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   74篇
  免费   4篇
  2023年   3篇
  2022年   2篇
  2021年   2篇
  2020年   1篇
  2019年   3篇
  2018年   2篇
  2017年   4篇
  2016年   5篇
  2015年   3篇
  2014年   1篇
  2013年   6篇
  2012年   6篇
  2011年   2篇
  2009年   2篇
  2008年   6篇
  2007年   5篇
  2006年   1篇
  2005年   3篇
  2003年   3篇
  2002年   3篇
  2001年   1篇
  1999年   1篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1986年   3篇
  1985年   1篇
  1984年   1篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
排序方式: 共有78条查询结果,搜索用时 15 毫秒
71.
This article traces the location of foreign banks in Germanyfrom 1949 to 2006. As suggested by New Economic Geography models,we find an inverted ‘U’-shaped concentration offoreign banks in Germany. Only after a competition between severalcities, Frankfurt has emerged as the pre-eminent financial centre,triggered by the ‘historical event’ of setting upthe German central bank in Frankfurt. After a strong increase,Frankfurt's share in the location of foreign banks in Germanydecreases slowly but significantly since the mid-1980s. We concludethat there will be a lesser role in Europe for second-tier financialcentres in the future.  相似文献   
72.
为探讨官庄遗址两周之际制陶原料的选取与陶泥料加工工艺的差异,本研究以官庄遗址泥料坑出土夹砂陶泥料、泥质陶泥料及泥制陶坯、夹砂陶坯,和遗址所在自然沉积地层中的全新世古土壤、马兰黄土、附近枯河河道河砂为主要研究对象,采用粒度、磁化率、X射线荧光光谱(XRF)分析方法对样品进行分析实验。研究结果表明:1)官庄制陶原料来自于遗址所处地点的晚更新世、全新世以来的沉积地层,其中夹砂陶泥料和陶坯中的羼合料主要取自于枯河河道中的河砂;2)遗址使用期间,早晚不同时期的陶泥料选取和加工工艺有所不同——早期以马兰黄土或全新世古土壤为原料,经严格的淘洗工序后,选用优势组分为1~11 μm的部分添加河砂制备成夹砂陶泥料,粗粒河砂与细粒黏土比例为1∶4;而晚期出现了以全新世古土壤为原料,直接或只经过简单淘洗工序后制备成泥质陶泥料。  相似文献   
73.
74.
The excavation of the Library site in Trondheim uncovered the medieval cemetry of St. Olav's church containing 388 skeletons, of which 248 had skulls with teeth. Sex assessment was based on osteological criteria, and for 145 skeletons sex classification was performed with a high degree of certainty. The remaining 103 were classified as uncertain male, uncertain female and sex undetermined. Mesio-distal and facio-lingual crown widths of permanent teeth in the group of reliably assessed males and females were used in sex-discriminant analyses. A combination of two or more teeth was less effective in discrimination than using one tooth alone. This was due to missing data in the combined variable sets and thereby loss of cases. Missing variables were due to post-mortem tooth loss, attrition or large deposits of calculus. The teeth were ranked according to their power in sex discrimination. The left maxillary first molar (26) represented by its facio-lingual dimension was the best sex discriminator (classified 85 per cent of the cases correctly), followed by the right maxillary first molar (16) also represented by its facio-lingual dimension (classified 77 per cent correctly). With only one variable in the discriminant function, a critical value could be calculated and tabulated for each tooth. This was used in sex assessment of the osteologically undetermined and uncertain groups. Only variables that could sex classify correctly at least 70 per cent of the cases with the Jack-knife procedure were used. Sex assessment could be made for 16 of 24 (66.7 per cent) of the osteologically sex-undetermined adult individuals and for 21 of 44 (47.7 per cent) of the children. Of 35 osteologically uncertainly sex-assessed skulls, only nine (six men and three women) corresponded with dental classification.  相似文献   
75.
In the ground, bone undergoes chemical and physical changes which affect its preservation. This fact has important implications for dating and other analytical procedures involving bone, as well as faunal analysis where differential preservation of bones of different species may affect conclusions regarding the relative significance of an animal to the economy of a given society. The diagenic processes in bone range from minor changes in the bone protein to complete structural and chemical breakdown.Using fresh cow bone, we conducted laboratory experiments which simulate the effect of temperature and bone size on the rate and nature of bone disintegration in archaeological sites. Temperature influences the rate of chemical change, and bone size and density affect the accessibility of the molecular constituents of bone to extrinsic chemical reactions. These findings clarify the importance of two well-known concepts in bone taphonomy. (1) The rate of chemical breakdown in bone tissues is related to the proximity of a given unit of tissue to the bone surface. This means that, in archaeological bone samples, tissue near the surface may be different chemically from tissue away from the surface and great care is necessary in choosing and preparing bone samples for analytical procedures. (2) In general, small bones are not as well preserved as large bones, therefore small animals are likely to be underrepresented in faunal assemblages.  相似文献   
76.
ABSTRACT

The residents of the Canary Archipelago consumed limpets since the arrival of humans ~2500 yrs. ago, and these harvested gastropods were deposited in large coastal shell middens. This work preliminarily explores shell margin oxygen isotope composition (δ18O) and body size of the black limpet (Patella candei d’Orbigny, 1840) from archaeological sites in the Canary Islands to assess possible seasonal variability and intensity of shellfish collection throughout the late Holocene. The shell margin δ18O values of 100 shells (radiocarbon dated between ~500 and ~1800 cal. yr BP) were analysed to estimate sea surface temperature (SST) at time of death. Paleotemperature estimates suggest shellfish harvesting was not year-round, and was avoided in the cooler months (when SST?<?20°C). This pattern differs from most higher latitude Mesolithic and Neolithic human groups, which gathered shellfish year-round, targeting winter more heavily. Preliminary body-size measurements suggest shell sizes have experienced a decline from aboriginal times to the present, which possibly resulted from increasing anthropogenic pressures. During aboriginal inhabitation, maximum adult shell size remained stable, suggesting that present-day harvesting practices are more intense than harvesting from aboriginal human groups. This intensive collection has likely diminished the average adult size of limpet populations in the islands by ~27%.  相似文献   
77.
Sampling seeds     
Problems of sampling carbonized plant material are discussed. Firstly, the problem of actually selecting a sample in the laboratory is considered, and some experiments which investigate various procedures are described. Secondly, the statistical aspects of determining optimal sample sizes are considered. Formulae are given for calculating optimal sample sizes and confidence intervals. Upper bounds, which are independent of the total population size, are provided for the sample size required to achieve any desired accuracy.  相似文献   
78.
Guanzhuang site is located in the west of Guanzhuang Village, Gaocun Township, Xingyang City, Henan Province. From the site, more than 3 000 pottery moulds have been unearthed, with various types, including the moulds for containers, tools, chariots, weapons, money and core, etc. According to the types and decorations of pottery moulds and the characteristics of co - existing pottery, the pottery moulds of Guanzhuang site can be divided into two periods—Phase I dating from the late Western Zhou Dynasty to the early Spring and Autumn Period, and phase TJ considered between the early and middle Spring and Autumn Period. The change of bronze ware styles from the Western Zhou Dynasty to the Spring and Autumn Period was important in the development of ancient Chinese bronze wares. Due to the lack of archaeological data, research on pottery moulds during the two - week period was still insufficient; discussion of the important issue of standardizing the sources of raw materials was also relatively weak. Environmental archaeology has relatively mature methods and practices in depositional dynamics, depositional processes and provenance tracing, which could provide new ideas for further in - depth discussions on this issue. In order to understand the material sources and craftsmanship of pottery moulds unearthed from Guanzhuang site in Xingyang, Henan Province, samples of Guanzhuang pottery moulds and natural sedimentary strata were studied using particle size analysis, XRF and petrographic analysis to give the following results. 1) The raw materials for mould - making were taken from the late Pleistocene Malan loess layer under the cultural layer of the site. The Malan loess underwent simple manual elutriation before being used to make pottery moulds. 2) A small amount of plant ash and calcium nodule powder was added during the production process of pottery moulds as an admixture to increase the high - temperature resistance. 3) The inner side of pottery mould for container was mainly made of Malan loess, while the outer one was made of a mixture of Malan loess and river sand with a blending ratio of about 7:5. Pottery moulds for various ware types had different processing techniques (e.g., moulds for containers were more refined). Besides, compared with early pottery moulds, later ones are relatively rougher, but the difference is not obvious. 4) The petrographic characteristics of double - layer container moulds indicate that there are different production processes for the inner and outer sides of mould. The inner side was made of Malan loess with finer particles—below 100 μm—as the raw material after elutriation, and there were traces of directional trimming. The outer one was made of a mixture of two parts of minerals (coarse and fine), and there was no obvious processing trace. Analysis of sample particle size is a new attempt to discuss the material sources of pottery moulds. The related discussion of mud - clarifying ponds is also helpful to understand the function of such relics and the formation process of accumulation in them. This study has important reference significance for exploring the material and craft characteristics of pottery moulds before and after the early Spring and Autumn Period in the Central Plains. © 2023, Sciences of Conservation and Archaeology. All Rights Reserved.  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