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Wake flow and vortex structures behind emergent vegetation patches elongated in the longitudinal direction

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Journal of Hydrodynamics 2021年第6期33卷 1148-1161页

作者： Zi-jian Yu Yu-qi Shan Chao liu Xing-nian liu State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China Department of Civil and Environmental Engineering University of AlbertaEdmontonCanada Institute for Disaster Management and Reconstruction Sichuan UniversityChengdu 610065China

In natural rivers,patches of vegetation generally expand over their steady wake region in the streamwise direction,forming elongated patches with length(L)greater than their width(b).This paper studies how the wake flows and the vortices develop as the emergent patches expand their length in the streamwise *** patches are modeled with the same width but different lengths in laboratory *** the patches,the steady wake region(L_(w))is not related to the width-related flow blockage(C_(d)ab),where C_(d) is the drag coefficient,a is the vegetation ***,L_(w) is related to the length-related flow blockage(C_(d)aL).On this basis,a model is proposed for predicting L_(w),which is in good agreement with the *** a patch becomes denser and/or longer(as C_(d)aL increases),the steady wake region becomes shorter(L_(w) decreases),and vortices are observed closer to the patch trailing edge,producing a turbulence of a greater magnitude beyond L_(w).When the flow blockage increases to the limit(C_(d)aL>8),the Karman vortices are observed directly behind the porous *** results can be used to explain the longitudinal elongation of the vegetation patches in the field.

关键词： Velocity profiles turbulent kinetic energy wakes vortex streets vegetation patch

Synthesis and modification of nanowires anchored on electrodes for electrochemical and electrophysical applications

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Nano Research 2024年第10期17卷 8863-8884页

作者： Feiyang Mo Zhitao Chen nian liu Xing Xie School of Civil and Environmental Engineering Georgia Institute of Technology311 Ferst Drive NWAtlantaGA 30332USA School of Chemical and Biomolecular Engineering Georgia Institute of Technology311 Ferst Drive NWAtlantaGA 30332USA

The integration of nanowires onto electrode surfaces marks a significant advancement over traditional electrode materials,conferring upon nanowire-modified electrodes a vast array of applications within electrochemical and electrophysical *** nanowires used for electrode modification can be catalogized into two distinct types:anchored nanowires and free-standing nanowires.A critical advantage of anchored nanowires lies in their enhanced electrical connectivity with the substrate,which reduces electrode resistance and facilitates charge ***,the anchorage of nanowires onto electrodes provides additional mechanical support,bolstering the structural stability of the nanowire ***,we review the development of anchored nanowires designed for applications in energy storage,electrocatalysis,and electric field treatment(EFT)over the past *** focus on the synthesis and modification strategies employed for anchored nanowires,culminating in the evaluation of these fabrication and enhancement *** this analysis,we aim to furnish comprehensive insights into the preparation of anchored nanowires,guiding the selection of appropriate fabrication processes and subsequent functional modifications.

关键词： electrode modification direct growth etching energy storage electrocatalysis electric field treatment

Investigation on Effects of Mooring Line Fractures and Connector Failures for A Hybrid Modular Floating Structure System

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China Ocean Engineering 2022年第6期36卷 880-893页

作者： liu Ya-qiong REN nian-xin OU Jin-ping School of Civil and Environmental Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China College of Civil Engineering and Architecture Hainan UniversityHaikou 570228China

The present work reports a Hybrid Modular Floating Structure(HMFS)system with typical malfunction *** effects of both fractured mooring lines and failed connectors on main hydrodynamic responses(mooring line tensions,module motions,connector loads and wave power production)of the HMFS system under typical sea con-ditions are comparatively *** results indicate that the mooring tension distribution,certain module motions(surge,sway and yaw)and connector loads(Mz)are significantly influenced by mooring line *** adjacent mooring line of the fractured line on the upstream side suffers the largest tension among the remaining mooring lines,and the case with two fractured mooring lines in the same group on the upstream side is the most dangerous among all cases of two-line failures in view of mooring line tensions,module motions and connector ***-fore,one emergency strategy with appropriate relaxation of a proper mooring line has been proposed and proved effective to reduce the risk of more progressive mooring line *** addition,connector failures substantially affect certain module motions(heave and pitch),certain connector loads(Fz and My)and wave power *** present work can be helpful and instructive for studies on malfunction conditions of modular floating structure(MFS)systems.

关键词： Hybrid Modular Floating Structure(HMFS)system mooring line fractures connector failures hydrodynamic responses emergency strategy

Tyrosine Hydroxylase as a Target for Deltamethrin in the Nigrostriatal Dopaminergic Pathway

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Biomedical and Environmental Sciences 2006年第1期19卷 27-34页

作者： GONG-PING liu QIANG MA nian SHI Department of Toxicology MOE key Laboratory of Environmental and Health Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 Hubei China Receptor Biology Laboratory Toxicology and Molecular Biology Branch Health Effects Laboratory Division National Institute for Occupational Safety and Health Centers for Disease Control and Prevention Morgantown WV 26505 USA

Objective To study the effects of deltamethrin on tyrosine hydroxylase in nigrostriatum of male rats. Methods Sprague-Dawley rats were daily treated with deltamethrin at 6.25 or 12.5 mg/kg body weight by gavage for 10 days. Then HPLC-fluorescence detection was used to analyze the contents of dopamine （DA）, 3,4-dihydmxyphenylacetic acid （DOPAC） and homoranillic acid （HVA） in substantial nigra and striatum. The activities of tyrosine hydroxylase （TH） were also detected by HPLC-fluorescence detection. TH mRNA or TH protein levels were measured by RT-PCR and immunohistochemistry method. Results The content of DA in stfiatum was significantly decreased by the treatments, suggesting an inhibition of DA synthesis by deltamethrin. The contents of DA metabolites DOPAC and HVA increased, indicating increased dopamine turnover. Furthermore, deltamethrin significantly decreased the activity, as well as the mRNA and protein levels of TH. Conclusions These findings reveal a novel aspect of deltamethfin neurotoxicity and suggest tyrosine hydroxylase as a molecular target of deltamethin on dopamine metabolism in the nigrostriatal pathway.

关键词： Deltamethrin Nigrostriatum Dopamine Tyrosine hydroxylase Parkinson's disease

Several classes of negabent functions over finite fields

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Science China(Information Sciences) 2018年第3期61卷 217-219页

作者： Gaofei WU nian LI Yuqing ZHANG Xuefeng liu State Key Laboratory of Integrated Service Networks Xidian University Faculty of Mathematics and Statistics Hubei Key Laboratory of Applied MathematicsHubei University Department of Informatics University of Bergen National Computer Network Intrusion Protection Center University of Chinese Academy of Sciences

A Boolean function is called bent[1]if and only if it has a flat spectrum with respect to the WalshHadamard *** functions have attracted a lot of attention due to their applications in coding theory and cryptography.A... 详细信息

关键词： Several classes of negabent functions over finite fields

Synthesis and characterization of cadmium-calcium hydroxyapatite solid solutions

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International Journal of Minerals,Metallurgy and Materials 2014年第6期21卷 604-608页

作者： Xin Zhao Yi-nian Zhu liu-qin Dai College of Light Industry and Food Engineering Guangxi University College of Environmental Science and Engineering Guilin University of Technology

A series of cadmium-calcium hydroxyapatite solid solutions was prepared by an aqueous precipitation method. By various means, the characterizations confirmed the formation of continuous solid solutions over all ranges of Cd/（Cd＋Ca） atomic ratio. In the results, both lattice parameters a and c display slight deviations from Vegard’s rule when the Cd/（Cd＋Ca） atomic ratio is greater than 0.6. The particles change from smaller acicular to larger hexagonal columnar crystals as the Cd/（Cd＋Ca） atomic ratio increases from 0-0.60 to 0.60-1.00. The area of the phosphate peak for symmetric P-O stretching decreases with the increase in Cd/（Cd＋Ca） atomic ratio, and the peak disappears when the Cd/（Cd＋Ca） atomic ratio is greater than 0.6; the two phosphate peaks of P-O stretching gradually merge together for the Cd/（Cd＋Ca） atomic ratio near 0.60. These variations can be explained by a slight tendency of larger Cd ions to occupy M（2） sites and smaller Ca ions to prefer M（1） sites in the structure.

关键词： hydroxyapatite solid solutions cadmium calcium substitution

Influence of Si Content on Properties of Ti1-xSixN Coatings

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Journal of Wuhan University of Technology(Materials Science) 2019年第4期34卷 774-780页

作者： WAN Qiang liu nian YANG Bing liu Huidong CHEN Yanming School of Engineering Huazhong Agricultural UniversityWuhan 430070China School of Power & Mechanical Engineering Wuhan UniversityWuhan 430072China

To investigate the evolution of microstructure and wear behavior of TiSiN coatings with the variation of Si in targets and lays the foundation for its controllable mass production, Ti1-xSixN composite coatings were deposited onto Si(100) and cemented carbide substrates using TiSi targets with different Si content by cathodic arc ion plating. The influences of Si on the microstructure and mechanical properties were studied. Nano-amorphous composite structure appeared in the Ti1-xSixN coatings when Si content in TiSi target was higher than 5 at%. However, further increase of Si content in TiSi target exhibited a negligible effect on the microstructure of Ti1-xSixN coatings. Hardness and deformation resistance were correlated to the content of Si in TiSi targets. Maximum hardness was obtained as the Si content in target increased up to 20 at%. Friction coefficient and wear rate significantly decreased with addition of Si in TiN coating, and then dually increased with the increase of Si content in targets.

关键词： cathodic arc ion plating Ti(1-x)SixN coating silicon content nanocomposite mechanical properties wear resistance

Effect of a rigid structure on the dynamics of a bubble beneath the free surface

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Theoretical & Applied Mechanics Letters 2021年第6期11卷 355-361页

作者： Shi-Min Li A-Man Zhang nian-nian liu College of Shipbuilding Engineering Harbin Engineering UniversityHarbin 150001China

The coupling effect between a pulsating bubble and a free surface near a rigid structure is a complicated physical *** this study,the evolution of an underwater explosion bubble and the free surface near a rigid structure is modeled by the boundary integral *** approach of“double-node method”is used to maintain the stability of fluid-structure junction in the simulations,and meshes on the free surface and the structure are transformed to an open domain to ensure the calculation accuracy and *** are conducted against an underwater explosion experiment near a rigid *** a result,the simulations trace the jetting behavior of the bubble and the rise of the free ***,the bubble migration and the height of the free surface for different structure draughts are analyzed.

关键词： Underwater explosion Bubble dynamics Boundary integral method

Ruthenium-promoted reductive transformation of CO2

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Science China Chemistry 2017年第7期60卷 841-852页

作者： Xuedong Li Xing He Xiaofang liu Liang-nian He State Key Laboratory and Institute of Elemento-Organic Chemistry Collaborative Innovation Center of Chemical Science and EngineeringNankai UniversityTianjin 300071China

The reductive transformation of CO_2 to energy related products including formic acid, CO, formamide, methanol and methylamine could be a promising option to supply renewable energy. In this aspect, ruthenium has found wide application in hydrogenation of various carbonyl groups, and has successfully been applied to reductive transformation of CO_2 with high catalytic efficiency and excellent selectivity. In addition, ruthenium complexes have also served as effective photosensitizers for CO_2 *** by reductive products, this review summarizes and updates advances in the Ru-catalyzed reduction of CO_2 along with catalyst development on the basis of mechanistic understanding at a molecular level.

关键词： carbon dioxide chemistry homogeneous catalysis reductive transformation ruthenium sustainable chemistry