多源异构土地利用数据的建库方案探讨

随着国土资源信息化建设的快速发展,各地积累了大量的土地利用数据及其变更数据,对这些海量数据的管理和使用,使得多源异构土地利用数据的集成成为当务之急。本文结合建库工作实际,简要介绍了多源异构土地利用数据存在的问题、整合建库的技术方案以及质量控制方案。     

国家速滑馆动态高精度施工测量关键技术及应用

国家速滑馆建筑结构在空间上的不规则性、多样性、复杂性及超大规模给施工测量带来较大的难度,因此,加强对动态高精度测量技术的研究和应用,是实现施工过程各专业、各环节高精度搭接的重要基础.国家速滑馆动态高精度施工测量关键技术解决了不均匀作用力下大跨度马鞍形索网同步张拉困难的技术难题;突破了特大异形柔性结构屋顶预制、安装和调控...     

我国风能资源的初步研究

本文用平均风速和平均最大风速确定风速韦伯分布参数k、c,并根据k、c计算了全国165个测站的理论风能的各种特征量,分析了风能特征量的分布规律,指出:我国风能资源以内蒙地区,渤海湾沿岸、东南沿海、东北平原、青藏高原等地为最丰富,四川盆地、塔里木盆地为最小;风能资源随高度升高先是迅速增加,而后逐渐减慢。     

压力注浆液地下作用机理

介绍了压力注浆液的性能和要求;根据不同地质条件下注浆工艺的不同,建立了各自的数学模型;并在实践中得到应用和验证。     

单片机控制交流稳压器

阐述了以89C2051单片机为核心的交流稳压器的设计原理,介绍了一种高精度的电网电压测量电路。     

The application of rock mass classification systems to underground excavation in weak limestone, Atatürk dam, Turkey

The Atatürk dam was built across the Firat River on clayey limestone. A grout curtain, providing impermeability in the left and right abutments, was done in grouting galleries. The well known rock mass classification systems for tunneling purposes [rock structure rating (RSR), rock mass rating (RMR) and rock mass quality index (Q)] were used to classify the rock mass along these galleries. Based on RSR, RMR and Q values, the rock masses in the galleries have been classified into three different classes. Correlation between the three classification systems is discussed and suggestions are made for using rockbolt, shotcrete with wiremesh and steel ribs for supporting the rock mass.     

过去20年矿床事业发展的概略回顾

文章概略回顾了过去20年在找矿和成矿理论研究方面获得的若干重要成就。指出这一阶段虽在一些国家存在矿业不景气，但找矿进展，特别是金、铜矿床、仍很出色。矿业中国都强调了超大型矿床的重要性。在成矿理论方面，主要就多样复杂的海底成矿，三大巨型成矿域，成矿模式，中酸性岩浆岩及有关成矿作用，层控矿床，同位素、微量元素及气液包裹体运用于成矿等问题的研究历史作了回顾。     

Experimental Research of Gas Hydrate Drilling Fluids Using Polyethylene Glycol as an Inhibitor

INTRODUCTION Gas hydrate is anice-like crystal compound gen-erally formed by water and natural gas molecules ,whichis mainly distributed under the oceanfloor andin the permafrost andis viewed as an energy resourcewith great potential (Jiang et al .,2002) .For the rel-ative exploration and development of gas hydrate inChina ,some specialists and scholars have suggestedthat relative test drilling exploitation should be donein the permafrost (Liu,2005 ; Li and Geng,2000) .Drillingin the per…     

基于Fisher判别法的台风暴雨泥石流预测模型

对台风暴雨泥石流发生的可能性进行定量预测,有助于减少危险区内的人员伤亡、降低经济损失。以台湾地区南投县陈有兰溪流域的47条泥石流沟为研究对象,从泥石流形成所需的地形地貌、物源和降雨条件中,初步选取台风暴雨泥石流发生的影响因子,包括沟床平均坡度、有效流域面积、形状系数、主沟长度、岩性、崩滑比和平均雨强。根据因子重要性排序结果,选择崩滑比和平均雨强作为模型的预测因子,基于Fisher判别法建立了台风暴雨泥石流预测模型。采用随机取样技术,选取70%的数据用于构建模型,剩余30%的数据用于验证模型。以精确度、准确率、漏报率和误报率指标,定量评价模型的预测效果,并确定最优的预测模型。结果表明:基于Fisher判别法构建的台风暴雨泥石流预测模型,综合考虑了泥石流形成所需的物源条件和降雨条件,弥补了降雨阈值模型仅依靠降雨资料分析的不足,预测效果更好。     

Effect of Agents on Hydrate Formation and Low-Temperature Rheology of Polyalcohol Drilling Fluid

In order to ensure safe drilling in deep water and marine gas hydrate bearing sediments,the needed characteristics of drilling fluid system were analyzed.Moreover,the effect of different agents on hydrate formation and the low-temperature rheology of designed polyalcohol drilling fluid were tested,respectively.The results show that clay can promote gas hydrate growth,while modified starch and polyalcohol can inhibit hydrate formation to some extent,and PVP K90 has a good performance on hydrate inhibition.Th...