Evaluating fine sediment mobilization and storage in a gravel‐bed river using controlled reservoir releases

Two controlled flow events were generated by releasing water from a reservoir into the Olewiger Bach, located near Trier, Germany. This controlled release of near bank‐full flows allowed an investigation of the fine sediment (<63 µm) mobilized from channel storage. Both a winter (November) and a summer (June) release event were generated, each having very different antecedent flow conditions. The characteristics of the release hydrographs and the associated sediment transport indicated a reverse hysteresis with more mass, but smaller grain sizes, moving on the falling limb. Fine sediment stored to a depth of 10 cm in the gravels decreased following the release events, indicating the dynamic nature and importance of channel‐stored sediments as source materials during high flow events. Sediment traps, filled with clean natural gravel, were buried in riffles before the release of the reservoir water and the total mass of fine sediment collected by the traps was measured following the events. Twice the mass of fine sediment was retained by the gravel traps compared with the natural gravels, which may be due to their altered porosity. Although the amount of fine sediment collected by the traps was not significantly related to measures of gravel structure, it was found to be significantly correlated to measures of local flow velocity and Froude number. A portion of the traps were fitted with lids to restrict surface exchange of water and sediment. These collected the highest amounts of event‐mobilized sediments, indicating that inter‐gravel lateral flows, not just surface infiltration of sediments, are important in replenishing and redistributing the channel‐stored fines. These findings regarding the magnitude and direction of fine sediment movement in gravel beds are significant in both a geomorphic and a biological context. Copyright © 2006 John Wiley & Sons, Ltd.     

冷水江市枣子排锑矿床地质特征及资源远景

本文概述了枣子排锑矿床的地质特征,阐明了矿床是以构造为主,地层、岩性（岩相）联合控矿。研究表明,本矿床有着良好的找矿前景。     

Finite element ana lysis for blasting law of jointed rock mass

On the basis of Mises strength theory, rock models are built including vertical, horizontal and diagonal joints to simulate jointed rock mass under blasting load by using FEM. The dynamic procedures of jointed rock mass under blasting are quantified and the effective stress-time curves of typical elements are compared to analyze the barrier of joints to the stress wave. The blasting law was studied according to the process of computer simulation and the effect of blasting, and some suggestions were given for solving the problems of overbreak and underbreak.     

湘西花垣铅锌矿田成矿构造系统与成矿规律

湘西花垣铅锌矿田发育典型的层控型铅锌矿床,找矿潜力巨大。该区在矿床成因、控矿因素等方面存在不同认识,主要观点有密西西比河谷型、沉积型、成岩期后改造型和盆源低温热液型4种观点。通过构造测量解析和古应力场恢复,分析了构造与成矿的关系,划分出成矿前构造主压应力近似垂直层面,成矿期构造主压应力方向为北西—北北西,成矿后构造主压应力方向为北东—北北东向;成矿期构造形成了矿田内李梅平缓背斜、渔塘背斜,并在藻灰岩层内形成各类含矿角砾岩、裂隙系统,这些裂隙为热液与藻灰岩中富含的有机质发生化学反应提供了丰富的反应界面,是铅锌矿液富集的主要原因。成矿后构造主要形成于燕山期,受北北东—南南西向挤压应力作用,形成了北东走向的大型走滑正断裂带,对加里东期成矿期赋矿褶皱造成破坏改造。     

爆破地震波在砼重力坝中的特性反应

根据某大坝右岸围堰爆破，对爆破地震波三维空间的频谱、加速度、速度、动力放大倍数进行了研究，得到爆破地震波在砼重力坝的不同高度、不同方向、不同介质中的反应特性。     

滑坡体快速探测新技术应用研究

通过工程实例,就瞬变电磁方法 (TEM) 和可控源音频大地电磁法(CSAMT)在滑坡体快速探测中的应用问题进行了研究。结果表明,通过瞬变电磁方法和可控源音频大地电磁法的使用,再加以适量的钻探施工,可以实现对滑坡体快速勘探的目的。     

建筑爆破倒塌过程的摄影测量分析系统

本文将近景摄影测量分析系统引入工程爆破领域,对建筑物倒塌过程的运动轨迹进行测量分析.本分析系统用非量测用摄影机采集建筑爆破倒塌过程的影像,用直接线性变换解法解析图像,再进行专业化的数据后处理,获得建筑物倒塌过程的构件(或部分结构体)的运动学和动力学参数以及爆破后座、动能、势能、机械能损失率等引申物理量,从而实现各种爆破...     

安丘市东周村城乡建设用地拆迁实践与探讨

为深入贯彻落实党的扩大内需,促进经济增长,加快城乡一体化进程,开展城镇建设用地增加要与农村建设用地减少相挂钩,2012年安丘市决定对新安街道东周村居民点进行拆迁工作,实现村庄居民点旧址复耕,复耕质量达到基本农田标准,最终达到科学化拆迁和可持续性发展。     

基于倾斜摄影的三维测图技术研究

近年来,随着无人机技术、机载定位技术、图像处理技术的快速发展,倾斜摄影测量技术已广泛应用于1∶1000大比例尺地形图测绘中。但由于各项技术限制,普通的无人机航空摄影测量难以满足1∶500大比例尺地形图测图。因此,本文以倾斜摄影测量技术为基础,从像控密度、模型分辨率、测图方式3方面展开研究,提出了一种适用于城镇1∶500大比例尺地形图的倾斜测图方法。试验结果表明,文成县大比例尺地形图的成果平面精度可达0.059 m,高程精度可达0.064 m,精度情况良好,对以后采取此种方法进行测绘具有一定的借鉴作用。     

月球探测摄影测量数据处理系统方案分析

本文提出了月球摄影测量数据处理系统的设计原则，探讨了月球摄影测量数据处理系统的组成和研究的内容，分析了在月球探测摄影测量数据处理中，首先应该解决的关键技术问题。结论：对月球探测摄影测量数据处理系统的研究，可以保障月球探测卫星工程测绘月球表面三维影像图及地形图任务的完成，同时，也可以为后续的月球探测计划提供摄影测量的基础理论、技术、方法和实践经验。