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The non-uniformity of a single crystal can sometimes be found in biominerals, where surrounding biomacromolecules are incorporated into the growing crystals. This unique composite structure, combining heterogeneity and long-range ordering, enables the functionalization of single crystals. Polymer gel media are often used to prepare composite single crystals, in which the growing crystals incorporate gel networks and form a bi-continuous interpenetrating structure without any disruption to single crystallinity. Moreover, dyes and many kinds of nanoparticles can be occluded into single crystals under the guidance of gel incorporation. On this basis, the bio-inspired method has been applied in crystal morphology control, crystal dyeing, mechanical reinforcement, and organic bulk heterojunction-based optoelectronics. In this paper, the composite structure, the incorporation mechanisms, and the multiple functions of gel-incorporated single crystals are reviewed. [ABSTRACT FROM AUTHOR]

Exploiting their sensitivity to cloud droplets and small raindrops, Ka-band cloud radar observations are used to investigate weak stratiform precipitation over Wuhan during cooling on 16–17 February 2022. During cooling, the surface temperature drops by about 8 °C with the lowest value less than 0 °C because of the strong cold air from the north. The cold air lifts the warm and humid air transported by the southeasterly and southwesterly winds, causing thick stratiform clouds and persistent weak precipitation. The Ka-band radar captures the full process of stratiform cloud occurrence; light rain and then mixed rain and snow; and the characteristics of clouds and precipitation at each stage due to its fine sensitivity to small hydrometeors, whereas the reanalysis data alone cannot capture the transition to the mixed rain and snow regime, which can cause dangerous freezing rain or sleet on the ground. Hence, a detailed analysis of cooling and cold surges and their hazards to society, and their reproduction in numerical predictions, needs to use high-sensitivity radar data as much as possible. [ABSTRACT FROM AUTHOR]

In this paper, a novel three-band microwave metamaterial absorber is presented. The proposed absorber consists of a metallic planar cross and square layer on the top and a metallic ground plane at the bottom. They are separated by a dielectric layer. The experimental results show that the proposed absorber exhibits triple band absorption responses lying in C-band, X-band, and Ku-band. The proposed absorber can perform absorption peaks at three resonant frequencies of 6.16, 8.76, and 12.54 GHz with the absorption of 99.87, 99.98, and 99.99% can be acquired, respectively. In addition, the absorber can operate at large incident angles for both TE and TM polarization. [ABSTRACT FROM PUBLISHER]