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Effect of Chemical Corrosion on the Anti-Pollution Flashover Performance of Methyl-Silica Superhydrophobic Coatings

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SSRN 2023年

作者： Wang, Shengwu Xie, Yulong Li, Lee Chen, Junwu Xie, Yi Zhao, Xiangen School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan430074 China State Key Laboratory of Silicate Materials for Architectures Wuhan University of Technology Wuhan430070 China Department of Building Environment and Energy Engineering The Hong Kong Polytechnic University Hong Kong

Methyl-silica superhydrophobic coatings have the capability of providing anti-pollution flashover protection for outdoor electrical insulators. However, in practical applications, the deposition and dissolution of atmospheric pollutants on the coating generates acidic or alkaline ions and leads to chemical degradation of the coating's surface property, which in turn causes a decrease in the anti-pollution flashover performance of the coating. Currently, there is a lack of research on the hydrophobic degradation characteristics of superhydrophobic methyl-silica coatings induced by chemical corrosion. Meanwhile, it is not clear how chemical corrosion affects the anti-pollution flashover performance of methyl-silica superhydrophobic coatings. To address the above issues, the static water contact angle and sliding angle on the corroded methyl-silica superhydrophobic coatings were tested to reflect the surface hydrophobicity degradation, and the results were theoretically interpreted;the surface leakage current amplitudes of the coatings aged to different degrees were measured under dirty and wet conditions to characterize the anti-pollution flashover performance of the corroded coatings. The surface leakage current amplitudes of the aged methyl-silica superhydrophobic coating under different corrosion environment temperatures, different applied electric field strengths, and different wetting times of surface pollutants are measured to characterize the anti-pollution flashover performance of the corrosion-aged coating, and the influences of the above factors on the anti-pollution flashover performance of the methyl-silica superhydrophobic coating are analyzed. © 2023, The Authors. All rights reserved.

关键词： Silica

Maintenance Accessibility Evaluation Method based on D-H Model and Comfort in a Virtual Maintenance environment

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Research Square

Research Square 2021年

作者： Zhou, Dong Wu, Hongduo Guo, Ziyue Zhou, Qidi Liang, Yuning School of Reliability and System Engineering Beihang University Beijing100191 China State Key Laboratory of Virtual Reality Technology and Systems Beijing100191 China State Key Defense Science and Technology Laboratory on Reliability and Environmental Engineering Beijing100191 China

In virtual maintenance, the most widely used accessibility evaluation method is to use virtual human reach envelope surface to judge and evaluate accessibility. However, this method can only give two kinds of evaluation results: reachable and unreachable. There is not enough data and theoretical support for the construction of envelope surface, and the precision and accuracy of evaluation need to be improved. In this paper, a parameterized accessibility evaluation method and a method of accessibility envelope surface construction are proposed. Firstly, to objectively describe the movement of human body, a 6-joint and 5-link D-H (Denavit-Hartenberg) link model is established from the waist to the fingertip of the human body, and the ranges of 10 degrees of freedom and angles related to accessibility are determined according to ergonomics. Then, comfort is introduced to refine the accessibility evaluation, and a multi-level accessibility evaluation system based on comfort is constructed according to RULA (the rapid upper limb assessment). In order to facilitate the application of this method in virtual environment, a method of accessibility envelope surface construction is proposed. Firstly, the reachable points are generated by Monte Carlo simulation based on the D-H model. Secondly, the accessibility envelope surface is composed of the outermost random reachable points. Finally, the comparison experiment with the reachable envelope provided by DELMIA in virtual environment shows that the proposed method is more accurate, meticulous and objective. Based on this method, an accessibility evaluation tool has been developed in CATIA and has been applied in some scientific research institutes. © 2021, CC BY.

关键词： Ergonomics

Model Test on the Development of Artificial Freezing Curtain in Gravelly Soil Layer Under Seepage

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SSRN 2024年

作者： Yuan, Chang Kong, Xiangbing Chen, Xin Lei, Lele Li, Dongwei Lai, Yuanming East China University of Technology Jiangxi Nanchang330013 China Geological Environment and Underground Space Engineering Research Center of Jiangxi Province Jiangxi Nanchang330013 China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and Resources CAS Gansu Lanzhou730000 China Université du Québec à Rimouski Department of Mathematics Computer Science and Engineering Canada Dalian University Liaoning Dalian116622 China South China University of Technology China

To investigate the development of artificial freezing curtain under seepage, model tests have been conducted in gravelly soil layer. The test results exhibit that the strong seepage of 7.5 m/d affects the formation of frozen curtain much greater than lower seepage below 5 m/d. With the seepage velocity increasing, the temperature field of the freezing curtain distributes asymmetrically gradually, and the curtain tends to close upstream, resulting in a notable increase of frozen time and closure time. Along the freezing pipe circle from the upstream to the downstream, the thickness of curtain is almost in a linearly increasing tendency. A Boltzmann unfrozen water content is used to express the measured unfrozen water content variation with temperature, and a hydro-thermal coupling model has been proposed to describe the developing process of artificial freezing curtain accounting for seepage and ice-water phase change. These findings indicate that the strong influence of strong seepage should be highly paid attention in artificial freezing engineering. © 2024, The Authors. All rights reserved.

关键词： Seepage

Satisfactory Degradation of Tetracycline by a Ph-Universal Cofe-Ldh/Mos2 Heterojunction Catalyst in Fenton Process: Performances, Mechanisms and Toxicity Assessments

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SSRN 2023年

作者： Wang, Meng Li, Xiaoyu Wu, Jiaoge Sun, Tian Xu, Xuan Fan, Faying Zhao, Yufei Gao, Wa Key Laboratory for Northern Urban Agriculture of Ministry of Agriculture and Rural Affairs College of Bioscience and Resources Environment Beijing University of Agriculture Beijing102206 China State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing100029 China Shandong Qingdao266101 China

Fenton or Fenton-like reactions have been widely used in various fields such as the solar energy conversion to generate hydroxyl radicals, environmental remediation, advanced treatment of exhaust gas, biology, and life science, however, the slow Fe3+/Fe2+ cycle and narrow applicable pH range still pose significant challenges. Here, a heterostructured CoFe-layered double hydroxide/MoS2 nanocomposites (CoFe-LDH/MoS2) was prepared via simple electrostatic interactions for Fenton degradation of organic pollutants. The ultrathin CoFe-LDH and MoS2 layers in the heterostructure establish a robust interfacial contact, leading to an abundance of exposed Mo6+ sites that significantly enhance the degradation rate by promoting Fe3+/Fe2+ cycling and ensuring rapid electron transfer. Consequently, the developed CoFe-LDH/MoS2+H2O2 system exhibited superior performance in the degradation of tetracycline (TCH) (> 85%) within 60 min across a wide pH range from acidic to basic (3˗11). More attractively, the CoFe-LDH/MoS2 heterojunction catalysts exhibited exceptional resistance to interference from common anions (Cl-, HCO3-, NO3- and SO42-) and demonstrated efficient degradation of diverse organic pollutants including rhodamine B, methyl orange, and phenol. Further, the heterojunction catalysts could maintain high efficiency even after ten cycles, making them suitable for large-scale applications in the degradation of organic pollutants. The mechanism study verified that the CoFe-LDH/MoS2 system had high efficiency in producing singlet oxygen (1O2) and hydroxyl radical (•OH) to degrade various organic pollutants. The present study effectively addresses the bottlenecks in the Fenton reaction and will serve as a foundation for creating efficient catalyst systems for related environmental remediation. © 2023, The Authors. All rights reserved.

关键词： Molybdenum compounds

Gaf-Convnext Algorithm with Transfer Learning for Human Activity Recognition Based on Wearable Plastic Fiber Sensors

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SSRN 2024年

作者： Zhang, Yue Wang, Shuang Chen, Zhixian Liu, Bin Liu, Juan Yang, Hong Hu, Yingying Fu, Yue Wu, Qiang Key Laboratory of Opto-Electronic Information Science and Technology of Jiangxi Province Nanchang Hangkong University Nanchang330063 China Faculty of Engineering and Environment Northumbria University Newcastle upon TyneNE1 8ST United Kingdom

Human activity recognition (HAR) is an important research topic in the field of human-computer interaction (HCI), and wearable HAR based on convolutional neural networks (CNNs) has achieved the most advanced performance. In this study, wearable plastic optical fiber (POF) sensors based on GAF-ConvNeXt algorithm are used for human activity recognition (HAR) for the first time. The GAF-ConvNeXt algorithm combinated of Gramian Angular Field (GAF) and the latest CNN model ConvNeXt can convert motion signals from one-dimensional time series into two-dimensional images, which can not only preserve the complete information of the signal, but also maintain its dependence on time, and thus present more depth features for accurate recognition of human activity. Furthermore, transfer learning was introduced to further optimize the GAF-ConvNeXt model, which effectively reduces the number of training samples, improve the recognition accuracy and accelerate the convergence speed. The GAF-ConvNeXt algorithm based on transfer learning can recognize seven motion modes with an accuracy of 99.75%, which has great application potential in the field of human motion recognition and HCI. © 2024, The Authors. All rights reserved.

关键词： Convolutional neural networks

Single-atom sites on perovskite chips for record-high sensitivity and quantification in SERS

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Science China Materials 2022年第6期65卷 1601-1614页

作者： Ran Feng Qing Miao Xiang Zhang Peixin Cui Cong Wang Yibo Feng Liyong Gan Jiaxing Fu Shibo Wang Ziyi Dai Liming Hu Yunjing Luo Weihai Sun Xiaoxian Zhang Jiawen Xiao Jinbo Wu Bingpu Zhou Mingqiang Zou Dawei He Xiaoyuan Zhou Xiaodong Han Beijing Key Laboratory of Microstructure and Properties of Solids Institute of Microstructure and Property of Advanced MaterialsFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China Key Laboratory of Luminescence and Optical Information Ministry of EducationInstitute of Optoelectronic TechnologyBeijing Jiaotong UniversityBeijing 100044China College of Physics and Center for Quantum Materials and Devices Analytical and Testing CenterChongqing UniversityChongqing 401331China Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China Faculty of Environment and Life Beijing Key Laboratory of Environmental and OncologyBeijing University of TechnologyBeijing 100124China Materials Genome Institute Shanghai UniversityShanghai 200444China College of Materials science and Engineering Huaqiao UniversityXiamen 361021China Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of MacaoAvenida da UniversidadeTaipaMacao 999078China Chinese Academy of Inspection and Quarantine(CAIQ) Beijing 100123China

Surface enhanced Raman scattering(SERS)is a rapid and nondestructive technique that is capable of detecting and identifying chemical or biological *** SERS quantification is vital for practical applications,particularly for portable detection of biomolecules such as amino acids and ***,few approaches can achieve sensitive and quantitative Raman detection of these most fundamental components in ***,a noblemetal-free single-atom site on a chip strategy was applied to modify single tungsten atom oxide on a lead halide perovskite,which provides sensitive SERS quantification for various analytes,including rhodamine,tyrosine and *** single-atom site on a chip can enable quantitative linear SERS responses of rhodamine(10^(−6)-1 mmol L^(−1)),tyrosine(0.06-1 mmol L^(−1))and cytosine(0.2-45 mmol L^(−1)),respectively,which all achieve record-high enhancement factors among plasmonic-free *** experimental test and theoretical simulation both reveal that the enhanced mechanism can be ascribed to the controllable single-atom site,which can not only trap photoinduced electrons from the perovskite substrate but also enhance the highly efficient and quantitative charge transfer to ***,the label-free strategy of single-atom sites on a chip can be applied in a portable Raman platform to obtain a sensitivity similar to that on a benchtop instrument,which can be readily extended to various biomolecules for low-cost,widely demanded and more precise point-of-care testing or in-vitro detection.

关键词： SERS single-atom site point-of-care testing in-vitro diagnosis charge-transfer mechanism lead halide perovskite

High Entropy Metal Phosphide Based Electrochemical Sensor for Sensitive Detection of Carbendazim

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SSRN 2023年

作者： Qian, Xin Qiu, Sihang Fu, Chengxi Lu, Shuanglong Duan, Fang Zhu, Han Fu, Qiang Du, Mingliang Key Laboratory of Synthetic and Biological Colloids Ministry of Education School of Chemical and Material Engineering Jiangnan University Jiangsu Wuxi214122 China School of Energy and Environment City University of Hong Kong 999077 Hong Kong Guangdong Key Laboratory of Electric Power Equipment Reliability Electric Power Research Institute of Guangdong Power Grid Co. Ltd. Guangdong Guangzhou510062 China

Carbendazim (CBZ) residue will cause serious harm if ingesting in human body for a long time, and therefore, developing effective electrochemical sensor for sensitive detection of CBZ is highly desirable. Herein, we reported a facile synthesis of FeCoNiCrMnP high-entropy phosphide nanoparticles supported on electrospun carbon nanofibers (FeCoNiCrMnP/CNFs) by combining the electrospinning and phosphorus-vapor assisted graphitization process. The FeCoNiCrMnP/CNFs/GCE sensor exhibits excellent detection performance with linear CBZ concentration range from 0.1 to 30 μM, low limit of detection (LOD) of 0.7 nM, high sensitivity of 84.85 μA μm-1 cm-2, and excellent anti-interference and stability. The excellent electrochemical performance was originated from the well distribution of HEP NPs, the excellent electrical conductivity, fast electron transfer ability, and large specific surface area. © 2023, The Authors. All rights reserved.

关键词： Entropy

Mechanisms of Interaction between Polystyrene Nanoplastics and Extracellular Polymeric Substances in the Activated Sludge Cultivated by Different Carbon Sources

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SSRN 2022年

作者： Wang, Yaxin Liu, Xiuhong Liu, Runyu Han, Weipeng Yang, Qing Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering Beijing University of Technology Beijing100124 China National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology Beijing University of Technology Beijing100124 China

Nanoplastics (NPs) are ubiquitously present in wastewater treatment plants, which would be removed by the flocculation of extracellular polymeric substances (EPS) from wastewater to activated sludge. However, the interaction mechanisms between NPs and EPS of activated sludge remain largely unexplored. In this work, the interaction mechanisms between polystyrene nanoplastics (PS-NPs) and EPS with sodium acetate (NaAc), methanol (MeOH) and glucose (GLC) as carbon sources were investigated. It was shown that the carbonyl of protein amide I region in extracellular polymeric substances was the principal functional group bound to polystyrene nanoplastics when these three carbon sources cultivated the activated sludge. The combination between PS-NPs and EPS increased the β-sheets content, decreased the ratio of α-helix to (β-sheet + random coil) as well as shifted the protein secondary structures to strong rigidity. The PS-NPs not only flocculated with activated sludge, but further enhanced the bioflocculation of activated sludge after inter acting with EPS. The sum of the increase in β-sheets and the decrease in the ratio of α-helix to (β-sheet + random coils) in EPS was 33% and 39% using NaAc as the carbon source, respectively. Therefore, the flocculation between PS-NPs and EPS in the activated sludge using NaAc as the carbon source was the strongest among these three carbon sources. This work lays a foundation for studying the microplastics (MPs) removal process in wastewater treatment and the interaction mechanisms between activated sludge and MPs. © 2022, The Authors. All rights reserved.

关键词： Flocculation

Effect of substrate elasticity on evaporation kinetics and evaporative deposition of aqueous polystyrene nanoparticles droplets

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Science China(Physics,Mechanics & Astronomy) 2020年第11期63卷 72-79页

作者： Ying-Song Yu Yi-Qi Zhu XianFu Huang Jin-Zhi Zhou An Zhou Department of Mechanics School of Civil EngineeringArchitecture and EnvironmentHubei University of TechnologyWuhan 430068China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China

Evaporation of aqueous polystyrene(PS)nanoparticles droplets on silicon and polydimethylsiloxane(PDMS)surfaces was *** results showed that softer PDMS surfaces yielded a longer constant contact radius(CCR)stage,which could be ascribed to surface deformation of PDMS induced by the vertical component of liquid-vapor interfacial *** depositions of nanoparticles with different crack patterns were found on both silicon and PDMS ***-situ observation of crack formation showed that nanoparticle movement on the silicon surface was impeded,resulting in radial cracks with periodic *** contrast,nanoparticles were shown to move easily on the PDMS *** observation indicated the difference in crack patterns on surfaces could be attributed to the friction force between nanoparticles and the substrate.A large friction force between nanoparticles and the substrate prevented cracks from moving,resulting in a radial crack pattern with periodic distribution,while a small friction force produced multiple large cracks.

关键词： droplet evaporation nanoparticle constant contact radius stage crack