MW5型潜水电磁打捞器在桩孔施工中的应用

通过工程实例，介绍了应用潜水电磁铁处理桩孔施工中掉铁件事故的方法及操作要领，它具有实用价值。     

中亚造山带东段铀、钼矿床分布与中间地块的关系

在近年来中亚造山带东段多金属矿床研究取得新进展的基础上,选择铀、钼两类矿床,结合铀、钼元素的地球化学行为探讨成矿物质来源的多样性和成矿的多阶段演化。此外,从构造研究角度,结合中亚造山带东段中大量中间地块存在的构造现象,讨论中间地块与成矿作用的关系:中间地块经历了从大陆边缘的裂解、漂移和板块碰撞造山作用,在漫长而复杂的地质过程中遭受的多次改造,有利成矿物质的反复被萃取和聚集。最后提出印支期华北克拉通北缘和北部造山带的成矿作用与底侵背景下的伸展作用密切相关。     

含液各向异性多孔介质应变局部化分析

工程中的含液多孔介质如饱和或非饱和岩土材料往往具有各向异性特性。采用Rudnicki建立的针对岩土材料的各向异性本构模型,对轴对称压缩试验中的含液多孔介质骨架的各向异性力学行为进行了分析;基于不连续分叉理论,导出了静态非渗流条件下处于轴对称应力状态的含液多孔介质应变局部化发生的临界模量、剪切带方向以及不连续速度矢量的显式表达式,在此基础上计算并讨论了材料参数变化和孔隙液体存在对各向异性多孔介质应变局部化的影响。     

随机介质理论预测近距离平行盾构引起的地表沉降

提出近距离双线水平平行盾构施工引起的总的地表沉降曲线符合正态分布规律。基于单线随机介质理论简化公式,针对现有不足,建立修正的随机介质理论简化计算公式,可以计算近距离双线平行盾构施工引起的地表沉降,同时能够考虑沉降曲线的不对称性,对计算参数取值进行了探讨。算例分析结果表明,文中方法预测值与实测值比较吻合,且计算比较简便。实测数据统计结果表明,先行隧道开挖后双线隧道的半径收敛值比先行隧道半径收敛值要大,而主要影响角则变小;提出可直接用于近距离界定的式（6）,认为双线隧道的地表沉降曲线形状与P值大小有关,近距离的界定范围为 。     

Application of the third medium method for frictionless contact problems in geomechanics

Traditional approaches in contact mechanics demand complicated search algorithms at the interface between the contacting bodies. Recently, a new contact method based on the concept of a third medium has been developed, which overcomes the drawbacks of conventional contact mechanics techniques. This new scheme is based on a space filling mesh, in which the contacting bodies can move and interact. The ability and accuracy of this method in predicting displacements, as well as the contact forces, is validated by solving selected numerical examples. The potential merits of this method for analysing geotechnical problems by the finite element method are addressed.     

AVO叠前反演在中等阻抗储层预测中的应用

新场气田须四下亚段TX94砂体为砂砾岩互层。前期勘探证实,砂岩为有效储层,由于砂岩与作为围岩的泥岩阻抗接近,而砾岩的阻抗又远远大于砂泥岩,常规地震属性及叠后反演无法准确识别砂岩。采用AVO叠前反演技术,综合应用纵波弹性阻抗和纵波、横波速度比,结合岩石物理模板,对砂岩进行了准确刻画。这里阐述了AVO叠前反演的原理,讨论了反演处理中的地震数据分析,岩石物理分析,子波提取,低频趋势模型建立等关键步骤。反演结果表明,AVO叠前反演能很好地识别砂岩,降低了勘探风险。     

商河县郑路镇中低产田项目治理综合效益分析

土地整理效益研究是土地整理理论及实践研究的重要组成部分,也是当今土地科学领域专家和学者关注的重要课题。结合商河县郑路镇项目区的自然和社会经济条件以及土地利用状况,对土地开发整理项目进行社会效益、生态效益及经济效益分析,指出土地整理应寻求社会、生态和经济三大效益的最大结合,实现效益最大化,最终促进农村经济的可持续发展。     

岩土介质三维快速拉格朗日数值分析方法研究

研究了FLAC3D（fast lagrangian analysis of continua in 3 dimensions）的特点,并与有限单元法作了比较。FLAC3D方法以结点运动方程为支配方程,追踪了介质从受荷到达到平衡状态的过程,而有限元法是根据介质力学平衡方程直接求解,这是二者主要区别。FLAC3D没有采用介质真实的阻尼特性和结点质量,给出的不是介质所经历的真实过程,不能正确反映过程的影响,因此给出的介质应力和变形计算结果的物理意义是不甚明确的。求解过程中的介质振动,是一种噪音,可引起弹塑性介质计算结果误差,而弹性介质的计算结果几乎不受影响。研究指出了FLAC3D方法的优缺点。还通过算例作了四个方面的研究：(1) Drucker-Prager屈服准则与Mohr-Coulomb屈服准则比较;(2) 膨胀角取值对计算结果的影响;(3) 大变形与小变形对计算结果的影响;(4) 精度设置对计算结果的影响。研究表明,Drucker-Prager准则与Mohr-Coulomb准则结果差异颇大;膨胀角取值对结果的影响是敏感和显著的;一般情况下,取小变形模式是合适的,计算精度取10-5是足够的。     

Historical space as narrative medium: on the configuration of spatial narratives of time at historical sites

This paper examines how narratives of history are organized spatially at historical sites and memorial spaces, especially in urban settings and in places invested with a sense of collective memory. Much recent research has focused on landscape, memory, and place and how relationships of political and social power influence the representation of historical events in public spaces. Although the meaning of such sites may be hotly contested for long periods of time, we focus here on narrative theory and the related, but unexplored, issue of how such historical stories are configured on the ground at actual historical sites. We identify a number of narrative strategies which are frequently used to configure historical stories in space. Declamatory strategies using markers presenting a snapshot of an event are common, but sequential and non-sequential linear strategies are also used, as are thematic strategies that cross-cut space and time to present complex historical stories at various spatial scales. Examples are drawn from a range of historical sites in North America, Europe and Israel.     

Group Time Delay in the Reflection of P-Polarized Electromagnetic Plane Waves at a Stratigraphic Interface

The group time delay (GTD) formulae of quasi-total reflection of inhomogeneous P-polarized electromagnetic waves (P-PEW, whose electric field parallels to the plane of incidence), caused by the Goos–Hänchen effect, is derived by the phase shift of the wave. A numerical example where the frequency equals to 1 GHz is given. The curves of calculating results show that there are three discontinuous points at the critical angle of phase shift vector, the critical angle of attenuation vector and 90^○. When the angle of incidence is equal to one of these three angles, the GTD will become infinite, and the electromagnetic wave will propagate along the interface. The GTD will be very large, when the angle of incidence is close to one of these three angles. The results indicate that there is an important relationship between the two critical angles and the conductivity and permittivity of the two strata, and that the GTD has an important relationship with the angle of incidence. These results can be used to determine the lithology of the strata and to delimit the interfaces of strata more effectively. It is suggested that this research may prove useful in electromagnetic logging analysis and, perhaps, in the design of logging instruments.