Field gamma spectrometry,Monte Carlo simulations and potential of non-invasive measurements

The determination of gamma dose rates is of prior importance in the field of luminescence dating methods. In situ measurements are usually performed by the insertion of dosimeters or a portable gamma spectrometer cell in sediments. In this paper, Monte-Carlo simulations using the Geant4 toolkit allow the development of a new technique of insitu gamma dose rate evaluations: a spectrometer cell is placed on the surface of sediments under excavation to acquire successive spectra as sediments are removed by excavations. The principle of this non-invasive technique is outlined and its potential is discussed, especially in the case of environments in which radioelements are heterogeneously distributed. For such cases, a simple method to reconstruct gamma dose rate values with surface measurements using an attenuator is discussed, and an estimation of errors is given for two simple cases. This technique appears to be applicable, but still needs experimental validation.     

探索契合的展陈空间与公共空间——以中国大运河博物馆为例

公共空间是博物馆为观众提供社会教育活动、休闲服务、艺术观赏的场所,也是展陈空间的衔接与延续.中国大运河博物馆的展陈空间与公共空间两者在设计与功能上相互影响、和谐共生,共同构成了博物馆的整体形象.中国大运河博物馆根据运河文化与地方特色设计打造每一处空间,将艺术氛围与服务设施巧妙结合,处处体现以人为本的服务理念,为观众提供...     

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。     

Le châtiment de Babel

Umberto Eco, La recherche de la langue parfaite dans la culture européenne, Paris, Le Seuil, collection “Faire l'Europe”, 1994, 436 p. (traduction de La ricerca della lingue perfetta nella cultura europa, Roma‐Bari, Laterza) ; ouvrage paru simultanément en italien, français, anglais (Basil Blackwell, Oxford), allemand (C.H. Beck, München) et espagnol (Critica, Barcelona).

Maurice Olender, Les langues du Paradis. Aryens et Sémites : un couple providentiel, Paris, Gallimard/Le Seuil, 1989 ; rééd. Paris, Le Seuil, Points‐Essais, 1994.