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提出计算机辅助配模系统采用与常规计算机绘图系统相同的硬件配置，可使系统具备良好的图形功能和入机界面；系统流程分＂数据输入＂，＂数据转换＂，＂配模设计＂和＂图形绘制＂四个阶段．墙体以中线数据（Ｔ，Ｌ，Ａｎｇ）定义，在图形环境下以人机交互方式输入墙厚及中线数据；由建筑平面常具备的对称性设计了映射算法以减少输入工作；根据图形变换原理建立了设计参数的简化算法，利用内圈外圈墙体的闭环特性简化墙面属性判别． 相似文献
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LOUISE HANSEN ACHIM BEYLICH VALENTIN BURKI† RAYMOND S. EILERTSEN‡ OLA FREDIN EILIV LARSEN ASTRID LYSÅ ATLE NESJE† KNUT STALSBERG JAN F. TØNNESEN Associate Editor – Nick Eyles 《Sedimentology》2009,56(6):1751-1773
The sediment fill of a silled bedrock valley in Western Norway has been investigated with respect to stratigraphy and infill history using a combination of mapping, georadar, seismic profiling and drilling. A small outlet glacier occupies the head of the valley that displays a stepwise down-valley profile and terminates in a lake at 29 m above sea-level. The valley is surrounded by high, steep bedrock slopes and is characterized by a series of filled basins each limited by sills of bedrock or moraine accumulations. Till, glacial outwash and/or rockslide deposits fill in the lower half of the two larger basins. (Fan) delta deposits fringed by the deposits of alluvial fans and colluvial cones dominate the upper fill of most basins. (Fan) delta deposits interfinger downstream with lake sediments in the larger basins and fluvial deposits comprise the top fill. The overall infill pattern was controlled by deglaciation as well as basin size and shape. An overall decreasing sediment supply following deglaciation is shown in the fill of a larger basin down-valley, whereas a recently increasing sediment supply during glacier growth is reflected primarily in an upstream basin. Only the lowermost basin was exposed to a sea-level drop from 75 m above sea-level to the present lake level associated with incision and river migration. This observation is in contrast to the basins above marine influence where incision has been limited due to fixed downstream sills resulting in insignificant erosion except for some fan-head entrenchment. It follows that the fills of these small valley basins display progradational and aggradational trends of deposition and paraglacial reworking has been limited. Additionally, the study demonstrates that georadar profiling, combined with other methods, is very useful for comprehensive investigation of valley basins. 相似文献
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开发WebGIS的ArcIMS新技术应用分析 总被引：34，自引：1，他引：33
本文论述了 Arc IMS的体系结构 ,阐述了 Arc IMS的运行机制 ,着重分析了 Arc XML在这一结构内的作用 ,并介绍了服务器端的逻辑和物理层次、客户端的基本功能 ,从而剖析了 Arc IMS的核心部分。同时从使用的角度 ,介绍了如何管理 Arc IMS服务器 ,并分别论述某功能部件。最后对站点安全这个万维网地理信息系统必须密切关注的问题 ,结合 Arc IMS平台的特点进行了分析 ,并提出一些解决方法。 相似文献
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SIG中的元数据共享服务体系研究与实践 总被引：1，自引：0，他引：1
元数据是数字地球建设的关键技术之一，是建设信息化城市和实施空间信息网格基础设施的重要内容。本文基于Web服务对象及其标准，建立了分布、异构的网格环境下的元数据服务管理模型，包括基于Web服务的空间元数据共享服务体系、空间元数据服务与发布流程及其实现。最后，探讨了如何使用目前JAVA技术中比较流行的JDBC和懒加载技术开发空间元数据服务管理模型。 相似文献
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The Late Paleoproterozoic Athabasca Basin contains more than 1.5 km of predominantly sandy strata, most of which are of braided fluvial origin. In the eastern part of the basin, at McClean Lake, sandstones and minor conglomerates of the Read Formation at the base of the succession are preserved within a steep-walled valley system. They consist predominantly of meter-scale sheet elements, characterized by massive and flat-laminated fine- to very coarse-grained sandstone with minor discontinuous cobble and boulder conglomerate along lower set boundaries. These are interpreted as sheet-flood and stream-flood deposits of a terminal dry-land system, deposited in an arid climatic setting. Analysis of closely spaced drill-core indicates that late stage run-off was confined to small shallow channels, typically only a few tens of meters wide and a few meters deep. Overlying strata of the Bird Member of the Manitou Falls Formation are predominantly coarse- to very coarse-grained sandstones with abundant small-scale cross-stratification and minor granule and small pebble conglomerate. At McClean Lake, these appear to have been deposited as sheet-elements by semi-ephemeral to perennial braided rivers under more humid conditions. At Key Lake, 160 km to the southwest, architectural analysis of a 184 m wide section indicates that at least part of the Bird Member was deposited in deeper, sandy-braided rivers characterized by seasonally varied flow. The closest modern analogue is the South Saskatchewan River, in which large simple flow-transverse bedforms become exposed and dissected during falling stage, and act as nuclei for sand-flat development. The presence of numerous low-relief 4th order surfaces suggests continued reworking of bar-tops during rising stage. The incremental character of downstream accretionary elements suggests periodic migration of barforms during peak-flood stages, separated by periods of low flow. This indicates similarities with modern perennial braided systems, and is counter to the idea that all pre-Devonian fluvial systems should consist of stacked sheets formed by individual flood events. Thin gravel layers accumulated as lags on fourth order surfaces, with discontinuous mud layers suggesting deposition within temporary ponds in channel thalwegs after major floods. Strata in overlying units indicate a return to semi-perennial conditions. 相似文献
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徽派传统建筑更被誉为中国建筑艺术的一朵奇葩。本文说明了徽州传统建筑的保护现状与存在的问题,并从五个方面提出了保护对策。 相似文献