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261.
辽宁省国土资源沙盘模型制作及特点 总被引:2,自引:1,他引:1
本文以辽宁省国土资源沙盘模型为例,详细介绍了现代沙盘模型的制作方法及特点。 相似文献
262.
电子地图作为现代信息技术条件下的一种新型地图图种,其核心是地理信息的屏幕可视化表达.多媒体电子地图将多媒体技术与电子地图结合起来,丰富了电子地图的内容.本文主要介绍了多媒体电子地图的数据构成及其可视化表达方法,并在南京多媒体电子地图试验系统中进行了初步的应用. 相似文献
263.
GPS-RTK技术测量方便、快捷,应用日渐广泛,但在精度要求高的工程测量项目的应用还是比较少。结合苏通大桥陆域范围的定测,介绍了GPS—RTK技术在重点工程测量中的应用方法。 相似文献
264.
Josh Lepawsky 《Geoforum》2005,36(6):370-719
The Malaysian government has embarked on an ambitious refashioning of the nation called Vision 2020 in pursuit of its goal of becoming a ‘developed country’. A pivotal component of this ‘vision’ is the planning and provision of information technology (IT) infrastructure in a multi-billion dollar urban mega-project called the Multimedia Super Corridor (MSC). The purpose of my paper is twofold. First, I situate an official planning document for the MSC entitled Physical Design Guidelines for the Multimedia Super Corridor in the activity of transnational planning practice. Second, I argue that a thematic series of organizing planning concepts and practices can be identified in this document. These concepts and practices work in two ways: first, by representing highly positioned notions of sub-urban, middle-class urban design conventional in specific North American cities as universally applicable to, and desirable for, the broader national development goals the MSC is intended to lead; second, by creating a ‘total image’ for the MSC that suggests an apparently seamless relationship between the MSC and the proper citizens for it at every imaginable scale. One important effect of these plans is the material transformation of a rural landscape of and for production into an urban landscape of and for consumption. This transformation raises the question of who can belong to the ‘nation’ being (re)imagined via the MSC. 相似文献
265.
266.
探地雷达在确定全新世海侵线方面的应用 总被引:1,自引:0,他引:1
针对全新世大暖期古海岸线位置的不确定性问题,提出了一种利用探地雷达进行最大海侵位置追踪的方法,在探地雷达可获得连续沉积地层图像的理论基础上,在具有丰富研究资料的莱州湾东岸开展了实验研究。结果表明,利用Mala RAMAC100MHz天线结合相应的图像处理手段,能够识别区域10 m以内浅地层中海陆相沉积物分界面,与已有钻孔和现场探挖浅孔剖面对比,具有较好的一致性。证实了利用探地雷达追踪全新世海侵时期古地层、将海相层尖灭点处确定为最大海侵线位置,进一步恢复古环境是可行的。本文为研究古海岸线位置提供的方法,即通过探地雷达探测地层,得到高清的可视化图像,这使得古海岸线位置确定更精确、更直观。 相似文献
267.
Kshitij C. Shrestha Yoshikazu Araki Takuya Nagae Toshihiro Omori Yuji Sutou Ryosuke Kainuma Kiyohito Ishida 《地震工程与结构动力学》2013,42(5):725-741
This paper presents the results on shaking table tests of half‐scale brick walls performed to investigate the effectiveness of newly developed Cu–Al–Mn superelastic alloy (SEA) bars in retrofitting of historical masonry constructions. Problems associated with conventional steel reinforcing bars lie in degradation of stiffness and strength, or pinching phenomena, under cyclic loading, and presence of large residual cracks in structures during and after intense earthquakes. This paper attempts to resolve the problems by applying newly developed Cu–Al–Mn SEA bars, characterized by large recovery strain, low material cost, and high machinability, as partial replacements for steel bars. Sets of unreinforced, steel reinforced, and SEA‐reinforced specimens are subjected to scaled earthquake excitations in out‐of‐plane direction. Whereas steel‐reinforced specimens showed large residual inclinations, SEA‐reinforced specimens resulted in stable rocking response with slight residual inclinations. Corresponding nonlinear finite element (FE) models are developed to simulate the experimental observations. The FE models are further used to examine the sensitivity of the response with respect to the variations in experimental conditions. Both the experimental and numerical results demonstrate the superiority of Cu–Al–Mn SEA bars to conventional steel reinforcing bars in avoiding pinching phenomena. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
268.
Alexandre A. Costa António Arêde Alfredo Campos Costa Andrea Penna Aníbal Costa 《地震工程与结构动力学》2013,42(14):2081-2095
The out‐of‐plane response of walls in existing stone masonry buildings is one of the major causes of vulnerability commonly observed in post‐earthquake damage surveys. In this context, a shaking table (ST) test campaign was carried out on a full‐scale masonry façade mainly focusing on the characterization of its out‐of‐plane overturning behaviour. The structure tested on the ST is a partial reproduction of an existing building from Azores, damaged during the 9 July 1998 Faial earthquake. The definition of the tested specimen as well as the selection of the input ground motion is reported in this paper. A specific emphasis is given to the definition of the time‐history to be applied during the tests because it was felt as an essential and crucial part of the work to obtain the desired overturning behaviour. The accelerogram to be imposed was selected from a large set of accelerograms (74) by means of a step‐by‐step procedure on the basis of several numerical analyses resorting to the rocking response of rigid blocks. A companion paper (Part 2) focuses on the ST test results and detailed data interpretation. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
269.
Christopher J. Stevenson Peter J. Talling Esther J. Sumner Douglas G. Masson Micheal Frenz Russell B. Wynn 《Sedimentology》2014,61(7):1982-2019
Submarine gravity currents, especially long run‐out flows that reach the deep ocean, are exceptionally difficult to monitor in action, hence there is a need to reconstruct how these flows behave from their deposits. This study mapped five individual flow deposits (beds) across the Agadir Basin, offshore north‐west Africa. This is the only data set where bed shape, internal distribution of lithofacies, changes in grain size and sea floor gradient, bed volumes, flow thickness and depth of erosion into underlying hemipelagic mud are known for individual beds. Some flows were 30 to 120 m thick. However, flows with the highest fraction of sand were less than 5 to 14 m thick. Sand was most likely to be carried in the lower 5 to 7 m of these flows. Despite being relatively thin, one flow was capable of transporting very large volumes of sediment (ca 200 km3) for large distances across very flat sea floor. These observations show that these relatively thin flows could travel quickly enough on very low gradients (0·02° to 0·05°) to suspend sand several metres to tens of metres above the sea floor, and maintain those speeds for up to 250 km across the basin. Near uniform hemipelagic mud interval thickness between beds, and coccolith assemblages in the mud caps of beds, suggest that the flows did not erode significantly into the underlying sea floor mud. Simple calculations imply that some flows, especially in the proximal part of the basin, were powerful enough to have eroded hemipelagic mud if it was exposed to the flow. This suggests that the flows were depositional from the moment they arrived at a basin plain location, and that deposition shielded the underlying hemipelagic mud from erosion. Reproducing the field observations outlined in this exceptionally detailed field data set is a challenge for future experimental and numerical models. 相似文献
270.