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441 results on '"Yao Ran"'

1. Analysis of landslide mechanism induced by excavation and rainfall: A case study of the Qianjin square landslide in Wanyuan City, Sichuan Province

Author

Tao JIANG, Shenghua CUI, and Yao RAN

Subjects
artificial excavation, rainfall, large landslides, deformation destruction features, formation mechanism, Geology, QE1-996.5
Abstract

In recent years, there has been a frequent occurrence of geological disasters caused by the coupling of human engineering activities and rainfall environment. However, research on the mechanism of coupling has not been deeply explored. In this paper, the landslide of Qianjin square in Wanyuan City induced by the coupling of excavation and rainfall is taken as an example, and the characteristics and formation mechanism of landslide deformation and failure are analyzed by combining the monitoring data of surface displacement and deep displacement of the landslide of Qianjin square and the rainfall data. The study shows that: (1) excavation is the main reason for the reactivation of the old landslide, while rainfall plays a triggering and accelerating role; (2) excavation provides good airspace conditions for the landslide on the one hand , and on the other hand causes the soil behind it to lose support, leading to the misalignment of the landslide from front to back; (3) after excavation, long-term strong to moderate rainfall in the study area, combined with tension cracks caused by excavation, make it easier for surface water to enter the interior of the slope. The bedrock fracture water is replenished by atmospheric rainfall, resulting in some unsaturated soil becoming saturated soil, increasing the pressure of pressurized water and decreasing effective stress. Additionally, groundwater may reach the slip zone and drive the deformation development. Finally, the process mechanism of landslide induced by excavation and rainfall coupling is proposed as “excavation-slope multi-stage cracking-concentrated rainfall-slip zone weakening-accelerated deformation”.

Published
2023
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2. Reliability modelling and analysis on MMC for VSC-HVDC by considering the press-pack IGBT and capacitors failure

Author

Li Hui, Zheng Meimei, Yao Ran, Lai Wei, Deng Jili, Long Haiyang, and Qu Haitao

Subjects
HVDC power convertors, fatigue, failure analysis, insulated gate bipolar transistors, HVDC power transmission, thermal stresses, power transmission reliability, voltage-source convertors, power capacitors, statistical analysis, reliability analysis models, press-packing IGBT device, film capacitors, MMC-HVDC simulation model, IGBT devices, temperature field model, corrosion failure mode, failure rate calculation, metallised film capacitor, reliability calculation, modular multilevel converter, VSC-HVDC system, equipment safe operation, failure statistical approach, physical failure method, capacitor failure, reliability analysis accuracy, main component failure rates, fault data, main component fatigue failure mode, MMC sub-module, junction temperatures, voltage stress, thermal stress, Engineering (General). Civil engineering (General), TA1-2040
Abstract

Modular multi-level converter (MMC) with press-packing IGBT devices is the popular and key equipment of VSC-HVDC system, its reliability is directly related to the equipment safe operation. However, it is difficult to analyse the reliability using the failure statistical approach due to less fault data. In order to improve the reliability analyses accuracy, it is necessary to use the physical failure method by considering the main components fatigue failure mode. The reliability analysis models are presented for the MMC sub-module with the press-packing IGBT device and metallised film capacitors. First, based on the MMC-HVDC simulation model, the losses and the junction temperatures of the IGBT devices were derived by the temperature field model, which the failure rates can be calculated. Furthermore, based the corrosion failure mode, the failure rate calculation of the metallised film capacitor was investigated using the voltage stress and thermal stress, the reliability calculation of the MMC sub-module was presented by combining the main components failure rates. Finally, the reliability of the VSC-HVDC based MMC was also presented with the different operation mode. The achievement is helpful to assess and improve the reliability of the VSC-HVDC.

Published
2019
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4. Optimization of Stamping Process Parameters for Small Curved Beam Parts of Rail Train Based on GA-PSO-BP Algorithm

Author

Ji, Hongchao, Li, Mengmeng, Yao, Ran, Pei, Weichi, Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Ivanov, Vitalii, Series Editor, Haddar, Mohamed, Series Editor, Cavas-Martínez, Francisco, Editorial Board Member, di Mare, Francesca, Editorial Board Member, Kwon, Young W., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, Xu, Jinyang, Editorial Board Member, Mocellin, Katia, editor, Bouchard, Pierre-Olivier, editor, Bigot, Régis, editor, and Balan, Tudor, editor

Published
2024
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14. Multiphysics Model Reconstruction Method of PP-IGBT and Stress Distribution Influencing Factors

Author

Duan, Zeyu, Li, Hui, Yao, Ran, Lai, Wei, Wang, Xiao, Li, Jinyuan, Chen, Zhongyuan, Wang, Ruimiao, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Xie, Kaigui, editor, Hu, Jianlin, editor, Yang, Qingxin, editor, and Li, Jian, editor

Published
2023
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15. Reliability Lifetime Prediction of SiC IGBT Devices with Different Packaging Approaches

Author

Li, Hui, Chen, Siyu, Yao, Ran, Zhou, Bailing, Lai, Wei, Li, Jinyuan, Chen, Zhongyuan, Li, Yaosheng, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Xie, Kaigui, editor, Hu, Jianlin, editor, Yang, Qingxin, editor, and Li, Jian, editor

Published
2023
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16. Multi-physical Finite Element Modeling and Influencing Factor Analysis for Solder Layer Failure of SiC MOSFET Device

Author

Yao, Ran, Li, Hui, Lai, Wei, Li, Hanrui, Duan, Zeyu, Chen, Siyu, Chen, ZhongYuan, Li, Yaosheng, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Xie, Kaigui, editor, Hu, Jianlin, editor, Yang, Qingxin, editor, and Li, Jian, editor

Published
2023
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30. Analysis on the Package Failure Modes and Condition Monitoring Methods of Wire-Bond IGBT

Author

Liu, Renkuan, Li, Hui, Yao, Ran, Wang, Xiao, Lai, Wei, Tan, Hongtao, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, He, Jinghan, editor, Li, Yaohua, editor, Yang, Qingxin, editor, and Liang, Xidong, editor

Published
2022
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38. Study on antioxidant activities of proteins and enzymatic hydrolysates of eight edible fungi

Author

WANG Yao-ran, ZHAO Yan, CHEN Ming-jie, WEI Chen-ying, ZHA Lei, and LI Zhi-ping

Subjects
edible fungi, protein, hydrolysate, antioxidant activity, amino acids, Food processing and manufacture, TP368-456
Abstract

Objective: This study focused on the antioxidant activities of eight edible fungiproteins and their hydrolysates. Methods: Eight edible fungi proteins were hydrolyzed using alkaline protease. DPPH free radical scavenging activity, ABTS free radical scavenging activity, Fe2+ chelation rate and reducing power were used to evaluate antioxidant activity. Results: SDS-PAGE electrophoretic profile results indicated that alkaline protease was efficient in hydrolyzing proteins into low molecular weight peptides and amino acid; the antioxidant activity of the alkaline proteolysis product of Volvariellavolvacea was the highest with DPPH free radical scavenging ability （5 140.45±5.35） μg Trolox/g, ABTS free radical scavenging ability （6.97±0.27） mmol Trolox/L, and Fe2+ chelation rate （79.86±0.45）% and the reducing power （0.350±0.001）. Moreover, the amino acid composition was also determined, containing eight essential amino acids （230.43±5.35） mg/g and hydrophobic （209.95±4.95） mg/g, negatively charged （115.89±2.32） mg/g and aromatic amino acids （57.86±1.74） mg/g with high antioxidant activity. Conclusion: The alkaline proteolysis product of Volvariellavolvacea has good antioxidant activity and was rich in essential, hydrophobic, negatively charged and aromatic amino acids.

Published
2022
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39. Improving Short-Circuit Withstand Capability by Targeted Optimization Package for Press-Pack IGBT Module

Author

Liu, Renkuan, Li, Hui, Luo, Xiaorong, Yao, Ran, Lai, Wei, Wei, Jie, Wang, Xiao, Li, Zhaoji, Zhang, Bo, and Chen, Xianping

Abstract

In this article, an electrical–thermal–mechanical (ETM) multiphysics transient finite-element (FE) model is proposed for the press-pack insulated gate bipolar transistor (PP-IGBT) module, and a targeted optimization package (TOP) is designed to enhance the short-circuit withstand capability (SCWC). First, an ETM transient FE model is proposed based on a 3.3-kV/ 50-A PP-IGBT and the coupling relation among electrical, thermal, and mechanical. The weak part of the SCWC is identified by combining the test with the simulation of the short-circuit transient process. Second, the pattern and dimension parameters of TOP are investigated to realize the best performance. Then, its SCWC improvement and reliability are verified through the SCWC, blocking voltage, and power cycling test. The SCWC of the TOP PP-IGBT has increased by over 100% compared to that of the conventional PP-IGBT.

Published
2024
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41. High-quality β-(AlxGa1−x)2O3 thin films on sapphire substrates by face-to-face annealing.

Author

Wu, Songhao, Ma, Chicheng, Yang, Han, Liu, Zichun, Ma, Yuanxiao, Yao, Ran, Zhang, Yiyun, Yang, Hua, Yi, Xiaoyan, Wang, Junxi, and Wang, Yeliang

Subjects
SUBSTRATES (Materials science), THIN films, SAPPHIRES, X-ray diffraction, CRYSTALLINITY, ATOMS
Abstract

High-quality β-(AlxGa1−x)2O3 thin films are fabricated through face-to-face annealing on sapphire substrates covered with epitaxial Ga2O3. Al atoms during high-temperature annealing are uniformly diffused from the sapphire substrate into the overlying Ga2O3 for (AlxGa1−x)2O3 formation. The transformation of the (−201) crystal facet into the (300) crystal facet is observed, which is likely due to the lowest E (hkl)surf of the (100) surface. The crystallinity can be further improved with increasing the annealing temperatures and the duration of the thermal treatment under a tolerance limit of 1400 °C, which also increases the Al content to 0.68 in β-(AlxGa1−x)2O3 with a bandgap of up to 6.0 eV. As a result, highly-crystalline (300)-plane β-(AlxGa1−x)2O3 is obtained with a low X-ray diffraction (XRD) full width at half maximum (FWHM) at around 0.08° (288 arcsec). These findings contribute to the understanding of the preparation of high-quality β-(AlxGa1−x)2O3 films on sapphire substrates. [ABSTRACT FROM AUTHOR]

Published
2024
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