哀牢山成矿带南段金成矿规律及找矿方向探讨

哀牢山成矿带是西南地区最有利金矿带.该带金矿成矿与断裂构造、喜马拉雅期岩浆活动关系密切.矿带空间展布及矿体定位严格受构造控制.在分析区域成矿特征、控矿因素基础上,结合各种综合信息开展成矿预测,圈定了4个金找矿远景区,进一步指出2个A级远景区找矿类型、找矿标志及找矿的重点地区.     

基于RS的新疆哈密地区生态环境需水分析

干旱半干旱地区水资源缺乏,准确地计算区域生态环境用水和生态环境需水,可以对稀缺水资源进行合理调配,同时起到生态保护的作用。研究过程主要分为两个步骤:(1)采用RS技术,对新疆哈密地区1990年、2000年、2005年中巴资源一号卫星(China Brazil Earth Resources Sat-ellite)数据进行解译,形成1990年、2000年、2005年哈密地区土地覆被图形数据和相应的属性数据,确定相应年份各景观类型的面积;(2)参考有关研究并结合哈密地区实际情况,确定各景观类型的单位生态用水定额和需水定额,进而计算出1990年、2000年、2005年哈密地区的生态用水量,并以2005年哈密地区生态用水量为主要依据计算出保持哈密地区生态环境现状的生态需水量。研究结果表明,为了实现哈密地区生态环境整体保持在现状水平不致恶化、局部区域生态环境(巴里坤湖区)有所改善的生态治理目标,区域内生态环境需水总量为7.526×109m3,这一庞大的需水量将对该地区水资源配置造成巨大的压力;而当结合各类景观的地物空间位置特征进行分析时,发现该区域生态用(需)水量最大的景观(低覆盖草地)可以利用山地积雪融水进行自给,区域内实际需要规划配置的生态环境需水量为2.66×108m3,仅占区域生态环境需水总量的3.53%。在区域生态用(需)水计算过程中应考虑各种景观类型的生态用(需)水量的时空差异性,以保证水资源调配的科学与合理。     

生态环境敏感性及其管理对策——以庆阳市为例

可持续发展理念已经深入人心,而生态环境与社会经济的协调发展成为研究热点之一。而干旱、半干旱区更是面临生态环境恶化与社会经济发展的双重压力,为促进生态环境保护与建设,加强不同生态敏感区的生态环境管理对策,以庆阳市为例,对土壤侵蚀敏感性、土壤沙漠化敏感性、水环境敏感性和生境敏感性进行了评价,并计算了生态敏感性综合指数,将庆阳市划分为生态环境不敏感区、中度敏感区、高度敏感区和极敏感区4个等级。并提出了不同敏感性区域的环境保护对策和产业调整方向,以作为庆阳市可持续发展规划决策的依据。     

基于微纳米孔隙理论的页岩气储层岩石物理建模方法

页岩储层由于其复杂的构造和孔隙特征,目前一般的岩石物理模型无法对其进行精确描述.微纳米孔隙作为页岩气主要的储集空间,对页岩整体弹性参数有较大影响.干酪根作为页岩中重要的有机质矿物,在页岩中的赋存状态随成熟度不同而变化,同时干酪根也是纳米级孔隙的主要发育场所.目前常规的岩石物理建模方法没有体现微纳米孔隙的作用,同时较少考虑不同成熟度下干酪根对页岩储层弹性性质的影响.本文采用一种微纳米孔隙理论描述页岩微纳米孔隙特性,考虑微纳米孔隙和不同成熟度下干酪根的赋存状态,应用上述微纳米孔隙模型、各向异性SCA-DEM模型、各向异性Eshelby-Cheng模型和Brown-Korringa固体替换方程等建立一种新的页岩储层岩石物理模型.利用中国西南某工区页岩气井对该模型进行验证,模型预测的横波速度与测井速度拟合较好.结果表明不同干酪根成熟度的页岩岩石物理建模结果具有一定的差异,据此可大致区分该工区井的干酪根成熟度;最后对微纳米孔参数进行正演分析,结果反映了页岩的纵横波速度随微纳米孔隙参数的变化趋势.     

Simulations of realistic granular soils in oedometer tests using physics engine

Discrete element method (DEM) has become a preeminent numerical tool for investigating the mechanical behavior of granular soils. However, traditional DEM uses sphere clusters to approximate realistic particles, which is computationally demanding when simulating many particles. This paper demonstrates the potential of using a physics engine technique to simulate realistic particles. The physics engines are originally developed for video games for simulating physical and mechanical processes that occur in the real world to produce realistic game experiences. The simulation accuracy and efficiency of physics engines have been significantly improved in the last two decades allowing them to be used as a scientific tool in many disciplines. This paper introduces modeling methodologies of physics engine including realistic particle representation and the contact model. Then, oedometer tests are simulated using realistic particles scanned by X-ray computed tomography (X-ray CT). The simulation results agree well with experimental results. This paper demonstrates that physics engines can output contact parameters for geotechnical analysis and force chains for visualization.     

天马和谢坊形变试验场地壳形变特征分析

本文对天马和谢坊试验场的三角和基线观测资料进行了应变分析,获得了该试验场的主应变值、主应变方向以及剪应变值。分析结果表明,该试验场的地壳形变特征基本上是由通过该场地的断层所制约,反映了该断层的性质。     

岩矿石物性标本制作与测定的简介

本文提出当今测定物性标本的现实意义和制作几何形状物性标本的具体办法以及在实际测定要注意的有关问题。     

Large Scale Jets in Microquasars

Relativistic jets are now believed to be a fairly ubiquitous property of accreting compact objects, and are intimately coupled with the accretion history. Associated with rapid changes in the accretion states of the binary systems, ejections of relativistic plasma can be observed at radio frequencies on timescale of weeks before becoming undetectable. However, recent observations point to long-term effects of these ejecta on the interstellar medium with the formation of large-scale relativistic jets around binary systems. In this paper, we review the observations of these large-scale structures in microquasars, highlighting their contributions at high energies.     

A unified description of the global structure of accretion disks

The global structure of accretion disks is investigated in a unified scheme. We use a general radiative cooling formula applicable to both optically thick and thin regimes and we include radial advection cooling. Within the -viscosity models, we found distinct families of global solutions. If the accretion rate is low, there are three non-intersecting solutions, corresponding to optically thick and thin, local cooling and optically thin advection cooling. If the accretion rate is high, and the viscosity coefficient is large, the two local cooling solutions coincide at radii R₁ and R₂ and exist independently below R₁ and above R₂ while the advection solution is stable at all radii. If the accretion is high and the viscosity is low, the two optically thin solutions will cross each other while the optically thick solution exists at all radii.     

Bounds for mass and rotation of black holes in the observable universe

The bounds for the energy change rate of a Maxwell field in the outer space of a rotating black hole, calculated by de Vries (1994) and de Vries (1995), enable us to deduce limits for the rotation and the mass of black holes. For this purpose we assume that a certain part of the anisotropies of the cosmic background radiation is due to absorption or superradiance of black holes (Teukolsky, 1973, Starobinskii and Churilov, 1973). The knowledge of these anisotropies yields bounds for rotation and mass of the black holes in the observable universe.