The use of air decks in production blasting in an open pit coal mine

The influence of air deck blasting on blast performance and blast economics and its feasibility has been studied in the production blasting of soft and medium strength sandstone overburden rocks in an open pit coal mine in India. The air deck blasting technique was very effective in soft and medium strength rocks. Its main effects resulted in reducing fines, in producing more uniform fragmentation and in improving blast economics. The fines were reduced by 60–70% in homogeneous sandstones. Oversize boulders were reduced by 80% and shovel loading efficiency was improved by 20–40% in blocky sandstones. The explosive cost was reduced by 10–35% dependent on the type of rock mass. Throw, backbreak and ground vibration were reduced by 10–35%, 50–80% and 30–94% respectively. For a particular rock mass and blast design environment, air deck length (ADL) significantly influenced the fragmentation. ADL as represented by air deck factor (ADF) in the range of 0.10–0.35 times the original charge length (OCL) produced optimum results. ADF beyond 0.35 resulted in poor fragmentation and in inadequate burden movement.     

紫金山矿区南山坪矿段承压水储存规律研究

紫金山矿区南山坪矿段岩浆岩分布约占矿段面积的90％,主要为燕山晚期中细粒花岗闪长岩、花岗闪长斑岩和似斑状花岗闪长岩,次为燕山早期中粗粒似斑状二长花岗岩和中细粒花岗岩,脉岩及次火山岩脉。通过对矿段内地质特征、富水性、断裂构造导水特征及水质检验成果等资料分析研究,初步揭露了矿段内硫化物矿床承压水形成原因与储存规律。     

南极冰下基岩热水驱动快速取心钻具研究

南极大陆冰下基岩岩心对研究南极大陆地质构造及成因具有重要意义,目前尚没有任何一个国家在南极内陆成功钻取冰下基岩样品,研制可快速钻至冰岩界面并完成基岩采样的钻进设备迫在眉睫。针对极地冰下基岩取样技术难题,提出了一种可结合热水钻系统使用的采用热水驱动的冰下基岩取心钻具概念设计。该钻具系统采用常规热水钻完成南极大陆上覆冰层钻进,然后更换热水取心钻具穿过已有钻孔快速到达冰岩界面,完成冰下沉积物和基岩取心钻进,大大缩短基岩取心时间,提高钻进效率。结合中国自主研发的热水钻系统参数,对螺杆马达压力损失和输出扭矩进行理论计算,提出了螺杆马达选择依据。该技术有望在未来极地冰下基岩取心钻进中发挥重要作用。     

Salt-Lake Basin Bedrock Weathered Crust Gas Reservoir in the Altun Mountains Front of the Qaidam Basin,Western China

The bedrock weathered crust in front of the Altun Mountains in the Qaidam Basin, western China, is different from others because this is a salt-lake basin, where saline water fluid infiltrates and is deposited in the overlying strata. A large amount of gypsum infills the bedrock weathered crust, and this has changed the pore structure. Using core observation, polarized light microscopy, electron probe, physical property analysis and field emission scanning electron microscopy experiments, the ch...     

中国海域基岩油气藏特征及未来勘探方向

基岩油气藏是一种特殊类型的油气藏。随着渤中19-6凝析气藏、永乐8-3-1基岩油气藏及渤中13-2油气田等取得重大突破,证实中国海域基岩油气藏具有巨大勘探潜力。截至目前,已在渤海盆地、北部湾盆地、琼东南盆地、珠江口盆地获得多个高产基岩油气田。中国海域基岩油气藏具有分布广泛、纵向层系多、岩性多、类型多样的特征,主要发育前寒武系变质岩和混合花岗岩、古生代碳酸盐岩、中生代火山岩以及花岗岩侵入体、中生代碎屑岩等4套储层,尤其以前寒武系变质岩和中生代花岗岩侵入体为主。研究表明基岩油气藏主要表现为新生古储,其形成主要受控于富烃凹陷、构造运动、储盖条件等多种控制因素的影响。在总结前人成果的基础上,指出了中国海域未来基岩油气藏勘探应重点关注6大勘探方向：渤海盆地残山,北黄海盆地东部坳陷东北部局部凸起,南黄海盆地凸起带,东海陆架盆地低凸起,北部湾盆地涠西南凹陷、珠江口盆地惠州凹陷和琼东南盆地松南低凸起,南海南部中建南盆地和万安盆地。     

物探方法在采矿坑回填土石与基岩分界面勘探中的应用

在矿山地质环境治理工作中发现有矿企存在明显的超采行为,且为掩饰违法行为用杂土、乱石回填采矿坑。为追究违法责任,行政部门需要确定实际开采范围及超采量。由于矿坑大部分被回填土石覆盖,无法直接测量,需要工程勘探揭露回填土石与基岩分界面。研究表明,采用物探方法中的高密度电阻率法、地质雷达法对土石回填的石灰岩矿坑进行先期勘探,推断回填土石与底部基岩分界面、浅覆盖区矿坑边界,可为钻探孔位布置、深度设计提供参考;通过综合分析物探、钻探成果确定回填土石与基岩分界面,与采矿许可范围对比可计算超采量。钻探工程表明物探推断结果较准确,二者相互配合可明显提高工作效率,降低勘探成本。     

长沙城市空间破碎化的格局特征及其影响因素

空间破碎化是城市空间结构研究亟待深化的重要课题。从形态、联系以及功能3个维度构建城市空间破碎化测度指标,并运用地理探测器模型,探讨长沙城市空间破碎化的格局特征及其影响因素。主要结论：① 城市空间破碎化可从形态分割、联系阻隔、功能失序三方面进行测度,形态分割可用平均地块面积指数表征,联系阻隔可用平均阻抗指数刻画,功能失序可用功能多样指数、邻接冲突指数来反映;② 长沙城市空间破碎化呈现圈层式分异为主、扇形扩展分异为辅的格局特征,低破碎化区主要分布在城市核心区,高破碎化区沿着特定的扇面向外围扩展,且主要分布在大型封闭社区、工业园区、山地绿地及大型站场等区域;③ 长沙城市空间破碎化的空间分异是多因素综合作用的结果,其中海拔、坡度等自然因素是基础因素,土地价格、人口密度、设施投入是主导因素;④ 长沙城市空间破碎化治理可从突破市场供给约束、市场需求约束和设施丰度约束三方面着手,采取针对性调控对策,以最大程度地消减空间破碎化带来的负面效应。     

景观破碎度在冬小麦面积抽样设计中的应用研究

将破碎度指标引入到遥感抽样调查中,重点探讨了面积规模指标与破碎度指标在分层抽样中的适用性。实验结果表明:在种植结构破碎区域,面积规模指标与破碎度指标的相关系数均在0.7以上,可以作为分层标志,随着抽样格网不断增加,面积规模指标的相关系数不断增大,而破碎度指标的相关系数则不断减小。当格网小于100m×100m时,破碎度指标作为分层标志效果要优于面积规模指标;在种植结构规整区域,面积规模指标要始终优于破碎度指标,破碎度指标更适合于种植结构破碎、抽样单元较小的遥感抽样调查方案中作为分层标志进行应用。     

和田绿洲景观破碎化特征及驱动因素

景观破碎化改变着区域景观结构的完整性和系统的连通性,对景观的稳定性和可持续发展具有重要影响.选取新疆和田绿洲为研究区,以1970年新疆考察数据与MSS影像,1990、2000、2013、2018年4期Landsat TM/ETM+同月相数据为主要数据源,采用景观指数法、移动窗口法、梯度分析及归因分析等方法开展绿洲景观破...     

Factors Influencing Species Composition in Canopy Gaps: The Importance of Edge Proximity in Hueston Woods,Ohio

In this research, we attempt to quantify the factors structuring woody species composition within forest gaps in the interior of Hueston Woods Nature Preserve, Ohio. Our results indicate that composition is related not only to factors commonly cited in other studies, including disturbance history, topographic position, and environmental factors (e.g., gap age, soil pH, slope, and aspect), but also to the proximity of forest edge communities. Partitioning of species variation to environmental factors, spatial factors, and spatially structured environmental factors reinforces the importance of both environment and edge proximity in explaining gap composition. These findings underscore the need for a more complete understanding of the potential impacts of edge effects in fragmented landscapes.