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980 results on '"Zhou, Hongping"'

151. A Tree Point Cloud Simplification Method Based on FPFH Information Entropy.

Author

Hu, Chenming, Ru, Yu, Fang, Shuping, Zhou, Hongping, Xue, Jiangkun, Zhang, Yuheng, Li, Jianping, Xu, Guopeng, and Fan, Gaoming

Subjects
POINT cloud, ENTROPY (Information theory), CLOUD storage, FOREST surveys, FOREST monitoring, GENETIC algorithms
Abstract

LiDAR technology has been widely used in forest survey and research, but the high-resolution point cloud data generated by LiDAR equipment also pose challenges in storage and computing. To address this problem, we propose a point cloud simplification method for trees, which considers both higher similarity to the original point cloud and the area of the tree point cloud. The method first determines the optimal search neighborhood using the standard deviation of FPFH information entropy. Based on FPFH information entropy and Poisson disc sampling theory, the point cloud is partitioned and sampled. By optimizing the separation thresholds of significant feature points and less significant feature points using a genetic algorithm with the Hausdorff distance and point cloud area as the objective function, the final simplified point cloud is obtained. Validation with two point cloud data sets shows that the proposed method achieves good retention of the area information of the original point cloud while ensuring point cloud quality. The research provides new approaches and techniques for processing large-scale forest LiDAR scan point clouds, reducing storage and computing requirements. This can improve the efficiency of forest surveys and monitoring. [ABSTRACT FROM AUTHOR]

Published
2023
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172. Design of double‐layer SiN x :H film and its application in c‐Si PERC solar cells

Author

Fan Jinxing, Wang Yin, Yang Yanhua, Xu Linyun, and Zhou Hongping

Subjects
Materials science, Silicon, Passivation, Biomedical Engineering, chemistry.chemical_element, Bioengineering, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, law.invention, Plasma-enhanced chemical vapor deposition, law, Solar cell, General Materials Science, business.industry, Energy conversion efficiency, Carrier lifetime, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Solar cell efficiency, chemistry, Optoelectronics, 0210 nano-technology, business, Refractive index
Abstract

The existing solar cell anti-reflection film technology still cannot adequately meet the light trapping needs of solar cells. In this Letter, double-layered SiN x :H films were prepared for c-Si solar cells by plasma enhanced chemical vapor deposition (PECVD). Herein, the authors introduce a simple, convenient method to lower the reflectance in silicon solar cells by applying double-layered SiN x :H film to increase the refractive index of such film. Compared to the single layer film devices, the reflectance of the double-layered SiN x :H film can be significantly reduced by >30% through enhanced absorption of light in solar cells. This method has achieved an average of 0.08% conversion efficiency, with the highest being 0.18%. In addition, the double-layer film solar cells also showed a better passivation performance than that of the single-layer film, so that the minority carrier lifetime was up to 137 µs. Therefore, the improvement of solar cell efficiency mainly come from the decrease of reflectivity and the improvement in film passivation performance. The work of this Letter demonstrated the light trapping advantages and passivation enhancement performance of double-layer films applied to single crystal silicon solar cells.

Published
2020

185. Street tree segmentation from mobile laser scanning data

Author

Li Qiujie, Liu Xu, Zhou Hongping, and Pengcheng Yuan

Subjects
Boosting (machine learning), Urban forest, Computer science, Street tree, Point cloud, General Earth and Planetary Sciences, Segmentation, Mobile laser scanning, Remote sensing
Abstract

Mobile laser scanning (MLS) measurement technology is well-suited for individual-tree-based urban forest inventory because it can capture a dense three-dimensional (3D) point cloud from vertical st...

Published
2020

190. Bifunctional Single-Molecular Fluorescent Probe: Visual Detection of Mitochondrial SO2and Membrane Potential

Author

Ai, Wenming, Bu, Yingcui, Huang, Houshi, Wang, Junjun, Ren, Mengjuan, Deng, Yu, Zhu, Yicai, Wang, Sen, Yu, Zhi-Peng, and Zhou, Hongping

Abstract

Mitochondrial membrane potential (MMP) and sulfur dioxide (SO2) significantly affect the mitochondrial state. In this work, TC-2and TC-8were constructed through side-chain engineering, in which TC-2bearing the poorer hydrophobicity could localize on mitochondria better. Interestingly, short-wave emission was captured due to the sensitive response of TC-2to SO2(LOD = 13.8 nM). Meanwhile, the probe could bind with DNA, presenting enhanced long-wave emission. Encouragingly, TC-2could migrate from mitochondria to the nucleus when MMP was decreased, accompanied by the increase of fluorescence lifetime (9-fold). Hence, TC-2could be used for dual-channel monitoring of mitochondrial SO2and MMP, which showed a completely different pathway from the commercial MMP detectors JC-1/JC-10. The cellular experiments showed that MMP was gradually decreased due to reactive oxygen species-triggered oxidative stress, and the SO2level was up-regulated simultaneously. Overall, this work proposed a new method to investigate and diagnose the mitochondrial-related diseases.

Published
2023
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