Damage or protection? The role of smoked crust on sandstones from Yungang Grottoes

Black crusts, such as dust deposit and smoked smudge, are the main pollutants in Yungang Grottoes, the world famous Buddhist heritage site. It is always considered that the black crust should be removed during the conservation process of stones. In this paper, the investigation of the role of smoked crust on the Yungang sandstones was performed to verify if the smoked layer on the stone surface would be harmful or protective. The results of SO₂ corrosion experiments with and without water both show that the samples covered with smoked layer can play a protective role on the sandstones, which means that the smoked layer on the stones can prevent the attack of SO₂ and water, the major deterioration agents in Yungang area. The multi-factor deterioration cycle experiments, including salt crystallization, freeze–thaw damage, wet–dry cycle and acid corrosion, also indicate that the smoked samples are less deteriorated and salt crystallization is the most severe damage to the sandstones.     

Cultivation of Naked Barley by Early Iron Age Agro-pastoralists in Xinjiang,China

ABSTRACT

We report an archaeobotanical analysis of flotation samples taken from Shirenzigou, an Early Iron Age agro-pastoralist site dated between the fourth and first century BC, located on the northern slope of the Tianshan Mountains in Xinjiang, China. The charred macro-botanical assemblage is dominated by naked barley grains with a few broomcorn and foxtail millet grains. In the context of Trans-Eurasian exchange of cereal crops, southwest Asian crops (wheat and barley) and two Asian millets (broomcorn and foxtail) were introduced to Xinjiang a few centuries to a millennium before Shirenzigou was occupied. The choice of barley cultivation in preference to wheat and millet may have been possibly driven by the relatively extreme local environment and the scheduling requirements of mobile pastoralism. Barley is well suited to this environment, and the choice of naked barley in preference to hulled barley may have been driven by the whole grain tradition prevailing in East Asia.     

瓷器文物修复中环保作旧材料性能比较研究

瓷器文物修复中作旧处理是修复中的关键步骤,作旧处理的好坏,关系到修复后瓷器的保存时效。传统作旧处理中所用的硝基清漆易于黄变,且所用稀释剂具有一定的污染性。为筛选环保且较耐久的瓷器修复作旧材料,以环保水性材料为主,选用水性氟碳树脂DF-01、水性氟碳乳液、水性木器清面漆和水性木器清底漆四种水性高分子材料分别作为瓷器修复作旧处理过程中的粘接材料,按照传统修复方法,以市售瓷板为处理对象,对其进行作旧处理。然后将上述样品分别进行干热、湿热和氙灯老化,通过测试上述样品老化前后的色差和光泽度,表征了上述材料的耐老化性能。结果表明,与传统材料硝基清漆相比,实验所选用的水性高分子材料具有较好的耐热老化、抗氙灯老化和抗湿热老化能力,且在操作过程中无味,有望解决传统瓷器文物修复材料易于黄变且对环境污染大的难题,具有一定的应用前景。     

记忆与诠释:陈独秀“十月革命”认知之心路历程

近现代中国思想脉络中的十月革命具有非同一般的价值和意义,但十月革命对马克思主义在中国传播的重要性似属后见之明,而非国人的"即时"反应。中国共产党历史上的重要人物陈独秀对十月革命的认知经历了一个变化过程。陈独秀早年关于俄国的记忆,结合时势变迁,以及他的人生经历与心理变化,使其对"十月革命"的认知和态度几经转折,从最初的犹豫与彷徨,到坚定态度诠释十月革命的正面价值,晚年则走向批判。陈独秀对"十月革命"认知之心路历程也是近现代中国知识分子追寻马克思主义,探索中国革命道路困境的表现。     

Multi‐analytical Studies of Archaeological Chinese Earthen Plasters: The Inner Wall of the Longhu Hall (Yuzhen Palace,Ancient Building Complex,Wudang Mountains,China)

The Yuzhen Palace is one of the nine palaces in the Ancient Building Complex built by order of the Yongle Emperor during the Ming dynasty. The buildings were built with dressed black bricks. As a result of the planned national South–North Water Diversion project, the water level in the Danjiangkou Reservoir that surrounds the Yuzhen Palace was expected to rise by approximately 15 m. To avoid submersion of the site, three gates were elevated by 15 m in 2013 and other buildings dismantled, for later reconstruction. The characterization of the construction materials has therefore become of primary importance. Here, we present results on the plasters of the Longhu Hall. The analysis of materials involved a multi‐analytical approach combining optical and electron microscopy with X‐ray and vibrational spectromicroscopies and thermogravimetry. The results indicated the use of two earthen plaster layers and a whitewash finish coating applied over a thin preparatory intermediate layer to improve the adherence of the finish coating to the earthen plaster. Ramie and straw fibres identified in the earthen plasters were added to reduce shrinkage and cracking during drying. The raw materials used and the application technique pointed to a well‐established construction industry using traditional earthen building materials together with lime technology.     

Application of Kernel Density Estimates to Lead Isotope Compositions of Bronzes from Ningxia,North‐West China

The aim of this paper is to apply kernel density estimates (KDEs) to the visualization and interpretation of lead isotope data from bronze assemblages found along the northern border of central China, here designated as the Arc. New lead isotope analyses of 30 leaded tin–bronze artefacts from the Wangdahu cemetery (c.500–300 bc ) in the Ningxia Hui Autonomous Region, north‐west China, provide the basis for the discussion. By using multivariate KDEs and the calculated likelihood of the overlap, the present work shows that the Wangdahu objects feature a unique linear array of isotope ratios, representing an important element of overall bronzes from the Arc in the first millennium bc . This characteristic isotope signature is fundamentally different from that of Dajing ores in north‐east China, as well from that of early Qin bronzes in Shaanxi and Gansu provinces. This suggests that a variety of metal resources were utilized by peoples living in the Arc. The KDE approach thus proves effective at presenting and comparing lead isotope data.     

Mapping Qijiaping: New Work on the Type-Site of the Qijia Culture (2300–1500 B.C.) in Gansu Province,China

Recent work at the Qijia Culture type-site of Qijiaping in the Tao River valley of Gansu Province, China, has shed light on the complex nature of this early Bronze Age site. Situated at the intersection between the mixed pastoralists of eastern central Asia and the agriculturalists of China’s northern Central Plain, Qijia peoples absorbed, evolved, and transmitted products and technologies that shaped cultural developments in both directions. The Tao River Archaeological Project (TRAP) used a combination of surface survey, geophysics, digital mapping, and targeted excavation to expand our understanding of the multicomponent nature of Qijiaping. This included identifying potential habitation, mortuary, and production locales; examining site-wide ceramic use; mapping anomalies through geophysics; and further exploring these through targeted excavations. The results have expanded our knowledge of the site structure of Qijiaping and its place in the wider Qijia interaction sphere, while also confirming the usefulness of this methodology.