Research Progress in Cenozoic N-S Striking Rifts in Tibetan Plateau

The formation of the Cenozoic N-S striking rifts in the Tibetan Plateau is the consequence of continuous contraction after the India-Asia collision. Its formation and evolution are of great significance for understanding the growth of the Tibetan Plateau. In recent years, geochronology, structural geology, geochemistry and geophysical exploration have been used to study the onset timing, mechanism and evolution process of the N-S striking rifts, and the N-S striking rifts are related to the deep dynamics in Tibet. However, it is still difficult to reach a consensus on the understanding of the N-S striking rifts in the Tibetan Plateau. This paper summarized the research status and existing problems on the onset timing, mechanism and their relationship with the deep layer of the plateau: the main extension period of the N-S striking rifts is Miocene; mechanisms controlling its formation are complex and may be various in different periods; the N-S striking rifts have a close genetic relationship with potassium and ultrapotassic rocks in the plateau, and their distribution may be affected by high-conductivity and low-velocity bodies. Based on existing knowledge, more precise geochronological constraints, deep process detection, and numerical modeling will be the future development trends in the study of N-S striking rifts.     

Some aspects of cast blasting techniques for dam construction

Summary A proposal is under consideration to construct a dam on an experimental basis by a cast (or directional) blasting technique, DBT. The dam site is located at Bharari Khad, a tributary of the Sutlaz river in Himachal Pradesh. Site investigations have been completed and a large scale blast has been designed for construction of the experimental dam.The paper describes the basic design concept of DBT and application of throw and caving methods for construction of dams. The preliminary tests required to design the blasting pattern are detailed. The technique has a great potential because it reduces construction cost and time particularly in inaccessible mountain regions.     

盾构施工地面长期沉降的神经网络预测

基于逆传播人工神经网络方法，建立了盾构施工地面长期沉降的非线性预测模型，建立了沉降与诸多影响因素：所处位置、时间、上覆土性参数及盾构施工参数等的关系模型。通过在上海地铁2号线龙东路一中央公园站区间资料的验证，发现与实际比较吻合。     

吉林省城市生态建设现状评价及对比分析

建设生态经济城市是吉林省建设生态省过程中的一项重要内容,对我省国民经济和社会发展具有重要作用和意义。本文针对吉林省各主要城市生态建设的基础条件和实际情况,采用层次分析方法构建了包含生态经济、生态环境、社会发展3个子系统32个评价指标因子在内的评价指标体系。应用模糊综合评判法和综合指数法对吉林省9个主要城市从经济水平、产业结构等方面进行了生态建设现状评价,从而为城市生态建设规划等科学决策提供理论依据。     

沃西大桥挂篮施工放样测量

结合浙江省新昌县沃西大桥的施工实际,提出了挂篮放样方法,监测了挂篮在施工过程中的高程变化,确保了大桥施工的顺利进行。     

开拓进取再创辉煌--武汉大学遥感信息工程学院建设发展思考

回顾了武汉大学遥感信息工程学院近几年来在遥感科学与技术新专业设置、科研建设成果、教学改革、教材建设和人才培养等方面的情况，介绍了摄影测量与遥感重点学科今后三年的建设目标和发展方向。     

上海城市三维景观模型的制作

通过实践分析了城市三维建模技术的现状，并提出了在数字城市建设中城市三维建模的要点以及今后的研究方向。     

Filtrate Quality from Different Filter Operations

A brief review of the literature on filtrate quality obtained in constant and variable declining rate operation systems is presented, with the general conclusion that both systems usually produce filtrate of similar quality, assuming the flow‐rate controllers in the constant flow rate system operate properly. A mathematical model of CR (constant rate) filters and VDR (variable declining rate) filters based on the model by Mackie and Zhao (1999) has been described and used to investigate filtrate quality under different operating conditions. A similar quality of filtrate was achieved in computations carried out for both modes of operation, while the total head loss was much lower in the VDR mode. For the same time of filter runs slightly better filtration quality resulted from CR operation, but for different filter runs resulting from the same head loss of flow just before a backwash, the VDR control system produced lower turbidity filtrate.     

南海东北部海陆联测与海底地震仪探测

利用三分量海底地震仪、陆上便携式地震仪和海上气枪震源在南海东北部首次进行了海陆联合的深地震探测,测线呈北北西-南南东方向,垂直于区域构造走向,总长达500km,所获得的数据质量好,深部信息丰富,可分辨出Pg、Pn、PmP等地震相,为南海东北部深部地壳结构及油气盆地形成演化的研究提供了重要的基础数据。     

汪清7.2级深震与黑龙江省及其临近地区地震活动趋势分析

20世纪以来，东北地区7级以上强深震与东北地区浅源中强地震活动在时间上表现出很强的相关性。认为汪清7．2级强深震后，黑龙江省及邻区发生5级以上中强震的危险性增大。