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。     

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。     

Determination of Partial Factors of Breast Wall on Top of Sloping Breakwater

- By applying the theory of structural reliability, reliability analyses for the stability of a breast wall on the top of a sloping breakwater are carried out. Based on the analyses, the method for determining partial action / load factors and partial resistance factors of breast walls is expounded, and the design expressions with partial factors are given. The values of partial action / load factors and partial resistance factors are recommended preliminarily according to the computation for breast walls with typical cross-sections.     

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     

无粘性泥沙起动条件对比研究

从泥沙起动的已有研究成果出发,推导出常见的3种泥沙起动条件的转换关系.利用这些关系,将国内外现有的几十种泥沙起动条件进行了统一,可得各种公式的K值一般在337～786之间.为合理选用起动公式提供了依据.在此基础上,用韩其为1965年在岷江五通桥茫溪河进行的卵石起动的野外水槽试验资料与一部分经典公式计算结果进行了对比研究.为岷江都江堰河段合理选用卵石起动公式提供了依据.     

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。     

4种荒漠植物的抗氧化系统和渗透调节的季节变化

研究了塔克拉玛干沙漠南缘4种荒漠植物的水势、渗透调节物质和抗氧化系统的季节变化。结果表明,4种荒漠植物的清晨水势和午后水势的最低值出现在7月,最高值出现在6月,说明在此区域,6月植物的水分状况相对较好,7月植物的水分状况最差。骆驼刺的MDA含量和活性氧（O-2和H2O2）积累随着季节变化均呈上升趋势,表明骆驼刺的膜脂过氧化和膜伤害随季节推进逐渐加剧;柽柳、花花柴和沙拐枣的MDA含量和活性氧积累最高峰值分别出现在7月、7月和8月,说明在水分亏缺最严重的7月和8月,植物面临的膜脂过氧化程度亦最高。4种植物的渗透调节物质积累和抗氧化酶活性的变化,与膜脂过氧化几乎同步。其中,柽柳是以脯氨酸和可溶性糖两者的积累来调节细胞质渗透势以适应极端环境,脯氨酸的积累是沙拐枣应对水分胁迫的主要物质之一,骆驼刺是以可溶性糖的积累来应对水分亏缺,花花柴这两者含量都不高,分析可能是以无机离子作为渗透调节物质。4个月SOD、POD和CAT活性的均值排序均为柽柳>沙拐枣>骆驼刺>花花柴,说明在整个生长季中,柽柳的活性氧积累最为严重,其保护酶SOD、POD和CAT对活性氧的清除均起到关键作用。     

Evaluation of total load sediment transport formulas using ANN

The calculated results from various sediment transport formulas often differ from each other and from measured data. Some parameters in the sediment transport formulas are more effective than others to estimate total sediment load. In this study, an Artificial Neural Network （ANN） model is trained using four dominant parameters of sediment transport formulas. ANN models are able to reveal hidden laws of natural phenomena such as sediment transport process. The results of ANN and some total bed material load sediment transport formulas have been compared to indicate the importance of variables which can be used in developing sediment transport formulas. To train ANN, average flow velocity, water surface slopes, average flow depth, and median particle diameter are used as dominant parameters to estimate total bed material load. Two hundreds and fifty samples are used to train the ANN model. Twenty-four sets of field data not used in the training nor calibration of ANN are used to compare or verify the accuracy of ANN and some well-known total bed material load formulas. The test results show that the ANN model developed in this study using minimum number of dominant factors is a reliable and uncomplicated method to predict total sediment transport rate or total bed material load transport rate. Results show that the accuracy of formulas in descending order are those by Yang （1973）, Laursen （1958）, Engelund and Hansen （1972）, Ackers and White （1973）, and Toffaleti （1969）. These results are similar to those made by ASCE （1982） based on laboratory and field data not used in this paper. Study results also show that the formulas based on physical laws of sediment transport, like those formulas that were developed based on power concept, are more accurate than other formulas for estimating total bed material sediment load in rivers.