Evaluation of residual drift demands in regular multi‐storey frames for performance‐based seismic assessment

This paper summarizes results of a comprehensive analytical study aimed at evaluating the amplitude and heightwise distribution of residual drift demands in multi‐storey moment‐resisting frames after earthquake excitation. For that purpose, a family of 12 one‐bay two‐dimensional generic frame models was subjected to an ensemble of 40 ground motions scaled to different intensities. In this investigation, an inelastic ground motion intensity measure was employed to scale each record, which allowed reducing the record‐to‐record variability in the estimation of residual drift demands. The results were statistically processed in order to evaluate the influence of ground motion intensity, number of stories, period of vibration, frame mechanism, system overstrength, and hysteretic behaviour on central tendency of residual drift demands. In addition, a special emphasis was given to evaluate the uncertainty in the estimation of residual drift demands. Results of incremental dynamic analyses indicate that the amplitude and heightwise distribution of residual drift demands strongly depends on the frame mechanism, the heightwise system structural overstrength and the component hysteretic behaviour. An important conclusion for performance‐based assessment is that the evaluation of residual drift demands involves significantly larger levels of uncertainty (i.e. record‐to‐record variability) than that of maximum drift demands, which suggests that this variability and corresponding uncertainty should be explicitly taken into account when estimating residual drift demands during performance‐based seismic assessment of frame buildings. Copyright © 2006 John Wiley & Sons, Ltd.     

地图的按需印刷和复制

文中论述了按需印刷和复制的概念、应用特点及与传统印刷方式相比的优点。数字印刷是地图按需印刷和复制的技术基础，文中分析了其成像方法和设备情况。指出了地图按需印刷和复制的技术途径及技术难点。     

世界天然气资源的储、产、供需动向及我国的对策

为了积极开拓利用天然气资源的途径,本文分析了世界天然气资源及其供需动向。我国进口天然气的国际资源条件是可能的,价格是有利的。东南沿海地区从东南亚进口液化天然气和从俄罗斯进口管输天然气是经济的、可行的。中东的液化天然气将是潜力较大的进口对象。     

城市地质工作的需求与目标

根据与政府部门大量接触和沟通的亲身体验，在分析市场需求的基础上，提出将城市地质的工作目标作远、近之分，城市地质工作首先要满足近期目标。提出城市地质调查体现了地矿与土地的结合，是地矿行政部门溶入国土资源管理的有效途径的观点。还进一步从基础地质调查、专项或重点调查、城市地质环境监测3方面分析了开展城市地质工作的最有利时机。最后就当前城市地质工作的战略部署提出3点建议。     

长江三角洲地区水资源供需平衡的估算模型研究

从地表热量平衡、水量平衡的基本理论出发,结合长江三角洲地区的气象、水文、土壤等资料建立了区域水资源量估算模型,计算了该地区的地表水、地下水及水资源总量;同时建立了用水系统的各个子模型,即根据本区农业生产状况建立了农业耗水的物理模型,由工业和生活用水量的变化,结合地区经济发展、人口增加等情况,建立了工业和生活用水的统计模型。利用实际资料进行了模型检验,对本地区未来水资源供需平衡状况进行了分析和预测。     

基于生态用水的地下水系统模拟与优化管理模型

通过对地下水系统与生态用水相互作用过程的研究，把生态用水作为重要的用水项目纳入到地下水系统模型考虑范畴，兼顾地下水的经济、环境和生态功能三者统一，在吉林省大安试验区建立了基于生态用水的地下水系统三维模拟与优化管理模型，采用该模型，分别模拟出试验区1998年和1999年地下水系统水资源各项均衡量，并确定了2000年地下水最佳开采利用方案，实现了地下水资源持续讥效利用，取得了良好的经济、生态和社会效益     

Effects of Task Demand and Familiarity with Scenes in Visuospatial Representations on the Perception and Processing of Spatial Information

This study examined the effects of task demand and familiarity on students' perception and processing of spatial information upon viewing visuospatial representations. Participants in South Korea were told that they would travel through an area, either drawing a map or observing the scenery depicted in photographs. The level of familiarity in the photographs was manipulated in three categories: neighborhood, Seoul (capital city of South Korea), and foreign cities. In two experiments, this study investigated students' eye movements, memory, and response sensitivity and bias. The results indicate that the participants in the map-drawing condition focused on structural information, such as routes, and that their memory of the scenes was more accurate. Moreover, the map-drawing group students were more sensitive and prudent in their responses. The increased level of familiarity also made students focus on structural information. The findings provide useful strategies for geography educators to use visuospatial representations.     

鲁西南大气降水与农田需水的供求状况及变化趋势

应用彭曼(Penman)法,并考虑对不同作物发育阶段的订正,估算了鲁西南地区的农田需水量。通过农田需水量与有效降水量差值分析,对二者的供求状况进行了评估。同时还分析了1961～2002年降水量和农田需水量的历史资料序列,发现二者都呈递减趋势,且递减的速度较为接近。     

黄土高原多沙粗沙区作物水分供需状况评价

采用最大可能蒸散、作物实际蒸散、水分盈亏、水分订正系数评价了黄土高原多沙粗沙区主要作物(春小麦、冬小麦、春玉米、夏玉米和棉花)和草地生长季水分供需状况,结果表明,需水量:冬小麦>棉花>春玉米>春小麦>夏玉米;水分订正系数:春玉米>夏玉米>棉花>春小麦>冬小麦。草地需水量为350～450mm,水分订正系数0.95以上,水分供需矛盾小,实施退耕还牧无论对缓解水资源短缺,还是改善生态环境,在黄土高原多沙粗沙区都是十分有效的措施。