琼州海峡南岸海岸动力地貌研究

岬湾相间的琼州海峡南岸在海岸动力条件作用下,岸滩发生侵蚀或堆积,特别是南岸中部的南渡江三角洲沿岸岸滩演变剧烈。该文从海岸动力地貌的角度,对琼州海峡南岸的海岸动力特征、泥沙运动以及岸滩演变进行分析。根据海峡南部三维潮流场数值模拟结果,结合经验公式初步分析潮流引起的泥沙运移速率和方向,得到岸外水域总的泥沙运移趋势为从西向东。根据波浪动力计算分析沿岸泥沙运移,探讨沙质岸滩的动态与地貌演变之间的关系,得出海峡南岸海岸地貌演变与盛行的NE和NNE向风浪有密切关系,岸滩的演变过程主要受制于这两个方向的风浪及其引起的泥沙沿岸运移。     

Study on Current-Random Wave Forces Acting on a Framework

—The forces of random wave plus current acting on a simplified offshore platform(jacket)mod-el have been studied numerically and experimentally.The numerical results are in good agreement withexperiments.The mean force can be approximated as a function of equivalent velocity parameter and theroot-mean-square force as a function of equivalent significant wave height parameter.     

长江中下游成矿带三维S波速度结构及对深部过程的约束

利用73个固定台站记录的163个远震事件数据,采用多道互相关技术挑选了5524条S波到时数据,并对S波到时数据进行地壳校正,在此基础上采用天然地震层析成像方法和远震S波到时信息,获得了长江中下游成矿带上地幔的三维S波速度结构模型.研究结果表明:(1)研究区域上地幔存在着明显的低速异常,且走向与成矿带相同,可能为上涌的软流圈热物质;(2)研究区域地幔过渡带和上地幔底部存在着明显的高速异常,可能为俯冲的古太平洋板块和拆沉的岩石圈;(3)成矿带上地幔的低速异常呈现由南向北逐渐变浅的空间分布特征,该特征表明软流圈热物质由南向北上涌.综合分析认为,成矿带中生代大规模岩浆活动和成矿作用的深部过程主要与岩石圈的拆沉密切相关.     

Types and genesis of manganese oxide ores in Guangxi, Southwest China

Systematic studies are diven to the genesis and spatial distribution of manganese oxide deposits in Guangxi,Southwest China.The deposits are classified as 3 types and 7 subtypes among which the karst depression type is regionally characteristic an of reat potential.A genetic model is presented for the mineralization on the basis of proto-rock,tectonic background,topographic features and climatic and hydrogeological conditions.     

绿水洞煤矿煤层(成)气赋存与地质条件的关系

依据绿水洞矿井地质构造和煤层构造变形特征,对该矿煤层(成)气赋存运移规律进行了系统的分析,就该矿生产中煤层(成)气涌出及可能产生的动力现象进行了地质评价,认为在矿井深部仍存在沿岩层裂隙和溶洞发生煤层(成)气涌出的可能,田湾向斜东翼为全井田煤层(成)气突出危险程度最高的区域。      

水-岩作用的线性规划模型与应用研究——以溪洛渡水电工程为例

采用水-岩作用热力学模拟的方法,以溪洛渡水电站工程为实例,从水化学方面对坝区复杂水文地质条件作了定量分析评价。研究成果充分反映了水-岩作用这种物理化学反应的结果,同时也为正确评价溪洛渡水电站复杂水文地质条件提供了可靠的依据。     

根据三斜距确定点的三维坐标及精度

本文绘出一种根据三斜距解算点的三维坐标的直接方法,无需初值、迭代及多值判断,非常适合计算机编程;给出的实用精度估算式能方便地实现根据三斜里估算待定点三维点位精度之目的;对其应用条件的讨论,提出了应用中的具体倾角限值,对指导实际工作具有重要意义。     

ESTIMATION OF ARTIFICIAL PRECIPITATION ENHANCEMENT RESOURCE CONDITION AND CLOUD SEEDING POTENTIAL BY GROUND-BASED REMOTE SENSING DATA*

In this paper,the data of continuous atmospheric vertical integral vapour and liquid water content during April-June of 1992-1994 obtained by a ground-based dual-channel microwave radiometer are used to analyse the statistical characteristics of atmospheric vapour and liquid water content,and the relative distribution characteristics of vapour and liquid water content in cloudy atmosphere,the correlative relation of integral liquid water content L and ground precipitation intensity I.and precipitation transform rate of precipitation system.Finally,the weather modification condition of precipitus stratiform clouds and seeding potential is analyzed and discussed.     

降雨年际气候变化的非线性动力统计模拟预测

文中应用非线性动力统计方法来模拟降水年际气候变化。经过对中国４２ 个测点近百年降雨变化的模拟预测检验,取得了较好的效果,并得出了一些有意义的结论。关键词：非线性,动力统计,模拟预测。     

Analysis of the Dynamic Performance of an Underground Excavation in Jointed Rock under Repeated Seismic Loading

Results from field observations of dynamic behaviour of an underground excavation have been compared with numerical studies of the rock deformation history. The field behaviour shows progressive accumulation of rock displacement and excavation deformation under successive episodes of dynamic loading. It is possible to reproduce the modes of rock response quite well using a Distinct Element model of the rock mass, but the way displacements develop is dependent on the joint model used in the analysis. It is suggested that, in rock masses subject to repeated dynamic loading, excavation design may need to take account of the prospect of repeated episodes of transient loading at the excavation site.