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   113篇
  免费   2篇
  2020年   1篇
  2019年   6篇
  2018年   6篇
  2017年   14篇
  2016年   3篇
  2015年   2篇
  2014年   5篇
  2013年   26篇
  2012年   1篇
  2011年   6篇
  2010年   6篇
  2009年   5篇
  2008年   7篇
  2007年   3篇
  2006年   1篇
  2005年   1篇
  2004年   2篇
  2003年   1篇
  2002年   1篇
  2001年   2篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1992年   2篇
  1987年   1篇
  1980年   1篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1970年   1篇
  1969年   1篇
排序方式: 共有115条查询结果,搜索用时 15 毫秒
31.
Every census of the United States contains numerous errors, as many in the population returns as elsewhere, but on this account it has never been concluded that these returns are useless. In the absence of better data they afford an approximation of good value and the results they exhibit are treated as matters of verity. Such in their aggregate they are, while in many of their details they may be grossly defective.  相似文献   
32.
This article describes the dynamical behavior of free-standing block structures under seismic loading. A comprehensive experimental investigation has been carried out to study the rocking response of four single blocks of different geometry and associations of two and three blocks. The blocks, which are large stones of high strength blue granite, were subjected to free vibration, and harmonic and random motions of the base. In total, 379 tests on a shaking table were carried out in order to address the issues of repeatability of the results and stability of the rocking motion response. Significant understanding of the rocking motion mechanism is possible from the high quality experimental data. Extensive experimental measurements allowed to discuss the impulsive forces acting in the blocks and the three-dimensional effects presented in the response.  相似文献   
33.
Abstract

Blitz argues for the necessity and possibility of political philosophy by uncovering its origins in the thought of Plato. By tracing its emergence from the political and moral, Blitz explains the nature of philosophy.  相似文献   
34.
Although there is a considerable amount of empirical evidence on inter-firm collaborations within technology-based industries, there are only a few works focussing on R&D cooperation by low-tech firms, especially small and medium-sized enterprises (SMEs). Providing further and new evidence based on a recently built database of CRAFT projects, this study analyses the relationship between technology and proximity in international R&D networks using HOMALS and statistical cluster techniques. The resulting typology of international cooperative R&D projects highlights that successful international cooperative R&D projects are both culturally/geographically closer and distant. Moreover, and quite interestingly, geographically distant projects are technologically more advanced whereas those located near each other are essentially low-tech. Such evidence is likely to reflect the tacit-codified knowledge debate boosted recently by the information and communication technology (ICT) “revolution” emphasized by the prophets of the “Death of Distance” and the “End of Geography”.  相似文献   
35.
Jess Walsh 《对极》1999,31(4):398-420
Despite sustained disciplinary interest in the social and institutional regulation of labor markets, the relations between welfare provision and work have received scant attention from geographers. This paper charts the functional and spatial interdependence of the urban welfare system and the agricultural industry in Southern California in the 1920s and 1930s. Employer groups actively constructed this interdependence and negotiated its unintended effects with strategies to discursively and physically manage the population of Mexican workers using welfare resources. These strategies, dependent on local grower control of the welfare apparatus, undergirded the racialized division of labor that concentrated Mexicans in casualized farm work.  相似文献   
36.
37.
The history of cross vaults began almost 2,000 years ago with a widespread use during the Middle Ages and Renaissance, becoming nowadays one of the most diffused and fascinating structural typologies of the European building cultural heritage. However, conversely to the undeniable excellence achieved by the ancient masons, the structural behavior of these elements is still at the center of the scientific debate. In this regard, with the aim of reviewing the knowledge on this subject as a concise and valuable support for researchers involved in conservation of historical buildings, with a focus on design rules and structural analysis, the present study firstly introduces the cross vaults from a historical perspective, by describing the evolution of the main geometrical shapes together with basic practical rules used to size them. Then, the article deals with the subsequent advancements in structural analysis methods of vaults, until the development of modern limit analysis.  相似文献   
38.
39.
Research on the operation of territorial governance and rural development programmes is dominated by qualitative methodologies, paying little attention heretofore to the characteristics and structures of new horizontal and vertical relationship formations that are the explicit objective of the governance and rural development model. Seeking to address this deficit in the literature, this article adds to a small number of existing contributions that use social network analysis (SNA) to examine the role of inter‐organizational networks in shaping geographic functional regions in the context of governance. Rooted in the methodological perspective of SNA, the analysis focuses on relations between local actors participating in three area‐based rural partnerships in Poland, which are conceptualized as territorially embedded institutional network clusters. The structure of inter‐sectoral relations, understood as interactions (competition, conflict, coordination, cooperation, and control) and flows (information, financial, human, or tangible resources), between the institutional partners of these partnerships is examined. Analysing in detail attributes of network relations, the article identifies structural characteristics of the area‐based partnerships, such as manifestations of how diverse local resources are engaged and how dominance by traditional powerful stakeholders can be overcome by network structures. Structural dynamics and transformations that represent expressions and manifestations of how territorially embedded governance networks are expected to operate are important areas of inquiry in political geography. In this context, the particular empirical and theoretical capacity of SNA is illuminated in this article as part of a broader presentation of primary field data on how network governance and rural development is taking shape in Central and Eastern Europe.  相似文献   
40.
The pressures on Charles the Bold (duke of Burgundy from 1467 to his death in 1477) to lead, or lend his support to, a crusade were many. His Italian allies and the papacy all pleaded for his help and participation; and these appeals were augmented by the exhortation contained in much of the literature popular at the Burgundian court and by the presence there of refugees from the East.Charles's response was mixed. Political and moral pressures made it impossible for him to ignore the question of the crusade, but, even if his attitude should be characterized as cautious rather than as indifferent, he never did go on crusade. Equally, however, he repeatedly justified his comparative inaction and, at the same time, made propaganda against his enemies by suggesting that their hostility alone prevented him from embarking on an expedition to drive back the infidel.This response, since it was not untypical of the princes of his generation, helps explain the West's failure to unite against the Turks. From the point of view of Burgundian history, Charles's cautious attitude towards the crusade tends to support the revisionists who argue that he was far less ‘rash’ than the traditional historical view allows.  相似文献   
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