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   92篇
  免费   5篇
  2023年   6篇
  2020年   3篇
  2019年   4篇
  2017年   1篇
  2016年   2篇
  2015年   2篇
  2014年   2篇
  2013年   8篇
  2012年   10篇
  2011年   5篇
  2010年   6篇
  2009年   5篇
  2008年   12篇
  2007年   4篇
  2006年   4篇
  2004年   3篇
  2001年   6篇
  1998年   2篇
  1996年   1篇
  1993年   1篇
  1992年   1篇
  1984年   2篇
  1981年   2篇
  1980年   2篇
  1979年   3篇
排序方式: 共有97条查询结果,搜索用时 62 毫秒
31.
A combination of Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD) and portable X-ray fluorescence spectroscopy (PXRF) was used on the clay fraction of Ertebølle ceramics from several Late Mesolithic sites in Scania, southern Sweden. The aim was to provide up-to-date information about clay types used during that period within the Scanian Ertebølle cultural unit, and to elucidate social aspects relevant to the organization of pottery production and the role of ceramics in the local societies. The results suggest similar clay preferences across the sites, site-based pottery production using local clays and zero mobility of ceramics between the sites. The chemical separation of the ceramics from the site of Soldattorpet into two compositional groups suggests possible multigroup occupation. The origins of aromatic hydrocarbons, extracted previously from the ceramic matrix of the vessels during a lipid residue study, were also investigated, and a discussion is provided.  相似文献   
32.
中子衍射和成像技术是利用中子束穿透性强、元素分辨率高等特点,对物体进行原位、无损和块扫描,实现材料组成定性定量分析和内部结构可视化检测。在此通过介绍中子衍射和成像技术的基本原理和特点,总结其在国内外文物领域的应用研究现状,显示中子衍射和成像技术在文物研究中的突出优势和广阔应用前景,为其在中国文化遗产保护领域的应用研究提供参考。  相似文献   
33.
The possibility of determining the human or animal origin of bones from the lattice parameters of their inorganic bioapatite phase, when subjected to a high temperature treatment using the powder X-ray diffraction (XRD) technique, has been explored on a wide number of specimens. Forty-two animal bones were treated in a furnace at 1100 °C for 36 min and compared to 53 cremated human bones from a range of ancient necropolises. The X-ray diffraction patterns of bioapatite were simulated using both monoclinic P21/b and hexagonal P63/m structures to verify any occurrence of phase transformation and any difference in the lattice parameters due to the model. It was determined that the differences between the a-axis and c-axis of the monoclinic and hexagonal lattice were unimportant. Some outlying values were revealed to be caused by the presence of chlorine ions diffused into the apatite structure increasing its average unit cell values. Nevertheless, our results clearly show that in terms of lattice parameters the variability of human specimens are completely overlapped by the non-human variability making the use of XRD in order to distinguish animal from human bones questionable.  相似文献   
34.
The Longmen Grottoes, also known as the Longmen Caves or Dragon's Gate Grottoes, are located near the city of Luoyang, Henan province, China. The grottoes were carved into the limestone cliffs during the period from 493 AD to 1130 AD. Limestone samples from different areas within the grottoes were analyzed by neutron activation analysis (NAA) to determine the concentrations of major, trace and rare-earth elements (REEs). Three compositional groups were identified corresponding to different areas within Longmen Grottoes. X-ray diffraction (XRD) was performed on a few samples to obtain information about the mineral structure. The results indicate that rocks in the northern area are comprised of dolomite, while rocks in the middle and southern areas are comprised of limestone. The NAA results provide information useful for identifying and relocating fragments from the grottoes that may have lost their identity. The compositional data also provides important clues regarding the geologic history of the limestone formation at Longmen.  相似文献   
35.
Archaeologists have known that an obsidian source exists in the Dasht-i-Nawur basin of central Afghanistan since at least the 1970s; however, regional political turmoil and instability have prevented in-depth study of this source. Data presented here from recent analyses of archival specimens of obsidian collected during a 1976 survey provide a preliminary geochemical profile for this obsidian source. These data suggest that the Dasht-i-Nawur source is easily distinguishable from other obsidian sources in the Near East and southwest Asia. Comparison of these data to an existing database of artifact compositional profiles suggests that initial hypotheses about restricted distribution of the Dasht obsidian may be correct. These data provide for the first time the characterization of a long-known but poorly studied obsidian source. Additionally, this study serves as one example of the benefits gained through working to maintain and preserve data archives of now-closed laboratories.  相似文献   
36.
Neutron tomography (NT) has been applied to visualize the inner structure of ancient Portuguese glazed tiles undergoing conservation treatments. Neutrons have the advantage of interacting strongly with hydrogen, so NT is able to map hydrogenous compounds with high sensitivity. The present study explores its potential for assessing the distribution of the consolidant Paraloid B-72 inside tiles, to evaluate the efficiency of two different methods of treatment: brushing and immersion in solution. Using a prototype NT setup at the Reactor Português de Investigação (Sacavém, Portugal), each two-dimensional image is obtained from a 90 s exposure, at a thermal neutron flux of 2 × 105 n cm−2 s−1 at the irradiation site. The neutron beam has a diameter of 5 cm, so fragments with outer dimensions up to 4.8 cm can be inspected. Samples are automatically rotated by an angle of 0.9° between successive images. Images were obtained before and after the application of the consolidant. The results obtained show that: (i) NT is a useful tool for visualization of the inner structure of ancient glazed tiles, and to assess penetration depth of consolidant and its distribution inside the tile; and (ii) brushing with 10% Paraloid® B-72 in acetone solution appears to be more efficient than immersion. Neutron tomography showed a greater and more uniform retention of resin inside the tile if the brush is used to apply the consolidant, to increase the cohesion of the object.  相似文献   
37.
This study presents compositional data from ceramics drawn from surface survey and controlled excavations from three prehispanic sites within the relatively small Lake Pátzcuaro Basin, representing a ceramic sequence stretching nearly 1500 years, from the Preclassic to Late Postclassic Tarascan state (ca. 50 B.C.–1525 A.D.). Using neutron activation analysis, we identify compositional groups and model the importance of volcanic materials as temper in the construction of prehispanic ceramics by matching mathematical simulations of clay–ash mixes to the compositional groups. Rather than discreet clay resources and spatially circumscribed production, we argue for a broadly dispersed and highly varied organization of pre-Tarascan and Tarascan state ceramic production in which the potters' distribution and use of specific volcanic ashy additives, not clays, structured the organization of production.  相似文献   
38.
Three small stone axes were collected by the joint Qatari‐German South Qatar Survey Project (SQSP) at two places close to the eastern and western coast of Qatar in autumn 2012. Associated with settlement remains, flint artefacts and pieces of ?Ubaid pottery, the implements have been dated to the fifth millennium BCE. Non‐destructive μ‐XRD2 and μ‐XRF analyses could, for the first time, prove the use of hematite as the raw material for the manufacture of these tools in Arabia. The absence of major hematite sources in the region and the special characteristics of hematite — a unique metallic shine of polished pieces and the blood‐red colour that appears during the manufacturing process — suggest the highly symbolic character of these objects.  相似文献   
39.
Vitreous tesserae from two mosaics in Herculaneum (Italy) dating from the 1st century AD have been investigated in order to gather information on Imperial Age opaque glass. The combined use of complementary micro-destructive analytical techniques, namely optical microscopy (OM), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), inductively coupled plasma-mass spectrometry (ICP-MS), transmission electron microscopy (TEM), and X-ray powder diffraction (XRPD) allowed to define the nature of formers, fluxes, chromophores and opacifying compounds and to determine the type of raw materials employed for their introduction. The results confirmed the high technological level of Imperial Age glassmakers and clarified some details of the production processes. Experimental data have been obtained concerning formation of antimony-based opacifiers. The presence of tin-containing Ca- and Pb-antimonates has been ascertained in various green, yellow and turquoise tesserae. Moreover, unusual divergences from the established Roman age ‘low magnesia–low potash’ (LMLK) glass composition have been found for some red and green samples.  相似文献   
40.
Mudbricks appear to have been one of the most common building materials used in domestic architecture in Bronze Age Crete. Well-preserved earthen construction materials from the sites of Vasiliki, Makrygialos and Mochlos in East Crete have been examined with regard to their macromorphological characteristics and their mineralogical and chemical composition in order to investigate the nature of the raw materials used, the technology of manufacture and the potential use of specific recipes. The methods applied include a combination of mineralogical and chemical analytical techniques, namely petrography, neutron activation (NAA), X-ray fluorescence (XRF), and X-ray diffraction (XRD) analysis. Finally, a range of raw materials from the immediate vicinity of each site were sampled and analyzed in order to compare with the archaeological data and identify potential sources. The analyses suggested that there is a degree of standardization in the recipes and the manufacturing process and that the selection of the raw materials depends on availability.  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