北祁连西段肃南地区下志留统肮脏沟组河流相的发现及其大地构造意义

北祁连地区位于中国中央造山带中段,具有典型造山带的特征.区内志留系肮脏沟组沉积环境存在较大争议,以致对其沉积期古地理格局的认识就存在很大差异.本研究选取志留系肮脏沟组发育齐全的肃南地区老虎沟剖面为研究对象,通过野外剖面实测、室内薄片鉴定和碎屑岩粒度分析等方法对老虎沟剖面肮脏沟组沉积充填序列、沉积构造和沉积相类型进行了细...     

徕卡三维激光扫描系统在建筑物精细建模中的应用

三维激光扫描技术作为一种新的测绘技术手段改变了传统的测量模式,利用三维激光扫描技术可以快速、高效、连续地获取海量的点云数据,通过处理可以快速得到被测目标的三维模型。本文主要结合徕卡Scan Station P40三维激光扫描系统介绍其在复杂建筑物精细建模中的应用,通过对点云数据及建模精度分析,得出了有益的结论。     

Hydrological characteristics of vegetated river flows: a laboratory flume study

Abstract

Laboratory flume experiments were undertaken to measure the vertical profiles of mean flow velocity for three different flow discharges and four different stem densities of Hydrilla verticillata. The data were used to calculate three parameters, namely Manning's roughness coefficient, the Reynolds number and the Froude number. In addition, empirical equations were obtained for the vertical distribution of measured flow velocity within the transitional zone and above the plant canopy. The results show that: (a) the vertical distribution of measured flow velocity exhibits three zone profiles; (b) Manning's roughness coefficient decreases with increasing depth-averaged flow velocity; (c) the relationship between Manning's roughness coefficient and the depth-averaged flow velocity is within the smooth left inverse curve; (d) Manning's roughness coefficient significantly changes with increasing density of Hydrilla; (e) the Froude number is independent of the density of Hydrilla; and (f) both the Reynolds number and the Froude number increase with increasing depth-averaged flow velocity.

Citation Shi, J.Z., Li, Y.-H., Hughes, J.M.R., and Zhao, M., 2013. Hydrological characteristics of vegetated river flows: a laboratory flume study. Hydrological Sciences Journal, 58 (5), 1047–1058.

Editor Z.W. Kundzewicz     

麻粒岩区构造地质编图原则探讨

麻粒岩区的边界及亚区划分标志常为等变线、断层或剪切带。主要地质单元包括灰色片麻岩、花岗片麻岩、混合岩、副变质表壳岩、层状侵入体、高级变质绿岩等，基性岩墙群为划分不同地质单元、建立其相对时序的重要标志。以上单元普遍被构造叠置，常可识别出侵入关系。表壳岩系底部不整合及地层层序的研究对于认识大陆克拉通化过程及沉积环境演化具有重要意义。早期大规模水平构造先后被两类变形序列叠加，第１类与麻粒岩相变质发生于同     

黑龙江东部林口地区下白垩统穆棱组砾岩的成因及其意义

大三江地区是中国东部重要的油气资源接替区,早白垩世时期该地区曾为一个统一的盆地,之后盆地遭受破坏分解。如何确定当时的盆地边界进而恢复盆地原型,是该地区亟待解决的关键地质问题之一。前人对盆地边界的确定大都以理论推测为主,缺乏实际证据。本次工作在黑龙江林口地区发现一套穆棱组底部砾岩,对砾石进行成分及分选特征、沉积特征等的统计与分析,结合古水流恢复和地震解释资料,认为该套砾岩整体为冲积扇相,以河道砾岩沉积和漫流砾岩沉积为主,物源主要来自盆地西部的张广才岭。结合地震资料分析,认为研究区穆棱组时期的沉积模型为冲积扇相向滨浅湖亚相的直接过渡。本研究不仅为大三江盆地西部边界的确定提供了直接证据,同时也为该地区今后的油气勘探指明了方向。     

基于理想点-可拓云模型的隧道围岩稳定性评价

为了对隧道围岩稳定性进行准确评价并解决研究过程中存在的模糊性和随机性以及评价指标不相容的问题,减少单一的主客观赋权法所带来的误差,将云模型引入可拓理论中,利用可拓理论能够实现矛盾问题向相容问题转化的特点和云模型具有处理事物双重不确定性的优势并结合理想点组合赋权法对隧道围岩进行稳定性评价研究。通过文献调研、数据统计的方式,选取具有代表性的6个指标组成隧道围岩评价指标体系,用理想点法赋予评价指标组合权重,并构建可拓云模型对隧道围岩稳定性进行综合评价。通过将此方法应用于工程实例并与其他方法对比,结果表明：基于理想点-可拓云模型的隧道围岩稳定性评价方法能够减少评价过程中存在的不确定性问题,克服单一赋权方法的不足,具有良好的适用性,可以应用于实际工程中。     

双鸭山矿区矿井充水规律研究

根据双鸭山矿区的水文地质条件及多年生产实践资料(矿井涌水量与其相关因素——地貌、采掘深度、回采面积、巷道长度、岩性、构造、降雨的关系),阐述了矿区充水的一般规律,提出了含水砂层覆盖下采区进行水文地质勘探的重点及开采含水砂层覆盖下煤炭资源的主要防治水措施,对同类水文地质条件矿井开采煤炭资源具有可借鉴意义。     

Dynamic interaction numerical models in the time domain based on the high performance scaled boundary finite element method

Consideration of structure-foundation-soil dynamic interaction is a basic requirement in the evaluation of the seismic safety of nuclear power facilities. An efficient and accurate dynamic interaction numerical model in the time domain has become an important topic of current research. In this study, the scaled boundary finite element method （SBFEM） is improved for use as an effective numerical approach with good application prospects. This method has several advantages, including dimensionality reduction, accuracy of the radial analytical solution, and unlike other boundary element methods, it does not require a fundamental solution. This study focuses on establishing a high performance scaled boundary finite element interaction analysis model in the time domain based on the acceleration unit-impulse response matrix, in which several new solution techniques, such as a dimensionless method to solve the interaction force, are applied to improve the numerical stability of the actual soil parameters and reduce the amount of calculation. Finally, the feasibility of the time domain methods are illustrated by the response of the nuclear power structure and the accuracy of the algorithms are dynamically verified by comparison with the refinement of a large-scale viscoelastic soil model.     

共散射点道集与角道集串级优化叠前偏移速度分析

推导了基于角度域共成像点道集的叠前深度偏移层析速度分析公式,提出一种共散射点（CSP）道集与角道集串级优化叠前偏移的速度分析方法。该方法通过基于CSP道集的叠前时间偏移速度分析获取初始速度,利用基于角度域共成像点道集（ADCIGs）的叠前深度偏移速度分析进行速度更新。实现步骤概括为：将叠前地震数据映射为CSP道集,利用CSP道集叠加速度谱拾取能量团获取均方根（RMS）速度场;通过Dix公式将RMS速度转换为层速度作为层析的初始输入速度,基于ADCIGs实现叠前深度偏移层析速度反演,最终得到高精度的叠前偏移速度场。断层模型和实际资料试算结果验证了该方法的正确性和有效性。     

Convection in a rotating annulus having sidewalls of height-dependent thermal conductance

Abstract

Thermal convection in a vertically-mounted, rotating annulus of a particular design proposed by Davies and Walin (1977) is investigated. The annulus used in the present study differs from the conventional type in some important aspects: the sidewalls are finitely conducting, and the thermal conductance of the sidewalls is height-dependent. The theoretical model due to Davies and Walin is briefly recounted. The present study aims to verify the theoretical model; we have acquired numerical solutions to the governing Navier-Stokes equations. The numerical results are supportive of the theoretical contentions. The near-linear dependence of the isothermal slope on the parameter D, which is a function of Ω and ΔT, is corroborated within reasonable limits. New data on the vertical and radial structures of the meridional and azimuthal flows are presented. The numerical results also confirm that the shape of the sidewall thickness has a substantial influence on the meridional flow patterns. In the bulk of the interior flow field, the dominant azimuthal flow field and the temperature field are linked by the thermal wind relation.