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   246篇
  免费   9篇
  2023年   2篇
  2022年   1篇
  2021年   1篇
  2020年   2篇
  2019年   8篇
  2018年   11篇
  2017年   6篇
  2016年   16篇
  2015年   5篇
  2014年   6篇
  2013年   65篇
  2012年   6篇
  2011年   13篇
  2010年   11篇
  2009年   10篇
  2008年   9篇
  2007年   3篇
  2006年   8篇
  2005年   5篇
  2004年   2篇
  2003年   1篇
  2002年   1篇
  2001年   9篇
  2000年   3篇
  1998年   3篇
  1997年   2篇
  1995年   3篇
  1994年   2篇
  1993年   2篇
  1992年   1篇
  1990年   2篇
  1987年   2篇
  1986年   3篇
  1985年   1篇
  1984年   2篇
  1983年   2篇
  1981年   2篇
  1980年   4篇
  1978年   4篇
  1977年   1篇
  1976年   2篇
  1974年   2篇
  1973年   1篇
  1972年   2篇
  1971年   2篇
  1969年   2篇
  1968年   2篇
  1966年   1篇
  1960年   1篇
排序方式: 共有255条查询结果,搜索用时 31 毫秒
121.
122.
123.
124.
125.
Expectations for survival of vertebrate remains have been well developed and intensely studied in the zooarchaeological taphonomic literature. Taphonomic studies of shellfish remains focus on marine species and on variables relevant to remains from paleontological contexts (e.g., fossil marine beds). In this paper we develop a conceptual framework from which to derive expectations concerning the preservation of freshwater mussel remains focusing on two parameters, shell microstructure and shell shape. Shell size does not influence survivorship. Our model is validated through application to late Holocene zooarchaeological mussel assemblages from north Texas. Taphonomically robust species are important regarding zooarchaeological and biogeographic interpretations based on mussel paleofaunas, and fragile species are important indicators of whether or not an assemblage is well preserved.  相似文献   
126.
Extraction of protein residues from archaeological matrices, such as pottery clay, lithics, and grinding stones, has proven to be methodologically challenging. Protein residue analysis is fraught with technical challenges in analytical chemistry. In cooking pottery, protein residues are thought to bind to clay surfaces in vessel walls through a variety of primarily non-covalent interactions. Removal of protein residues requires the disruption of these interactions, and a diverse set of tools has been proposed and applied. Here, we test extraction procedures through varying combinations of physical parameters and solvents to derive an optimal approach yielding efficiencies of recovery from experimental pottery above 60%. The utility of our extraction approach was further validated through liquid chromatography?Cmass spectrometry analysis of experimental residues. We have identified several hurdles to developing a successful study of protein residues from pottery, each of which is surmountable with additional method development in the realm of archaeological chemistry.  相似文献   
127.
Adipocere has, infrequently, been reported from archaeological contexts normally on the external surface of bodies. In contrast to those cases, this study focuses on a white, powdery and greasy substance found inside two right human femora during sampling. These samples were obtained from two identified individuals buried in the late 19th century, who were exhumed from a rock‐cut and a brick‐lined grave in a steeply sloping graveyard with wet soil conditions. Both individuals were buried in coffins. Fourier transform infrared spectroscopy was used to test the composition of the substances, and both were found to conform to the spectrum of adipocere. This is likely to be a breakdown product of the fats in bone marrow in an anaerobic, moist environment mediated by bacteria. None of the other individuals (n = 6) buried in similar graves displayed evidence of adipocere; this includes those whose femora were in a similar state of preservation (n = 4). Contemporaneous data on precipitation for the month of burials do not highlight any obvious trends, but one of the individuals was found in a water‐logged grave. The similar preservation of other femora buried in brick‐lined graves highlights the interplay of multiple factors in the formation and degradation of adipocere. More importantly, it demonstrates differential preservation, which may impact on DNA and other biomolecular research. Furthermore, this adds to the limited data currently available on adipocere found in archaeological contexts. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
128.
Isotopic analysis of human bone is becoming an increasingly important tool for the archaeologist in divining past life-ways. The isotopic ratios within bone are often assumed to be preserved as in life, but diagenetic change can alter the ratios, invalidating the results of isotopic analysis. Diagenesis can be evaluated in a number of ways, but most often spectroscopic techniques are utilised as the most efficient and easiest to understand methods for the archaeologist. Many isotopic studies do not report the possibility of diagenetic change, and if it is reported it has often been quantified using a single method of chemical analysis, FTIR spectroscopy. This study set out to test the value of FTIR analysis using human remains from the prehistoric site of Ban Non Wat, Northeast Thailand, and to compare the results with the non-destructive technique of FT-Raman spectroscopy. The study shows that FTIR spectroscopic analysis gives far less detail on the condition of bone than Raman spectroscopy, which does not merely indicate recrystallisation has occurred, but also shows clearly whether or not collagen is present, allows identification of ionic substitions which have occurred and identification of secondary minerals which have formed. Raman spectroscopy, combined with LA-ICP-MS analysis also revealed that soil composition and groundwater flow are the conditions which most affect diagenesis at Ban Non Wat.  相似文献   
129.
130.
Heritage sites regarded as important are safely managed by the state, voluntary or private sectors but the majority of sites, despite statutory protection, remain unrecognised and without a role in their host communities. New schemes such as the Local Heritage Initiative in the UK aim to encourage communities to recognise their heritage assets and in managing them effectively to contribute to their preservation. With reference to the case of Nether Poppleton near York (UK), the present study explores the factors and conditions for effective community management displayed in one locality by groups who are successfully conserving and managing a diverse set of local heritage sites. Interviews and joint tasks enabled an analysis of the complex range of factors and conditions that can lead to a successful community-based initiative. Future research will determine the extent to which these factors, if applied to other sites, might produce the same results. The importance of this agenda is underscored by the increasing reliance on community-based heritage management in the UK and elsewhere.  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