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   4368篇
  免费   183篇
  4551篇
  2020年   66篇
  2019年   87篇
  2018年   112篇
  2017年   109篇
  2016年   142篇
  2015年   94篇
  2014年   97篇
  2013年   1302篇
  2012年   133篇
  2011年   163篇
  2010年   161篇
  2009年   127篇
  2008年   100篇
  2007年   105篇
  2006年   107篇
  2005年   68篇
  2004年   52篇
  2003年   58篇
  2002年   58篇
  2001年   67篇
  2000年   60篇
  1999年   75篇
  1998年   51篇
  1997年   41篇
  1996年   33篇
  1995年   44篇
  1994年   31篇
  1993年   42篇
  1992年   29篇
  1991年   36篇
  1990年   40篇
  1989年   40篇
  1988年   29篇
  1987年   40篇
  1986年   40篇
  1985年   45篇
  1984年   52篇
  1983年   48篇
  1982年   38篇
  1981年   45篇
  1980年   42篇
  1979年   40篇
  1978年   36篇
  1977年   36篇
  1976年   26篇
  1975年   27篇
  1974年   27篇
  1973年   29篇
  1972年   29篇
  1970年   27篇
排序方式: 共有4551条查询结果,搜索用时 0 毫秒
131.
The restoration of paintings on elements in cultural heritage buildings (fundamentally, churches) involves two structural problems: capturing the geometry of the construction element and its development. In many cases, the geometries are regular (e.g., cylinders, spheres, elliptical domes). However, there are cases in which the elements cannot be adapted to any known geometry, much less one that can be mathematically developed. The development of surfaces becomes essential for the restoration of paintings over “flat elements” (over which work is performed on the ground) that are subsequently transferred to the real surface (ceilings). The mathematical transformations that allow regular geometries to be developed are widely known (cartographic projections). However, when the geometry is irregular, there is no development. This study presents a new methodology based on differential rectification and its application for the development of oculi in the Los Santos Juanes Church (Valencia), whose geometry is completely irregular both in shape and as a result of construction defects (and damage caused by fire). The present study focuses on the restoration of paintings damaged by fire.  相似文献   
132.
Kelly, R.S. & Nel, A., October 2017. Revision of the damsel-dragonfly family Campterophlebiidae (Odonata) from the Early Jurassic of England reveals a new genus and species. Alcheringa 42, 87–93. ISSN 0311-5518.

Historical fossil insect collections from England were re-examined and the taxa revised. Lateophlebia gen. nov. is erected for Liassophlebia anglicanopsis (Zeuner) in Campterophlebiidae. Petrophlebia anglicana Tillyard is confirmed in this family and Archithemis liassina (Strickland) is transferred to this family. Lastly, Archithemis brodiei (Geinitz), Archithemis Handlirsch, and Architemistidae Tillyard (reduced to this sole species) are transferred to the Heterophlebioidea.

Richard Kelly [], School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK; Department of Natural Sciences, National Museum of Scotland, Chambers Street, Edinburgh, EH1 1JF, UK. André Nel [], Institut de Systématique, Évolution, Biodiversité, ISYEB—UMR 7205CNRS, MNHN, UPMC, EPHE, Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, CP 50, Entomologie, F-75005, Paris, France.  相似文献   

133.
134.
Summary.   Olive oil and fish products from the south of Hispania and North Africa played an important role in the Roman economy. The authors call attention to the asymmetrical distribution of archaeological data available on this subject, in particular the location of amphora kilns, and try to give an explanation, based on the evolution of European archaeology in the twentieth century.  相似文献   
135.
136.
This article examines the impact of decentralization reforms on improving access to domestic water supply in the rural districts of Kondoa and Kongwa, Tanzania, using a users' and a gender perspective. The article addresses the question whether and to what extent the delivery of gender-sensitive water services to rural households improved after the reforms. Household- and village-level data were obtained through a household survey and qualitative methods. The findings show an increase of the proportion of households using improved sources of domestic water between 2002 and 2011. However, more than half of users still travel over a kilometre and use more than an hour to collect water in the dry season. Despite the increased proportion of women in water management committees, the outcomes of these decentralized arrangements differ for men and women. Overall, the reforms have produced contradictory effects by improving access to water supply for some users, and creating or reinforcing existing inter- and intra-village inequalities.  相似文献   
137.
In this paper, we argue that beyond understanding nations as imagined communities, the metaphor of an ‘imagined family’ or ‘filial community’ is a more useful concept towards understanding links between gender and nationhood as family relations in four ways: (1) providing a clear, hierarchical structure; (2) prescribing social roles and responsibilities; (3) being linked to positive affective connotations; and (4) reifying social phenomena as biologically determined. In order to empirically substantiate our claim, we will explore the prevalence and use of family metaphors in a key symbol of nationhood discourses. Through a qualitative analysis of national anthems as ‘mnemonics of national identity’, we demonstrate the widespread presence of family metaphors, discussing how they reproduce ideas of family and gender. Finally, we discuss how the ‘imagined family’ as present in anthems and other forms of national representation could inform future studies of nationalism and national politics.  相似文献   
138.
This article addresses Syrian leader Adib al-Shishakli's assault on the Syrian Druze minority in the mid-1950s, the Syrian Druze reaction, and contemporaneous observations and reactions from both the Israeli government and the Israeli Druze community to Shishakli's assault. The events analyzed in this article provide insight into the difficulties and opportunities the Jewish state had in cultivating minority allies in a hostile region, on the one hand, and the dilemmas Middle Eastern minorities had in seeking out the regionally beleaguered Jewish state's support, on the other.  相似文献   
139.
140.
Abstract

Engaging communities in the protection of heritage means that the communities living around the heritage sites are involved in the process of identifying issues that affect the conservation of these sites and can propose ways by which they can be addressed. In Ghana, the Elmina Castle project shows close collaboration between the communities living around these slave forts and castles, the legal custodians, and other stakeholders. This case study unpicks the process to show how the existing traditional systems were approached and involved. The result of this participatory collaboration is a strategic document which will be implemented to ensure proper protection of these sites in the wake of development and modernization.  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