液相色谱质谱联用法研究红花染纺织品褪色分子机理

以红花染纺织品作为主要研究对象,通过紫外光和LED两种光老化方式,研究不同褪色因素影响下纺织品中显色组分红花苷的降解变化情况,实验发现不同酸化作用对红花苷造成不同的影响。采用液相色谱质谱联用的方法,鉴定出红花苷、芹菜素等多种组分,并首次从红花中鉴定出国外报道的但一直未确定的组分Ct4的分子结构,实际是三香豆酰亚精胺,一种酚酰胺类化合物,可作为一种染色工艺指标对现代染和古代染色工艺进行区分。以故宫院藏两件红花染褪色纺织品文物为例阐述褪色机理,显色组分红花苷的降解,产生不同程度的裂化产物小分子,使原本微量存在的三香豆酰亚精胺相对含量增高,从而造成褪色明显,文物在长期日晒下正面原本红色外观呈现橘色打底。同时强调了博物馆应高度重视相同类型文物保存环境中的挥发性酸性气体监测。     

Revisiting Kalundu Mound,Zambia: Implications for the Timing of Social and Subsistence Transitions in Iron Age Southern Africa

African Archaeological Review - Novel trajectories of food production, urbanism, and inter-regional trade fueled the emergence of numerous complex Iron Age polities in central and southern Africa....     

PANEL DATA MODELS WITH SPATIALLY DEPENDENT NESTED RANDOM EFFECTS

This paper focuses on panel data models combining spatial dependence with a nested (hierarchical) structure. We use a generalized moments estimator to estimate the spatial autoregressive parameter and the variance components of the disturbance process. A spatial counterpart of the Cochrane‐Orcutt transformation leads to a feasible generalized least squares procedure to estimate the regression parameters. Monte Carlo simulations show that our estimators perform well in terms of root mean square error compared to the maximum likelihood estimator. The approach is applied to English house price data for districts nested within counties.     

《晋书·地理志》县级封国考论

反映西晋前期政区全貌的《晋书·地理志》中记载了58个县级封国,包括公国、侯国两类。虽然西晋朝廷已设置公、侯、伯、子、男五等爵,但这些封国所对应的爵位,却是位在五等爵之下的一般县公、县侯。各家县公主要是由曹魏宗王降封而来。为县侯者,有功臣、敌国降将、曹魏宗室,还有不少是曹魏时即已受封而入晋后仍保留爵位者。     

Charcoal reflectance measurements: implications for structural characterization and assessment of diagenetic alteration

Charcoal is a valuable source of archaeological and palaeoenvironmental proxy data. However growing evidence suggests that production conditions can strongly influence post-depositional alteration of charcoal. Consequently, both reconstruction of production temperature and understanding of the potential for diagenetic alteration are of great interest. Here, we use mean random reflectance (Ro_mean) in conjunction with other chemical characterization methods to address these questions. Ro_mean was obtained for a suite of modern analogue charcoal, produced under controlled conditions, and for a series of natural charcoal samples, obtained from archaeological and palaeoenvironmental deposits. Ro_mean proves to be a robust measure to assess formation temperature for samples produced at 400 °C and above, even after exposure to highly oxidizing conditions. Ro_mean is also useful for samples formed between 300 °C and 400 °C. However, if an assemblage of charcoals has been exposed to oxidizing conditions, lower temperature charcoals may be preferentially lost. It is apparent that charcoal produced at lower temperatures is more highly susceptible to chemical oxidation, and that there is a continuum in charcoal degradation potential, dependant upon fuel material and production conditions.     

Chihr de l’encens (Yémen)

Frankincense burners found in al‐Shihr’s excavations in Yemen, a frankincense harbour during the Islamic period, represent a rare corpus of this type, which is an indication of both specific use and goods from South Arabia. Although associated with the pre‐Islamic South Arabian kingdoms, the frankincense burner evolved throughout the Islamic period. This is proved by the long chronological sequence of the al‐Shihr site (780–1996). Texts quoting the presence of frankincense, its use and its trade in al‐Shihr are cited in this article to support the reputation of this harbour‐town, which is part of the maritime trade networks of medieval Islam. The aim of this article is to create a renewal of interest in future archaeological research about this object, which is so often neglected in spite of its importance as a testimony of the customs and exchanges that are deeply rooted in Arabian civilisation.