合肥市地下空间开发地质环境适宜性评价

为查明合肥市地下空间开发地质环境影响因素,评价该市地下空间开发地质环境的适宜性,通过研究地质环境条件,选取工程地质条件、水文地质条件、地壳稳定性、地面及地下空间条件4个要素作为地下空间开发地质环境适宜性评价因子.在单因子地下空间开发适宜性评价的基础上,利用层次分析法确定权重,以MAPGIS为平台,运用模糊数学综合评价方...     

2018年春季西北五省省会城市大气质量与健康风险评价

城市大气污染及其引起的健康效应一直是关注的热点.本研究对2018年春季西北五省省会城市PM2.5、PM10、NO2、SO2、CO和O3浓度数据进行了系统分析,并采用美国环境保护署(United States Envi-ronmental Protection Agency,USEPA)推荐的健康风险评价模型评估了PM2...     

高精度重力方法在高青地区探测古潜山构造中的应用

本文根据作者几年来把高精度重力勘探方法应用在胜利油田进行古潜山构造探测的生产实践经验,总结了在油气勘探中高精度重力方法应用的新进展,阐述了它在勘探程度极高的胜利老油区依然可以解决一些石油地质问题,尤其与其它物探资料的联合解释取得了明显的地质效果。依据高青测区所取得的高精度重力资料,基本查清了区内的古潜山分布规律,为下一步古潜山油气藏的勘探部署提供了重要的参考资料。     

Impacts of native vegetation on the hydraulic properties of the concentrated flows in bank gullies

To quantify the impacts of native vegetation on the spatial and temporal variations in hydraulic properties of bank gully concentrated flows, a series of in situ flume experiments in the bank gully were performed at the Yuanmou Gully Erosion and Collapse Experimental Station in the dry-hot valley region of the Jinsha River, Southwest China. This experiment involved upstream catchment areas withone-and two-year native grass(Heteropogon contortus) and bare land drained to bare gully headcuts, i.e., Gullies 1, 2 and 3. In Gully 4, Heteropogon contortus and Agave sisalana were planted in the upstream catchment area and gully bed, respectively. Among these experiments, the sediment concentration in runoff in Gully 3 was the highest and that in Gully 2 was the lowest, clearly indicating that the sediment concentration in runoff obviously decreased and the deposition of sediment obviously increased as the vegetation cover increased. The concentrated flows were turbulent in response to the flow discharge. The concentrated flows in the gully zones with native grass and bare land were sub-and supercritical, respectively. The flow rate and shear stress in Gully 3 upstream catchment area were highest among the four upstream catchment areas, while the flow rate and shear stress in the gully bed of Gully 4 were lowest among the four gully beds, indicating that native grass notably decreased the bank gully flow rate and shear stress. The Darcy–Weisbach friction factor(resistance f) and flow energy consumption in the gully bed of Gully 4 were notably higher than those in the other three gully beds, clearly indicating that native grass increased the bank gully surface resistance and flow energy consumption. The Reynolds number(Re), flow rate, shear stress, resistance f, and flow energy consumption in the gully beds and upstream areas increased over time, while the sediment concentration in runoff and Froude number(Fr) decreased. Overall, increasing vegetation cover in upstream catchment areas and downstream gully beds of the bank gully is essential for gully erosion mitigation.     

沂沭断裂带深反射地震资料处理

地震时间剖面可以对地质目标进行精细刻画,但由于变质岩、侵入岩地区存在地质体不规则、地质界线间波阻抗差异不明显、断裂构造倾角高陡等特征,导致地震原始资料具有波场复杂、干扰波发育、资料信噪比低等特点.为获得客观反应实际地质情况的沂沭断裂带深反射地震剖面,通过对研究区原始地震资料细致分析,针对各种干扰波的不同特性特征,分别采...     

锥束CT图像重建算法的快速实现

本文基于锥束CT滤波反投影重建的FDK算法,通过两种算法改进并结合基于共享内存的OpenMP并行技术和代码优化,实现了锥束CT图像的快速重建.基于锥束CT实际投影数据的重建结果表明,图像重建速度得到了较大的提高,断层图像重建质量与FDK原型算法相当.     

四川九寨沟诺日朗瀑布钙华大坝放射性及沉积环境意义

以九寨沟诺日朗瀑布钙华大坝为研究对象,采用便携式手持伽马仪对大坝坝体进行放射性强度测量,同时对钙华大坝取样,进行主量、微量元素分析,以研究大坝形成的沉积环境.结果表明:大坝表层伽马辐射量平均值为27.57 Ur(当量铀),变异系数为18.73％;钙华主微量元素分析显示钙华颜色与本身所含的色素元素和矿物有关;大坝钙华(L...     

胸部多排螺旋CT扫描在肋软骨隆鼻术整形中的临床应用研究

目的:探讨胸部多排螺旋CT扫描在肋软骨隆鼻术中的应用价值.方法:收集符合纳入标准120例拟行自体肋软骨隆鼻术患者,都进行了胸部多排螺旋CT术前检查,并进行多种三维重建分析自体肋软骨是否符合手术标准,部分病例进行了术后CT复查评估.结果:CT准确评估肋软骨无钙化(1级)28例和轻度钙化(2级)62例,均可行自体肋软骨隆鼻...     

江苏金坛和尚墩旧石器遗址地层的古地磁年代与磁化率研究

北方黄土研究中磁化率分析已越来越多运用到第四纪风尘堆积研究中。采用古地磁极性柱结合磁化率曲线比对定年的方法,初步确定江苏金坛和尚墩遗址750cm厚的地层年龄为330kaBP,对应磁化率曲线判断该区域分别经历了24kaBP左右、110kaBP左右、190—240kaBP左右、300kaBP左右的4个暖湿期,其中间隔有3个干冷时期,具有完整的3个气候旋回。对应地层发育的4个古土壤层、3个黄土层的风尘堆积—古土壤序列。研究表明,虽然古地磁极性定年的方法有一定的局限性,但在以磁化率信息为辅助的条件下,可在一定程度上消除这些局限,获得较为准确的地层年代,多种证据表明这种方法是可靠的。     

渤海湾盆地新生代沉降特征及其动力学机制探讨

综合分析了渤海湾盆地新生代以来断裂发育的分布规律,以及伸展量和沉积沉降随时间和空间的变化规律,并结合现今的深部结构特征,试图揭示盆地新生代沉降的地球动力学机制。发现在断陷阶段,断裂发育在时间和空间上控制了沉积沉降中心的迁移;坳陷阶段后期,在断裂作用非常弱的情况下,以渤中坳陷为中心,出现裂后加速沉降现象,并逐渐波及到相邻坳陷。断陷阶段的断裂发育和沉积沉降主要受板块运动形成应力场的控制,其沉降是岩石圈水平伸展和岩石圈垂向热减薄耦合作用的结果;而裂后加速沉降可能是岩石圈垂向密度突然变化及其后迅速热衰减造成的。