容积率对地价的作用机理及实证研究--以南京市为例

文章在分析容积率对于城市地价影响的作用机理基础上,应用有关城市土地经济学理论和模型,采用边际分析方法,对南京商业、住宅、工业用地的样点数据进行实证分析。研究结果表明,城市规划与城市地价的相互关系十分复杂,但建立两者相互作用的模型是可行的,同时指出城市规划按地价理论来实施并且通过城市规划的实施促进地价空间的合理分布是必要的。研究地价、城市规划的关系,其意义不仅仅局限于如何在城市规划中充分利用地价理论优化城市土地利用结构、提高土地利用效率,同时也是为了在城市规划工作中寻找内在规律,为编制出最佳的土地利用规划及在城市中形成最佳地价空间分布及地价水平奠定基础。     

用SVG实现基于 Web的地震数据图形化服务

SVG是一种基于XML的用来描述二维矢量的标志语言,是一种全新的矢量图形规范,为了能够对相关人员提供方便直观快捷的地震数据表现形式,本文对利用SVG实现地震数据图形化表示的方法进行了讨论与研究。     

基于多源激光点云融合的建筑物BIM建模

墙体、窗户等单元构件是建筑物重要组成部分,精细提取其几何参数及位置信息对于完整表达建筑物整体模型具有重要意义.针对单一点云数据源无法获取建筑物单元构件相关参数并完整表达室内外模型重建问题,本文提出一整套融合室内外多源点云数据的BIM模型重建技术.为验证方法的有效性,选取河南理工大学测绘与国土信息工程学院教学楼为实验区域...     

汕头礐石大桥地震反应台阵建设简介

虽然大跨度斜拉桥正在被越来越多地采用,但其抗震理论和动力分析方法都尚处在探索之中．有待进一步验证和改进。汕头礐石大桥地震反应台阵的建成,为获取这类结构的地震反应数据．开展相应的研究提供了保证。从桥址的地震地质背景、台阵测点布设与设备安装、台阵的技术系统等方面的对地震反应台阵作了介绍。     

Adaptability of rainfall simulators as a research tool on urban sealed surfaces – a review

Rainfall simulators can be a useful research tool for some purposes but are quite unsuitable for others. They have been useful in soil erosion and infiltration studies for over eight decades, but the possibility of using a rainfall simulator in urban nonpoint source pollution involving urban non-erodible surfaces has not been fully explored. In this review, the versatility of different rainfall simulators of varying sizes, configurations and styles used in the past two decades are appraised for possible adaptation to urban sealed surfaces. Recommended criteria for detailed rainfall simulator reporting are also outlined.

EDITOR M.C. Acreman

ASSOCIATE EDITOR not assigned     

Measurement of surface water runoff from plots of two different sizes

Intensities and amounts of water infiltration and runoff on sloping land are governed by the rainfall pattern and soil hydraulic conductivity, as well as by the microtopography and soil surface conditions. These components are closely interrelated and occur simultaneously, and their particular contribution may change during a rainfall event, or their effects may vary at different field scales. The scale effect on the process of infiltration/runoff was studied under natural field and rainfall conditions for two plot sizes: small plots of 0·25 m² and large plots of 50 m². The measurements were carried out in the central region of Chile in a piedmont most recently used as natural pastureland. Three blocks, each having one large plot and five small plots, were established. Cumulative rainfall and runoff quantities were sampled every 5 min. Significant variations in runoff responses to rainfall rates were found for the two plot sizes. On average, large plots yielded only 40% of runoff quantities produced on small plots per unit area. This difference between plot sizes was observed even during periods of continuous runoff. Copyright © 2002 John Wiley & Sons, Ltd.     

四川盆地东北部二叠系层序发育的动力学分析

运用可容空间分析法,在野外剖面岩性、岩相厚度和旋回变化分析的基础上,对川东北地区宣汉县渡口镇羊鼓洞二叠系剖面的旋回层序进行研究,识别出3种类型5种亚类型的高频旋回层序类型,并将剖面中栖霞组、茅口组以及吴家坪组下部划分为118个高频旋回层序。根据测井曲线的旋回变化,将普光4井的长兴组划分出49个高频旋回层序,据此运用Fischer图解绘制了二叠系可容空间变化曲线。将可容空间变化曲线与相对海平面升降曲线之间进行对比发现,二者之间存在着良好的对应关系。采测井曲线的频谱分析,对研究区长兴组进行了米兰科维奇沉积周期进行研究,结果表明:长兴组中广泛地保存着124,44.89,35.11,21.16和17.72ka的米兰科维奇沉积周期;地层中的沉积旋回主要受古气候变化的控制,偏心率、地轴倾角和岁差周期引起的地层旋回厚度变化范围分别为:12.47—13.74m,3.56—5.21m,1.78—2.41m,其中受偏心率周期的影响最大。在构造活动相对较弱的川东北二叠系中,层序发育的动力学因素主要为相对海平面的变化和气候变化两个方面。相对海平面的变化主要是三级层序的控制因素,而气候变化则是高频层序旋回的主要动力。     

鄂尔多斯盆地南缘早古生代碳酸盐岩高频沉积旋回分析

鄂尔多斯盆地南缘早古生代碳酸盐岩台地的演化可分低能和高级缓坡、具局限性内陆架盆地的镶边陆架、虎蒸发性内陆架盆地的镶边陆架及断边缘４个阶段，在不同的演化 ，高频沉回旋类型具有明显差异，说明沉积背景控制了碳酸盐岩高频沉积旋回的复杂性、多样性、根据对和线个演经阶段高频旋回的分级栩比及周期计算表明，其驱动机制应与米兰科维奇的天文轨道有关。     

The influence of leaf litter diversity and soil fauna on initial soil erosion in subtropical forests

Although the protective role of leaf litter cover against soil erosion is known for a long time, little research has been conducted on the processes involved. Moreover, the impact of soil meso‐ and macrofauna within the litter layer on erosion control is not clear. To investigate how leaf litter cover and diversity as well as meso‐ and macrofauna influence sediment discharge in subtropical forest ecosystems, a field experiment has been carried out in Southeast China. A full‐factorial random design with 96 micro‐scale runoff plots and 7 domestic leaf species was established and erosion was triggered by a rainfall simulator. Our results demonstrate that leaf litter cover protects soil from erosion (?82 % sediment discharge on leaf covered plots) by rainfall and this protection is removed as litter decomposes. The protective effect is influenced by the presence or absence of soil meso‐ and macrofauna. Fauna presence increases soil erosion rates significantly by 58 %, while leaf species diversity shows a non‐significant negative trend. We assume that the faunal effect arises from arthropods slackening and processing the soil surface as well as fragmenting and decomposing the protecting leaf litter covers. Even though the diversity level did not show a significant influence, single leaf species in monocultures show rather different impacts on sediment discharge and thus, erosion control. In our experiment, runoff plots with leaf litter from Machilus thunbergii showed the highest sediment discharge (68.0 g m^?2) whereas plots with Cyclobalanopsis glauca showed the smallest rates (7.9 g m^?2). Copyright © 2015 John Wiley & Sons, Ltd.     

Statistical determination of significant curved I-girder bridge seismic response parameters

Curved steel bridges are commonly used at interchanges in transportation networks and more of these structures continue to be designed and built in the United States. Though the use of these bridges continues to increase in locations that experience high seismicity, the effects of curvature and other parameters on their seismic behaviors have been neglected in current risk assessment tools. These tools can evaluate the seismic vulnerability of a transportation network using fragility curves. One critical component of fragility curve development for curved steel bridges is the completion of sensitivity analyses that help identify influential parameters related to their seismic response. In this study, an accessible inventory of existing curved steel girder bridges located primarily in the Mid-Atlantic United States (MAUS) was used to establish statistical characteristics used as inputs for a seismic sensitivity study. Critical seismic response quantities were captured using 3D nonlinear finite element models. Influential parameters from these quantities were identified using statistical tools that incorporate experimental Plackett-Burman Design (PBD), which included Pareto optimal plots and prediction profiler techniques. The findings revealed that the potential variation in the influential parameters included number of spans, radius of curvature, maximum span length, girder spacing, and cross-frame spacing. These parameters showed varying levels of influence on the critical bridge response.