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Interaction between local corrosion and flow field of natural gas long-distance pipeline by artificial rectangular defect pit

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Journal of Iron and Steel Research(International) 2022年第6期29卷 1026-1038页

作者： zhuo-wei Tan Zhen-bo Wang Shu-yu Bai Da-lei zhang sheng-zhu zhang Frank Cheng Shao-hua Xing You-hai Jin China University of Petroleum(East China) Qingdao 266580ShandongChina Xiangtan University Xiangtan 411105HunanChina School of Materials Science and Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina China Academy of Safety Science and Technology Beijing 100012China University of Calgary CalgaryAB T2N 1N4Canada State Key for Marine Corrosion and Protection Luoyang Ship Material Research InstituteQingdao 266237ShandongChina

The corrosive environment in long-distance natural gas pipeline was simulated by the online high shear stress flow test platform.The interaction between flow fields and local corrosion in different local corrosion stages was studied by machining different depths rectangular defect pit(RDP)on X80 pipe steel specimens.The electrochemical signals of each specimen under high shear stress flow were measured online using an integrated three-electrode and electrochemical system.Raman spectroscopy confirmed that the corrosion scale of X80 pipeline steel in CO_(2)-saturated National Association of Corrosion Engineers solution was composed of FeCO_(3).The scanning electron microscope images displayed variations in microstructure of the corrosion scale at different RDP depths and different areas.The flow field fluctuations induced by RDP were analyzed by computational fluid dynamics simulations and the development of local corrosion pits was discussed in terms of integrity of corrosion scale,convective mass transfer,and diffusion mass transfer.

关键词： CO_(2) corrosion Flow condition Rectangular defect pit Local corrosion Corrosion electrochemistry

Stress analysis on large-diameter buried gas pipelines under catastrophic landslides

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Petroleum Science 2017年第3期14卷 579-585页

作者： sheng-zhu zhang Song-Yang Li Si-Ning Chen Zong-Zhi Wu Ru-Jun Wang Ying-Quan Duo China Academy of Safety Science and Technology Beijing 100012 China College of Mechanical and Transportation Engineering China University of Petroleum Beijing 102249 China State Administration of Work Safety Beijing 100713 China

This paper presents a method for analysis of stress and strain of gas pipelines under the effect of horizontal catastrophic landslides. A soil spring model was used to analyze the nonlinear characteristics concerning the mutual effects between the pipeline and the soil. The Ramberg–Osgood model was used to describe the constitutive relations of pipeline materials. This paper also constructed a finite element analysis model using ABAQUS finite element software and studied the distribution of the maximum stress and strain of the pipeline and the axial stress and strain along the pipeline by referencing some typical accident cases. The calculation results indicated that the maximum stress and strain increased gradually with the displacement of landslide.The limit values of pipeline axial stress strain appeared at the junction of the landslide area and non-landslide area. The stress failure criterion was relatively more conservative than the strain failure criterion. The research results of this paper may be used as a technical reference concerning the design and safety management of large-diameter gas pipelines under the effects of catastrophic landslides.

关键词： Buried gas pipeline Catastrophic landslide Finite element analysis Stress Strain

Plant RNA-binding proteins:Phase separation dynamics and functional mechanisms underlying plant development and stress responses

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Molecular Plant 2024年第4期17卷 531-551页

作者： sheng Fan Yu zhang Shaobo zhu Lisha Shen Temasek Life Sciences Laboratory 1 Research LinkNational University of Singapore1 Research LinkSingapore 117604Singapore Department of Biological Sciences National University of Singapore14 Science Drive 4Singapore 117543Singapore

RNA-binding proteins(RBPs)accompany RNA from synthesis to decay,mediating every aspect of RNA metabolism and impacting diverse cellular and developmental processes in eukaryotes.Many RBPs undergo phase separation along with their bound RNA to form and function in dynamic membraneless biomolecular condensates for spatiotemporal coordination or regulation of RNA metabolism.Increasing evidence suggests that phase-separating RBPs with RNA-binding domains and intrinsically disordered regions play important roles in plant development and stress adaptation.Here,we summarize the current knowledge about how dynamic partitioning of RBPs into condensates controls plant development and enables sensing of experimental changes to confer growth plasticity under stress conditions,with a focus on the dynamics and functional mechanisms of RBP-rich nuclear condensates and cytoplasmic granules in mediating RNA metabolism.We also discuss roles of multiple factors,such as environmental signals,protein modifications,and N6-methyladenosine RNA methylation,in modulating the phase separation behaviors of RBPs,and highlight the prospects and challenges for future research on phase-separating RBPs in crops.

关键词： RNA-binding proteins phase separation biomolecular condensates RNA metabolism development stress resilience

Solvent-free carbon sphere nanofluids towards intelligent lubrication regulation

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Friction 2024年第1期12卷 95-109页

作者： sheng zhang Wen LI Xiaoliang MA Xiaoqiang FAN Minhao zhu Tribology Research Institute School of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu 610031China Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

By simply switching the electrical circuit installed on steel/steel contact,the tribological behaviors of nanofluids(NFs)can be regulated in real time,thereby achieving the desired performance of friction reduction and wear resistance.Herein,solvent-free carbon spherical nanofluids(C-NFs)were successfully prepared for intelligent lubrication regulation.C-NFs with excellent lubrication performance can immediately reduce the coefficient of friction(COF)despite applying a weak electric potential(1.5 V).Moreover,polyethylene glycol 400(PEG400)containing 5.0 wt%C-NFs remained responsive to electrical stimulation under the intermittent voltage application with an average coefficient of friction(ACOF)reduction of 20.8%over PEG400.Such intelligent lubrication regulation of C-NFs under an external electric field(EEF)mainly depends on the orderly arranged double-electric adsorption film of ion canopy-adsorbed carbon spheres(CSs).The intermittent electrical application can continuously reinforce the adsorption film and its durability for real-time controlling the sliding interfaces.Electrical-stimulation-responsive intelligent lubricants provide a new technical support for realizing intelligent stepless control of devices.

关键词： solvent-free carbon spherical nanofluids(C-NFs) intelligent lubrication regulation lubrication performance adsorption film

Inhibition of EGFR attenuates EGF-induced activation of retinal pigment epithelium cell via EGFR/AKT signaling pathway

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International Journal of Ophthalmology(English edition) 2024年第6期17卷 1018-1027页

作者： Yu-sheng zhu Si-Rui Zhou Hui-Hui zhang Tong Wang Xiao-Dong Chen Faculty of Life Sciences and Medicine Northwest UniversityXi’an 710069Shaanxi ProvinceChina First Affiliated Hospital of Northwest University Northwest UniversityXi’an 710069Shaanxi ProvinceChina Department of Ophthalmology Xi’an No.1 HospitalXi’an 710002Shaanxi ProvinceChina Shaanxi Institute of Ophthalmology Shaanxi Provincial Key Lab of OphthalmologyClinical Research Center for Ophthalmology Diseases of Shaanxi ProvinceXi’an 710002Shaanxi ProvinceChina

AIM:To explore the effect of epidermal growth factor receptor(EGFR)inhibition by erlotinib and EGFR siRNA on epidermal growth factor(EGF)-induced activation of retinal pigment epithelium(RPE)cells.METHODS:Human RPE cell line(ARPE-19 cells)was activated by 100 ng/mL EGF.Erlotinib and EGFR siRNA were used to intervene EGF treatment.Cellular viability,proliferation,and migration were detected by methyl thiazolyl tetrazolium(MTT)assay,bromodeoxyuridine(BrdU)staining assay and wound healing assay,respectively.EGFR/protein kinase B(AKT)pathway proteins and N-cadherin,α-smooth muscle actin(α-SMA),and vimentin were tested by Western blot assay.EGFR was also determined by immunofluorescence staining.RESULTS:EGF treatment for 24h induced a significant increase of ARPE-19 cells’viability,proliferation and migration,phosphorylation of EGFR/AKT proteins,and decreased total EGFR expression.Erlotinib suppressed ARPE-19 cells’viability,proliferation and migration through down regulating total EGFR and AKT protein expressions.Erlotinib also inhibited EGF-induced an increase of proliferative and migrative ability in ARPE-19 cells and clearly suppressed EGF-induced EGFR/AKT proteins phosphorylation and decreased expression of N-cadherin,α-SMA,and vimentin proteins.Similarly,EGFR inhibition by EGFR siRNA significantly affected EGF-induced an increase of cell proliferation,viability,and migration,phosphorylation of EGFR/AKT proteins,and up-regulation of N-cadherin,α-SMA,and vimentin proteins.CONCLUSION:Erlotinib and EGFR-knockdown suppress EGF-induced cell viability,proliferation,and migration via EGFR/AKT pathway in RPE cells.EGFR inhibition may be a possible therapeutic approach for proliferative vitreoretinopathy(PVR).

关键词： erlotinib epidermal growth factor receptor protein kinase B epithelial-mesenchymal transition retinal pigment epithelium cell

Slicing capacity-centered mode selection and resource optimization for network-assisted full-duplex cell-free distributed massive MIMO systems

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Science China(Information Sciences) 2024年第1期67卷 203-220页

作者： Jie WANG Jiamin LI Pengcheng zhu Dongming WANG Hongbiao zhang Yue HAO Bin sheng National Mobile Communications Research Laboratory Southeast University 2. Purple Mountain Laboratories China Mobile Research Institute

Network-assisted full-duplex(NAFD) cell-free distributed massive multiple-input multipleoutput(MIMO) systems enable uplink(UL) and downlink(DL) communications within the same timefrequency resources,which potentially reduce latency by avoiding the overhead of switching UL/DL modes.However,how to choose UL/DL modes remains an important factor affecting system performance.With the dramatic increase in the number of users and access points(APs),massive access brings significant overhead in the mode selection.Additionally,the different quality of service(QoS) among users also makes the effective utilization of resources difficult.As one of the most promising technologies in sixth-generation(6G),network slicing enables the adaptive configuration of limited UL/DL resources through the resource isolation assisted NAFD technique.Therefore,we propose a slicing capacity-centered scheme.Under this scheme,APs are motivated by slicing requirements and associated slices to form different subsystems.Collaborative mode selection and resource allocation are performed within each subsystem to reduce overhead and improve resource utilization.To implement this scheme efficiently,a double-layer deep reinforcement learning(DRL)mechanism is used to realize the joint optimization of mode selection and resource allocation.Simulation results show that the slicing capacity-centered scheme can effectively improve resource utilization and reduce overhead.

关键词： network-assisted full-duplex network slicing mode selection resource optimization deep reinforcement learning

Compositional evolution for mixed aerosols containing gluconic acid and typical nitrate and the effect of multiply factors on hygroscopicity

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Journal of Environmental Sciences 2024年第5期139卷 206-216页

作者： Yue zhu Shufeng Pang Yunhong zhang School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing 100081China

The aging process of atmospheric aerosols usually leads to a mixture of inorganic salts and organic compounds of anthropogenic origin.In organic compounds,polyhydroxy organic acids are important components,however,the study on composition and hygroscopic properties of the mixture containing inorganics and polyhydroxy organic acids is scanty.In this study,gluconic acid,the proxy of polyhydroxy organic acids,is mixed with the representative nitrate(Mg(NO_(3))_(2),Ca(NO_(3))_(2))to form aerosols.ATR-FTIR and optical microscopy are employed to study the component changes and hygroscopicity as a function of relative humidity.As relative humidity fluctuates,the FTIR-ATR spectra display that the internal mixed gluconic acid(CH_(2)(CH)_(4)(OH)_(5)COOH)and nitrate can react to release acidic gases,forming relevant gluconate and further affecting the hygroscopicity.The specific presentation is particles cannot be recovered to their original size after the dehydration-hydration process and there will be some disparities in GF for mixed particles.For the gluconic acid-Ca(NO_(3))_(2)/Mg(NO_(3))_(2)mixtures with molar ratios of 1:1,higher degree of reaction resulting in the production of large amounts of gluconate should be responsible to the lower hygroscopicity compared to ZSR model.For 1:2 gluconic acid-nitrate mixed systems(with higher nitrate content),the hygroscopicity of mixtures are higher than the ZSR prediction.A possible reason could be‘salt-promoting effect’on the organic fractions of the surplus inorganic salt in the mixture.These data can improve the chemical composition list evaluation,in turn hygroscopic properties and phase state of atmospheric aerosol,and then the climate effect.

关键词： Hygroscopicity Gluconic acid Reaction ZSR simulation Size growth factors

Influence of the Acoustic Liner in Large Eddy Simulation of Longitudinal Thermoacoustic Instability in a Model Annular Combustor

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Journal of Thermal Science 2024年第2期33卷 710-724页

作者： MENG sheng zhang Man GAO Yi AECC Commercial Aircraft Engine Co. Ltd.Shanghai200241China School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai200240China

Although extensive efforts have been made to dampen the thermoacoustic instability,successfully controlling the pressure oscillations in modern gas turbines or aeroengines remains challenging.The influence of the acoustic liner on the longitudinal thermoacoustic mode in a model annular combustor is investigated by Large Eddy Simulation(LES) in this work.The result of the self-excited longitudinal thermoacoustic instability without the liner agrees well with the frequency and acoustic analysis of the pressure mode based on experimental data.Three different bias flow velocities of the liner located downstream of the combustor are then simulated.The results reveal that the existence of the liner influences not only the acoustic field but also the flow field.When the bias velocity is large,it leads to intense turbulence-induced fluctuations,and the pressure oscillation is modulated intermittently.It shows that the weak coupling between flow and pressure oscillations plays a significant role in the onset of the intermittency of a thermoacoustic system.Based on the dynamic analysis of the thermoacoustic system with the acoustic liner,this intermittency is caused by the influence of the flow field on the flame-acoustic coupling.Finally,a low-order modeling method based on Van der Pol(VdP) oscillator with additive stochastic forcing is conducted to reproduce the evolving dynamics of the thermoacoustic system.Although the numerical cases demonstrated in this work are relatively simpler than those in a practical combustion system,the results are helpful for us to understand the effect of the acoustic liner and show the attractive potential to apply this device to suppress thermoacoustic instability.

关键词： thermoacoustic instability acoustic liner Large Eddy Simulation low-order modeling

Coupling N-doping and confined Co3O4 on carbon nanotubes by polydopamine coating strategy for pleiotropic water purification

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Rare Metals 2024年第7期43卷 3146-3160页

作者： Wen-Long Tu Gang Wang Yue zhang Hong-Yang zhu Rong-Rong Du Hong-Yao Zhao sheng Tang Zeng-Jing Guo Jun Yang Fu Yang Cheng-zhang zhu School of Environmental and Chemical Engineering Jiangsu University of Science and Technology School of Chemistry and Chemical Engineering Liaocheng University School of Material Science and Engineering Jiangsu University of Science and Technology School of Environmental Science and Engineering Nanjing Tech University

The development of effective and sustainable solutions for pleiotropic water purification becomes urgent and attractive.Heterogeneous Fenton-like catalysts for activation of peroxymonosulfate（PMS） to purify organic wastewater show great promise.In this work,by tuning metal loading with an in-situ polydopamine coating strategy,oxygen vacancy-enriched Co3O4loading on N-doped carbon nanotubes（CNTs） were constructed to enhance PMS activation efficiency for pollutants degradation.Impressively,the obtained modified CNTs afford a well-developed N-containing network structure,which is further endowed with abundant Co（Ⅱ）/Co（Ⅲ） redox cycles and significant metal-carbon interactions.In particular,the surface N doping in CNTs might induce the oriented enrichment of pollutants around the catalyst,which reduces the migration distance and correspondingly improves the utilization of reactive oxidative species.The electron transfer efficiency of the catalyst can be further improved by incorporating oxygen vacancy-enriched Co3O4.The performance results show that the optimal NC/Co-1 could mineralize 20 × 10-6of bisphenol A（BPA） by almost 98% in 8 min.A low reaction activation energy(26.05 kJ·mol-1) in BPA degradation was demonstrated by the NC/Co-1.More importantly,NC/Co-1 can inherit excellent degradation performance towards oxytetracycline,2,4-dichlorophenol,and tetracycline,showing wide practical flexibility.In addition,by virtue of the photothermal conversion property,NC/Co-1 achieves an additive function for interfacial solar water evaporation(1.84 kg·m-2·h-1,112.51%),showing impressive potential for clean water recovery under complicated environmental pollution conditions.

关键词： Carbon nanotube Advanced oxidation process Co 3 O 4 Photothermal conversion Solar water evaporation