高分辨率遥感影像的精纠正

论述了对高分辨率遥感影像进行精纠正获得正射影像的关键技术。若干实际不同分辨率的高分辨率遥感影像被用于相应的实验,实例证明了本文算法的正确性。     

基于压差式水位传感器的冰层厚度自动监测系统

本自动监测冰厚装置原理,是通过测量冰层底面与冰下水中一固定端之间垂直距离来实现的。该距离是一只浮桶从固定端运动到冰层底面的行程。随浮桶一起运动的压差式水位传感器分别给出浮桶位于固定端和冰层底面的位置,而浮桶的运动则依靠数据采集仪控制浮桶内水泵排吸水改变浮桶的重力来实现,并且该仪器能够记录传感器的信号和设置水泵开关的开、闭时间。为了避免浮桶对冰层厚度变化的影响且浮桶不至于与冰层底面冻结,浮桶只是在测量行程时上浮到冰层底面,其他时间均在固定端位置。文中给出系统的工作原理和现场实测结果的初步分析。     

Attenuation of compressional waves in peridotite measured as a function of temperature at 200 MPa

A technique has been developed to determine attenuation in rocks at high temperature using a gas-media, high-pressure apparatus. A pulse transmission technique and a spectral ratio method are used to study compressional seismic properties of rocks. Seismic waves are transmitted to and from the sample through buffer rods of mullite. The effect of seismic wave reflections within the sample assembly are cancelled out by taking ratios of the spectra measured at different temperatures. In order to obtain good signal-to-noise ratio for resolving the attenuation at high pressure and temperature, special care is taken in the sample assembly and the ultrasonic coupling between the sample, buffer rods and transducers. A very tight connection of the sample-buffer rod-transducer is essential for obtaining high frequency signals (>300 kHz) at high temperature. A small mass is attached to each outside end of the transducer to drive low frequency signals (<250 kHz) into the sample. Before attenuation measurements, the sample and the buffer rods are tightly compacted in a platinum tube at high pressure and room temperature to ensure pressure seal of the sample assembly. The frequency range of measurement covers 50 to 450 kHz for the sample. Attenuation is very small in the buffer rod compared to the sample for the entire temperature range of the study. Because of the small attenuation, a wide frequency band of 50 kHz to 3.2 MHz can be covered for investigating the attenuation in the buffer rod. The technique has been used to measure attenuation at high confining pressure, and temperatures including sub- and hyper-solidus of upper mantle rocks. Therefore, effects of partial melting on attenuation can be studied.The method is applied to the attenuation measurement in a peridotite as a function of temperature to 1225°C at 200 MPa confining pressure. At high temperature, signal amplitude decays more rapidly at high frequency than at low frequency, from which attenuation (andQ) can be determined using a spectral ratio method. No frequency dependence ofQ is resolved for both the sample and the buffer rod over the entire temperature and frequency ranges of the measurement. The results show thatQ decreases rapidly with increasing temperature even in the temperature range below the solidus of peridotites. Such temperature sensitivity ofQ is probably more useful to probe thermal structure in the upper mantle than that of conductivity at temperatures below the solidus. The results in this study are compared with available seismic velocity, electrical conductivity and solidus data for peridotites, suggesting that there is no discontinuous change in both mechanical and electrical properties of peridotites at the solidus temperature. Even at hypersolidus temperatures, it appears that velocity drops and conductivity increases continuously (not abruptly) with increasing melt fraction. This implies that mechanical and electrical properties of the upper mantle will gradually change at the boundary where the geotherm crosses the solidus.     

超高温高压流变仪的研发及应用

随着我国能源勘探及地球深部探测等向深部发展,深井越来越多,地层温度、压力越来越高。保证高温高压状态下钻井液流变性能的稳定是深井安全钻进的必要前提,测定钻井液高温高压流变性是评价和优选钻井液体系最基础的工作。依托国家科技部重大仪器设备开发专项,通过对压力控制系统、温度控制系统、剪率控制系统、粘度检测系统等方面技术难题的攻关,研制成功了国内首台超高温高压流变仪。该仪器可在高温高压及低温高压条件下对钻井液、完井液、压裂液等样品的流变性进行高精度测量。     

UBD/MPD技术标准现状分析

近年来,欠平衡钻井（UBD）和控制压力钻井（MPD）因能大幅度提高机械钻速、有效降低井下复杂情况的发生、减少非生产时间而得到了飞速发展,国内外也对两项技术制定了相关标准。从石油行业标准I、ADC标准、API标准入手,着重讨论欠平衡钻井和控制压力钻井的标准现状,探讨建立控制压力标准应包含的主要内容。     

圆钢管约束高强灌浆料局部承压性能研究

以圆钢管约束高强灌浆料局部承压性能试验为基础,基于ABAQUS有限元计算平台,通过建立分段模型(Multi-section Model简称MSM模型)进行数值模拟,探究圆钢管约束高强灌浆料在局部承压作用下的力学性能,并将软件计算得到的荷载-位移曲线与试验结果进行对比分析。结果表明,分段模型适用于圆钢管约束高强灌浆料局部承压作用下的数值模拟,且计算结果与试验结果吻合较好;增大试件高径比、钢管壁厚和高强灌浆料强度均可提高其极限承载力。     

坑式钢管静压桩在地基加固中的应用

坑式钢管静压桩是解决既有建筑物因软弱土层地基产生沉降变形的一种技术方法。针对山西北化关铝化工有限公司质检楼地基沉降变形及工程地质条件,提出了采用坑式钢管静压桩进行加固处理的设计方案,介绍了坑式钢管静压桩施工方案和施工流程及注意事项;总结了施工过程中遇到的问题,并对施工后的监测数据进行了分析。结果表明,坑式钢管静压桩施工对软弱地基加固效果良好,可成功地解决软弱土层产生的地基沉降开裂问题。     

洪家渡水电站左坝肩高边坡稳定及加固措施研究

贵州洪家渡水电站左坝肩高边坡开挖高度310 m,采用弹塑性有限元数值模拟方法对左坝肩高边坡施工期岩体应力应变状态进行分析研究,并结合现场变形观测资料对计算结果进行验证,从而对左坝肩高边坡的稳定性进行评价并提出相应的加固措施。     

NUMERICAL EXPERIMENTS AND ANALYSIS OF DIGITAL FILTER INITIALIZATION FOR WRF MODEL

Initialization and initial imbalance problem were discussed in the context of a three-dimensional variational data assimilation system of the new generation “Weather Research and Forecasting Model”. Several options of digital filter initialization have been tested with a rain storm case. It is shown that digital filter initialization, especially diabatic digital filter initialization and twice digital filter initialization, have effectively removed spurious high frequency noise from initial data for numerical weather prediction and produced balanced initial conditions. For six consecutive intermittent data assimilation cycles covering a 3-day period, mean initialization increments and impact on forecast variables are studied. DFI has been demonstrated to provide better adjustment of the hydrometeors and vertical velocity, reduced spin-up time, and improved forecast variables quantity.     

深水压力舱密封技术研究

管道屈曲技术试验过程当中,发现深水压力舱的出厂自带密封工艺耗时过长、密封效果不好、安全性不佳、返工现象普遍.针对这一现象,采用全新的密封工艺流程与方法:在前期处理中对螺柱编号与清理以防止螺母安装过程中的卡死现象;采用自创的精度控制方法防止漏水以及返工;根据不同的工作压力对密封技术进行梯度划分,选取不同的密封方案.经过实...