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   859篇
  免费   39篇
  2024年   4篇
  2023年   17篇
  2022年   7篇
  2021年   5篇
  2020年   24篇
  2019年   24篇
  2018年   52篇
  2017年   46篇
  2016年   29篇
  2015年   26篇
  2014年   37篇
  2013年   166篇
  2012年   37篇
  2011年   41篇
  2010年   37篇
  2009年   26篇
  2008年   23篇
  2007年   21篇
  2006年   18篇
  2005年   9篇
  2004年   4篇
  2003年   15篇
  2002年   16篇
  2001年   12篇
  2000年   19篇
  1999年   41篇
  1998年   32篇
  1997年   15篇
  1996年   8篇
  1995年   7篇
  1994年   5篇
  1993年   2篇
  1992年   5篇
  1991年   5篇
  1990年   3篇
  1989年   6篇
  1988年   3篇
  1987年   3篇
  1986年   3篇
  1985年   2篇
  1984年   2篇
  1983年   5篇
  1982年   5篇
  1981年   4篇
  1980年   7篇
  1979年   2篇
  1978年   4篇
  1977年   6篇
  1975年   3篇
  1950年   2篇
排序方式: 共有898条查询结果,搜索用时 15 毫秒
891.
A large sample of human bones from a series of archaeological sites in the south‐eastern Iberian Peninsula was selected for δ13C and δ15N stable isotope analysis. Except for some contrast samples, the remains date from the first half of the second millennium cal BC and are ascribed to the Argar Culture, which developed during the Bronze Age in south‐eastern Iberia. Most authors have considered that this region reached a high degree of social hierarchical organization at this time, as demonstrated by the funerary record, both with regard to the grave goods and to the evidence of physical effort and diseases on the human remains. Results of the isotope analysis revealed the existence of differences among the settlements studied, as well as differences over time within every settlement and among the various individuals tested. Some variances can be assigned to social classes/status and others are linked to chronological factors. In particular, changes in δ13C can be explained by the increasing aridity of the first half of the second millennium cal BC, although other causes can be put forward too.  相似文献   
892.
ABSTRACT

For many European rural areas, the rural development programmes based on the LEADER approach constitute the main policy for promoting tourism. Going a step further than a rural development programme, LEADER represents an ideal method for overcoming some of the challenges involved in rural tourism development, such as the integration of tourism supply through public-private organizations or the coordination of multi-level policies. Despite its potential, there are difficulties involved in putting this approach into practice. This article aims to provide in-depth understanding of the challenges faced by some managers responsible for developing tourism strategies through the LEADER approach. To do this, semi-structured in-depth interviews have been held with Local Action Groups managers from Castilla-La Mancha (Spain). The main findings reveal that the actions of regional governments lead to the limitation and strangulation of the principle of subsidiarity according with the LAG manager? opinion.  相似文献   
893.
894.
Archaeological examples of violence in prehistory have increased in recent years. The evidence, methodology employed and interpretation of the data have been diverse, but in each case the myth of the ‘peaceful past’ is questioned. This work provides new data on the issue from the north‐eastern Iberian Peninsula, associated with the Bell Beaker culture (c.2800–2350 cal BC). Material from two megalithic tombs, Can Gol I and Can Gol II (Barcelona Province), in particular a set of flint arrowheads, has been revisited. Use‐wear analysis on the arrowheads confirmed the presence of impact fractures. This indicates that the arrowheads were not funerary offerings, but that they entered the graves lodged in the bodies of the deceased. The data from the only site with evidence of massive death by violence in the neighbouring region (Costa de Can Martorell) reinforce the hypothesis of episodes of conflict and violence during prehistory. However, the interpretation of the nature of such violence remains open to debate: was it an act of warfare or an occasional skirmish? And is the image of the Bell Beaker warrior identified in other European contexts also applicable to this area?  相似文献   
895.
陕西境内遗址出土后短时间内表面产生白色物质CaSO42H2O是非常普遍的现象。本研究利用土柱模拟遗址出土后表面产生CaSO42H2O的过程,通过监测土柱中土壤的湿度、含盐量及离子变化综合分析CaSO42H2O产生的原因,研究结果表明遗址出土后形成了新的界面层,在蒸发的作用下,地下水沿土壤孔隙向上迁移,同时将可溶盐带入土壤中,表面的可溶盐含量逐渐增大,达到峰值后不再增加,实验后测得表面土壤中的Ca2+和SO2-4是原始土壤的数十倍,说明遗址表面产生CaSO42H2O是水盐运移的结果。本研究可为遗址出土后预防CaSO42H2O的产生提供依据。  相似文献   
896.
The authors describe the discovery of the remains of two unidentified skeletonised individuals in a small town located in southern Italy. The bodies were discovered while workers were preparing to lay an oil pipeline. The two individuals were found at a depth of 2 meters, and in very close proximity to one other. The recovery process of the skeletonised remains and their related findings, carried out by a team of forensic anthropologists and archaeologists, is described here.Archaeological examination determined that the remains date back to the 4th millennium B.C. Forensic anthropological and odontological examinations were performed to determine the biological profile of the skeletal remains by estimation of age and height, as well as the determination of sex. Age determination was performed by the Kerley and Ubelaker (1978, Revision in the microscopic method of estimating age at death in human cortical bone. Am. J. Phys. Anthropol., 49, 545–546) histological method using a 1 mm thick piece of bone tissue taken from the diaphyses of femur in both individuals. Dental age was estimated by examining root transparency. In order to determine the height of the individuals, various research methods based on the dimensional values of particular skeletal structures were applied. DNA analysis showed genotype differences of all the systems as compared to the haplotypes of present day subjects. This provided confirmation that the skeletal remains were from individuals of an ancient population (4th millennium B.C.). In addition, radiocarbon dating provided useful information as to the approximate period of death of the individuals. Interpretation was further enhanced by analysis of various bone fragments from each of the skeletons by high resolution mass spectrometry. 3D computerized imaging was used to analyse the patterns of skull fractures present, which resulted in supporting the hypothesis that the fractures were caused by stoning.  相似文献   
897.
898.
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