利用Lageos 1 SLR资料解算1990-2001年的地球定向参数     

ZHU Yuanlan FENG Chugang ZHOU Yonghong 《中国科学院上海天文台年刊》2003,(1)

利用 12年的Lageos 1卫星激光测距资料 (1990 - 2 0 0 1)解算得到了地球定向参数 (EOP) ,将该序列的结果与同期的EOP(IERS)C0 4进行比较 ,其外符精度为 :极移XP— 0 .4 0mas,YP— 0 .4 2mas ,日长变化Dr— 0 .0 35ms。  相似文献   

Reliability assessment of granular filters in embankment dams     

Roberto Mínguez  Fernando Delgado  Ignacio Escuder  Manuel G. de Membrillera 《国际地质力学数值与分析法杂志》2006,30(10):1019-1037

Empirical criteria have been used successfully to design filters of most embankment large dam projects throughout the world. However, these empirical rules are only applicable to a particular range of soils tested in laboratory and do not take into account the variability of the base material and filter particle sizes. In addition, it is widely accepted that the safety of fill dams is mainly dependent on the reliability of their filter performance. The work herein presented consists in a new general method for assessing the probability of fulfilling any empirical filter design criteria accounting for base and filter heterogeneity by means of first‐order reliability methods (FORM), so that reliability indexes and probabilities of fulfilling any particular criteria are obtained. This method will allow engineers to estimate the safety of existing filters in terms of probability of fulfilling their design criteria and might also be used as a decision tool on sampling needs and material size tolerances during construction. In addition, sensitivity analysis makes possible to analyse how reliabilities are influenced by different sources of input data. Finally, in case of a portfolio risk assessment, this method will allow engineers to compare the safety of several existing dams in order to prioritize safety investments and it is expected to be a very useful tool to evaluate probabilities of failure due to internal erosion. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

胶东“玲珑-焦家式”金矿资源潜力与找矿   总被引：1，自引：1，他引：0  

李士先  王建收 《山东国土资源》2006,22(12):36-41

“玲珑焦家式”金矿的成岩成矿,从新太古代至中生代存在着继承性的成因关系,成矿具有长期性、多源性特点,但中生代燕山早期岩浆活动是主导成矿因素。区域化探成果显示胶东金矿直接矿源岩———郭家岭花岗岩金的丰度比原始矿源岩———早前寒武纪变质沉积岩系及侵入岩系金的丰度低1/2。郭家岭花岗岩面积在2 km2以上岩体定量估计金亏损总量与胶东金矿总量预测的资源量相当,从一个侧面展现了胶东金矿资源的潜力。望儿山金矿的找矿实践展示,焦家式金矿在1 000 m以下尚有巨大潜力,整个胶东金矿产区在3 000 m以上的资源潜力应在5000 t以上。  相似文献   

上扬子地台震旦系铅锌矿床类型及找矿方向   总被引：13，自引：0，他引：13  

齐文  侯满堂  王根宝 《地球科学与环境学报》2006,28(2):30-36

上扬子地台含铅锌矿地层主要为震旦系。震旦系在上扬子地台主要发育上统灯影组,次有下统陡山沱组。将上扬子地台震旦系铅锌矿床成因划分为一级为叠生矿床,二级为层控矿床,三级为热水沉积改造矿床和热水沉积再造矿床四级类型,该类型按铅锌比例进一步划分为富铅型、富锌型、铅锌共生型。研究区内最重要的铅锌矿床成因类型为南郑马元、会东大梁子铅锌矿为代表的富锌型。陕西南郑、紫阳—镇坪地区,湖北武当、神农架、黄陵地区,以及地台西缘的安宁河、甘洛—小江、峨边—寻甸等地区的震旦系是寻找铅锌矿的最有利地段。  相似文献   

应用ATA的对数周期馈源方案于FAST的可能性探讨     

吴盛殷  熊继衮  吕善伟  张江林  徐祥  南仁东  金乘进 《天文学进展》2004,22(2):179-187

介绍应用于美国凤凰计划的Allen望远镜阵(ATA)的对数周期馈源(LPA)概况，初步给出此种馈源的基本参数及性能，仿真估算了其驻波比和方向图，并结合正在进行中的我国500m孔径球面射电望远镜(FAST)计划，探讨了应用这种宽带馈源的可能性及其限制。  相似文献   

显性语法知识传授中的发现原则     

PatMoore 《成都信息工程学院学报》2002,17(4):289-299

尽管语法在交际教学法鼎盛时期一度遭到冷遇，但现在又重新被英语语言教学所接纳，作为一种新的语法教学方式，发现原则综合了传统归纳发和演绎法的长处，概述了发现原则的理论依据，指出发现原则旨在鼓励学习者积极参与而非被动接受，符合当前认知主义对二语学习的认识。  相似文献   

2D/3D Dust Continuum Radiative Transfer Codes to Analyze and Predict VLTI Observations     

I. Pascucci  Th. Henning  J. Steinacker  S. Wolf 《Astrophysics and Space Science》2003,286(1-2):113-118

Radiative Transfer (RT) codes with image capability are a fundamental tool for preparing interferometric observations and for interpreting visibility data. In view of the upcoming VLTI facilities, we present the first comparison of images/visibilities coming from two 3D codes that use completely different techniques to solve the problem of self-consistent continuum RT. In addition, we focus on the astrophysical case of a disk distorted by tidal interaction with by-passing stars or internal planets and investigate for which parameters the distortion can be best detected in the mid-infrared using the mid-infrared interferometric device MIDI. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Characters of the Pco2 and CO2 Flux in the East China Sea in Autumn     

纪雷  崔鹤  辛淑平  王军  张龙军  陆贤昆 《中国海洋湖沼学报》2003,21(2):180-186

Pco2 of air and seawater samples from the East China Sea(ECS) were measured in situ in autumn, 1994,Ocean currents,terrestrial fluviation,biological activities,etc.,Pco2 char-acters in air and seawater were investigated,CO2 flux and its character in the East China Sea are discussed on the basis of the Pco2 profiles of air and seawater,It was clear that the nearshore was the source of CO2;and tht the oulter sea area was the sink of CO2; and that the shelf area of the EXS is a net sink for atmospheric CO2 in autumn.  相似文献   

基于RDBMS的积件技术的应用研究     

李毅心 《成都信息工程学院学报》2006,21(2):206-209

积件技术是教学软件发展的方向，探讨了用Power Builder前台结合SQL Server关系数据库后台进行多媒体教学积件管理的应用模式，并结合具体教学示例，进行了分析说明。  相似文献   

The O4f + O6V eclipsing binary system Sk−67°105 in the Large Magellanic Cloud     

Pablo G. Ostrov  Emilio Lapasset 《Monthly notices of the Royal Astronomical Society》2003,338(1):141-146

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