Models, Narratives, and French Ways off Doing

Books reviewed in this article:
Jean-Yves Grenier, Claude Grignon, and Pierre-Michel Menger, eds., Le Modèle et le récit     

A Raman spectroscopic study of glass trade beads excavated at Mapungubwe hill and K2, two archaeological sites in southern Africa,raises questions about the last occupation date of the hill

Thousands of glass trade beads were excavated over a 75 year period on Mapungubwe Hill and at K2, two archaeological sites in the Limpopo valley, South Africa. An assemblage of 175 beads that appeared to be different in shape, size and colour (red, yellow, green, blue, white, black, pink, plum) was studied with Raman scattering. At least seven different chromophores or pigments (lazurite, lead tin yellow type II, Ca/Pb arsenate, chromate, calcium antimonate, Fe–S “amber” and a spinel) have been identified. Pigment identification allows the recognition of specific productions and indicated that many of the pigments colouring the beads excavated on Mapungubwe hill were manufactured after the 13th century, confirming the presence of modern beads in the archaeological record, some dating from the 19th century. This date is in agreement with the last occupation date for the hill suggested by the earlier excavators and raises questions about the revision of this date to 1290 AD by archaeologists in the 1970’s.     

Feminist geographies in Aotearoa New Zealand: cultural,social and political moments

Abstract

Aotearoa New Zealand is a nation of promise, potential and enigma: it was the first country in the world where women gained the vote in 1893 and now boasts the youngest woman world leader in 2017. It is also a postcolonial nation where structural racism, homophobia, and sexism persist, yet it has also given legal personhood to a river. Our Country Report foregrounds Aotearoa New Zealand feminist geographic scholarship that responds to, reflects, and sometimes resists such contrasts and contradictions at the national scale. We employ the lens of the 2017 national election to critically engage with current gendered and indigenous politics in the country. Analyzing these politics through three ‘feminist moments,’ our paper highlights the breadth and scope of current Aotearoa New Zealand feminist geographic scholarship and directions.     

天然染料苏木的光褪色机理研究

有机质文物如书画和纺织品在修复保护过程中常常遇到褪色问题,对于染料分子是一种不可逆的损伤,因此有必要采用一定的科学方法对原因机理进行研究。苏木在文化遗产领域常作为天然染料用于纺织品染色,但色牢度较差。通过溶液动力学模拟实验借助紫外光老化过程推测降解副产物,追踪了对曾经在文物中检测到的有效化学组分巴西苏木素和原苏木素B在N,N-二甲基甲酰胺基质里光催化老化代谢过程,分别获得20组不同老化程度的紫外老化的标准品。实验表征手段主要采用紫外可见漫反射光谱、超高效液相色谱四极杆飞行时间质谱联用及核磁共振氢谱对颜色变化趋势和老化过程进行分析。通过苏木染色及丝织品光老化实验,得到17组不同褪色程度的纺织品样品。采用液质联用在负离子模式下结合化学计量学统计分析差异代谢物及老化机制,巴西苏木素、苏木红素及原苏木素B可能的转化及降解产物分别得到一定的推论。结果显示褪色纺织品随着光老化的发生反射光谱最大波长总体发生蓝移。巴西苏木素季碳羟基容易发生脱水反应产生一系列变化,原苏木素B光老化过程容易转化成原苏木素C、尿石素C等化合物。苏木染褪色纺织品总体可分为两类组间差异,通过主成分分析出差异代谢物巴西苏木素、原苏木素B以及C等多种老化产物,这些总体因素造成体系的光老化颜色变化。这些探索性发现期待为今后天然染料的相关研究提供启发,助力提升有机质文物的科学价值认知。