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1.
古代铁器腐蚀产物的结构特征   总被引:4,自引:2,他引:4  
运用X射线衍射、扫描电子显微镜和穆斯堡尔谱分析方法,对河南渑池出土的T_1H_1∶250汉代铁斧表面腐蚀物进行了研究。提出了铁器文物抗腐蚀的原因在于表面氧化膜具有结构上的连续性、改密而不破损。铁器文物最理想的保存环境应该是碱性、干燥无水、无硫、氯等有害元素。  相似文献   
2.
秦博 《四川文物》2020,(2):23-35
黄河中下游地区40余处遗址的400多座二层台墓资料显示,生土二层台墓的数量在仰韶中晚期以前较熟土台墓多,龙山时代式微。该变化的背后是棺椁的逐渐成熟,生土台墓中小部分带有盖板或原始棺椁,同时熟土台并非判断墓葬带有棺椁的充要条件。通过生土台高度和墓葬深度的二元变量分析,墓葬开挖时预留生土台并未考虑稳固墓室,而应该与构建殓尸空间(或椁室)、进行一系列丧葬活动有关,在台面上放置随葬品的情况存在一定的时空差异。二层台墓的分布具有集中埋葬的倾向,采用二层台墓的群体并无明显的性别和死亡年龄指向,从仰韶中期以来,其所代表的社会群体占据着更为优越的社会财富。  相似文献   
3.
位于长江入海口的“长江口二号”清代沉船是中国目前发现的保存最为完整的古代木制沉船之一,已于2022年11月完成整体打捞。在进行水下考古调查时,沉船出水的部分青花瓷出现的病害现象引起了考古工作者的关注,特别是裂纹中黑色污染物及表面铁锈状污染物对文物的外观产生了很大影响。本工作选取了三件具有典型被污染特征的青花瓷标本作为代表,使用能量色散X射线荧光分析(EDXRF)、光学显微镜(OM)、X射线衍射分析(XRD)、拉曼光谱分析(Raman)和扫描电子显微镜-能谱分析(SEM-EDS)等方法,对污染物进行了研究,探讨了其形成原因以及环境的影响作用,并对其潜在危害进行了分析。研究表明,污染物主要以方解石、菱铁矿等碳酸盐以及铁的氧化物、氢氧化物和硫化物为主。长期处于河口淤泥中的还原性环境是导致菱铁矿和亚稳的铁硫化物形成的原因,船体中铁质构件腐蚀对局部环境的污染是重要的影响因素,这也反映出被污染的青花瓷所处位置和环境的特殊性。出水的部分青花瓷釉中裂纹的形态表明其形成是由物理撞击造成,而釉中硅灰石晶体的选择性腐蚀会导致腐蚀坑的形成,裂纹和腐蚀坑均为外部污染物进入釉层内部提供了通道,导致瓷器劣化。出水后...  相似文献   
4.
A team comprising a former Russian policymaker and American analysts of the current Russian energy policy examines the course of that policy and its limitations during the post-Soviet period. In the process, they critically analyze key problems in Russia's oil, gas, coal, and electricity sectors that represent a potential drag on growth of the entire Russian economy and at the very least call into question the sustainability of further increases in exports to the West. The authors explore in considerable depth and detail both the factors underlying the recent increase in government intervention in the energy sector and the likely consequences for domestic production, consumption, resource security, and critical exports. Journal of Economic Literature, Classification Numbers: L71, O13, Q40, Q48. 11 figures, 3 tables, 29 references.  相似文献   
5.
A noted American analyst of Russian, Central Asian, and Transcaucasian oil and gas industries and markets offers his own perspective on issues raised in the preceding paper on Russia's energy policy (Milov et al., 2006). While generally concurring that Russia indeed pursues an ad hoc (rather than systemic) energy policy, he expresses divergent views on the role of government-regulated versus market-based pricing in final and primary energy use, reasons for the intense flows of oil and gas to Europe, the role of pipelines in determining oil export allocations, and the contribution of regional monopolies and refining capacity to domestic oil product prices. Journal of Economic Literature, Classification Numbers: L71, O13, Q40, Q48. 20 references.  相似文献   
6.
A range of factors, including consumer concerns about food safety, the growing popularity of rural tourism and policy initiatives to promote endogenous rural development, is converging to promote a relocalization of food production and service provision, especially in those regions marginalized by the globalization of the food supply system. The recent outbreak of foot and mouth disease in the UK has starkly illustrated the fragility of localized systems which depend heavily on consumers travelling to them. Within such a context, the importance of successful marketing strategies has become even more apparent. This paper reports on a questionnaire survey which investigated promotional and marketing strategies among a diverse range of producers and service providers in marginal agricultural areas of the EU. The findings suggest that many producers are situated towards the "formal" end of a marketing continuum, whereby ability to promote quality products and services (QPS) lies with a range of intermediaries. This raises doubts about the future economic benefits of QPS, should current marketing structures persist. The discussion offers critical reflections on interdisciplinary and international research of this nature, and advocates further theoretical and methodological development in order to explore in more depth many of the aspects raised in this exploratory investigation.  相似文献   
7.
天然氧化铜矿与铜制品腐蚀产物区别的探讨   总被引:1,自引:0,他引:1  
在一些新石器时代的遗址中经常会出现一些铜渣、小块孔雀石等与炼铜有关的遗物。为探究这些孔雀石到底是天然的氧化铜矿还是铜制品的腐蚀产物,本工作对天然氧化铜矿和青铜器腐蚀产物进行岩相分析和元素成分分析。结果表明,天然氧化铜矿大都具有一些特殊的结构构造,而在铜制品的腐蚀产物中却很难发现这些结构构造;同时,二者在元素成分上也有显著不同,Bi、Sb、As、Fe、Mo、Co、Mn等微量元素可以作为区分天然氧化铜矿和青铜器腐蚀产物的一个判别标志。结合岩相分析和成分分析,可以确定一个遗址出土的孔雀石或蓝铜矿是天然氧化铜矿还是铜制品的腐蚀产物;同时,可进一步判断是红铜的腐蚀产物还是青铜的。这一结论对探讨铜冶金的起源有重要意义。  相似文献   
8.
A Sensitive High Resolution Ion MicroProbe (SHRIMP II) has been used to make high spatial resolution in situ micro-analyses of oxygen isotopes in fish otoliths, and teeth from fossil herbivores and a Neanderthal. Large intra-tooth variations in the oxygen isotopic composition (up to 9‰) were observed in the enamel of herbivores from the Neanderthal fossil site of Payre, consistent with preservation of seasonal cyclicity. The range of isotopic compositions observed in Neanderthal tooth enamel was much smaller (∼3‰), possibly the result of a longer enamel maturation time averaging out variability. An archaeological otolith from a Preceramic site in Northern Peru exhibited marked changes in δ18O over life, due either to the fish occasionally migrating from the sea to a lower salinity habitat, or to short-lived rises in sea water temperature. A fish otolith from Australia's Willandra Lakes World Heritage Area showed clear seasonal variations, but also a general trend towards isotopically heavier and more saline water, as indicated by higher δ18O and Sr/Ca values resulting from increased evaporation. The results of these case studies are compared to results of oxygen isotope analysis using more conventional methods and demonstrate the ability of the SHRIMP II to provide precise high spatial resolution in-situ oxygen isotope analyses of a variety of biogenic materials. This approach has major advantages over conventional methods. It can provide rapid, micro-scale isotopic analyses of sub-permil precision without the need for chemical preparation of the sample.  相似文献   
9.
徐敬霞 《神州》2012,(20):39-40
当前中专英语教学现状不容乐观。造成这一现状的原因是多方面的。文章就中专学校的生源及其素质、中专学校英语教师的素质与水平及中专学校对英语教学的态度等三个方面的因素对中专英语教学的影响阐述自己的观点并提出了提高英语教学质量的对策。  相似文献   
10.
琥珀制品在两汉时期风靡一时,琥珀印在琥珀制品中颇具特色。本文在对中国境内考古发现所见两汉琥珀印资料收集与整理的基础上,对其出土地域、自身特征、出土位置及伴出物品等问题进行了探讨。研究表明出土琥珀印的墓葬等级较高,且出土位置特殊,并伴随有水晶、玛瑙、海蓝宝等贵重宝石。这些宝石的产地可能源自南亚或东南亚地区,而这类随葬品在两汉墓葬中的流行亦体现了当时物质交流的成果。  相似文献   
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