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FLOW STRUCTURE OF PARTLY VEGETATED OPEN-CHANNEL FLOWS WITH EELGRASS

Journal of Hydrodynamics 2009年第3期21卷 301-307页

作者： wang Chao YU Ji-yu wang Pei-fang GUO Peng-cheng Key Laboratory of Integrated Regulation and Resource Department on Shallow Lakes Ministry of Education Hohai University Nanjing 210098 China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing 210098 China College of Environmental Science and Engineering Hohai University Nanjing 210098 China Yellow River Engineering Consulting Co. Ltd. Zhengzhou 450003 China

Aquatic vegetation can influence the transport of sediment and contaminants by changing the mean velocity and turbulent flow structure in channels. It is important to understand the hydraulics of the flows over vegetation in order to manage fluvial processes. Experiments in an open-channel flume with natural vegetation were carried out to study the influence of vegetation on the flows. In a half channel with two different densities of vegetation, the flow velocity, Reynolds stresses, and turbulence intensities were measured using an Acoustic Doppler Velocimeter （ADV）. We obtained velocity profiles in the lateral direction, Reynolds stresses in the vertical direction, and the flow transition between the vegetated and non-vegetated zones in different flow regimes. The results show that the streamwise velocity in the vegetated zone with higher density is almost entirely blocked. Reynolds stress distribution distinguishes with two different regions： inside and above the vegetation canopies. The turbulence intensities increase with increasing Reynolds number. The coherent vortices dominate the vertical transport of momentum and are advected clockwise between the vegetated zone and non-vegetated zone by secondary currents （a relatively minor flow superimposed on the primary flow, with significantly different speed and direction）, generated by the anisotropy of the turbulence.

关键词： open channel aquatic vegetation velocity profile turbulence characteristics

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Realization of Oriented and Nanoporous Bismuth Chalcogenide Layers via Topochemical Heteroepitaxy for Flexible Gas Sensors

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Research 2022年第4期2022卷 211-221页

作者： Zhiwei wang Jie Dai Jian wang Xinzhe Li Chengjie Pei Yanlei Liu Jiaxu Yan Lin wang Shaozhou Li Hai Li Xiaoshan wang Xiao Huang Wei Huang Institute of Advanced Materials(IAM) Nanjing Tech University(NanjingTech)30 South Puzhu RoadNanjing 211816China Frontiers Science Center for Flexible Electronics Xi'an Institute of Flexible Electronics(IFE)and Xi'an Institute of Biomedical Materials EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi'an 710072China Key Laboratory for Organic Electronic e Information Displays(KLOEID)and Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(IAM)Nanjing University of Posts and Telecommunications9 Wenyuan RoadNanjing 210023China

Most van der Waals two-dimensional(2D)materials without surface dangling bonds show limited surface activities except for their edge *** Bi_(2)Se_(3),a topological insulator that behaves metal-like under ambient conditions,has been overlooked on its surface ***,through a topochemical conversion process,ultrathin nanoporous Bi_(2)Se_(3) layers were epitaxially deposited on BiOCl nanosheets with strong electronic coupling,leading to hybrid electronic states with further bandgap *** oriented nanoporous Bi_(2)Se_(3) layers possessed largely exposed active edge sites,along with improved surface roughness and film forming ability even on inkjet-printed flexible *** room-temperature NO_(2) sensing performance was achieved compared to other 2D materials under bent *** work demonstrates that creating nanoscale features in 2D materials through topochemical heteroepitaxy is promising to achieve both favorable electronic properties and surface activity toward practical applications.

关键词： chemical bonds roughness

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Alloy anodes for sodium-ion batteries

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Rare Metals 2021年第2期40卷 272-289页

作者： Shu-Min Zheng Yan-Ru Tian Ya-Xia Liu Shuang wang Chao-Quan Hu Bao wang Kai-Ming wang State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing100190China Nanjing IPE(Institute of Process Engineering)Institute of Green Manufacturing Industry Nanjing211135China School of Fashion Beijing Institute of Fashion TechnologyBeijing100029China School of Science University of Science and Technology LiaoningAnshan114051China

Sodium-ion batteries(SIBs)have emerged as one of the most promising candidates for next-generation energy storage systems because sodium is abundant in *** practical application of SIBs critically depends on developing robust electrode materials with high specific capacity and long cycling life,developing suitable anode materials is even more ***-type anodes are attractive for their high gravimetric and volumetric specific capacities,demonstrating great potential for high-energy SIBs,however,huge volume swelling hampered their practical *** the encouraging breakthroughs on alloy anodes for SIBs,herein,we present a review of the up-to-date progress and works carried out with alloy-based anode materials for *** review the synthetic strategies and their detailed electrochemical *** particular,we extensively reveal the important roles of alloy-based anodes in the development of *** progress of alloy-type anodes and their compounds for sodium storage is *** efforts to enhance the electrochemical performance of the alloy-based anode materials are ***,we proposed multi-component alloys/high-entropy alloys(HEAs)as further research directions for alloy-based anodes.

关键词： Alloy-based anodes High-entropy alloy Multi-component alloy Sodium-ion battery

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Solitary Excitations of Dipolar Bosons in Optical Lattice under Magnetic Fields

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Communications in Theoretical Physics 2006年第2X期46卷 233-238页

作者： wang Shi-En Department of Physics Honghe University Mengzi 661100 China Department of Materials Tsinghua University Beijing 100084 China Department of Physics Wenshang Normal Academy Wenshaag 663000 China Department of Physics Beijing Normal University Beijing 100875 China

We obtain the multisolitary solutions of the extended Bose-Hubbard model which describes dipolar Bose- Einstein condensates in optical lattices under time-dependent magnetic fields, and indicate that the nonlinearity is due to both on-site short-range interactions and also （long-range） dipole-dipole interactions which can act between neighboring sites. The discrete breathers as nonlinear excitations are always oscillatory in time and can also be spatially localized, while the oscillatory frequencies are determined by an external field. We show that these excitations will be observable and discuss how the parameters can be tuned in future experiments.

关键词： solitary excitation extended Bose-Hubbard model bosons optical lattice

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Blunt myocardial injury and gastrointestinal hemorrhage following Heimlich maneuver:A case report and literature review

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World Journal of Emergency Medicine 2022年第3期13卷 248-250页

作者： Chu wang Zhen-zhou wang Tian-bing wang Trauma Medicine Center Peking University People's HospitalBeijing 100044China

Dear editor,In 1975,*** Heimlich introduced the Heimlich maneuver[2],which has become the initial treatment for emergency foreign-body airway *** is recommended by American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.[2]During thrusts,airway pressure increases,thereby expelling foreign bodies.

关键词： airway obstruction gastrointestinal

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p-adic Modular Symbols and ∧-adic Modular Forms

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Acta Mathematica Sinica,English Series 2006年第2期22卷 331-338页

作者： Fu Zheng wang LMAM&Department of Mathematics.Peking University

A construction of A-adic modular forms from p-adic modular symbols is described. It shows that each A linear map satisfying some certain conditions from the module of p-adic modular symbols to A corresponds to a A-adi... 详细信息

关键词： Modular symbol Manin symbol A-adic modular form

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Synthesis and application of a novel 9,9-diethyl-1,2-diaryl-1,9-dihydrofluoreno[2,3-d]imidazole for blue organic light emitting diode

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Chinese Chemical Letters 2020年第1期31卷 64-66页

作者： Xueying wang Zhangcheng Liao Tianqi wang Haixia Lin Zixing wang Yongmei Cui Department of Chemistry College of Sciences.Shanghai UniversityShanghai 200444China Key Laboratory of Advanced Display and System Applications Ministry of EducationShanghai UniversityShanghai 200072China

Two novel 2-(4-(9,9-disubstitued-9 H-fluoren-2-yl)phenyl)-9,9-diethyl-l-phenyl-1,9-dihydrofluoreno-[2,3-d]imidazole derivatives 2 a and 2 b were synthesized and *** photophysical and electrochemical properties,thermal stability property,and electroluminescence(EL)performance of 2 b were *** fabricated device based on 2 b doping into 4,4’-N,N’-dicarbazole-biphenyl(5%)as an emitter present a maximum brightness of 1272 cd/m^2 at 4 V with the CIE coordinate of(0.1590,0.0465).

关键词： Fluorene Imidazole Photoluminescence Electroluminescence

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Azimuth Control for Large Aperture Telescope Based on Segmented Arc Permanent Magnet Synchronous Motors

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Research in Astronomy and Astrophysics 2021年第7期21卷 84-90页

作者： Xiao-Li Song Da-Xing wang wang-Ping Zhou Nanjing Institute of Astronomical Optics&Technology National Astronomical ObservatoriesNanjing 210042China CAS Key Laboratory of Astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China School of Automation Nanjing University of Information Science&TechnologyNanjing 210044China

A tracking control algorithm based on active disturbance rejection controller(ADRC) is proposed to overcome the telescope's mount fluctuation. The fluctuations are caused by internal and external disturbance when the large aperture telescope runs at ultra-low speed with direct drive. According to the high-precision and high-stability requirements of a large aperture telescope, the ADRC position controller is designed based on segmented arc Permanent Magnet Synchronous Motors(arc PMSMs). The tracking differentiator of ADRC is designed to undergo a transition process to avoid overshoot in the position *** speed of target tracking process is observed by the extended state observer and the position information in the system is estimated in real time. The current control variable of the segmented arc PMSM is generated by implementing a non-linear state error feedback control law. The simulation results demonstrate that the proposed control strategy can not only accurately estimate the position and speed of the tracking target, but also estimate the disturbance to compensate the control variables. Experiments showed that the speed error is less than 0.05′′s^(-1) when using the ADRC, and it can realize high tracking performance when compared with PID controller, which improves the robustness of a large aperture telescope control system.

关键词： techniques:telescopes instrumentation:miscellaneous methods:miscellaneous techniques

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Characterization and Thermal Conductivity of Modified Graphite/Fatty Acid Eutectic/PMMA Form-Stable Phase Change Material

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Journal of Wuhan University of Technology(Materials Science) 2013年第3期28卷 586-591页

作者：孟多 wang Lijiu School of Civil and Architectural Engineering Liaoning University of Technology Institute of Building Materials Dalian University of Technology

We prepared and characterized a form-stable composite phase change material （PCM） with higher thermal conductivity. Capric acid（CA）-myristic acid（MA） eutectic as core, poly-methyl methacrylate （PMMA） as supportive matrix and modified graphite （MG） powders serving as the thermal conductance improver were blended by bulk- polymerization method. The composite PCMs with different MG mass fraction （2%, 5%, 7%, 10% and 15%） were characterized by FT-IR, SEM, DSC technique and mechanical tests. Thermal conductivities of the composites were measured by transient hot-wire method. The results indicate that MG powders have been successfully inserted into the CA-MA/PMMA matrix without any chemical reaction with each other. The MG/CA-MA/PMMA composites maintain good thermal storage performance while the thermal conductivity has been enhanced significantly. The composite PCM added with 15 wt% MG powders increases approximately as 195.9% in thermal conductivity. Moreover, the thermal conductivity improvement of the composite PCMs is also verified by the melting-freezing experiment, which is profitable for the heat transfer efficiency in latent heat thermal energy storage system.

关键词： form-stable composite PCM fatty acid eutectic poly-methyl methacrylate modified graphite thermal conductivity

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p-adic Transcendence and p-adic Transcendence Measures for the Values of Mahler Type Functions

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Acta Mathematica Sinica,English Series 2006年第1期22卷 187-194页

作者： Tian Qin wang Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 P. R. China College of Computer Sciences Henan University Kaifeng 475001 P. R. China

We prove the p-adic transcendence and p-adic transcendence measures for the values of some Mahler type functions.

关键词： p-adic transcendence p-adic transcendence measure Mahler type function

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