首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   193篇
  免费   2篇
  2023年   1篇
  2021年   1篇
  2020年   12篇
  2019年   6篇
  2018年   27篇
  2017年   9篇
  2016年   12篇
  2015年   6篇
  2014年   3篇
  2013年   88篇
  2012年   2篇
  2011年   5篇
  2010年   3篇
  2009年   4篇
  2008年   3篇
  2007年   2篇
  2006年   2篇
  2005年   1篇
  2003年   6篇
  2002年   1篇
  1999年   1篇
排序方式: 共有195条查询结果,搜索用时 46 毫秒
1.
近年来,随着我国港口资源整合、港区功能调整和港口城市的转型升级,沿海港口与所在城市的关系发展面临新的变化和挑战。本文以我国沿海港口为例,结合定量分析与定性讨论,聚焦我国沿海港口港城关系问题,剖析港城关系的演变及驱动机制。研究发现:我国大部分沿海港口已进入极度协调发展阶段,但发展趋势逐渐放缓,区域分化特征显著,港城协同度差距呈现再扩大的发展趋势。在研究期间,我国城市驱动型港口城市数量显著增加,港口驱动型和港城互驱型港口城市数量减少。建议通过政府政策引导、港产城融合发展和港口转型升级等方式,不断提升我国沿海地区港城关系整体协调发展水平,为新时期我国沿海港口与所在城市的高质量发展提供重要支撑。  相似文献   
2.
The seismic vulnerability of city centers is commonly assessed by extending the study methods applied to single buildings to urban aggregations. This approach is not always applicable at territorial scale, as it is uneconomical in terms of time and costs. An innovative method provides reasonable large-scale a priori estimation of parameters not directly evaluable from the exterior of buildings by elaborating values which can be measured from the outside. Those parameters are treated as continuous variables, by assigning them a suitable probability density function. The Bayesian approach is adopted, which allows the update of initial hypotheses by using new data gathered during on-site surveys. In this regard, a rapid survey form for the on-site data collection is proposed. An example of its application to a façade of a building structural unit in Santo Stefano di Sessanio in L’Aquila province (Italy) is proposed, showing promising preliminary results for buildings belonging to Italian historical centers.  相似文献   
3.
Historical towers, in particular medieval towers, are an important part of cultural heritage, and their preservation mandates monitoring and detailed analyses of vulnerability under seismic actions as well as of their long-term performance. Certain aspects of structural nature are linked to the masonry behavior as a unilateral material, and other are aspects related to the interaction with soft soil conditions. This study aims to contribute to the aspects of preservation by exploring the role of the soil-structure interaction in predicting the behavior of the structures, with specific reference to the well-documented case history of the medieval Ghirlandina Tower (Modena, Italy). A significant contribution comes from an experimental identification analysis, performed in the presence of ambient vibration. A novel finding is that the soil structure interaction cannot be neglected, in contrast to most published identification analyses that usually assume the structure to have rigid constraint at base.  相似文献   
4.
Buddhist monasteries in Sikkim Himalayas constitute important religious and architectural heritage. These random rubble (RR) stone masonry structures located in high seismically active regions of the Himalayas have suffered varied degrees of damages in the past earthquakes. The study presents seismic vulnerability assessment of four archetypal monastic temples using finite element (FE) analyses. Linear and nonlinear analyses of these structures were conducted in Abaqus FE environment. These analyses identified the damage prone areas of the structures and provided load-deformation behavior under lateral loads. Fragility analyses indicate a high probability of collapse for the specified design level earthquake of the region. The study shows that performance of the structure can be enhanced by improving the strength and stiffness of the stone masonry walls.  相似文献   
5.
ABSTRACT

Historic heritage buildings are a part of historic basis of each society and an economic resource. Therefore, preserving and maintenance of these buildings are cultural, economic and social demand. This research investigates the seismic performance of a historical building named Arg of Tabriz (Arge Alishah) that dates back to 14th century and is located at the city center of Tabriz (NW of Iran). Static, modal, and finally nonlinear dynamic (time history) analysis were performed by both “Considering Soil-Structure Interaction (SSI)” and “fixed base (ignoring SSI)” Cases.

It is found from the results that, SSI extremely affects mode shapes and their frequencies and depending on the frequency content of the records, can has an incremental or decremental effect on structural responses. As expected, the building of Arg could carry gravity loads easily and despite its stability against earthquake loading in fixed base case, showed a weakness (especially in eastern and western walls direction) and overturned when it was analyzed in SSI case because of yielding of the surrounding soil.  相似文献   
6.
7.
In this paper, I suggest that the category of ‘ward,’ a designation used for Aboriginal Australians in the 1950s and 1960s, has re-emerged in contemporary Northern Territory (NT) life. Wardship represents an in-between status, neither citizens nor non-citizens, but rather an anticipatory citizenship formation constructed by the Australian state. The ward is a not-yet citizen, and the deeds, acts, and discourses that define the ward's capacities to act as a political subject can maintain their anticipatory nature even as people ‘achieve’ formal citizenship. Wardship can be layered on top of citizen and non-citizen status alike. Rather than accounting for the grey areas between ‘citizen’ and ‘non-citizen,’ therefore, wards exist beyond this theoretical continuum, demanding a more nuanced accounting of political subjectivities and people's relationships to the state.I trace the emergence of the category ‘ward’ in the 1950s and 1960s in Australia and its re-emergence for Aboriginal Australians impacted by the 2007 Northern Territory Emergency Response legislation. The promise of citizenship offered by the status of ‘ward’ is built upon expectations about family life, economic activity, and appropriate behaviour. These assumptions underscore an implicit bargain between individuals and the state, that neoliberalised self-discipline will lead to both formal citizenship rights and a sense of belonging. Built-in impediments, however, ensure that this bargain is difficult, if not impossible, to fulfil.  相似文献   
8.
The extent to which North Atlantic Holocene climatic perturbations influenced past human societies is an area of considerable uncertainty and fierce debate. Ireland is ideally placed to help resolve this issue, being occupied for over 9000 yr and located on the eastern Atlantic seaboard, a region dominated by westerly airflow. Irish bog and lake tree populations provide unambiguous evidence of major shifts in surface moisture through the Holocene similar to cycles recorded in the marine realm of the North Atlantic, indicating significant changes in the latitude and intensity of zonal atmospheric circulation across the region. To test for human response to these cycles we summed the probabilities of 465 radiocarbon ages obtained from Irish archaeological contexts and observe enhanced archaeological visibility during periods of sustained wet conditions. These results suggest either increasing density of human populations in key, often defensive locations, and/or the development of subsistence strategies to overcome changing conditions, the latter recently proposed as a significant factor in avoiding societal collapse. Regardless, we demonstrate environmental change is a significantly more important factor in influencing human activity in the landscape than has hitherto been acknowledged.  相似文献   
9.
通过对上海及邻近地区地震危害性分析,结合地震研究工作结果,根据上海博物馆文物防震保护的具体要求,研究确定了该博物馆文物防震保护的设防水准及地震动参数。场地地震动输入峰值加速度水准确定为50年超越概率3%,地震动反应谱采用上海市标准《建筑抗震设计规范》(DGJ08-9-92)中给出的地震影响系数曲线(阻尼比0.05),并将输入峰值加速度调整为180gal。研究采用了目前通用的拟合反应谱的方法,通过拟合选定的地震动反应标准谱,合成了6条人造地震波时程曲线,拟合精度控制在相对误差不大于5%;同时结合上海市《建筑抗震设计规范》(DGJ08-9-92)中所附的一条强震记录,共同作为上海博物馆结构地震反应分析的输入地震动。又根据上海博物馆建筑的结构特征分析,结合建筑结沟动力特征的实测结果,通过采用层模型结构时程分析计算方法,计算并获得了在遭遇设防地震时,上海博物馆建筑物每一层的地震动反应,表明上海博物馆建筑各楼层的地震动反应具有明显的楼层放大作用。对各楼层地震动反应的统计分析,给出了上海博物馆建筑物每一层的地震动参数,以此可作为今后文物地震危害性分析,及研究设计隔震装置等防震措施的依据。  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号