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   183篇
  免费   7篇
  2024年   2篇
  2023年   4篇
  2022年   2篇
  2020年   2篇
  2019年   1篇
  2018年   5篇
  2017年   4篇
  2016年   5篇
  2015年   8篇
  2014年   5篇
  2013年   22篇
  2012年   15篇
  2011年   15篇
  2010年   21篇
  2009年   18篇
  2008年   10篇
  2007年   9篇
  2006年   10篇
  2004年   1篇
  2003年   5篇
  2002年   3篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1997年   1篇
  1996年   1篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1981年   2篇
  1980年   2篇
  1979年   6篇
  1978年   2篇
排序方式: 共有190条查询结果,搜索用时 187 毫秒
111.
The Early Bronze Age barrows at Irthlingborough and Gayhurst in central England are notable for the large number of cattle (Bos taurus) remains associated with their human Beaker burials. Previous work using strontium isotope analysis has indicated that most of the cattle analysed, and one aurochs (Bos primigenius), were of local origin [Towers, J., Montgomery, J., Evans, J., Jay, M., Parker Pearson, M., 2010. An investigation of the origins of cattle and aurochs deposited in the Early Bronze Age barrows at Gayhurst and Irthlingborough. Journal of Archaeological Science 37, 508–515.]. In this study, stable isotope analysis of enamel and bone was carried out to investigate whether the mature cattle had experienced similar husbandry practices, climate and environment. Bulk carbon, nitrogen and sulphur isotope analysis of collagen suggested most were consuming similar sources of plant protein from environments probably local to the sites and this was supported by high resolution intra-enamel carbon isotope profiles. Oxygen isotope profiles indicated the aurochs and most of the cattle experienced similar climatic regimes: the only exception being an animal with a non-local strontium isotope ratio. However, a comparison of seasonality profiles of the local animals using estimated tooth formation times showed that there was no consistency in season of birth: the animals appeared to have been born throughout the year. Cattle can breed throughout the year but it requires considerable human effort and intervention to successfully overwinter young stock; it is therefore unlikely to have been carried out without good reason and benefit if winters were harsh. One reason is to ensure a continuous supply of milk. Measuring oxygen isotope profiles to identify year-round calving may thus be a potential indicator of dairying economies.  相似文献   
112.
水硬石灰兼具石灰和水泥的优点,低收缩、耐盐、适中的抗压和抗折强度、水溶盐含量低,同时与传统的砖石建筑兼容性好,是一种天然、无污染、耐老化的无机材料。本工作针对花山岩画的开裂特点制订出相应的力学参数要求,配制出两种不同的水硬石灰砂浆,并对这两种砂浆的力学性能进行了分析。同时探讨了不同养护条件对水硬石灰砂浆拉拔强度的影响。现场试验结果说明,填补粘结材料可以提供一定的粘结强度,并且具有使用方便,污染小的特点,可用于花山岩画开裂岩体应急保护加固处理。  相似文献   
113.
Sydney (Yellow Block) Sandstone is the primary building material used in many nineteenth century buildings in Sydney, Australia. As a natural material, it is subject to deterioration in the salty environment and in extreme cases will need to be removed and replaced. Two cornice pieces have been removed from State Heritage Registered, the Australian Museum due to evidence of visual decay patterns including surface degradation, slight sanding, granular disintegration, contour scaling and flaking, pitting, discoloration, soiling, alga growth and there are missing parts. Stone samples removed from within these building elements were tested for their engineering properties after over 100 years of natural exposure. It was found that the stone has become weaker, softer, less durable, and has an increased capacity to absorb water. The stone was found to be more susceptible to attack from sodium sulfate ingress as opposed to sodium chloride, which would have contributed to the weathering effects noted on the stone. The degree of exposure experienced by each building element was also found to be a factor in the loss of stone quality.  相似文献   
114.
The nature of long bone formation and the pathways of interaction between bone samples and the burial environment suggest that portions of the bones disconnected from the arterial system are resistant to diagenetic alteration. Preliminary work on femurs from Early Bronze Age hunter-gatherers in Cis-Baikal, Siberia shows that the nature and progression of chemical changes in the bone matrix due to microbial attack can be analyzed using laser ablation inductively coupled plasma mass spectrometry. Intra-osteon variability in elemental concentrations and strontium isotope ratios (87Sr/86Sr) indicate the presence of unaltered portions of bone within diagenetically modified bone and suggest that useful data remain accessible. These biogenic signals can potentially be useful for mobility research in broad terms and the smaller timescales within an individual's lifetime (months, years), accessible therein. Laser ablation micro-sampling of femur specimens showed that intra-osteon elemental composition of Ba, Re, and Cs varied within and was correlated between multiple osteons of a single bone. Portions of chemically unaffected bone were identified within, and effectively discriminated from diagenetically altered bone tissue. Areas showing visual alterations and erratic or uncorrelated Ca and Sr elemental results also had anomalous Sr isotope ratios, suggesting diagenetic alteration in those places. Compositional and isotopic analysis of intact portions of bone supports the hypothesis that hunter-gatherer groups in Cis-Baikal made numerous major movements during their lives. Microscopic analysis of long bones clarifies aspects of biodeterioration and correlations between trace elemental results and diagenetic alteration. Micro-sampling of intact portions of bone expands the scope of available materials for research on mobility and other aspects of human past behavior.  相似文献   
115.
Investigators have long recognised the effects of microbial activity on archaeological bone. These investigators, however, have focused on single or groups of microbes rather than on complex microbial aggregates such as biofilms, a focus that has affected our understanding of archaeological bone biodeterioration. In this paper, we report on the investigation of a biofilm in archaeological human bone from the site of Tell Leilan, Syria (2900–1900 BCE). Scanning electron microscopy indicated that the biofilm is characterised by single cells and microcolonies of bacteria and fungi, as well as calcite crystals that were all embedded within extracellular polymeric substances. Using culture techniques and DNA sequencing, we isolated and identified several microbes from the biofilm including Amycolatopsis sp., Penicillium chrysogenum, Aspergillus sp., Chaetomium sp., and Cladosporium sp. Having characterised the Leilan biofilm, we are now closer to understanding the complex process of bone biodeterioration in archaeological bone collections.  相似文献   
116.
Trace element analysis related to archaeological bone is viewed as one way to determine levels of element exposure in past populations. This area of research is complex because there is the potential for the incorporation of trace elements from the burial environment into archaeological bone. We tested the hypothesis that matching the spatial distribution of trace elements within cortical bone with the biological structures would provide evidence of biogenic uptake. We examined samples from a non-segregated Royal British Naval cemetery (1793–1822) in Antigua, West Indies. A key historical question related to this population was the extent of exposure to lead and the resulting health effects. Images from conventional light microscopy (histological) analysis of the bone samples were matched with elemental maps of calcium, strontium, and lead that were created through the use of synchrotron radiation X-ray fluorescence (SR-XRF). Biogenic uptake of both strontium and lead was indicated based on the localization of these trace elements within discreet microstructural elements. The successful integration of histological information with XRF data is a powerful technique for the interpretation of past biological events through trace elements.  相似文献   
117.
章太炎是20世纪中国现代学术的重要奠基人,他对甲骨文的态度引起学术界的关注和争论。本文以章氏晚年弟子的回忆、章氏晚年的讲演记录和书信为主要资料,认为章太炎晚年对甲骨文仍然持消极、怀疑态度,但已有转变的趋向;对他持这种态度的原因进行了剖析。章氏的甲骨文态度已成为一种文化现象,学界对他甲骨文态度的不同评论,一定意义上折射出现代学术史上的学派分野。  相似文献   
118.
Early Stone Age cut marks are byproducts of hominins' tool-assisted animal carcass consumption and provide a potential avenue of inference into the paleoecology of hominin carnivory. If diagnostic cut mark characteristics can be linked to flake and core tool use or the completion of distinct butchery actions, it may be possible to infer ancient tool preferences, reconstruct the consumption of specific muscular tissues, and illuminate landscape-scale stone resource use. Recently, diagnostic morphological criteria including cut mark width and depth have been used to identify marks made by different classes of experimental and archaeological stone tools (Bello, S.M., Parfitt, S.A., Stringer, C., 2009. Quantitative micromorphological analyses of cut marks produced by ancient and modern handaxes. Journal of Archaeological Science 36: 1869–1880; de Juana, S., Galan, A.B., Dominguez-Rodrigo, M., 2010. Taphonomic identification of cut marks made with lithic handaxes: an experimental study. Journal of Archaeological Science 37: 1841–1850; Dominguez-Rodrigo, M., de Juana, S., Galan, A. B., Rodriguez, M., 2009. A new protocol to differentiate trampling marks from butchery cut marks. Journal of Archaeological Science 36: 2643–2654). The work presented here adds to this experimental butchery database by using measurements of cut mark cross-section taken from bone surface molds to investigate how stone tool characteristics including flake versus core tool type, edge angle, and tool weight, influence cut mark width and depth, ultimately testing whether cut mark size is a useful indicator of tool identity. Additionally, these experiments investigate the influence of contextual factors, including butchery action, carcass size, and bone density on cut mark size. An experienced butcher used replicated Oldowan flakes and bifacial core tools in experimental trials that isolated skinning, bulk and scrap muscle defleshing, and element disarticulation cut marks on goat and cow skeletons. This sample explores cut mark traces generated under realistic butchery scenarios and suggests the following results: 1) Core and flake tools were equally efficient at completing all butchery tasks in size 1 and 3 bovid carcasses. 2) Samples of cut mark width and depth produced by core and flake tools were similar and cut marks could not be accurately classified to a known tool type. 3) Skinning and disarticulation activities produced significantly wider and deeper marks than defleshing activities. 4) Cut marks on cows tended to be wider and deeper than those on goats. 5) Cut mark width is negatively correlated with bone density when carcass size and bone portion are taken into consideration. These results suggest that a general quantitative model for inferring tool type or edge characteristics from archaeological cut mark size is not warranted.  相似文献   
119.
陈胜前  罗虎 《考古》2012,(4):7-13,109
华龙洞旧石器时代遗址出土了丰富的动物骨骼化石、加工使用痕迹清晰的骨器和百余件石制品。其石制品组合具有旧石器时代晚期工业的特征。动物骨骼化石上同时发现了动物啃咬与人工切割的痕迹,推断该遗址的动物骨骼被人类利用,但人类可能是利用动物残余的食腐者,而非这些动物的狩猎者。  相似文献   
120.
贾湖骨笛是迄今为止我国历史上最早、形态完整、现今仍可演奏的吹管乐器,是9000~7500年前中国古代科技文明最重要的实物载体之一。由于骨笛经历数千年的埋藏,出土时多数已经破损。如何对破损的贾湖骨笛进行精确复制,是学界急待解决的难题。我们巧妙地利用CT扫描、数据处理、三维模型重建、虚拟复原与激光快速成型技术,复原出与M494:2号骨笛实物十分接近复原品。这种利用计算机虚拟修复的思想与技术为破损贾湖骨笛的复原开辟了一条新的技术途径。  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