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   154篇
  免费   13篇
  2023年   1篇
  2021年   2篇
  2020年   1篇
  2019年   9篇
  2018年   8篇
  2017年   8篇
  2016年   8篇
  2015年   9篇
  2014年   5篇
  2013年   38篇
  2012年   6篇
  2011年   4篇
  2010年   2篇
  2009年   8篇
  2008年   6篇
  2007年   4篇
  2006年   1篇
  2005年   1篇
  2004年   3篇
  2003年   8篇
  2002年   4篇
  2000年   3篇
  1999年   1篇
  1997年   2篇
  1995年   4篇
  1994年   1篇
  1993年   3篇
  1992年   2篇
  1990年   1篇
  1989年   2篇
  1986年   1篇
  1985年   2篇
  1982年   1篇
  1981年   2篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
  1968年   1篇
  1967年   1篇
  1948年   1篇
排序方式: 共有167条查询结果,搜索用时 15 毫秒
101.
102.
103.
Contrary to oral interviews, statistics or primary sources in print, the use of film does not occupy an important place in the training of social scientists. Yet, as this article argues, before film and video can become standard data gathering tools, social scientists need to reflect on the ways filming techniques are taught. To do so, this article offers an account of a filming course taught for several years to third year students at the university of Tours.  相似文献   
104.
105.
The Middle to Upper Palaeolithic transition is the key period for our understanding of Neanderthal and modern human interactions in Europe. The site of Les Cottés in south-west France is one of the rare sites with a complete and well defined sequence covering this transition period. We undertook an extensive radiocarbon dating program on mammal bone which allows us to propose a chronological framework of five distinct phases dating from the Mousterian to the Early Aurignacian at this site. We found that the Mousterian and Châtelperronian industries are separated from the overlying Protoaurignacian by a gap of approximately 1000 calendar years. Based on a comparison with Upper Paleolithic sites in Europe we see an overlap in the ages of Châtelperronian industries and Aurignacian lithic assemblages, which are usually associated with Anatomical Modern Humans, which is consistent with an acculturation at distance model for these late Neanderthals. The Proto and Early Aurignacian appear contemporaneous indicating that this transition was rapid in this region. Anatomically Modern Humans are present at the site of Les Cottés at least at 39,500 cal BP roughly coincident with the onset of the cold phase Heinrich 4.  相似文献   
106.
Recent studies on urban poverty in Canadian cities suggest a growing spatial concentration of poor populations within metropolitan regions. This article assesses trends in the intra‐urban distribution of the poor population from 1986 to 2006 in eight of Canada's largest cities. We consider five well‐known dimensions of segregation, as identified by Massey and Denton (1988) , in order to examine changes in the spatial distribution of poor populations within metropolitan areas: evenness, exposure, concentration, clustering, and centralization. These indices were calculated for low‐income populations at the census tract level using data from five Canadian censuses. Although each metropolitan area has distinctive characteristics, we were able to identify some general trends. The results suggest that, in 2006 compared to 1986, low‐income populations lived in more spatially concentrated areas, which were, at the same time, socioeconomically more homogeneous and more dispersed throughout the metropolitan area. In addition, we observed that over the last twenty years areas of poverty have been located, for the most part, in neighbourhoods adjacent to downtown cores. Nevertheless, we found that poverty has mostly increased in suburban areas located outside inner‐city neighbourhoods. Growing socioeconomic homogeneity and dispersion of low income areas in metropolitan areas reveal new spatial patterns of urban poverty distribution. These findings should be cause for concern as social isolation in the most disadvantaged neighbourhoods could affect the life chances and opportunities for the residents of those areas.  相似文献   
107.
108.
Systematic use of animal manure has been demonstrated to be detectable in the plant δ15N value but evidence of manure affecting isotopic composition is mainly based on studies of fresh plant material. These findings can potentially be applied to archaeobotanical assemblages and thus provide information about prehistoric manuring practice. Prehistoric grains are generally found in a charred state of which the exact charring conditions are unknown but most likely often multifarious. In this study we examined the influence of grain weight and a range of charring conditions with regards duration, temperature, oxygen availability, and manuring. The charring was applied to emmer, spelt and naked barley with assessment of weight loss, N concentration and δ15N. There were only small and non-systematic variations in δ15N in relation to grain weight class. We also found that charring did not distort δ15N in either a systematic or substantial way and conclude that manuring most likely will be detectable in archaeobotanical charred grains. As certain within-grain variability in δ15N existed, especially in the intensively manured grains, the resolution of this kind of information should be carefully considered. However, despite attempts to deliberately tamper and distort the grain δ15N signature, the changes observed in this study were too small to be of any consequences for the archaeobotanical applicability of the method. Thus the isotope method offers unique evidence about prehistoric manuring practice.  相似文献   
109.

On the western border of the Stj?rdal region in the province of Nord‐Tr?ndelag, Norway, at the Hoset farm in Lånke, the Department of History at the University of Trondheim, Norway, has been carrying out a detailed study of a single farm area, in cooperation with the Nordic Deserted Farms Project This study is particularly interesting since it was planned as an interdisciplinary approach, involving archaeological, pollen‐analytical, pedological and geological specialists, in addition to historians, all of which have contributed their own evidence on the cultural and natural environment and agricultural settlement history of the area from the Iron Age onward. In this way it was hoped that answers would be found to questions which have been neglected in the past by Norwegian historians, such as settlement continuity or discontinuity, farm structure, farming methods and settlement patterns in more remote areas. It was also hoped to gain more experience in the different scientific techniques, their potentialities and limitations (e.g. radiocarbon dating, pollen analysis, phospate analysis) and to foster a spirit of mutual co‐operations between the various departments within the university.  相似文献   
110.
Stable oxygen isotopic analysis of tooth enamel was used to investigate seasonality and season of birth in sheep. Analyses were performed on the teeth of eight modern sheep bred at the Carmejane farm in south-eastern France and born in different periods of the year. This reference data set confirms that oxygen isotopic records in the second and third molars can be used to differentiate between sheep born in late winter and those born in early autumn. The results show that inter-individual variability in the timing of tooth formation is low for the second lower molar and more pronounced for the third lower molar in this population. The duration of the process of enamel mineralization has been estimated at approximately six months. The teeth of four sheep and two goats from the late Neolithic site of Collet-Redon in south-eastern France were analyzed using the same methodology. At this site, lambing occurred between the late winter and early spring. A slight difference appears in the seasonal sequence recorded in sheep and goat, although it cannot be determined, whether this is due to different timing of tooth development, or an actual shift in the birth period. From the distribution of slaughter ages and birth period, it is suggested that domestic caprines were killed throughout the year and that Collet-Redon was probably a permanent settlement.  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