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Your search keyword '"Yan Xiaoqun"' showing total 17 results
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17 results on '"Yan Xiaoqun"'

2. Study on stage characteristics of hydraulic concrete fracture under uniaxial compression using acoustic emission.

Author

Yan, Xiaoqun, Su, Huaizhi, Ai, Li, Soltangharaei, Vafa, Xu, Xiaoyang, and Yao, Kefu

Subjects
*CONCRETE fractures, *ACOUSTIC emission, *HYDRAULIC fracturing, *CONCRETE fatigue, *HYDRAULIC structures
Abstract

Acoustic emission (AE) can monitor and evaluate the cracking situations of hydraulic structures for it is real-time and non-destructive. However, a current challenge of this approach is to accurately identify the various stages during the cracking process. The innovation of this paper lies in the application of AE data in analyzing the stage characteristics during the whole process of hydraulic concrete fracture. First, the slope changing of the cumulative ringing count curve was used to determine the cracking stages of hydraulic concrete. Second, the function of inter-event times (denoted as F-function) was used to further investigate the AE characteristics proximity to the final fracture. Last, the spatial-temporal-energy evolution of cracks was studied. The results show that: (1) The whole process of hydraulic concrete failure shows an obvious stage characteristic from the perspective of AE feature and it can be distinguished to five stages by the slope change of the cumulative ringing count curve; (2) The F-function can be used to identify the last two cracking stages, and it is capable of early warning the macroscopic cracking in ahead of b-value; (3) The spatial-temporal-energy distribution of cracks helps to better understanding the generation and evolution for cracks inside hydraulic concrete. [ABSTRACT FROM AUTHOR]

Published
2024
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8. Early-warning model of deformation safety for roller compacted concrete arch dam considering time-varying characteristics

Author

Zhiping Wen, Yan Xiaoqun, Hongping Liu, Yang Meng, and Huaizhi Su

Subjects
Roller-compacted concrete, business.industry, Hydrostatic pressure, 020101 civil engineering, 02 engineering and technology, Structural engineering, Deformation (meteorology), 0201 civil engineering, Arch dam, Monitoring data, Early warning model, Partial least squares regression, 0202 electrical engineering, electronic engineering, information engineering, Ceramics and Composites, 020201 artificial intelligence & image processing, Material properties, business, Geology, Civil and Structural Engineering
Abstract

During its long process of serving time, roller compacted concrete (RCC) arch dam effected by the comprehensive combination of many factors shows a typical time-varying characteristic on its structure and material properties, which is objectively reflected in the prototype monitoring data. On the basis of the analysis on influence variables of dam deformation and the working mechanism of the RCC arch dam, in this paper, time-varying early-warning model for the RCC arch dam is established by introducing time-varying factors into hydrostatic pressure components and expanding temperature components, then the modeling method of time-varying early-warning model above is proposed combined with the partial least squares algorithm and genetic algorithm.

Published
2018
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13. Computation and Analysis of High Rocky Slope Safety in a Water Conservancy Project

Author

Yang Meng, Su Huaizhi, and Yan Xiaoqun

Subjects
Article Subject, Computation, lcsh:Mathematics, Linkage (mechanical), Deformation (meteorology), lcsh:QA1-939, Displacement (vector), Finite element method, law.invention, law, Section (archaeology), Modeling and Simulation, Safety coefficient, Geotechnical engineering, Geology, Mathematical simulation
Abstract

An integrated method, covering the actual monitoring analysis, practical geological model, and theoretical mathematical simulation model, is systematically proposed and successfully applied. Deformation characteristic of a unique high rocky slope was firstly analyzed from multiple angles and multiple layers by changeable elevations and distances. Arrangements of monitoring points were listed and monitoring equipment was designed to comprise a complete monitoring system. Present larger displacement was concluded for bottom larger displacement caused by water erosion and middle larger displacement formed by seepage. Temporal and spatial displacements rule study of multiple-points linkage effects with water factor proved this conclusion. To better excavate useful message and analyze the deep rule from the practical monitoring data, the slope geological model was conducted and rock mechanic parameters were researched. Finally, a unique three-dimensional finite element model was applied to approach the structure character using numerical simulations. The corresponding strength criterion was used to determine the safety coefficient by selecting a typical section. Subsequently, an integrated three-dimensional finite element model of the slope and dam was developed and more detailed deformation evolution mechanism was revealed. This study is expected to provide a powerful and systematic method to analyze very high, important, and dangerous slopes.

Published
2015

14. Multisource information fusion-based approach diagnosing structural behavior of dam engineering

Author

Huaizhi Su, Xiaoran Sun, Zhiping Wen, and Yan Xiaoqun

Subjects
Engineering, business.industry, 020101 civil engineering, 02 engineering and technology, Building and Construction, Civil engineering, Construction engineering, 0201 civil engineering, Information fusion, Mechanics of Materials, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, business, Civil and Structural Engineering
Published
2017
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15. Multisource information fusion‐based approach diagnosing structural behavior of dam engineering.

Author

Su, Huaizhi, Wen, Zhiping, Sun, Xiaoran, and Yan, Xiaoqun

Subjects
CONCRETE dams, DAM design & construction, HYDRAULIC structures, STRUCTURAL stability, MACHINE design
Abstract

Summary: Considering the effect of many factors on structural behavior, the diagnosing problem on structural behavior of dam engineering is investigated. Dempster–Shafer theory of evidence (DST) and set pair theory (SPT) are combined to fuse the multisource space–time information on dam safety. The structural behavior of dam engineering is identified and its development is forecasted by implementing the information fusions with 3 levels, namely, data fusion, feature fusion, and decision fusion. First, a multisource information fusion system on dam safety is built and an information fusion‐based flowchart is presented to diagnose the dam structural behavior. Second, the batch estimation algorithm is adopted to implement the data fusion on same type information. Third, DST and SPT are applied to the decision fusion on heterogeneous information of dam safety. The index connection number and partial connection number in SPT are introduced to determine the basic probability assignment in DST and identify the dam structural behavior, respectively. Last, one actual dam undergoing structural reinforcements is taken as an example. Its structural behavior is diagnosed, and the reinforcement effect is assessed. It is indicated that the proposed approach is more suitable to be used to evaluate the safety status and reinforcement effect of dangerous dam. [ABSTRACT FROM AUTHOR]

Published
2018
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17. Antibacterial Effect of Kampo Herbal Formulation Hochu‐Ekki‐To (Bu‐Zhong‐Yi‐Qi‐Tang) on Helicobacter pyloriInfection in Mice

Author

Yan, Xiaoqun, Kita, Masakazu, Minami, Masato, Yamamoto, Toshiro, Kuriyama, Hiroko, Ohno, Tomoyuki, Iwakura, Yoichiro, and Imanishi, Jiro

Abstract

Because Helicobacter pylori (H. pylori)infection is a major cause of gastroduodenal diseases in humans, the eradication of H. pyloriusing antibiotics is very effective for the treatment of gastroduodenal diseases. However, it has recently been reported that resistance to these antibiotics is developing. In the present study, the antibacterial effect of a Kampo (traditional Japanese medicine) herbal formulation, Hochu‐ekki‐to (HET; Formula repletionis animalis et supletionis medii), against H. pyloriwas examined in vitroand in vivo. HET inhibited the growth of antibiotic‐resistant strains of H. pylorias well as antibiotic‐sensitive strains at a dose of 2.5 mg/ml in vitro. When 1,000 mg/kg of HET was administered orally to C57BL/6 mice for 7 days before or after inoculation with H. pylori, H. pyloriin the stomach was significantly reduced in the HET‐pre‐treatment group compared with the control group. Furthermore, HET in combination with antibiotics completely eradicated the bacteria in mice. The expression of interferon (IFN)‐γ was induced in the gastric mucosa of the mice pre‐treated with HET. There were no significant differences between the colonization of H. pyloriin the control and HET treatment groups in IFN‐γ gene‐deficient mice. These results suggest that the antibacterial effect of HET may be partly due to IFN‐γ induction, and that HET may be clinically useful for treatment of H. pyloriinfection.

Published
2002
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