Numerical Simulation of Abnormal Wave Height Change Induced by Excavated Waterway with Boussinesq Equation

A nonlinear numerical model has been set up by use of Boussinesq Equation with finite differ-ence method,and has been applied to the simulation of the abnormal change of wave height induced by ex-cavated waterway.Numerical results demonstrate that the abnormal change of wave height is due to theadding of the reflected wave height induced by excavated waterway to the incident wave height.Becausethe angle between the incident wave and the axis of the waterway is smaller than the critical angle,the re-flected wave produced by the waterway may propagate to the breakwater and may be added with the inci-dent wave,then the abnormal change of wave height before the breakwater may be caused.So the wave re-flection caused by the change of water depth cannot be neglected.     

A Probabilistic Model for Fatigue Crack Propagation Analysis

A simple probabilistic model for predicting crack growth behavior under random loading is pre-sented.In the model,the parameters c and m in the Paris-Erdogan Equation are taken as random variables,and their stochastic characteristic values are obtained through fatigue crack propagation tests on an offshorestructural steel under constant amplitude loading.Furthermore,by using the Monte Carlo simulation tech-nique,the fatigue crack propagation life to reach a given crack length is predicted.The tests are conducted toverify the applicability of the theoretical prediction of the fatigue crack propagation.     

A Study on the Distribution of Wave Phases

Probability distributions of wave phases in association with distributions of surface elevations arestudied with wave records.Wave records of different nature are used for comparison.These are surface fluc-tuations acquired during wind wave flume experiments,representing wave generation under strong wind:andwave records measured in the northern part of Taiwan for waves in natural environments.Three probabilitymodels,the unifrom distribution,the beta distribution,and a model from Tayfun and Lo(1989)are adoptedto study the possible distributions of wave phases.It is found that when surface elevations become skewed,wave phases deviate from the usually assumed uniform distribution and a better model would be the beta dis-tribution.     

全国矿业权实地核查数据采集与信息系统开发建设

全国矿业权实地核查是国土资源部“十一五”期间在矿产资源领域开展的一项基本国情专项调查。主要任务是核实全国范围内的近15万个有效矿业权（不含油气）实际情况与登记数据的一致性,重点核准矿业权实际位置是否在法定许可范围内。该专项由部统一领导,部矿产开发管理司负责。中国地质调查局发展研究中心按照要求承担实地核查工作。     

明长城资源调查与测量综述

由于历史的原因和技术条件所限,我国一直未能实施长城资源的综合科学调查,缺乏关于其空间分布、保存状况、实际长度等方面的科学数据资料。为了摸清明长城“家底”,国家测绘局和国家文物局发挥各自优势,联合开展了长城资源调查与测量工作。按照“文物部门定性、测绘部门定量”的基本策略,提出了“影像为基、立体量测、带状建库”的总体研究思...