论岩体表征单元体积REV岩体力学参数取值的一个基本问题

本文论述了岩体力学性质的尺寸效应,提出了与岩体弹性参数相应的表征单元体REV的力学描述,根据中心极限定理推导了估算裂隙岩体REV 的数学表达式。研究表明,岩体表征单元体的大小是岩体力学性质尺寸效应的客观反映。本研究成果为合理选取岩体力学参数提供了一条新途径。     

基于水库气枪震源数据的频域水准比例因子反褶积方法分析

基于2016年福建南一水库气枪实验资料,利用频率域水准因子反褶积方法和互相关时延检测技术,研究水准比例因子及台站的背景噪声水平对反褶积计算结果的影响,并对反褶积法消除不同枪压引起的震源影响效果进行分析。结果表明:(1)水准比例因子越小,反褶积计算后的波形信噪比越小,当水准比例因子取值过小时,走时识别误差较大;(2)台站气枪记录的信噪比越大,走时识别精度越高,参考台记录的信噪比对结果的影响远大于远场台,当远场台记录的信噪比大于10时,走时误差一般小于6ms,而当参考台记录的信噪比为30左右时,走时误差可能达到20ms;(3)气枪震源差异较大时,频域水准反褶积方法去除震源效应的效果较好,而在震源差异较小时,可能引入方法误差。     

地震台站噪声水平定量评估及其在气枪源探测中的应用

对福建气枪源探测实验中所接入315个实时传输台站分1~10 Hz、0.1~1 Hz、10~60 s 3个频段进行台网噪声水平评估研究。统计240个小时的背景噪声记录,得到各台站的噪声水平MODE线,再利用本文提出的全球新高低噪声模型线与MODE线所占面积比来量化台网噪声水平,根据不同色标将台网噪声水平划分为十个等级进行评估,评选出优质台站。进一步研究背景噪声对气枪激发效果的影响,验证了台站接收能力与背景噪声密切相关,分析了不同台基（固定、加密、流动、海底）环境噪声水平的影响,得出环境噪声水平由低到高分别为固定台、加密台、流动台、海底台。通过台网噪声评估能有效提高气枪震源信号的检测能力,也为优质台站重点维护提供重要参考。     

Threshold for initiation of motion of unimodal and bimodal sediments

Experimental data,obtained from previous studies,on Critical Tractive Stress(CTS) of non-uniform sediments, have been used to verify the adequacy of existing relationships for CTS of non-uniform bimodal sediments.Keeping in view the performance of such relationships,a new relationship for computation of dimensionless CTS of individual size fraction of non-uniform unimodal and bimodal sediments has been proposed in the form of power law.The coefficient and exponent of the proposed power law have been empirically correlated with sediment characteristics for available sediment data.The proposed relationship has been validated with independent flume and field data to assess their applicability for unimodal and bimodal sediments.     

精密弦矢导线法与边角导线法比较浅析

精密导线法分为边角导线法和弦矢导线法，是监测水库拱坝水平位移的重要方法。弦矢导线法是根据导线边工变和矢距变化的观测值来得坝体的实际变形量；边角导线法则是根据导线边长变化和导线的转折角观测值来计算坝体的变形量。比较分析了边角导线法和弦矢导线法的设计原理与设计方法，认为精密弦矢导线法与精密边角导线法相比具有如下优点：（1）复测简单，速度快，劳动强度小；（2）精密高且稳定，不受折光等外界条件影响；（3）便于采用数字化遥测，可为实现位移值计算自动化奠定良好基础。     

Numerical Investigation of Vertical Turbulent Jets in Different Types of Waves

The effects of various types of waves on vertical plane turbulent jets are studied numerically in the paper. A three-dimensional numerical model in σ-coordinate is developed to study these problems by use of large eddy simulation method. Turbulence is modeled by a dynamic coherent eddy model. Numerical results including the distribution of velocity,the decay law of the mean velocity along axis,the turbulent Reynolds stresses and the volume flux per unit width without wave,in the first-order Stokes waves,in ...     

Integration of Real-Time Chemical Sensors for Deep Sea Research

There is a great demand for in-situ real-time chemical sensors in the oceanographic research, to measure the chemical components under the deep sea. The ISE (Ion Selective Electrode) is commonly used as a detecting part of deep-sea electro-chemical sensors. The paper highlights the solidification and micromation of the working and reference electrodes. The sensors of pH and H2S with a thermal probe are accomphshed after the solution of configuration of electrodes and signal processing. The sensor system has been tested successfully in the cruise of DY105-12, 14 sponsored by China Ocean Mineral Research and Exploitation Association(COMRA).     

Test Study on Erosion and Siltation Patterns of Sandy Bottom Before Mound Breakwater Under the Effect of Waves

In this paper, the effect of waves on erosion of the sandy bottom before mound breakwaters is studied. The sandy bottom basically presents two erosion patterns, between which there is a transitional state, under the action of partially standing waves. The two erosion patterns can be determined by dimensionless parameter Us, defined in this paper. The erosion locations, depths and lengths can be estimated by a series of equations presented in the text. Irregular waves are employed in the test besides regular waves, and the effect of the irregular waves can be estimated by the element of equivalent waves, such as T1/3, H1/3.     

X射线岩石CT的历史与现状

采用X射线CT技术无损探测岩石内部结构和裂纹演化过程 ,起源于 2 0世纪 80年代后期 ,由最初对CT图像的认识逐步深化为对岩石裂纹演化规律的分析和应用研究。基于室内岩石试件扫描断面的CT图像 ,目前在岩石变形破坏过程的实时监测、加荷条件多样化、裂纹演化规律性、裂纹宽度的定量测量、岩石裂纹三维图像重建、损伤演化与损伤变量分析、CT成果应用研究等方面取得了一系列进展。岩石CT面临的主要问题是如何获得各种试验条件下精确的CT图像及其成果的应用研究。岩石CT的生命力在于自身理论、技术发展和在相关领域的应用程度     

滇中地区缺水成因分析及对策研究

近年来，滇中地区总需水量日益增加，而供水水源始终不能满足需求，水资源供需矛盾日渐突出，严重制约了该地区经济社会的可持续发展。从多角度分析了滇中地区的水资源紧缺及其缺水成因，根据该地区实际情况，研究了缺水问题的一些对策。