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The use of computer vision-related technologies can more efficiently achieve target detection of UAVs and accurately identify the status of substation equipment. Therefore, this paper proposes research on UAV target detection and substation equipment status recognition technology based on computer vision. Taking key technical links such as image preprocessing based on computer vision technology, image feature extraction, and construction of UAV target detection coordinate system as breakthrough points, realizing UAV target detection work lays a solid foundation for the identification of substation equipment status. It lays the foundation and promotes the scientific and effective identification of the status of substation equipment. It provides a guarantee for improving the accuracy of UAV target detection and promoting the efficient and stable identification of substation equipment status. CLC number: TN919.8 Document identification code: A.

In recent decades, various manufacturing floors have followed lean initiatives. The focus of lean-initiative approaches is to improve efficiency by eliminating non-value-added activities. Value str...

Multiple object detection is a key challenge in object detection. Feature extraction and occlusion handling are two key elements in multiple object detection. However, existing methods do not perform well in these aspects during detecting multiple objects. A region-based convolutional network (R-CNN) has achieved a great success in region-based feature extraction, and the part filters in a deformable part-based model (DPM) are very suitable for detecting occluded objects. In this letter, we present a framework that integrates the R-CNN and the DPM for detecting multiple objects. In addition, we propose a new filter based on the dense subgraph discovery algorithm for refining the candidate proposals generated by the DPM. Through combining these two models, we can detect each single object with high accuracy among all objects in an image, especially in the situation that objects are stayed close together. Different from the traditional methods, our framework has the capability to detect multiple objects belonging to various classes rather than only one typical class such as a person or a car. Experimental results on the PASCAL VOC dataset show that our framework achieves better performance compared to using only the R-CNN or the DPM alone in multiple object detection.

Nitrogen-doped graphene (NG) with a nitrogen content from 4.05 wt% to 5.47 wt% was rapidly prepared via microwave heating of graphene under NH 3 flow. The as-synthesized NG samples were then used as electrocatalysts in the oxygen reduction reaction (ORR) in alkaline solution. The NG samples showed excellent ORR catalytic activity with an onset potential of 0.17 V, which is comparable to that of commercial Pt/C electrocatalyst (0.21 V). The structure, composition, and nitrogen species of the NG samples were examined by transmission electron microscopy, Raman spectroscopy, elemental analysis and X-ray photoelectron spectroscopy. The onset potential increases with the content of graphite nitrogen in the NG samples, indicating that graphite nitrogen might be the main factor controlling the performance of the NG samples in the ORR. The results showed that NG prepared by rapid microwave heating is a promising ORR catalyst for fuel cells.

Nowadays, mobile devices, virtual reality and augment reality technologies are developing faster and faster. With a variety of equipments, people are no longer only using PC to handle tasks. Some traditional system frameworks are migrating to these new technology areas, and direct volume rendering is one of them. In this paper, we propose a real-time and intuitive volume data exploration framework on mobile devices. Our framework introduces a direct-touch transfer function design method that is able for the user to pick voxels directly on a volume rendered image. With one-pass shader, user interaction and volume rendering can be handled efficiently in real-time. The user only needs to learn a few related knowledge to explore a volume data and get its rendered image. As a result, the time cost of transfer function design for direct volume rendering is significantly reduced. Our framework is implemented with OpenGL ES 3.0 and GLSL shader. Experimental results show the advantages of our framework. Researchers, and even general users, can easily obtain volume rendered images of volume data.

An efficient process to prepare basic imidazolium ionic liquids (ILs) solution free of halide has been developed based on the rapid ion exchange between alkyl sulfate anion (ROSO3−, R = alkyl) and OH− in ethanol. Eight halide-free ILs with a flexible range of cations and anions were prepared by neutralizing the basic IL solution with corresponding acids. The viscosity, ionic conductivity or melting points of the ILs obtained by present method were examined and discussed. The results implied that the whole process is green since only ethanol and water were used as solvents and by-products were only solid KROSO3 and KY (Y = desired anion). Furthermore, a typical imidazolium ionic liquid, [Emim]HSO4, was synthesized by different precursors with various amounts of Br impurity, and its effect oxygen reduction reaction (ORR) of Pt/C catalyst was systematically investigated.

A quick and efficient approach to prepare nitrogen doped graphene (NG) is proposed in this paper via microwave heating in NH 3 atmosphere. Results show that graphene, as an allotrope of carbon, is a good microwave-absorbing material and can reach a high temperature in minutes, facilitating nitrogen incorporation into the structure under NH 3 . Elemental analysis and X-ray photoelectron spectroscope (XPS) verified the success of N-doping with the nitrogen content of 5.04 wt%. For comparison, both plain grapheme (G) and the NG were used as supporting materials for platinum to investigate their potential application in fuel cells. Transmission electron microscope (TEM) images showed that the NG improved the distribution of Pt particles. Themogravimetry (TG) and differential scanning calorimeters (DSC) revealed better thermal stability of the Pt/NG than that of the Pt/G. Furthermore, the Pt/NG catalysts exhibited higher electrochemical active surface area, methanol catalytic activity, and tolerance to CO poisoning than those of the Pt/G under fuel cell conditions. It suggests that the NG prepared by microwave synthesis has provided a new way to improve electrocatalytic activity in fuel cells.

Pt nanoparticles are deposited onto graphene sheets via synchronous reduction of H2PtCl6 and graphene oxide (GO) suspension using NaBH4. Lyophilization is introduced to avoid irreversible aggregation of graphene (G) sheets, which happens during conventional drying process. Pt/G catalysts reveal a high catalytic activity for both methanol oxidation and oxygen reduction reaction compared to Pt supported on carbon black (Pt/C). The performance of Pt/G catalysts is further improved after heat treatment in N2 atmosphere at 300 °C for 2 h, and the peak current density of methanol oxidation for Pt/G after heat treatment is almost 3.5 times higher than Pt/C. Transmission electron microscope (TEM) images show that the Pt particles are uniformly distributed on graphene sheets. X-ray photoelectron spectroscopy (XPS) results demonstrate that the interaction between Pt and graphene is enhanced during annealing. It suggests that graphene has provided a new way to improve electrocatalytic activity of catalyst for fuel cell.

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A quick and green process to prepare [Rmim]OH solutions is developed based on fast ion exchange between OH− and halide ions (halide = Cl− or Br−) in ethanol. Five ionic liquids were synthesized by neutralizing the obtained [Rmim]OH solution with acids to verify the feasibility of the whole process. The halogen content in the finally obtained ionic liquids and the experimental factors influencing the content are mainly discussed. Moreover, two other alcohols besides ethanol, propanol and iso-propanol, were further examined as solvents. The results show that this process, together with the alkylation and hydroxide anion route, is simple and efficient for preparing various ionic liquids, and that the process is a complementary synthetic route to existing strategies to prepare various ILs.