排序方式： 共有122条查询结果，搜索用时 0 毫秒
51.
本文概述了用蔗糖处理饱水木质文物的发展历史,并对蔗糖的脱水机理、防虫防霉处理、渗透效果等进行了阐００指出在饱水木质文物的保护方面,蔗糖是一种比较理想的保护材料。 相似文献
52.
The degradation of archaeological wood at freezing and thawing temperatures is studied at the site of Qajaa in West Greenland through a combination of environmental monitoring, measurement of oxygen consumption and microscopy of wood samples. Permanently frozen wood is still very well preserved after 2–4000 years, while wood samples that thaw every summer show attack by soft rot and an average density loss of 0.1 g cm–3 (corresponding to 25% of the dry mass) over the past 27 years. Future increases in temperature may increase the decay rate significantly (Q10 = 4.2 at 0–10°C) but the effects on site depend on local hydrology. 相似文献
53.
This paper presents the results of the analysis carried out on a polychrome wood mask from Papua New Guinea during conservation work at Pigorini Museum's restoration laboratory. The significance of this study is that no prior work has characterized the painting materials of Papua New Guinea masks both with spectroscopic and internal microstratigraphic analysis. In fact, these objects were studied especially from an anthropological or conservative point of view and the wood was wrongly defined by its visual appearance. Microstratigraphic and spectroscopic investigations discovered a refined execution technique that up to now has not been demonstrated. The stratigraphy of the painted layers demonstrates a deep knowledge of the materials and of the application techniques on the part of the Papua New Guinea people, together with the ability to foresee the aesthetic result for the artefact. The analysis of the constitutive materials and of the stylistic features supplied valid results in favour of provenance of the mask from Papua New Guinea. 相似文献
54.
David R. Greenwood 《Alcheringa: An Australasian Journal of Paleontology》2013,37(2):351-363
An initial study of a collection of fossil conifer wood is reported from the late early Miocene Yallourn Clays, an interseam unit intergrading into the base of the early to middle Miocene Yallourn seam of the LaTrobe Valley, Victoria in southeastern Australia. The fossil wood shares characteristics with the modem genera Dacrycarpus and Dacrydium. On the basis of contiguous, uniseriate tracheid pitting and 1–2 podocarpoid cross field pits, it is placed in the form genus Podocarpoxylon, and the new species P. latrobensis. The wood is compared with extant Podocarpaceae and other Australian fossil woods. Its ring anatomy is consistent with low temperature or rainfall seasonality in the early Miocene. 相似文献
55.
Jan Kunnas 《Scandinavian journal of history》2013,38(3):281-311
Quantitative calculations on the use of natural resources provide valuable tools, which can give new insights to old questions and rise new ones. In this article, I compare the wood consumption in the production of potash, saltpeter and pine wood tar in 19th century Finland. My calculations shows that in the 19th century the cumulative wood consumption in the production of potash might have been higher or at least on the same level as in the production of tar, while the production of saltpeter consumed only a fraction. In the 1830s their combined wood consumption reached the level of slash‐and‐burn cultivation. 相似文献
56.
一种饱水木质文物含水率无损检测方法的研究 总被引：1，自引：0，他引：1
含水率是评估饱水木质文物糟朽程度最常用的物理参数之一。目前含水率检测常用方法有烘干法、电阻法、近红外光谱法等,但这些方法或属于破坏性分析,或检测范围不适用。为寻找一种适用于饱水木质文物含水率的无损检测方法,基于饱水木材组成理论模型,建立了含水率与湿态密度、灰分含量三者之间关系,进而提出一种检测含水率的便捷方法——溶液密度法。采用上述方法对天长、淮北等地出土饱水木质样品含水率进行测试,并与烘干法测得标准值进行验证。结果发现两者数据较为接近,相对误差在10%以内,证明了该方法的可靠性。进一步研究发现,样品越糟朽,使用该方法获取的数据与标准值之间相对误差越小。说明该方法更适用于糟朽饱水木材含水率的检测。 相似文献
57.
文中采用扫描电镜(SEM)和透射电镜(TEM)对海门口遗址饱水古木进行降解机理分析。结果表明:古木细胞次生壁收缩严重并与胞间层分离;胞间层保存较完好,呈连续网状。说明古木纤维素和半纤维素降解相对严重,木质素降解相对较轻。古木主要是受细菌降解,通过SEM和TEM均可见明显的细菌腐朽特征。细菌首先侵入细胞腔,再通过S3层侵入细胞壁内部。细胞壁内由于降解而产生的空隙在几十到几百纳米之间。饱水古木也受到了一定程度的真菌降解,但这类真菌主要降解古木内淀粉等物质,对细胞壁物质降解能力差,主要是使古木变色。 相似文献
58.
Here we present a database of responses by South African agate and chalcedony to heat treatment. This will assist analyses of heated stone tools not only in South African archaeological sites, but wherever heated agate and chalcedony pieces were knapped. The minerals are abundant worldwide. To replicate potential heating methods during the Stone Age we placed some minerals in a wood fire, some under coals, and others were buried in sediments beneath fires. Thermal responses include lustrous flaked surfaces, pot lid fractures, semi-circular internal fractures, rough internal surfaces, and crazing. Aerobic heating is implied by pot lid fractures. To explain the thermal responses we analyzed the minerals using X-ray fluorescence, Raman spectroscopy, and carbon and sulfur analyses. Our chalcedony contains more water and impurities than agate, making it more vulnerable to thermal damage. Our method of combining field experiments with chemical analyses has global applications even though we expect that mineral components of agate and chalcedony will vary slightly in different parts of the world. 相似文献
59.
在部分岭南战国秦汉墓葬中,随葬器物的空间分布和保存状态显示出"架棺"的迹象。结合广州汉墓中"架棺"和"架举棺室"的实例,以及部分岭南战国秦汉墓葬中墓底柱洞和凹槽的发现情况,推测"架棺"葬俗在战国秦汉时期岭南地区的越人墓葬中使用较为普遍。"架棺"的方式较为复杂,此葬俗的文化含义也值得深入研究。 相似文献
60.
《Conservation and Management of Archaeological Sites》2013,15(1-4):397-405
AbstractThe peat moors of lowland Somerset contain a wealth of waterlogged archaeological sites, including some of the most significant prehistoric monuments in the country. There has been a long history of attempts to preserve archaeological sites in situ and monitoring of the burial environment began in 1982. The monitoring has become more complex over time, but the results suggest the same continuing problem of a drop in the water table over the summer months across the whole landscape. With the sole exception of the portion of the Neolithic Sweet Track that benefits from an irrigation system, all the other known sites remain at risk of gradual destruction. The solutions must be found on a landscape scale using agri-environment payments to secure sustainable management of the peat resource. Unfortunately, short-term changes to these payments and long-term changes to the climate are likely to worsen the situation and eventually to require a more drastic solution to the problem. Evidence has been generated to support an ecosystems approach to sustainable peatland management. 相似文献