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Automatic bearing diagnosis based on improved empirical wavelet decomposition and nonparametric test
Hongyan Jiang,Keqin Zhao,Lifei Chen,Dianjun Fang,Feng Cheng,Yong Chen 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.12
The 1/3-binary tree structure bandwidth is fixed, while the bands containing fault information sometimes do not fall equally in the fixed structure. To solve this problem, it is proposed to utilize the power spectrum to replace the Fourier spectrum, and to reconstruct the signal based on the scale space representation for the empirical wavelet decomposition. The fluctuation characteristics of the power spectrum frequency components and the energy distribution within frequency bands are taken full advantage of in this method. A new size parameter updating mechanism is employed to accelerate the signal reconstruction process. At the same time, it is thought that fault frequency is affected by the factor of slippage phenomena in order to realize a self-running diagnosis of bearing failure, and the occurring probability of the bearing fault is introduced to transform the envelope spectrum into a scalar indicator. As a result, without human intervention, the whole failure diagnosis process of the rolling bearing can be achieved by the manner of nonparametric testing. Simulation signal analysis results and experimental analysis results demonstrate the effectiveness and superiority of the proposed method.
Preparation and mechanism investigation of highly sensitive humidity sensor based on Ag/TiO2
Yang Chen,Zhang Hongyan,Gu Weiyuan,Chen Chu 한국물리학회 2022 Current Applied Physics Vol.43 No.-
In this paper, a high-performance silver-doped titanium dioxide (Ag/TiO2) humidity sensor was synthesized using a hydrothermal synthesis method for respiratory monitoring. The sensing mechanism was studied by the first principles of density functional theory (DFT). Calculations show that the doping of Ag+ ions increases the adsorption energy of TiO2 to water molecules. Furthermore, the Ti–O bond in TiO2 is broken due to the doping of Ag+ ions, which promotes the generation of Ti3+ defects. Experiments show that the doping of Ag+ ions can increase the hydroxide groups, Ti3+ defects and oxygen vacancies on the surface of TiO2, thus effectively improving the responsivity, linearity and hysteresis of the TiO2 humidity sensor. Compared to TiO2, the resistance of the Ag/TiO2 (0.5 mM) humidity sensor reaches 4.5 orders of magnitude with a high response of 39707.1, maximum hysteresis rate of 4.6%, response/recovery time of 31 s/15 s and the best linearity in a range of 11%– 95% RH. In addition, the Ag/TiO2 humidity sensor has been successfully used to detect different modes of respiration and determine the respiratory rate under different respiratory states. Significantly, this work demonstrates potential application value in human healthcare and activities monitoring.
Study on the detection behavior of defect-rich single-walled carbon nanotubes toward perchlorate
Chen, Yi,Nguyen, Thuy Hang,Zhang, Shao Lin,Zhang, Z.,Yue, Hongyan,Jian, Jiawen,Yang, Woo-Chul World Scientific Publishing Company 2018 Functional materials letters Vol.11 No.2
<P>Defect-rich single-walled carbon nanotubes (SWCNTs) were prepared by a water vapor flow-assisted chemical vapor deposition process. The correlation between defect density and water flow was quantitively studied using Raman spectrum. The detection capabilities of defective SWCNTs films toward perchlorate anions were investigated. It was found the defect-rich SWCNTs could adsorb more perchlorate anions owing to the strong chemical bonding between anions and defective sites. However, the detective response of defective SWCNTs toward perchlorate was not in compliance with anion adsorption. A tradeoff phenomenon between response and adsorption was found as the defect density of SWCNTs increased. This work is expected to provide a guidance to the future design of SWCNTs based ion detector.</P>
Hongyan Chu,Yingjie Hong,Caixia Zhang,Qi Chen,Ruilong Ding,Congbin Yang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.7
In order to improve the printing quality, this study focused on the thermo-fluidsolid coupling process of ink roller-ink. One of the highlights of this study is to consider the influence of temperature on the rubber hyperelastic parameters, viscoelastic parameters, and ink viscosity. The other highlight is to improve the elastohydrodynamic lubrication theory and Hertz contact theory through the rubber elastic modulus, which is determined by the relaxation curve considering the temperature and working conditions. Furthermore, based on the improved theory, the thermo-fluid-solid coupling model of ink roller-ink was established. Finally, the effect of temperature on the coupling process was analyzed. The results show that under the working conditions, with increasing temperature from 20 °C to 40 °C, the contact half-width increases from 4.2335 mm to 4.4701 mm, and the minimum ink film thickness decreases from 0.5097 mm to 0.1410 mm, and the maximum ink pressure decreases from 0.6802 MPa to 0.6618 MPa.
Hu Hongyan,Wang Xiaowei,Wu Zhijun,Chen Mo,Chai Tuanyao,Wang Hong 한국식물학회 2022 Journal of Plant Biology Vol.65 No.6
Plants have evolved complex signaling networks that enable them to adapt to adverse environmental conditions. The dehydration-responsive element-binding (DREB) transcription factors are important for plant responses to abiotic stresses. In this study, a new member of the AP2/ERF transcription factor gene family, PcDREB2A, was cloned and characterized from Polygonum cuspidatum, a traditional Chinese medicinal herb. PcDREB2A, which includes a typical AP2 domain, was clustered in the A-2 subgroup of the DREB subfamily. At the seedling stage, PcDREB2A expression was induced by cold, salt, and drought stresses. A yeast one-hybrid assay and an analysis of transiently transformed tobacco revealed that PcDREB2A can specifically bind to the DRE motif and transactivate reporter gene expression. Following 200 and 250 mM mannitol treatments, the PcDREB2A-overexpressing Arabidopsis thaliana lines had longer roots and a significantly higher fresh weight than the wild-type plants. Furthermore, under drought stress conditions, the PcDREB2A-overexpressing A. thaliana plants accumulated less malondialdehyde than the control plants. These results indicate that PcDREB2A encodes a novel DREB transcription factor in P. cuspidatum. Furthermore, the data generated in this study may be useful for researchers and breeders interested in genetically engineering plants to increase drought tolerance without inhibiting growth.
Erdong Chen,Martha Sajatovic,Hongyan Liu,Ashley Bukach,Curtis Tatsuoka,Elisabeth Welter,Samantha S. Schmidt,Yvan A. Bamps,Shelley C. Stoll,Tanya M. Spruill,Daniel Friedman,Charles E. Begley,Ross Shego 대한신경과학회 2018 Journal of Clinical Neurology Vol.14 No.2
Background and Purpose Epilepsy is a chronic neurological disease that represents a tremendousburden on both patients and society in general. Studies have addressed how demographicvariables, socioeconomic variables, and psychological comorbidity are related to thequality of life (QOL) of people with epilepsy (PWE). However, there has been less focus on howthese factors may differ between patients who exhibit varying degrees of seizure control. Thisstudy utilized data from the Managing Epilepsy Well (MEW) Network of the Centers for DiseaseControl and Prevention with the aim of elucidating differences in demographic variables,depression, and QOL between adult PWE. Methods Demographic variables, depression, and QOL were compared between PWE whoexperience clinically relevant differences in seizure occurrence. Results Gender, ethnicity, race, education, income, and relationship status did not differ significantlybetween the seizure-frequency categories (p>0.05). People with worse seizure controlwere significantly younger (p=0.039), more depressed (as assessed using the Patient HealthQuestionnaire) (p=0.036), and had lower QOL (as determined using the 10-item Quality of Lifein Epilepsy for Adults scale) (p<0.001). Conclusions The present results underscore the importance of early screening, detection, andtreatment of depression, since these factors relate to both seizure occurrence and QOL in PWE.
Jixiang Chen,Weili Jiang,Hongyan Hu,Xiaoyan Ma,Qian Li,Xianpeng Song,Xiangliang Ren,Yan Ma 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.3
The joint action and sublethal effects of methoxyfenozide and lufenuron were measured against Spodoptera exigua. Methoxyfenozide and lufenuron exhibited optimum synergistic toxicity on S. exigua at a mass ratio of 4:6, and the co-toxicity coefficient (CTC) was 165.705. Third instars larvae of S. exigua were treated with methoxyfenozide (LC 15 = 21.004 ng/cm 2 ), lufenuron (LC 15 = 27.134 ng/cm 2 ), or a mixture of methoxyfenozide and lufenuron (MML, LC 15 = 16.503 ng/cm 2 ) through feeding for 72 h. Ingestion of MML by larvae significantly inhibited larval and pupal weights and pupation rate, and prolonged the larval and pupal development of S. exigua compared to individual treatment ofmethoxyfenozide or lufenuron. Both methoxyfenozide and MML treatments significantly decreased the fertility of female S. exigua. No significant changes were observed in case of adult emergence and egg hatching for different treatments. The MML-treated S. exigua exhibited significantly lower activities of polyphenol oxidase (PPO) and cytochrome P450 (CYP450) than those in S. exigua treated separately with methoxyfenozide or lufenuron. Finally, methoxyfenozide, lufenuron, and MML treatments decreased chitinase, acetylcholinesterase (AChE), carboxylesterase (CarE), and glutathione-s-transferase (GST) activities in S. exigua.
Ping Hongyan,Wang Degang,Fu Maxian,Chen Kaihong,Zhang Jiuhong,Li Ke,Jiang Xuewu,Duan Shouxing,Zhang Xuan 대한독성 유전단백체 학회 2022 Molecular & cellular toxicology Vol.18 No.4
Background Diethylstilbestrol (DES) has been shown to disrupt the morphology and proliferation of gubernaculum testis cells. Objective This study aimed to elucidate the mechanism underlying DES induced damage to gubernaculum testis based on proteome analysis. Results Neonatal mice were exposed to DES or control vehicle and the gonads were collected for isobaric tags for relative and absolute quantitation based proteomics analysis. We found that at the early and late stages of gubernaculum development, treatment with different concentrations of DES upregulated the expression of proteins which were generally involved in several function categories including single-organism process, cellular process, binding, catalytic activity, cell part and organelle. KEGG pathway analysis showed that cardiac muscle contraction, oxidative phosphorylation, calcium signaling and cGMP-PKG signaling pathway were the most dysregulated pathways associated with DES in the late stage of gubernaculum development, while steroid biosynthesis was the only enriched pathway in the early stage of gubernaculum development. Conclusion Proteomics profi ling and functional analysis reveal new clues on how DES interferes with cellular processes and disrupts the development of gubernaculum. These findings have potential applications in the treatment of genitourinary diseases such as cryptorchidism.