热资源的开发前景进行了评价。     

鄂东北大别杂岩中混合岩的形成时代研究

本文通过锆石 U-Pb 定年、角闪石39Ar-40Ar定年和Rb-Sr等时线定年等的研究，认为大别杂岩中混合岩化作用发生在110～130Ma之间，与燕山晚期角闪岩相变质、花岗岩浆活动和区域构造抬升是现呈构造-热事件的不同产物。