相山铀矿田巴泉隐爆角砾岩(筒)地质特征与铀成矿

巴泉铀矿床位于相山矿田的北部边缘,是典型的隐爆角砾岩(筒)型铀矿床。隐爆角砾岩(筒)是由与相山火山机构有密切联系的燕山晚期侵入于震旦系变质岩中的潜花岗斑岩岩枝发生隐爆作用而生成。矿床是多阶段岩浆活动、多次隐爆作用和多期铀成矿作用互为响应、连续发展地质过程的产物,是集岩浆岩体-角砾岩体-铀矿体为一体的综合地质单元。燕山晚期潜花岗斑岩浆和英安玢岩浆的侵入、隐爆作用形成的角砾岩(筒),以及断裂构造的频繁运动,对铀成矿乃至矿床的形态和规模起到重要的控制作用。隐爆角砾岩(筒)的形成具有脉动性、隐爆性,显示隐爆角砾岩岩性的复杂多变,矿化蚀变种类、组合和强弱变化具有规律性。铀矿体(化)主要赋存于隐爆角砾岩和震碎角砾岩中,矿化显现出中富边贫、上强下弱的特征。     

Experimental and computational validation and verification of the Stokes–Darcy and continuum pipe flow models for karst aquifers with dual porosity structure

In our previous study, we developed the Stokes–Darcy (SD) model was developed for flow in a karst aquifer with a conduit bedded in matrix, and the Beavers–Joseph (BJ) condition was used to describe the matrix–conduit interface. We also studied the mathematical well‐posedness of a coupled continuum pipe flow (CCPF) model as well as convergence rates of its finite element approximation. In this study, to compare the SD model with the CCPF model, we used numerical analyses to validate finite element discretisation methods for the two models. Using computational experiments, simulation codes implementing the finite element discretisations are then verified. Further model validation studies are based on the results of laboratory experiments. Comparing the results of computer simulations and experiments, we concluded that the SD model with the Beavers–Joseph interface condition is a valid model for conduit–matrix systems. On the other hand, the CCPF model with the value of the exchange parameter chosen within the range suggested in the literature perhaps does not result in good agreement with experimental observations. We then examined the sensitivity of the CCPF model with respect to the exchange parameter, concluding that, as has previously been noted, the model is highly sensitive for small values of the exchange parameter. However, for larger values, the model becomes less sensitive and, more important, also produces results that are in better agreement with experimental observations. This suggests that the CCPF model may also produce accurate simulation results, if one chooses larger values of the exchange parameter than those suggested in the literature. Copyright © 2011 John Wiley & Sons, Ltd.     

海底双层管单层连接管道结构受力分析

粘性高的海洋石油通常需要通过海底保温管道加温输送.温度变化会引起管道变形,并在管壁内产生较大的温度应力.同时,管道正常运营期间还受到管道内压、外压、管内流体粘滞力和土体摩擦力等环境荷载的作用.复杂的环境可能导致海底管道轴向应力过大发生破坏.为了提高铺管效率,提出了双层管单层连接管道这一特殊管道形式,并从理论上分析温度变化和环境荷载对该管道的影响,计算正常运行时管道不同位置处横截面内最大Von-Mises应力.最后得到了Von-Mises应力沿管道轴线分布情况,发现内管和单层连接管的应力一般比外管大,变径管和内管的焊缝处是Von-Mises应力最大的地方.     

外壁恒温条件下冻结管壁热流密度变化规律数值计算研究

应用相似理论将冻结温度场方程和参数无量纲化,然后建立无量纲的数值计算模型,研究了在外表面恒温情况下冻结管壁的无量纲热流密度与各无量纲影响参数间的关系.结果表明:无量纲热流密度随未冻土与冻土的导热系数之比线性增加,与冻土与未冻土的容积比热之比成线性关系,随无量纲结冰潜热线性增长,与无量纲盐水温度成线性关系;可表示为无量纲时间的负三分之一次方的线性函数.最后对167706次数值计算结果进行了回归分析,得到具有较高精度的回归计算公式.     

改进型中心管模型能量转换性能试验及样机设计

为了提高中心管振荡水柱波浪能利用技术能量转换效率,基于新的认识和目前常用的2.4米导航灯标,对中心管尾部设计了三种模型并在造波水槽中进行能量转换性能试验。试验结果表明:直管型中心管俘获宽度比最高达到了70.25%,但通频带宽度窄;加长喇叭口型中心管略好于喇叭口型中心管;在喷咀比为0.02条件下,加长喇叭口型中心管浮体有较高双峰俘获宽度比,波峰为40.0%,波谷为31.6%,通频带宽,为随机波下高效转换创造了条件。最高俘获宽度比和双峰通频带特性实验数据结果都优于历史文献值。根据试验数据对一些适合小型海洋仪器供电的样机进行了设计,设计的样机具有较高的性价比。     

手掘式顶管在市政排水工程中的应用

从混凝土管材的选定、工作坑的设计及施工、顶管顶进中若干关键问题入手,介绍了手掘式顶管施工技术在成都市中心城水环境综合整治工程G标段管道排水工程中的应用。     

风管式气举反循环钻具及其在大口径钻井施工中的应用

目前大口径钻井施工中常用的泥浆正循环钻进存在着泥浆流速慢、携渣能力差、重复破碎严重、钻井效率低、钻头磨损快、能源消耗大、钻井事故发生率高等问题,气举反循环钻进工艺可有效解决上述问题。风管式气举反循环钻井工艺简单易实现,能有效减少重复破碎,钻进效率高,能源消耗少,钻头寿命长,成井质量好,对涌水和漏失均有很好的抑制作用。介绍了风管式气举反循环钻井工艺原理、专用钻具及其现场使用情况。     

Mechanics of a Grip System of Three-Key-Board Hydraulic Tongs Developed for Offshore Oil Pipe Lines

-This paper carries out the analysis of mechanics of a grip system of three-key-board hydraulictongs developed for offshore oil pipe lines which has been successfully used in oil fields in China.The mainimprovement of this system is that a lever frame structure is used in the structural design,which reducesgreatly the stresses of the major components of the oil pipe tongs.Theoretical analysis and numerical calcu-lation based on thirteen basic equations developed show that the teeth board of the tongs is not easy to slipas frequently happens to other systems and is of higher reliability.     

PHC管桩和预制方桩受力性状试验对比分析

通过在同一场地的预应力高强混凝土管桩（PHC桩）和预制方桩中埋设钢筋应力计的静载对比试验,比较了两类桩的荷载-沉降曲线、桩身轴力分布情况、桩侧摩阻力和桩端摩阻力发挥性状的异同,研究了PHC管桩的荷载传递机制,发现其侧阻和端阻的发挥规律与预制方桩相同,但在PHC管桩和方桩侧表面积相近的条件下,在最大试验荷载作用时,两者的侧阻和端阻发挥程度不同,PHC管桩平均单位侧阻比预制方桩低8.1 %,而端阻比方桩高24 %以上。     

深部地热能开发保温管技术研究现状及发展趋势

地热能是一种清洁的可再生能源,用地热能替代高碳能源是减少碳排放的有效途径之一。井下保温管技术是影响地热能开采效率的关键技术之一。本文从保温管的结构、材料、保温材料及制作工艺方面介绍了井下保温管的发展研究现状,指出纳米保温材料与真空油管的融合将是未来的发展趋势,真空纳米保温管是用于深部地热能开采的首选,同时也指出了真空纳米保温管的基础结构因素对保温性能的影响机制是研究的重点,为优化保温管的制作工艺、降本增效提供参考。