新型聚多巴胺纳米颗粒光热蒸发性能评价

聚多巴胺具有与黑色素相似的吸光性能,是一种被广泛关注的高分子近红外吸收材料,在光热转化方面有良好前景。但由于其本身聚合机理多样,内部结构复杂,目前对聚多巴胺功能性设计的研究较少。本文通过设计Fe3+和硅烷偶联剂与多巴胺反应,提高了聚多巴胺的吸光特性和亲水性;通过X射线光电子能谱(XPS)、傅里叶变换红外光谱(FTIR)等表征证明,成功合成了高吸光度亲水聚多巴胺纳米颗粒,吸光度达到90%。同时将合成的纳米颗粒真空抽滤,堆叠构建亲水输运通道。实验表明:在太阳光蒸发环境,一个太阳光强下,使用本文设计的光热膜进行纯水蒸发实验,纯水蒸发速率可以达到1.1 kg/(m^(2)·h),光热转化效率为80%,比普通聚多巴胺提高15%,证明该材料有很好的光热转化性能,在海水淡化领域有着良好的应用前景。

Age-friendly Streets Based on Street View Images: A Case Study of Beijing Pingguoyuan Street

Many urban block planning in China can not be well satisfied for the elderly’s quality of life and activity demand.The study of urban block travel senility is helpful to discover the real needs of the elderly for walking space,distinguish the senility level of public walking space,and promote the development of the construction of the senility city.Based on literature research,this paper firstly summarizes the needs of the elderly in the pedestrian space in terms of their traffic feelings and visual experience,and then carries out image semantic segmentation operations on street view images by taking street view images,image semantic segmentation and other research methods.Factor division was carried out on the summary data of the elderly walking space experience,and scoring was carried out according to the elements in the image.Finally,it was found that the development of the elderly walking space in Pingguoyuan Street through the street view pictures was of great significance.