Nanoscratch-Induced Formation of Metallic Micro/Nanostructures With Resin Masks

Metallic micro/nanostructures present a wide range of applications due to the small size and superior performances. In order to obtain high-performance devices, it is of great importance to develop new methods for preparing metallic micro/nanostructures with high quality, low cost, and precise position. It is found that metallic micro/nanostructures can be obtained by scratch-induced directional deposition of metals on silicon surface, where the mask plays a key role in the process. This study is focused on the preparation of keto-aldehyde resin masks and their effects on the formation of scratch-induced gold (Au) micro/nanostructures. It is also found that the keto-aldehyde resin with a certain thickness can act as a satisfactory mask for high-quality Au deposition, and the scratches produced under lower normal load and less scratching cycles are more conducive to the formation of compact Au structures. According to the proposed method, two-dimensional Au structures can be prepared on the designed scratching traces, providing a feasible path for fabricating high-quality metal-based sensors

An efficient YOLO v3-based method for the detection of transmission line defects

The UAV inspection method is gradually becoming popular in transmission line inspection, but it is inefficient only through real-time manual observation. Algorithms are available to achieve automatic image identification, but the detection speed is slow, and video image processing is not possible. In this paper, we propose a fast detection method for transmission line defects based on YOLO v3. The method first establishes a YOLO v3 target detection model and obtains the a priori size of the target candidate region by clustering analysis of the training sample library. The training process of the model is accelerated by adjusting the loss function to adjust the learning direction of the model. Finally, transmission line defect detection was achieved by building a transmission line defect sample library and conducting training. The test results show that compared with other deep learning models, such as Faster R-CNN and SSD, the improved model based on YOLO v3 has a huge speed advantage and the detection accuracy is not greatly affected, which can meet the demand for automatic defect recognition of transmission line inspection videos

Crosstalk between Tumor Cells and Macrophages in Stroma Renders Tumor Cells as the Primary Source of MCP-1/CCL2 in Lewis Lung Carcinoma

The chemokine MCP-1/CCL2 is produced by a variety of tumors and plays an important role in cancer progression. We and others previously demonstrated that the primary source of MCP-1 in several mouse tumors, including 4T1 breast cancer, M5076 sarcoma and B16 melanoma, was stromal cells. In the present study, we identified that tumor cells were the primary source of MCP-1 in Lewis lung carcinoma (LLC), because MCP-1 mRNA was highly expressed in tumors grown in both WT and MCP-1-/- mice with elevated serum MCP-1 levels. Since LLC cells isolated from tumors expressed low levels of MCP-1 in vitro, it appeared that the tumor-stromal cell interaction in a tumor microenvironment increased MCP-1 expression in LLC cells. In fact, co-culture of LLC cells with normal mouse peritoneal macrophages or normal lung cells containing macrophages increased MCP-1 expression by LLC cells. Macrophages from TNFα-/- mice failed to activate LLC cells and anti-TNFα neutralizing antibody abolished the effect of WT macrophages on LLC cells. When LLC cells were transplanted into TNFα-/- mice, the levels of MCP-1 mRNA in tumors and serum MCP-1 levels were markedly lower as compared to WT mice, and importantly tumors grew more slowly. Taken together, our results indicate that TNFα released by tumor cell-activated macrophages is critical for increased MCP-1 production by tumors cells. Thus, disruption of tumor-stromal cell interaction may inhibit tumor progression by reducing the production of tumor-promoting proinflammatory mediators, such as MCP-1

Design and Implementation of Transmission Line Insulator Online Monitoring Platform Based on Image Analysis

Abstract The safe operation of insulators directly determines the safety level and reliability of the entire system. In this paper, digital image processing technology is used to analyze and process insulator images, and the performance of composite insulators is comprehensively evaluated from three aspects: degree of deterioration, surface pollution, and degree of water repellency, which is used as the basis for judging insulator detection. For this purpose, an insulator online monitoring system based on telemetry image analysis is specially designed to determine the degree of aging, surface pollution, and hydrophobicity of insulators and to conduct practical tests. At the same time, the system can realize the offline operation of the insulator live, avoid the danger of climbing and live trial operation, and ensure the personal safety of power maintenance personnel. The system hardware uses advanced integration technology and high-performance and reliable equipment. The software is developed using popular development tools, is simple to operate, and has important engineering value.</jats:p

Two-Dimensional Omnidirectional Wind Energy Harvester with a Cylindrical Piezoelectric Composite Cantilever

To improve the response-ability of the energy harvester to multidirectional wind, this paper proposes a wind energy harvester to scavenge wind-induced vibration energy. The harvester comprises a cylindrical beam instead of conventional thin rectangular cantilevers, a bluff body (square prism or circle cylinder), and a piezoelectric tube bonded to the bottom side of the beam for energy conversion. Benefiting from the symmetry of the cylindrical structure, this harvester can respond to airflow from every direction of the two-dimensional plane. The performance of the harvester under a wind speed range of 1.5–8 m/s has been tested. The results demonstrate that the proposed harvester can respond to the wind from all directions of the two-dimensional plane. It provides a direction for the future in-depth study of multidirectional wind energy harvesting.</jats:p