Shadow–highlight feature matching automatic small crater recognition using high-resolution digital orthophoto map from Chang’E Missions

This paper introduces a new method of small lunar craters’ automatic identification, using digital orthophoto map(DOM) data. The core of the approach is the fact that the lunar exploration DOM data reveal contrasting highlight and shadow characteristics of small craters under sunlight irradiation. This research effort combines image processing and mathematical modeling. Overall it proposes a new planetary data processing approach, to segment and extract the highlight and shadow regions of small craters,using the image gray frequency(IGF) statistical method.IGF can also be applied to identify the coupling relationships between small craters’ shape and their relative features. This paper presents the highlight and shadow pair matching(HSPM) model which manages to perform highprecision automatic recognition of small lunar craters.Testing was performed using the DOM data of Chang’E-2(CE-2). The results have shown that the proposed method has a high level of successful detection rate. The proposed methodology that uses DOM data can complement the drawbacks of the digital elevation model(DEM) that has a relatively high false detection rate. A hybrid fusion model(FUM) that combines both DOM and DEM data, was carried out to simultaneously identify small, medium, and large-sized craters. It has been proven that the FUM generally shows stronger recognition ability compared to previous approaches and it can be adapted for high precision identification of craters on the whole lunar surface.The results meet the requirements for a reliable and accurate exploration of the Moon and the planets.

分级多孔碳纳米纤维用于高效太阳能驱动水净化

碳材料通常用于太阳能水蒸发,因为它们可以吸收宽带光并有效地产生热量.然而,具有光滑表面的传统碳材料受到大约10%的中等反射的限制,损失了反射能量.在此,我们提出了一种多界面策略,以提高碳纳米纤维(CNFs)的固有光吸收,从而实现更高效的太阳能驱动水净化.通过简单的牺牲模板方法,在CNFs中引入分级孔来构建多个界面得到高表面粗糙度碳纳米纤维(HPCNFs).由于高表面粗糙度和源自分级孔的丰富内部空气介电界面,HPCNFs在宽带光(300–2500 nm)吸收显著改善,高达97.62%,这使得在1个太阳光照下的太阳光转换为蒸汽的效率达到96.13%,蒸发率高达1.78 kg m^(-2)h^(−1),超过了大多数相关的纯碳材料.当用于太阳能水蒸发脱盐时,HPCNF膜表现出对离子的高度排斥(<0.05 mg L^(−1)盐离子),并以每天11.18 kg m^(-2)的速率从湖中产生淡水,足以满足4–5个人的日常需求.这项工作为高效碳基太阳能水蒸发材料的设计提供了一种简便策略.

可拉伸和高取向有机/无机复合纳米纤维膜用于多方向应变传感器和光驱动热电器件

静电纺丝技术是制备纳米纤维膜的一种有效、简易方法,广泛用于基于能量收集的可穿戴电子器件.然而,由于超低的性能以及难以建立稳定的温差,其在热电领域的应用鲜有报道.本文结合静电纺丝技术和表面涂层的方法设计了具有优异拉伸性能和热电性能的高取向有机/无机复合纳米纤维膜.取向结构有利于载流子的快速传输,与无序结构的纳米纤维膜相比,其热电功率因子增加了7倍.此外,基于独特的取向纳米纤维结构,我们设计了新颖的辐射冷却-光热加热电极用于制备光驱动热电器件,为构建薄膜热电器件面内温差提供了一种新思路.而且,通过将两个高取向有机/无机复合纳米纤维膜正交堆叠,组装了用于识别人体关节复杂运动的多方向应变传感器.这些研究将推动静电纺纳米纤维基热电器件在下一代可穿戴电子器件领域的发展和应用.