浅谈海缆追踪系统及其应用     

王艳  曾亮 《地球物理学进展》2012,27(1):386-391

海底电缆的监测和维护已成为海洋工程勘察的一个重要组成部分,其精确跟踪定位更是世界性难题.文章首先对比分析了3种海缆追踪方法及相应的商业化系统,接着详细论述了有源系统TSS350国内首次对高压海缆的追踪应用效果.海缆追踪系统在国外小电流及断点电缆追踪上的成功应用已经证明了系统的性能;而国内湛江高压电缆实验高精度的路由追踪和埋深定位又为海缆追踪系统开辟了更广泛的应用空间.海缆追踪系统的原理、技术指标及其应用为国内海缆的监测和维护提供了解决办法,也为弥补国内研究空白提供了方法基础.  相似文献   

Prediction of railway ground vibrations: Accuracy of a coupled lumped mass model for representing the track/soil interaction     

《Soil Dynamics and Earthquake Engineering》2015

Recent advances in railway-induced ground vibrations showed that the track/soil interaction plays an important role in the low frequency range. This paper contributes to the numerical analysis of train/track/foundation dynamics by presenting the accuracy of a coupled lumped mass (CLM) model devoted to the railway foundations and to the track/soil coupling. Following a summary of the background and the advantages of the CLM model, the coupling strategy is quantified through two application cases. Firstly, the dynamic track deflection is calculated for different railway lines considering various degrees of complexities of foundations. Then, the foundation responses are compared depending on whether detailed coupling is introduced or not. The benefit of the proposed model is emphasized by presenting free-field ground vibration responses generated by a tram and a high-speed train, obtained by a revisited two-step prediction model developed by the authors.  相似文献   

Coupling the k-nearest neighbor procedure with the Kalman filter for real-time updating of the hydraulic model in flood forecasting   总被引：2，自引：0，他引：2  

《国际泥沙研究》2016,(2):149-158

  相似文献   

Propagation of electromagnetic waves from an induction source in media with time-dependent conductivity and permittivity     

A.A. Dolgun  E.P. Shurina  M.I. Epov 《Russian Geology and Geophysics》2009,50(11):983-990

Electromagnetic wave propagation from an induction source (a transmitter coil) in media with time-dependent conductivity and permittivity is simulated using the vector finite-element method. A special algorithm is suggested for source approximation.  相似文献   

Evaluation of a Model for Predicting Simultaneous Contrast on Color Maps     

《The Professional geographer》2013,65(3):280-294

Perceptions of colors of individual map symbols are affected by simultaneous contrast, or induction, from surrounding colors. In an experiment with human subjects, reaction times were significantly slower, with significantly more errors, for test maps on which an induction model predicted that colors would be misinterpreted. Reaction times and error rates improved significantly with map color adjustments that the model predicted would remove induced confusions. These results represent progress toward establishing objective guidance for the design of effective color schemes in computer-assisted mapping environments common in cartography, geographic information systems, and scientific visualization.  相似文献   

Electromagnetic induction prediction of soil salinity and groundwater properties in a Tunisian Saharan oasis     

F. Bouksila  M. Persson  A. Bahri  R. Berndtsson 《水文科学杂志》2013,58(7):1473-1486

Abstract

Electromagnetic induction measurements (EM) were taken in a saline gypsiferous soil of the Saharan-climate Fatnassa oasis (Tunisia) to predict the electrical conductivity of saturated soil extract (ECe) and shallow groundwater properties (depth, Dgw, and electrical conductivity, ECgw) using various models. The soil profile was sampled at 0.2 m depth intervals to 1.2 m for physical and chemical analysis. The best input to predict the log-transformed soil salinity (lnECe) in surface (0–0.2 m) soil was the EMh/EMv ratio. For the 0–0.6 m soil depth interval, the performance of multiple linear regression (MLR) models to predict lnECe was weaker using data collected over various seasons and years (R _a ² = 0.66 and MSE = 0.083 dS m^-1) as compared to those collected during the same period (R _a ² = 0.97, MSE = 0.007 dS m^-1). For similar seasonal conditions, for the Dgw–EMv relationship, R ² was 0.88 and the MSE was 0.02 m for Dgw prediction. For a validation subset, the R ² was 0.85 and the MSE was 0.03 m. Soil salinity was predicted more accurately when groundwater properties were used instead of soil moisture with EM variables as input in the MLR.

Editor D. Koutsoyiannis; Associate editor K. Heal

Citation Bouksila, F., Persson, M., Bahri, A., and Berndtsson, R., 2012. Electromagnetic induction predictions of soil salinity and groundwater properties in a Tunisian Saharan oasis. Hydrological Sciences Journal, 57 (7), 1473–1486.  相似文献   

层状各向异性地层中三维感应测井响应快速计算及资料处理   总被引：3，自引：1，他引：2       下载免费PDF全文

肖加奇  张国艳  洪德成  杨善德 《地球物理学报》2013,56(2):696-706

本文采用广义反射系数法推导了水平层状各向异性地层中电磁场的积分解析解,并利用快速汉克尔变换技术实现了三维感应仪器测井响应的快速计算.三维感应测井响应与地层水平电导率、垂直电导率和井斜角及仪器方位角同时有关,单一分量的测井曲线不能满足资料解释的需要.通过对仪器测量分量响应特征的考察,本文提出了一种基于组合量测井曲线的资料直观解释方法.数值模拟显示,交叉分量相关组合量可准确划分地层纵向边界,并可直观识别各向异性层;与单独分量相比,主分量相关组合量提高了纵向分辨率、减弱了与地层电导率参数的非线性关系.  相似文献   

Induction of tributyltin-binding protein type 2 in Japanese flounder, Paralichthys olivaceus, by exposure to tributyltin-d27     

Nassef M  Tawaratsumita T  Oba Y  Satone H  Nakayama K  Shimasaki Y  Honjo T  Oshima Y 《Marine pollution bulletin》2011,62(2):412-414

In this study, individual Japanese flounder were intraperitoneally injected with 2 μg tributyltin-d27 (TBT-d27) fish⁻¹. Blood samples were collected on day 7 after injection. TBT-binding protein types 1 and 2 (TBT-bp1, -bp2) in the blood serum were quantified by western blotting analysis. As a result, the concentration of TBT-bp2 in TBT-d27 treated group increased to 220% of that in the solvent control, whereas the TBT-bp1 concentration decreased to 65% of that in the solvent control. Additionally, a positive relationship between the concentrations of TBT-bp2 and TBT was observed in blood sera of wild and cultured flounder. We suggest that TBT-bp2 is produced in response to TBT exposure and may play an important role in fish physiology.  相似文献   

Low induction number, ground conductivity meters: A correction procedure in the absence of magnetic effects     

David Beamish 《Journal of Applied Geophysics》2011,75(2):244-253

Ground conductivity meters, comprising a variety of coil–coil configurations, are intended to operate within the limits provided by a low induction number (LIN), electromagnetic condition. They are now routinely used across a wide range of application areas and the measured apparent conductivity data may be spatially assembled and examined/correlated alongside information obtained from many other earth science, environmental, soil and land use assessments. The theoretical behaviour of the common systems is examined in relation to both the prevailing level of subsurface conductivity and the instrument elevation. It is demonstrated that, given the inherent high level of accuracy of modern instruments, the prevailing LIN condition may require operation in environments restricted to very low (< 12 mS/m) conductivities. Beyond this limit, non-linear departures from the apparent conductivity that would be associated with a LIN condition occur and are a function of the coil configuration, the instrument height and the prevailing conductivity. Using both theory and experimental data, it is demonstrated that this has the potential to provide biased and spatially distorted measurements. A simple correction procedure that can be applied to the measured data obtained from any of the LIN instruments is developed. The correction procedure would, in the limit of a uniform subsurface, return the same (correct) conductivity, irrespective of the ground conductivity meter used, the prevailing conductivity or the measurement height.  相似文献   

急流在梅雨期持续暴雨过程中的作用   总被引：11，自引：6，他引：5  

赵娴婷  魏建苏  朱定真 《气象科学》2011,31(2):211-216

本文利用实况资料和客观分析资料,对造成江苏2010年7月9-14日的暴雨过程中高低空急流特点、配置及对暴雨的影响进行了分析.结果表明:高空动量下传,引起低空扰动加强,从而使得低空急流加强和维持.低层高能的平流为江苏境内暴雨和大暴雨的产生提供了充足的能量.低空西南风急流是暴雨产生的重要因子,仅在700 hPa出现强劲西南风急流,就可以导致江苏境内的强降水发生.分析还表明:阶段性暴雨起始的时候,暴雨落区上方都出现了负散度和正散度相互交错的情况,直至6h后才有高空辐散低空辐合的典型形势.高低层急流配置和次级环流的维持为暴雨的持续提供了有利条件.  相似文献