Flexible fiber‐shaped supercapacitors have shown great potential in portable and wearable electronics. However, small specific capacitance and low operating voltage limit the practical application of fiber‐shaped supercapacitors in high energy density devices. Herein, direct growth of ultrathin MnO2 nanosheet arrays on conductive carbon fibers with robust adhesion is exhibited, which exhibit a high specific capacitance of 634.5 F g−1 at a current density of 2.5 A g−1 and possess superior cycle stability. When MnO2 nanosheet arrays on carbon fibers and graphene on carbon fibers are used as a positive electrode and a negative electrode, respectively, in an all‐solid‐state asymmetric supercapacitor (ASC), the ASC displays a high specific capacitance of 87.1 F g−1 and an exceptional energy density of 27.2 Wh kg−1. In addition, its capacitance retention reaches 95.2% over 3000 cycles, representing the excellent cyclic ability. The flexibility and mechanical stability of these ASCs are highlighted by the negligible degradation of their electrochemical performance even under severely bending states. Impressively, as‐prepared fiber‐shaped ASCs could successfully power a photodetector based on CdS nanowires without applying any external bias voltage. The excellent performance of all‐solid‐state ASCs opens up new opportunity for development of wearable and self‐powered nanodevices in near future.

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Intelligent vehicle detection and counting are becoming increasingly important in the field of highway management. However, due to the different sizes of vehicles, their detection remains a challenge that directly affects the accuracy of vehicle counts. To address this issue, this paper proposes a vision-based vehicle detection and counting system. A new high definition highway vehicle dataset with a total of 57,290 annotated instances in 11,129 images is published in this study. Compared with the existing public datasets, the proposed dataset contains annotated tiny objects in the image, which provides the complete data foundation for vehicle detection based on deep learning. In the proposed vehicle detection and counting system, the highway road surface in the image is first extracted and divided into a remote area and a proximal area by a newly proposed segmentation method; the method is crucial for improving vehicle detection. Then, the above two areas are placed into the YOLOv3 network to detect the type and location of the vehicle. Finally, the vehicle trajectories are obtained by the ORB algorithm, which can be used to judge the driving direction of the vehicle and obtain the number of different vehicles. Several highway surveillance videos based on different scenes are used to verify the proposed methods. The experimental results verify that using the proposed segmentation method can provide higher detection accuracy, especially for the detection of small vehicle objects. Moreover, the novel strategy described in this article performs notably well in judging driving direction and counting vehicles. This paper has general practical significance for the management and control of highway scenes.

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Blue phosphorene (blue-P), an allotrope of black phosphorene, is prone to oxidize under ambient conditions, which significantly hinders its incorporation in anode for Li/Na ion batteries (LIBs/NIBs). Combining blue-P and hexagonal boron nitride (h-BN) together to construct h-BN/blue-P heterostructure (BN/P) can break the limitation of the restricted properties of blue-P. By means of first-principles computations, we explored the potential of using BN/P as anode material for LIBs/NIBs. Our computations show that the adsorption energies of Li/Na in BN/P are stronger than those in blue-P. Interestingly, although Li has similar chemical properties to Na, their the most energetically favorable sites on BN/P are different. Li prefers to insert into the interlayer of BN/P while Na prefers to absorb on the blue-P surface of BN/P. Furthermore, BN/P can achieve high theoretical specific capacities 801 and 541 mAh/g and low diffusion barriers 0.08 and 0.07 eV for LIBs and NIBs, respectively. All these characteristics suggest that the BN/P could be an ideal candidate used as promising anode material for high-performance LIBs/NIBs.