Herein, we use experiments and numerical simulations to demonstrate a novel class of magnetically responsive photonic crystals (MRPCs) based on photonic nanorods which exhibit multiple optical properties in a magnetic field (H) due to their fixed photonic nanorods and H-tunable lattice defects. As an example, superparamagnetic FeO@polyvinyl pyrrolidone (PVP)@SiO photonic nanorods were fabricated through a polyacrylic acid-catalysed hydrolysis-condensation reaction of γ-mercaptopropyltrimethoxysilane around chain-like PC templates formed by monodispersed FeO@PVP particles under H. For the as-proposed MRPCs, with increasing H, the photonic nanorods firstly experience in situ rotational orientation along the H direction, followed by alignment and connection into long parellel nanochains via the spaces between the ends of adjacent photonic nanorods (named lattice defects). As the number and size of the lattice defects changes with H, the MRPCs exhibit visible red-shifts and blue-shifts of their diffraction wavelengths in addition to monotonous enhancement of their diffraction peaks. These optical properties are very different from those of previously reported MRPCs. The diversity of the structural colors and brightness of these MRPCs with H is also closely dependent on the applied time of H, the concentration of the photonic nanorods, and the structural parameters of the nanorods, including nanorod length and interparticle distance. Due to the difficult duplication of their various optical properties as well as their easy fabrication and low cost, MRPCs based on photonic nanorods are suitable for wide applications in forgery protection and information encryption.
This paper applied dry combustion method to determinate the carbon content rates in different organs of natural white birch trees in xiaoxinganling mountain area and carried on the analysis and comparison. The results showed that: the average carbon content rates of leaves,branches,trunks and roots was 49.31 %,46.60,46.70%,45.67%,respectively.According to the average values, the sequence of carbon content rates in different organs from the maximum to the minimum was leaves,trunks,branches and roots. Additionally, in different layers of a tree, the sequence of carbon content rates in leaves from the maximum to the minimum was: the upper strata, the middle strata, the lower strata. The sequence of carbon content rates in branches was: the upper strata, the lower strata, the middle strata. The sequence of carbon content rates in trunks was: bark, sapwood, heartwood.The sequence of carbon content rates in roots was: level 2 root, level 1 root, level 3 root. Single tree average rate of carbon 46.49% Higher than 51.25% in northern China. Variance analysis showed that the differences of Bark and sapwood achieved significant level (p<0.05) as well as the differences of bark and heartwood, while the rest were not significant.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.