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   55篇
  免费   2篇
  2023年   3篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2016年   7篇
  2015年   1篇
  2014年   2篇
  2013年   14篇
  2012年   1篇
  2011年   1篇
  2010年   2篇
  2009年   4篇
  2008年   1篇
  2006年   3篇
  2005年   1篇
  2003年   2篇
  2002年   2篇
  2001年   1篇
  1999年   1篇
  1993年   1篇
  1990年   1篇
  1989年   1篇
  1984年   1篇
  1983年   1篇
  1974年   1篇
  1969年   1篇
排序方式: 共有57条查询结果,搜索用时 31 毫秒
41.
For many years cultural layer 7 at the Ushki sites, Kamchatka was considered to represent the earliest human occupation of Beringia, because four radiocarbon dates indicated an age of 16,000–17,000 calendar years ago (cal BP). In 2003, however, Goebel et al. reported that layer 7 more likely formed only 13,000 cal BP, nearly 4000 years later than N.N. Dikov, the site’s primary excavator, originally reported. Some researchers have downplayed the significance of the new dates, continuing to regard Dikov’s early dates as evidence that at least some of the hearth and dwelling features previously excavated at Ushki-1 date to as early as 17,000 cal BP. Here we present four new radiocarbon dates (and two previously unpublished dates) on curated charcoal from hearth features excavated at Ushki-1 more than 20 years ago. They indicate that these hearths and associated dwelling features date to about 13,000 cal BP. We now know 15 radiocarbon dates on charcoal from a variety of features and profiles across Ushki-1 and Ushki-5 that indicate the age of layer 7 is about 13,000 cal BP. We discount the four 16,000–17,000 cal BP dates, first, because two of them came from a deeply dug human burial pit and were likely secondarily introduced into the burial; second, because provenience data for the other two dated samples were never reported and do not exist in the records of the radiocarbon laboratories that produced them; and, third, because sediments immediately underlying layer 7 at Ushki-1 are only a few centuries earlier than 13,000 cal BP, providing an important lower-limiting age for the layer-7 occupation. We conclude that the age of all of the layer-7 features at Ushki-1 and Ushki-5 should be considered to be about 13,000 cal BP, at least until the earlier obtained old dates of 16,000–17,000 cal BP can be replicated.  相似文献   
42.
ABSTRACT

This contribution summarizes the multiple uses of 3D web technologies in commercial archaeology. Considering the breadth of this topic, we will describe each different branch of these technologies with the example of case studies based on work of the Italian company Arc-Team. Our overview begins with 3D visualization for scientific purposes, showing a project funded by the Autonomous Province of South Tyrol (Italy) in order to improve knowledge about WWI. Second, we analyze a similar project, funded by the Autonomous Province of Trentino (Italy), but with the aim to increase tourism at a high alpine WWI site. The third example is the development of another prototype for tourism: a 3D web-map for the cultural valorization of the historical border (1753) between the region Tyrol and the Most Serene Republic of Venice. In the forth case study, we discuss the implementation of 3D within web platforms for archaeological project management of RAPTOR (Ricerca Archivi e Pratiche per la Tutela Operativa Regionale), a webGIS developed to aid in preservation and conservation efforts of cultural heritage for the Italian Ministry of Cultural Heritage and Activities and Tourism (MiBACT). Fifth, we explore recent uses of 3D models for web-coworking during the process of excavation management, thanks to the developments of real-time 3D acquisition techniques based on SLAM algorithms and archeorobotic devices. Finally, 3D web-coworking is also analyzed illustrating some simple web tools that afford rapid feedback in data visualization, considering not only excavation field-work but also exploration projects. This overview, based on six different case studies, represents the four fields in which 3D web technologies are currently used in commercial archaeology: scientific communication; tourism improvement; preservation of cultural heritage; and real time field-work management. Some specific topics such as tourism improvement and field-work management are investigated in greater depth in order to allow us to analyze variables deriving from customer requests (e.g. restrictions regarding sensitive geolocation or preferences for specific web platforms) and from differences among data acquisition technologies based on various sensors.  相似文献   
43.
44.
The first objective of this study is to reconstruct levels and types of physical activity and associated sexual and social differences using human skeletal remains from the predominately 19th century Dutch cemetery of Middenbeemster. For most individuals, life in the Beemster centred around dairy farming and was heavily based on manual labor, with a purported higher class of wealthier individuals performing less manual labor. Two skeletal markers of activity are examined in the upper limb of late young adult and middle‐aged adults of both sexes (26–49 years, n = 69): osteoarthritis (OA) and entheseal changes (EC). Results support the hypothesis that the majority of the population engaged in high levels of physical activity; however, a group with a clearly lower or different pattern of activity, possibly representing a higher, less active class, was not discernible. This may be due to a low number of less active individuals in the analysed sample and/or the heterogeneity of occupations and activities. A gendered division of labour was evident in the EC data with males having more pronounced muscle attachments in almost all sites, especially the biceps brachii, used primarily in lifting. Females had more pronounced triceps brachii, which may be due to activities that required pushing or pulling with the elbow in a flexed position. The prevalence and severity of OA did not differ between the sexes. While this could be interpreted to indicate men and women engaged in a similar level of strenuous activity, hormonal and anatomical differences limit the strength of the comparison. The second objective of this study is to evaluate the concordance of OA and EC as activity markers. The correlation between OA and EC is very low, illustrating their variable and complex etiologies. Etiological factors need further research for OA and EC to become more reliable activity markers. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
45.
It was during two train-journey meetings with the physicist William Lawrence Bragg (1890–1971) that both Charles Percy Snow's (1905–1980) civil service career and, if the anecdotal evidence is to be believed, the ‘two cultures’ metaphor originated. The first part of this paper is concerned with the background, consequences and significance of the first of these journeys: Kettering station in 1939. It will address the somewhat hazy record of Snow's wartime work found in existing accounts, and argue that Snow's wartime experience helped shape his characterisation of the scientific side of his ‘two cultures’. The second part of this paper deals with Bragg's intellectual influence on Snow, tracing the former's interest in ‘two cultures’ arguments prior to probable encounters between the two on the Cambridge to London train in the late 1940s and early 1950s, including a historically hazy one in which together they allegedly coined the famous phrase. In examining their early relationship, it becomes clear that Bragg was a key influence and support in Snow's career as an administrator and as a cultural commentator.  相似文献   
46.
Eight prehistoric wells dug to a depth of ∼2 m below the modern ground surface were found in the alluvial sediments of McClellan Wash on Gila River Indian Community in southern Arizona. Charcoal from the sediments filling the wells yielded radiocarbon ages of ∼1000 B.C. The time in which wells were dug coincides with a period of general regional aridity and high ENSO activity in the American Southwest. Digging to access water may have occurred in response to period(s) of resource uncertainty, or as a logistical activity that engaged increasingly resource-tethered Late Archaic/Early Agricultural populations. These activities laid the foundation for agricultural practices that eventually became the dominant mode of subsistence in the low-lying areas of the Sonoran Desert.  相似文献   
47.
秦俑二号坑土壤干缩特征研究   总被引:1,自引:0,他引:1  
通过对秦俑二号坑土壤胀缩作科学研究,监测数据对比,运用土壤干缩特征理论,构建了秦俑二号坑土壤干缩特征曲线,结果发现秦俑二号坑干燥进程较为迅速,2000年以前二号坑干燥化尚未对彩绘陶器造成威胁和侵害,但近年来土壤含水量已由挖掘初期的15%~20%,降低到目前的2%~8%,对坑下文物表面彩绘构成威胁。通过补充土壤水份等办法可以减缓这种变化。  相似文献   
48.
The Topper and Big Pine Tree sites are located along the central Savannah River in South Carolina. Both sites contain significant Clovis horizons and the Topper site is reported to contain a pre-Clovis assemblage characterized by a smashed core and microlithic industry. The stratigraphic position of the early assemblage at Topper is indeed below Clovis and radiocarbon and luminescence ages support its pre-Clovis age. However, the human origin of the proposed artifacts has not been conclusively proven. The late Quaternary stratigraphic sequence developed for this segment of the Savannah River provides support for a regional pattern of river metamorphosis over the last 50,000 years in southeastern U.S. streams.  相似文献   
49.
路德维格一世在1825—1848年间任巴伐利亚的国王,1863年他从尼姆鲁德遗址获得了7个浅浮雕艺术品。最近进行的对这些浮雕作品的修复使得其上残留的原始彩绘重新被人们发现,本文讨论了对这些原始彩绘面貌进行重现的可能性及存在的相关问题。  相似文献   
50.
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