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   291篇
  免费   8篇
  2023年   2篇
  2022年   1篇
  2020年   7篇
  2019年   9篇
  2018年   1篇
  2017年   14篇
  2016年   12篇
  2015年   17篇
  2014年   10篇
  2013年   21篇
  2012年   18篇
  2011年   17篇
  2010年   17篇
  2009年   11篇
  2008年   8篇
  2007年   12篇
  2006年   20篇
  2005年   10篇
  2004年   7篇
  2003年   3篇
  2002年   9篇
  2001年   7篇
  2000年   2篇
  1999年   3篇
  1998年   2篇
  1997年   6篇
  1996年   6篇
  1995年   6篇
  1994年   6篇
  1993年   8篇
  1992年   4篇
  1988年   1篇
  1987年   1篇
  1985年   6篇
  1984年   5篇
  1983年   7篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
排序方式: 共有299条查询结果,搜索用时 272 毫秒
31.
This paper presents preliminary results of new radiocarbon dating of human, faunal and fish skeletal remains from a number of the cemeteries from the Middle and Lower Dnieper Basin, Ukraine. The results appear to demonstrate the presence of a radiocarbon reservoir effect during the Neolithic–Eneolithic periods, the first time that this has been identified in this region. The data indicate that the radiocarbon reservoir effect is currently only evident during these periods, and not in the earlier Epipalaeolithic–Mesolithic periods, prompting the suggestion that the radiocarbon reservoir effect is associated with elevated fish consumption from the Neolithic period onwards.  相似文献   
32.
This study presents the application of multi-element soil analyses (X-ray fluorescence spectroscopy and inductively coupled plasma optical emission spectroscopy of 1 M HCl extracts) to grid samples from 3 archaeological house plans embedded in sandy clays, clays and sands to assess effects of site lithology on geochemical signatures of human occupation.  相似文献   
33.
A paucity of archaeological remains of Atlantic salmon in Northeast North America has been cited as evidence that the species may have been present in the region only during and after the Little Ice Age (ca. 1450–1850 AD), one of coldest periods of the Holocene. However, significant problems of preservation, recovery and identification remain. Here, improved methods of identification use vertebra structure to distinguish salmon from trout, and strontium/calcium ratios to differentiate sea-run from landlocked salmon. In addition to the Little Ice Age, Atlantic salmon is identified in tightly dated contexts at 7000–6500 and 3500–3000 calendar years BP, during climate periods that were comparatively warm and wet.  相似文献   
34.
Zooarchaeologists have often employed studies of bone fracture morphology as a means of understanding past human cultural activity, and various methodological approaches have been developed for analyzing archaeological broken bone assemblages. It is widely understood that bones degrade over time, however, few studies have attempted to define and quantify the rate at which bones degrade and fracture morphologies change. This study examines degradation in frozen bones (−20 °C) and bones exposed to hot (40 °C) dry conditions. These two simulated environmental conditions represent extreme real-world climates, and allow for an actualistic understanding of the rates of degradation that bones experience in nature. When frozen, bones degrade slowly but significantly, and demonstrate measurable differences in samples frozen for 1, 10, 20, 40, and 60 weeks. In hot, dry conditions, bones degrade very quickly, and demonstrate measurable differences after 1, 3, 7, 14, and 21 days. These data allow for a more detailed understanding of the relationship between the cultural and natural processes that result in bone fracture, and the time period during which bones can be expected to maintain fresh fracture characteristics. This research also has implications for understanding human subsistence and survival strategies and for interpreting the archaeological record.  相似文献   
35.
Intra‐individual variations in carbon (δ13C) and nitrogen (δ15N) isotope measurements of dentine collagen in ungulate teeth can be related to diet and environmental changes at different periods during the life of the animal. A protocol of serial sampling of first, second and third molar roots was applied to modern caribou (17–27 months old) of the Qamanirjuaq herd (Rangifer tarandus groenlandicus), Canada. Based on a previous study, we predicted that M2 would reflect winter, M3 summer and M1 a complete year in terms of the isotopic record. Relatively high δ15N values (ca. 6 to 8‰), previously attributed to winter stress, were found in different molars of different specimens, reflecting a period of growth between April 1966 to April 1967. Previous results on other teeth from the same population confirmed that a high δ15Ncoll value signal corresponded to the winter of 1966/67. This temporary increase in δ15N value was probably linked to diet and/or environmental change. Collagen from M1 reflects the first winter whereas M2 and M3 reflect the second winter of life of young caribou. A longer time record including summer is represented by the bone collagen of the mandible. Results obtained on molar roots and mandible bone of the modern caribou of Banks Island herd (Rangifer tarandus pearyi) confirmed this seasonal record. Such collagen isotopic analysis on M1, M2 and M3 roots and jawbone can be applied to reindeer found in archaeological sites. Mandibles retaining deciduous premolars are preferable to avoid the possible loss of the winter tooth signal observed in animals older than 2 years. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
36.
Foraging ranges, migrations, and travel among Middle Holocene hunter–gatherers in the Baikal region of Siberia are examined based on carbon and nitrogen stable isotope signatures obtained from 350 human and 203 faunal bone samples. The human materials represent Early Neolithic (8000–6800 cal BP), Late Neolithic (6000–5000 cal BP), and Early Bronze Age periods (∼5000–4000 cal BP) and come from the following four smaller areas of the broader region: the Angara and upper Lena valleys, Little Sea of Baikal’s northwest coast, and southwest Baikal. Forager diets from each area occupy their own distinct position within the stable isotope spectrum. This suggests that foraging ranges were not as large as expected given the distances involved and the lack of geographic obstacles between the micro-regions. All examined individuals followed a similar subsistence strategy: harvesting game and local fishes, and on Lake Baikal also the seal, and to a more limited extent, plant foods. Although well established in their home areas, exchange networks with the other micro-regions appear asymmetrical both in time and direction: more travel and contacts between some micro-regions and less between others. The Angara valley seems to be the only area with the possibility of a temporal change in the foraging strategy from more fishing during the Early Neolithic to more ungulate hunting during the Late Neolithic–Early Bronze Age. However, the shift in stable isotope values suggesting this change can be viewed also as evidence of climate change affecting primary productivity of the Baikal–Angara freshwater system.  相似文献   
37.
This paper presents the results of new stable isotopes (carbon and nitrogen) analysis of human, faunal and fish remains from thirteen cemeteries from the Middle and Lower Dnieper Basin, Ukraine. The results are integrated with earlier analyses, undertaken solely on human samples, in order to provide a comprehensive overview of subsistence across the Upper Palaeolithic through to Eneolithic periods in this region. This is the first time that a combined sample of human, faunal and fish remains has been studied in order to interpret subsistence strategies across these periods in Ukraine. The total dataset comprises 113 samples of human, faunal and fish remains, 59 of which include new analyses of faunal and fish remains that have not previously been made available for study (Table 1). The analysis of the faunal and fish remains allows for a consideration of trophic levels which indicates that the consumption of freshwater fish occurs from the Epipalaeolithic period onwards. Whilst the majority of the cemeteries and the individuals therein cluster in relatively tight groups, there is a significant offset between the human and faunal samples due to the consumption of freshwater resources. The fish samples analysed in the study appear to exhibit a relatively random distribution when compared to the other samples analysed. In general, freshwater resources remain significant through until the end of the Neolithic period and into the Eneolithic period at the sites investigated.  相似文献   
38.
通过对几版藏于卡内基博物馆的甲骨的分析,发现它们反面的钻凿与正面刻辞的时代相异,提出殷墟甲骨中可能确实存在异代使用的现象。只是这些后刻的刻辞并非真正的卜辞,而是后来习刻者练习契刻的作品。这一问题的探讨对我们了解当时的甲骨保存制度、甲骨契刻技术的传承都是有益的。  相似文献   
39.
Bones treated at low temperature do not present major modifications although, macroscopically, boiled bones may be distinguished from unboiled ones as they are smoother, lighter and more transparent. Such observations should correspond to textural modifications at a nanometric level and should depend on boiling time. In this study, contemporary human bones, boiled during various time intervals, were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and nitrogen adsorption (BET). The results were used to estimate the boiling time in four archaeological samples (Neolithic bones from Malalmuerzo cave, Spain). It is concluded, comparing Neolithic bones to contemporary ones and from the textural characterization at a nanometrical level, that two of the archaeological bones were boiled and that they were boiled for less than 6 hours.  相似文献   
40.
Abstract

After a 20-year hiatus (1955–1975) during which few archaeologists discussed fluoride dating, the method again received attention in the 1980s and 1990s when some argued for its validity. As a dating method, fluoride dating depends on the rate at which fluorine ions replace hydroxyl ions in osseous tissue. The rate of replacement is influenced by the properties of the skeletal part (SP), sediment chemistry (K), and sediment hydrology (H), and the replacement rate influences estimates of time. Calibrated AMS radiocarbon assays of 10 black bear (Ursus americanus) femora from a natural-trap cave in central Missouri are weakly correlated with fluorine concentrations, determined by neutron activation analysis in the 10 femora. Despite minimal variation in SP, K, and H, results indicate fluoride dating can be considered a valid dating method only in cases when the chronological validity of its results are confirmed with independent chronometric data. As similarities in fluorine amounts across specimens increase, provenience information and bone orientation data as well as fine resolution data on K and H become critical to the application of fluoride dating.  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