Fabrication of silk sericin-anthocyanin nanocoating for chelating and saturation-visualization detection of metal ions.

Silk sericin (SS) is a natural water-soluble protein with the potential to chelate metal ions via its polar groups. However, the difficulty of identifying the saturation of SS limits its application as filter films. One solution is to construct SS filter films with an indicator to reflect the degree of saturation of silk sericin. Hence, the nanocoating consisting of co-assembled SS protein and anthocyanin (C3G) nanoparticles is designed, constructed, and characterized to chelate metal ions with a saturation-visualization detection behavior. Here, metal ions Zn2+ and Al3+ are chosen as models to explore the chelating ability of SS and indicator behaviors of C3G, which could indicate the saturation degree of SS. Interestingly, after the saturation of SS in the solution and filter film situations, the visible color progressively shifts from pink to blue (Zn2+) or violet (Al3+), with the corresponding redshift of UV-Vis absorbance of C3G. Remarkable removal effectiveness of Zn2+ and Al3+, namely 93.16% and 53.97%, as well as an evident saturation-visualization detection, were identified by filter paper films with the nanocoating. Our research provides a fresh viewpoint for designing SS filter films that could effectively remove metal ions while enabling real-time viewing.

Temporal and spatial features of the palace building space of Qinghai's Kumbum Monastery and its evolution.

Kumbum Monastery is the centre of Tibetan Buddhism and religious culture in Qinghai. Its palace buildings are the typical examples of Tibetan Buddhist monastery buildings and living fossils of Tibetan social history. This study selected 12 palace buildings of Kumbum Monastery as the study objects, used typological approaches and numerical method to analyse their spatial features, classified these features into four types (the ring road surrounding Dugang-style palace space, single-sided eaves of the Duguang-style palace space, three-stage palace space with cloisters connecting to Dugang, and other variants) according to their spatial structures, and discussed the temporal evolution of the spatial features from spatial and temporal perspectives to obtain the development process for the palace buildings of Kumbum Monastery. The analysis showed that: 1) Because the Han people migrated to Qinghai, the architectural space of the monastery followed the practices of Tibet in the same period and began to adopt the practices of the Han people under the effect of religious indoctrination and sociopolitical influence of the Ming dynasty. 2) Due to the influence of religious development facilitated by the political environment in the Qing dynasty, all the palace buildings of Kumbum Monastery adopted the practice of monasteries in Lhasa. After being implicated by the political rebellion, the monastery initiated to add the spatial layout elements of the buildings in Qinghai. Therefore, the monastery was obtaining the cues from the Han culture. 3) The dominance of religious significance over the spatial designing of the palace buildings of Kumbum Monastery gradually shifted to the political dominance. This paper revealed the spatial and temporal features and evolution of the palace building space, explored the generation process of the palace buildings space of Tibetan Buddhist monasteries in Qinghai, and provided a reference for the static conservation and dynamic development of Tibetan Buddhist monastery buildings in Qinghai.