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Accurate wucai seedling segmentation is of great significance for growth detection, seedling location, and phenotype detection. To segment wucai seedlings accurately in a natural environment, this paper presents a lightweight segmentation model of wucai seedlings, where U-Net is used as the backbone network. Specifically, to improve the feature extraction ability of the model for wucai seedlings of different sizes, a multi-branch convolution block based on inception structure is proposed and used to design the encoder. In addition, the expectation "maximizationexpectation" maximization attention module is added to enhance the attention of the model to the segmentation object. In addition, because of the problem that a large number of parameters easily increase the difficulty of network training and computational cost, the depth-wise separable convolution is applied to replace the original convolution in the decoding stage to lighten the model. The experimental results show that the precision, recall, MIOU, and F1-score of the proposed model on the self-built wucai seedling dataset are 0.992, 0.973, 0.961, and 0.982, respectively, and the average recognition time of single frame image is 0.0066 s. Compared with several state-of-the-art models, the proposed model achieves better segmentation performance and has the characteristics of smaller-parameter scale and higher real-time performance. Therefore, the proposed model can achieve good segmentation effect for wucai seedlings in natural environment, which can provide important basis for target spraying, growth recognition, and other applications. [ABSTRACT FROM AUTHOR]

We demonstrate a novel approach based on sulfurization of MoO3 powder pre-exfoliated on the SiO2/Si substrate to synthesize high crystalline quality and large-sized monolayer MoS2 films uniformly covering the whole substrate. The surface morphology, thickness, crystalline quality, and luminescence mechanism of the MoS2 films were characterized by the optical microscopy, Raman spectroscopy, and photoluminescence spectroscopy. The results reveal that MoS2 films directly synthesized on the bare SiO2/Si substrate by our method have high surface coverage superior over those of one-step chemical vapor deposition (CVD) method and exhibit uniform monolayer with larger lateral length up to ∼120 µm compared to those of the traditional two-step CVD method. Our proposed growth strategy opens up new pathways for CVD synthesis of high crystalline quality and large-sized uniform monolayer MoS2 films and can also be utilized for synthesizing other two-dimensional materials. [ABSTRACT FROM AUTHOR]

Although different kinds of metal oxide nanoparticles are extensively investigated as anode materials for lithium-ion batteries (LIBs), their cycle life and energy/power density are still not suitable for commercial applications. Metal oxides have a large storage capacity, but they suffer from low electrical conductivity and severe volume change during the charge/discharge process. Herein, we present a facile route to prepare self-assembled ZnO/Co3O4 nanocomposite clusters through calcination of preformed Prussian Blue Analogue (PBA) Zn3[Co(CN)6]2 nanospheres. These self-assembled ZnO/Co3O4 nanocomposite clusters exhibit superior lithium storage capabilities with good cycling properties. A reversible capacity of 957 mA h g−1 was retained at a current density of 100 mA g−1 up to 100 cycles. The enhanced electrochemical performance of the ZnO/Co3O4 nanocomposite anode can be ascribed to the rational design of the self-assembled cluster structures and the synergetic effect of two-component functional nanoparticle systems. [ABSTRACT FROM AUTHOR]

A facile two-step strategy involving a room-temperature synthesis and subsequent thermal calcination of a binary-metal-based metal–organic framework (MOF) has been successfully developed for the preparation of porous Mn1.8Fe1.2O4 nanocubes. The as-prepared Mn1.8Fe1.2O4 inherits the morphologies of MOFs and shows a porous structure with a relatively high specific surface area (124 m2 g−1) due to the release of small gas molecules (CO2 and NO2) in the calcination process in air. The as-prepared porous Mn1.8Fe1.2O4 nanocubes exhibit greatly enhanced performance for Li storage. The capacity of the porous Mn1.8Fe1.2O4 retained 827 mA h g−1 after 60 cycles at a current density of 200 mA g−1. The enhanced electrochemical performance is attributed to the interconnected porous structures and large amount of mesopores, which effectively improve structural stability, reduce the diffusion length for lithium ions and electrons, and buffer volume expansion during the Li+ insertion/extraction processes. These results indicate that the as-prepared porous Mn1.8Fe1.2O4 nanocubes can be promising anode materials for high-performance LIBs. [ABSTRACT FROM AUTHOR]