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   11篇
  免费   0篇
  2020年   1篇
  2018年   2篇
  2017年   1篇
  2016年   1篇
  2015年   3篇
  2014年   1篇
  2013年   1篇
  1994年   1篇
排序方式: 共有11条查询结果,搜索用时 15 毫秒
1.
Strengthening social, economic and territorial cohesion is a central objective of the European Union (EU) and the Structural Funds reflect the main financial effort of the EU to pursue this goal. So far we have gone through four programming periods; to what extent the EU Funds have become more effective in promoting growth and reducing the disparities between EU Member countries is a matter of concern. We investigate the existence (or not) of learning effects and efficiency improvements following the reforms of Regional Policy. The study is applied to data from EU regions (EU12) in the most recent programming periods where data are available. The results suggest an improvement of the Funds efficiency in growth in 2000–2006 when compared to the previous programming period. Moreover, the returns from investments of Funds tend to be higher in richer, higher-educated and more innovative regions. Finally, the Cohesion group has not been able to transform the large transfers received into additional growth.  相似文献   
2.
The fundamental frequency of a structure enables better assessment of its seismic demand for an efficient design and planning of its maintenance and retrofit strategy. The frequency is independent of the type of external loads, however, depends on structural stiffness, mass, damping and boundary conditions. In the case of slender masonry structures such as towers, minarets chimneys, and pagoda temples, it is influenced by mass and stiffness distribution, connection to adjacent structures, material properties, aspect ratio and slenderness ratio. In this present article, the data collected from various literature reviews on the slender masonry structures regarding dynamic, geometrical, and mechanical characteristics have been correlated to identify the major parameters influencing the fundamental frequency of such structures. The database has been used for developing an empirical formulation for predicting the fundamental frequency of such structures. The comparison between the experimental fundamental frequencies and the estimated fundamental frequencies are carried out in order to define reliability and accuracy of these empirical formulae.  相似文献   
3.
Policy development is of little moment if those policies are never implemented. In this article a governor who had considerable success in implementing major changes in the mental health delivery system of his state suggests seven principles of successful policy implementation. The relevance, general utility, and applicability of these principles should be of interest to those political scientists who study issues related to policy implementation.  相似文献   
4.
This study represents an isotopic survey of modern plants developed to establish baseline isotopic values in order to explore prehistoric herd management strategies employed by the South American camelid herders that occupied the southern Andean highlands during the past 3000 years. We present carbon (δ13C) and nitrogen (δ15N) isotopic compositions of natural pastures collected from different plant communities along an altitudinal gradient in the dry Puna of Argentina. Our results show that C3 plants are the most abundant along the whole altitudinal gradient and that C3 and C4 plants exhibit a differential distribution, the latter being less abundant in those sites located above 3900?meters above sea level (masl). At the same time, plants growing at low-altitude sites with low water availability exhibit higher δ15N values than plants growing at high-altitude sites with higher water availability. These results explain the negative correlation found between altitude and South American camelid bone collagen δ13C and δ15N values published in previous studies. This work represents a fundamental step towards the building of an isotopic ecology for the dry Puna area with the ultimate goal to explore herd management strategies employed by human groups in the past. In this sense, modern plant and South American camelid tissue isotopic compositions would provide a frame of reference to interpret isotopic compositions measured on archaeofaunal remains recovered at pastoral sites, with the aim to explore mobility and pastureland use by prehistoric herders.  相似文献   
5.
This article addresses the laboratory testing of a full-scale double-T shaped adobe wall, under in-plane horizontal cyclic loading of increasing amplitude, with the aim of contributing to the understanding of the seismic behavior of adobe structures. The wall was built with lime adobes taken from an existing building and mortar with a traditional composition. The behavior of the wall was assessed in terms of: shear stress versus horizontal drift and moment versus rotation relationships; maximum lateral strength; drift and rotation at peak stress; evolution of stiffness, lateral displacements, dissipated energy, and natural frequency; and damage pattern. The wall exhibited brittle behavior and in-plane strength corresponding to 56% of the vertical load. Cracking was observed with an X-shaped pattern whereas no sliding occurred at its base. This research supported the subsequent development of a repair and retrofit solution and also of numerical models to simulate the seismic behavior of two adobe buildings.  相似文献   
6.
Abstract

This paper presents the results of research carried out for more than a decade at Vuelta de Obligado, San Pedro, north-east of Buenos Aires province. The objectives were to understand the dynamics of the strategy followed on the 1845 battlefield by the two groups who fought (Anglo-French and Argentine), and to assess the impact of formation processes on the results produced. This has been achieved through the use of several sources of information: the archaeological record, written documents, Argentine and European plans and sketches, as well as data provided by the current population.  相似文献   
7.
In structural analyses, masonry infill walls are commonly considered to be non structural elements. However, the response of reinforced concrete buildings to earthquake loads can be substantially affected by the influence of infill walls. In this article, an improved numerical model for the simulation of the behavior of masonry infill walls subjected to earthquake loads is proposed and analyzed. First, the proposed model is presented. This is an upgrading of the equivalent bi-diagonal compression strut model, commonly used for the nonlinear behavior of infill masonry panels subjected to cyclic loads. Second, the main results of the calibration analyses obtained with two series of experimental tests are presented and discussed: one on a single frame with one story and one bay tested at the LNEC Laboratory; and the second, on a full-scale four story and three-bay frame tested at the ELSA laboratory.  相似文献   
8.
ABSTRACT

Slender masonry structures such as towers, minarets, chimneys, and Pagoda temples can be characterized by their distinguished architectural characteristics, age of construction, and original function, but their comparable geometric and structural ratios yield to the definition of an autonomous structural type. These structures constitute a part of the architectural and cultural heritage. Their protection against earthquakes is of great importance. This concern arises from the strong damage or complete loss suffered by these structures during past earthquakes. Seismic vulnerability assessment is an issue of most importance at present time and is a concept widely used in works related to the protection of buildings. However, there is few research works carried out on developing the seismic vulnerability assessment tools for such structures.

This article presents a new method for assessing the seismic vulnerability of slender masonry structures based on vulnerability index evaluation method. The calculated vulnerability index can then be used to estimate structural damage after a specified intensity of a seismic event. Here, 12 parameters are defined to evaluate the vulnerability index for slender masonry structures. Implementation of this methodology is carried out in different types of slender masonry structures to develop vulnerability curves for these structure types.  相似文献   
9.
Single and double flat-jack tests are presently used widely for assessing the mechanical characteristics of stone masonry. This technique remains as one of the most versatile in situ test procedure for the estimation of the main mechanical properties of masonry walls. Nevertheless their application is still controversial due to the difficulty of accepting in some cases the results as reliable. This article presents and discusses the results of an experimental campaign resorting to flat-jack technique carried out with the scope of the rehabilitation process of the historical city center of Coimbra.  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