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   958篇
  免费   63篇
  2023年   9篇
  2022年   7篇
  2021年   13篇
  2020年   24篇
  2019年   54篇
  2018年   51篇
  2017年   71篇
  2016年   65篇
  2015年   49篇
  2014年   38篇
  2013年   188篇
  2012年   37篇
  2011年   39篇
  2010年   32篇
  2009年   32篇
  2008年   20篇
  2007年   19篇
  2006年   14篇
  2005年   16篇
  2004年   14篇
  2003年   16篇
  2002年   11篇
  2001年   14篇
  2000年   16篇
  1999年   11篇
  1998年   6篇
  1997年   9篇
  1996年   7篇
  1995年   10篇
  1993年   9篇
  1992年   5篇
  1991年   4篇
  1990年   5篇
  1986年   4篇
  1977年   9篇
  1976年   5篇
  1975年   5篇
  1972年   5篇
  1971年   4篇
  1970年   3篇
  1969年   5篇
  1968年   3篇
  1967年   4篇
  1966年   4篇
  1965年   3篇
  1964年   3篇
  1961年   3篇
  1960年   3篇
  1959年   4篇
  1950年   3篇
排序方式: 共有1021条查询结果,搜索用时 0 毫秒
31.
The aim of this work is to characterize the original concrete from Roman buildings for public spectacles, theatre and amphitheatre, from Emerita Augusta, Mérida, Spain. An advanced knowledge of the Roman concrete composition is required for a reliable restoration and preservation of these ancient monuments. The concrete was studied through mineralogical (optical polarized microscopy and X-ray diffraction) and petrophysical (bulk and real density, open porosity to water and Hg, mechanical strength and ultrasonic velocity) analyses. With this work, it is possible to fill the gap that exists in this field and the characterization of the materials used in the Roman concrete from these two buildings, never previously studied, despite the significance of this archaeological ensemble, declared a World Heritage Site by UNESCO in 1993. The results allowed us to determine the composition of the Roman concrete and to infer the provenance of the aggregates used in these monuments.  相似文献   
32.
Building on existing research concerned with social distance in multi-ethnic states, this study of college students in Gansu Province and Ningxia Hui Autonomous Region provides a picture of social attitudes, intra-group attachment, and inter-group social distance along ethnic and religious lines in Northwest China. The study measures inter-ethnic group fissures in Chinese society as measured in social distance between three ethnic groups: Han, Hui, and Tibetan. Comparative survey methods are used to examine inter- and intra-group relations by mapping dimensions of social distance among 382 university students. Our results indicate only very subtle differences that suggest a closer majority–minority relationship than the previous literature indicates, especially between the Hui and Han. The findings show some clustering and segregating patterns along ethnic lines, specifically when accounting for degrees of trust and tolerance and levels of ethnic and religious attachment. The Hui and Han in Ningxia exhibit closer inter-group relations in comparison to wider measurements of social distance between the Tibetan and Han in Gansu. Where the survey data revealed clustering among ethnic groups, the analysis shows that religious, geographical, and economic differences fail to account for the attitudinal differences between ethnic groups.  相似文献   
33.
This article aims at presenting and discussing the strategies for updating the finite element numerical modeling of stone masonry arch bridges using operational modal analysis. The study comprehended three bridges: two old ones, the St. Lázaro and the Lagoncinha bridges, and a recently constructed bridge in Vila Fria, Portugal. Updating of the bridge models is performed by comparing the numerical and experimental modal parameters. Three-dimensional detailed numerical models are used to perform modal analysis of the bridges. Experimental modal identification of the bridges is based on the measurement of their acceleration responses during normal operation. The assigned material properties are also based on available results obtained from in situ and laboratory tests and on the results of visual inspection and historical research carried out for both old bridges.  相似文献   
34.
Abstract

This special issue addresses the influences of planning cultures and histories on the evolution of planning systems and spatial development. As well as providing an international comparative perspective on these issues, the collection of articles also engages in a search for new conceptual frameworks and alternative points of view to better understand and explain these differences. The articles focus on three main aspects: the change in planning systems and its impact on spatial development patterns; the interrelationship between planning cultures and histories from a path-dependency perspective; and the variations in physical development patterns resulting from different planning cultures and histories. Papers from different parts of the European continent present evidence at different scales to illustrate these aspects. In all cases, the specific combinations of political, ideological, social, economic and technological factors are important in determining urban and regional planning trajectories as well as spatial development patterns.  相似文献   
35.
36.
37.
38.
39.
This article breaks new ground in examining how “new Irish” immigrant women have responded to the collapse of Ireland’s Celtic Tiger economy and the different forms of gender discrimination and marginalisation they face both within their minority ethnic communities and the Irish host society. It approaches Ebun Akpoveta’s Trapped: Prison Without Walls (2013) as an exemplary work of fiction which exposes unresolved injustices and inequalities suffered by immigrant women. Akpoveta creates a narrative that complicates previous representations of cultural encounters between newcomers and long-established members of Ireland’s host society, not least because her Nigerian female protagonist arrives as a postgraduate student rather than an asylum seeker or refugee. She fictionalises female experiences of marginalisation, gender-based violence and family dysfunction within an all-Nigerian family that outwardly appears to be a model of integration and social inclusion in an open and welcoming Irish multicultural society.  相似文献   
40.
Intersectionality is a complex concept to deal with when doing research but also when teaching the interrelationships between space and social relations. Here we present “Relief Maps” as a visual tool for teaching intersectionality and its spatial dimension in higher education courses. “Relief Maps” are a model developed for research and applied in a Geography and Gender course at the Universitat Autònoma de Barcelona (UAB) with the aim of promoting student reflection on the relationships between power structures, places and lived experiences, starting from their everyday lives.  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