马里亚纳岛弧系的垂向旋转运动与海槽的形成

处于垂向旋转应力场作用下的马里亚纳岛弧系发生了垂向旋转运动,岛弧表面张裂而一分为二,形成东海脊和西海脊.东海脊的旋张掀斜运动使早期形成的岛弧向海沟轴方向不断迁移、沉降,同时导致马里亚纳海槽形成. 马里亚纳海槽新月形形态的形成是由于沟-弧系水平方向的差异性运动和岛弧系向东的差异性旋张掀斜运动所致.马里亚纳海槽实质上是岛弧系中发育的负向构造,始终属岛弧系的一部分.     

海洋矢量过程旋转谱估计的统计分布及置信区间

本文利用一些复随机变量的分布和统计推断理论,导出了向量过程的正旋谱、负旋谱、谱差、总谱、外自谱、频域外自相关函数、外自谱的位相函数等估计量的渐近分布以及它们的置信区间,并简略地讨论了所得置信区间的最优性。最后用锚系海流计资料实例说明了所得置信区间公式在海流资料分析中的应用。     

一种改进的扇形波束旋转扫描散射计海面风矢量反演算法

扇形波束旋转扫描散射计（RFSCAT）是约十年前才被提出来的一种新型星载微波散射计。与其它旋转扫描散射计类似,其星下点附近区域和刈幅边缘区域的风场反演误差相对较大。在本文设定的参数条件下,RFSCAT散射计刈幅边缘区域的风向反演精度相对于轨道中间区域降低了约9°。针对这一问题,本文为RFSCAT散射计提出了一种改进的风矢量反演算法。新算法的主要特征是,根据风向反演偏差直方图,在整个刈幅区域内,对模糊解风向取值区间进行自适应扩展,以获取并保留更多可能风向解。利用模拟的100条轨道的L2A数据,对新算法进行反演验证。实验结果证明,新算法能够有效改善RFSCAT散射计星下点附近区域和轨道刈幅边缘区域的风向反演精度。星下点和刈幅边缘上的风矢量单元的风向反演精度相对于标准的MLE算法分别提高了1.6°和9°。     

叠前联合反演技术在渤海中深层储层预测中的应用

渤海A油田中深层砂泥纵波阻抗叠置严重,常规叠后反演手段无法有效预测储层,为此提出叠前联合反演技术思路：通过实钻井数据开展储层敏感性分析,采用坐标旋转技术构建储层识别因子并作为目标曲线,以叠前同时反演获得的纵横波阻抗、密度等弹性参数体作为输入,采用多属性神经网络反演获得全区储层识别因子数据体,从而对砂岩储层厚度及空间展布进行准确预测。该技术获得的目标储层预测结果在纵向与已钻井吻合良好,横向展布符合地质沉积规律认识,为后续钻井提供了重要的参考依据,具有广阔的应用前景。     

考虑波浪引起的主应力轴旋转效应的砂土本构模型及其验证

Principal stress axes rotation influences the stress-strain behavior of sand under wave loading. A constitutive model for sand, which considers principal stress orientation and is based on generalized ...     

High precision fiber SINS with spin technology

Fiber strapdown inertial navigation system （FSINS） is presently used in several applications related to marine navigation. However, the absolute position from FSINS contains the error that increases with time, which prevents its long-term use for the ship cruise. In order to improve the performance of FSINS based on our present inertial sensors, the spin technology was proposed in the system to mitigate the navigation errors and a prototype of the proposed system was developed in Navigation Lab. The prototype contains the IMU, temperature controller, rotating configuration, navigation and I/O electronics group, control and display, power supply subsystem and other modules. In the proposed spin technology, the IMU is rotated back and forth in azimuth through four orthogonal positions relative to the ship’s longitudinal axis. Experimental testing was conducted for the prototype in the laboratory and the results showed that the RFSINS’s navigation performance is improved 10 times.     

Peak earthquake response of structures under multi-component excitations

Accurate estimation of the peak seismic responses of structures is important in earthquake resistant design. The internal force distributions and the seismic responses of structures are quite complex, since ground motions are multi- directional. One key issue is the uncertainty of the incident angle between the directions of ground motion and the reference axes of the structure. Different assumed seismic incidences can result in different peak values within the scope of design spectrum analysis for a given structure and earthquake ground motion record combination. Using time history analysis to determine the maximum structural responses excited by a given earthquake record requires repetitive calculations to determine the critical incident angle. This paper presents a transformation approach for relatively accurate and rapid determination of the maximum peak responses of a linear structure subjected to three-dimensional excitations within all possible seismic incident angles. The responses can be deformations, internal forces, strains and so on. An irregular building structure model is established using SAP2000 program. Several typical earthquake records and an artifi cial white noise are applied to the structure model to illustrate the variation of the maximum structural responses for different incident angles. Numerical results show that for many structural parameters, the variation can be greater than 100%. This method can be directly applied to time history analysis of structures using existing computer software to determine the peak responses without carrying out the analyses for all possible incident angles. It can also be used to verify and/or modify aseismic designs by using response spectrum analysis.     

锥形聚晶金刚石复合片和可旋转切削齿技术简介

PDC钻头有着较高的钻进效率,一直受到客户们的青睐,但它受所钻地层、孔深和温度等因素的制约,使得钻头切削齿寿命较低。最近几年,国内外专家针对如何提高切削齿性能开展了诸多研究,并取得了不少成绩。主要介绍了美国史密斯钻头的2项最新PDC切削齿技术——锥形聚晶金刚石复合片和ONXY 360旋转切削齿。实钻试验表明,采用这2种新型切削齿技术的PDC钻头,钻进效率和寿命都有了明显提高。     

倾角传感器在并联机器人精度检测中的应用

为了减少目前并联机器人精度检测技术的手动操作环节,提出一种基于倾角传感器的并联机器人旋转精度检测方法。基于倾角传感器和并联机器人的旋转关系进行建模,研究了该旋转矩阵检测的实现原理和算法模型,构建了一套并联机器人旋转检测实验系统。实测实验结果表明,该方法可以有效地检测出并联机器人的旋转精度:x轴和y轴旋转精度检测的均方根误差分别为0.012 3″和0.297 8″;倾角传感器在8 h内x轴和y轴的内符合精度为0.011″和0.014″;x轴和y轴分别漂移了4.5″和8.9″,但是两轴满足高精度测量的要求。     

基于上限法的条形锚板抗拔承载力分析

以极限分析上限理论为基础,利用旋转块体集的组合来构造条形锚板的运动许可速度场。分析了不排水黏土中深埋和浅埋条形锚板的抗拔承载力上限解,研究了锚板在不同埋置倾角和深度条件下的抗拔承载力和破坏面的特性,并将计算结果与已有计算方法进行了对比。分析结果表明：在不排水黏土中深埋条形锚板抗拔承载力与锚板的埋置方位和锚板的粗糙度无关,但完全光滑条件下破坏面扇圆部分的半径只有完全粗糙条件下的一半;在考虑无重土情况下浅埋条形锚板的抗拔承载力系数随锚板埋深比的增大而增大,破坏面也随埋深比的增加而逐渐扩大。所得上限解与已有文献解答较为吻合,而且求解所得破坏面更为直观,能为工程设计提供参考依据。