哈尔滨市磨盘山水利枢纽区三维渗流数值模拟模型研究

哈尔滨市磨盘山水库防渗型式拟采用垂直砼防渗墙及帷幕灌浆方案。为了分析左岸不同长度防渗对水库渗漏量及坝基渗透稳定性的影响。对磨盘山水利枢纽区渗流场进行了三维数值模拟研究。结果表明，随着左岸防渗长度的增大。渗漏量及下游渗流出口渗透比降基本呈线性趋势减小。当左岸防渗长度为200m时。渗漏量及各渗透比降均小于允许值，为推荐的渗控方案。     

The importance of plant root characteristics in controlling concentrated flow erosion rates

While it has been demonstrated in numerous studies that the aboveground characteristics of the vegetation are of particular importance with respect to soil erosion control, this study argues the importance of separating the influence of vegetation on soil erosion rates into two parts: the impact of leaves and stems (aboveground biomass) and the influence of roots (belowground biomass). Although both plant parameters form inseparable constituents of the total plant organism, most studies attribute the impact of vegetation on soil erosion rates mainly to the characteristics of the aboveground biomass. This triggers the question whether the belowground biomass is of no or negligible importance with respect to soil erosion by concentrated flow. This study tried to answer this question by comparing cross‐sectional areas of concentrated flow channels (rills and ephemeral gullies) in the Belgian Loess Belt for different cereal and grass plant densities. The results of these measurements highlighted the fact that both an increase in shoot density as well as an increase in root density resulted in an exponential decrease of concentrated flow erosion rates. Since protection of the soil surface in the early plant growth stages is crucial with respect to the reduction of water erosion rates, increasing the plant root density in the topsoil could be a viable erosion control strategy. Copyright © 2003 John Wiley & Sons, Ltd.     

Optimal distribution of linear control intensity over the frequency range

In this paper, a control strategy for structural systems is proposed and developed in the frequency domain. The algorithm is substantially based on a linear derivative feedback and a convolution of the control parameter, whose distribution in the frequency field is chosen in such a manner as to comply with the requirements of an ad hoc formulated constrained optimum problem, with the response data monitored until the instant of control action application. Some numerical testing is carried out by referring to given recorded accelerograms, showing a good performance of the proposed approach. Copyright © 2002 John Wiley & Sons, Ltd.     

Comparative study of the inelastic response of base isolated buildings

This article presents a numeric comparative study of the inelastic structural response of base isolated buildings. The comparative study includes the following isolation systems: laminated rubber bearings, New Zealand one, pure friction and the frictional pendulum ones. The study is based on obtaining non‐linear response spectra for various design parameters using six earthquake records. Usually the base isolation of a new building seeks to maintain the structure in the linear elastic range. The response of old weak buildings or the response of new ones subjected to extreme earthquakes may not be, necessarily, in the aforementioned ideal elastic range. Consequently, it is important to characterize the response of isolated buildings responding inelastically. A conclusion from this research is that the isolators affect significantly the structural response of weak systems. Rubber isolators seem slightly less sensitive to plastification that may occur in the structure compared to friction isolators. Ductility demands in the structure are affected significantly by friction and neoprene protected systems, in particular sliding ones where larger demands are obtained. Copyright © 2002 John Wiley & Sons, Ltd.     

液压油污染控制

工程机械液压系统故障大约有70T是由液压油污染引起的，本文阐述了水电施工机械设备液压油的污染对液压系统的影响及如何控制液压油污染，保证其清洁度，从而预防液压系统故障。     

停止开采深层地下水 修复与改善生态环境

沧州市水资源短缺，深层地下水严重超采，已形成大面积区域地下水位降落漏斗，地面沉降已达2m，生态环境严重恶化．为保障经济社会的可持续发展，要积极引调地表水，开发利用地下咸水，加强雨洪控制利用，逐步替代最后终止深层地下水的开采。从根本上修复和改善生态环境。     

防汛信息共享与元数据应用研究

分析了FGDC、CEN／TC287等元数据标准，讨论了基于GIS的防汛信息共享与元数据的应用，设计了防汛信息元数据库，实现了元数据支持下的防汛信息共享。     

空间数据质量相关问题探讨

阐述研究空间数据质量问题的必要性和重要性,进而依据GIS数据流程系统分析了产生数据质量问题的各种因素;并重点介绍了空间数据质量问题中基本的误差和不确定性分析方法以及常用的误差控制与校正方法。     

用于监控多移动目标的电子地图系统

介绍了一种监控移动目标的电子地图系统，该系统利用独特的方法对地图文件进行组织，该方法易于程序管理和查找地图文件，并可动态添加地图文件，系统采用的串口通信方式使用方法灵活，应用简便，实际应用结果表明系统可靠，运行稳定。     

地形图扫描数字化精度分析

本文分析了地形图扫描数字化的误差来源，讨论了误差控制方法及质量控制指标，探讨了成果数据相对于地形原图的位置精度，具有一定实用价值。