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N_2O emissions from regional agricultural lands——A case study of Guizhou Province, southwestern china

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science china Earth sciences 2000年第1期43卷 103-112页

作者：徐文彬洪业汤陈旭晖 c.s.li state Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Institute of Environment and Resources chemistry Zhejiang University Hangzhou 310027 China soil and Fertilizer Institute Guizhou Academy of Agricultural Sciences Guiyang 550013 China Institute for the study of Earth Oceans and Space University of New Hampshire Durham USA.

To preliminarily study N2O emissions and the importance of environmental parameters on N2O flux from subtropical agroecosystem in china, N2O flux measurements were made at three cultivated agricultural lands in Guizhou Province, southwestern china. Based on the test and validation of daily N2O flux and its several associated variables between DNDc model and field measurements, DNDc model has been employed to estimate total N2O emissions from entire agricultural lands and its spatial distribution at county scale in Guizhou in 1995, and to assess the contributions of cropping practices on N2O emissions.

关键词： N_2O emission agricultural lands DNDc model

INFLUENcEs OF EDGING ROLL sHAPE ON THE PLAsTIc sTRAIN DIsTRIBUTION OF sLAB DURING MULTI-PAss V-H ROLliNG PROcEss

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Acta Metallurgica sinica(English Letters) 2006年第1期19卷 51-56页

作者： H.L. Yu X.H. liu c.s. li X.M. Zhao Y. Kusaba The state Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110004 China sumitomo Metal Induswies Ltd. Japan 6000891 Amagaski 660 JapanManuscript received 7 April 2005 in revised form 8 August 2005

Multi-pass slab vertical-horizontal （V-H） rolling process with variable edging roll shape have been simulated with explicit dynamic finite element method and updating geometric method. The distributions of plastic strain contour in slab daring rolling process with different edging roll and under different rolling stage have been obtained. The results show that there exist two thin strain assembling zones in slab when the flat edging roll is used, and there just exist one strain assembling zone in slab when the edging roll with groove is used. And compared the deformation equality between flat edging roll and edging roll with groove, the lateris better than the former, which supplies the theory prove to the slab deformation distribution during V-H rolling process and is helpful for predicting the slab texture.

关键词： strain V-H rolling multi-pass finite element method (FEM),updating geometric method

Researching and Teaching china and Hong Kong English

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基础教育外语教学研究 2015年第6期 56-61页

作者： David c. s. li

*** To put theory into practice-and let World Englishes (WE) and English as a lingua franca (ELF) insights inform local English curricula-much remains to be done,including basic research in local (ized) English features across all linguistic *** main challenge is intelligibility in international communication,currently the focus of intensive ELF ***,ownership and intelligibility are important issues that bear principally on social interaction,and so should receive more attention in the teaching of speaking and ***'needs that relate to reading and writing are rather different.

关键词：英语学习学习方法阅读知识阅读材料

Tribological behavior of lubricant-impregnated porous polyimide

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Friction 2024年第4期12卷 711-725页

作者： Jinbang li Ningning ZHOU Janet s.s.WONG school of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211China Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms Beijing Institute of Control EngineeringBeijing 100029China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

Porous materials impregnated with lubricants can be used in conditions where limited lubricant is *** this work,three porous polyimides(PPI)with different densities were ***(PAO)impregnated PPI(iPPI)discs were rubbed against steel and sapphire *** operando observations of the iPPI-sapphire contacts show that oil is released under an applied load,forming a meniscus around *** at the outlet is created at high sliding *** amount of released oil increases with increasing PPI *** moduli,E*,estimated based on the actual contact size show that trapped oil in iPPIs contributes to load *** higher speeds,tribological rehydration of the contact occurs in low density iPPI,with that E*rises with *** high density PPIs,high speeds give a constantly high E*which is limited by the viscoelastic properties of the PPI network and possibly the rate of oil *** of iPPI-steel contacts is governed by the mechanical properties of the PPI,the flow of the lubricant,and the roughness of the PPI *** low-and medium-density(highly porous,high roughness)PPIs,large amount of oil is released,and lubrication is mainly via lubricant restricted in the contact in the pores and possibly tribological *** high density(low porosity)PPI,with lower roughness,hydrodynamic lubrication is achieved which gives the lowest *** results show that polymeric porous materials for effective lubrication require the optimization of its surface roughness,stiffness,oil flow,and oil retentions.

关键词： polyimide porous material friction mechanism polymer limited lubrication

Dynamic Event-Triggered consensus control for Input constrained Multi-Agent systems With a Designable Minimum Inter-Event Time

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IEEE/cAA Journal of Automatica sinica 2024年第3期11卷 649-660页

作者： Meilin li Yue Long Tieshan li Hongjing liang c.L.Philip chen the school of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731China IEEE the Yangtze Delta Region Institute University of Electronic Science and Technology of ChinaHuzhou 313000 the Laboratory of Electromagnetic space cognition and Intelligent control Beijing 100089China the school of computer science and Engineering South China University of TechnologyGuangzhou 510006

This paper investigates the consensus control of multi-agent systems(MAss) with constrained input using the dynamic event-triggered mechanism(ETM).consider the MAss with small-scale networks where a centralized dynamic ETM with global information of the MAss is first ***,a distributed dynamic ETM which only uses local information is developed for the MAss with large-scale *** is shown that the semi-global consensus of the MAss can be achieved by the designed bounded control protocol where the Zeno phenomenon is eliminated by a designable minimum inter-event *** addition,it is easier to find a trade-off between the convergence rate and the minimum inter-event time by an adjustable ***,the results are extended to regional consensus of the MAss with the bounded control *** simulations show the effectiveness of the proposed approach.

关键词： constrained input designable minimum inter-event time directed communication topology dynamic event-triggered mechanism MAss consensus control

Enhancing visible-light-driven NO oxidation through molecular‐level insights of dye-loaded sea sands

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Rare Metals 2024年第2期43卷 543-554页

作者： Yu-Han li Bang-Fu chen sónia A.c.carabineiro You-Yu Duan Ping Tan Wing-Kei Ho Fan Dong Engineering Research center for Waste Oil Recovery Technology and Equipment Ministry of EducationChongqing Key Laboratory of Catalysis and New Environmental MaterialsChongqing Technology and Business UniversityChongqing400067China Nanchang Institute of Technology Nanchang33044China LAQV-REQUIMTE Department of ChemistryNOVA School of Science and TechnologyUniversidade NOVA de Lisboa2829-516CaparicaPortugal college of Physics and center of Quantum Materials and Devices Chongqing UniversityChongqing401331China Department of science and Environmental studies The Education University of Hong KongHong Kong999077China

Natural minerals,abundant and easily obtained through simple physical processing,offer a cost-effective and environmentally friendly solution for dyeing wastewater disposal and air pollution *** study investigates the photocatalytic removal of NO using natural different types of dyes,loaded on natural sand,under visible light *** examining various coating concentrations of dyes and sand weights,we discovered that sand loaded with Rhodamine B(RhB)exhibits high activity for the photo-oxidation of NO.A combination results of X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPs),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric(TG)analyses confirm the presence of siO_(2),cacO_(3),Al_(2)O_(3)and iron oxides as the main components of the ***,studying RhB-loaded individual components reveals that cacO_(3)plays a crucial role in enhancing the NO removal *** results and theoretical calculations demonstrate the establishment of a directional charge transfer channel from cacO_(3)to RhB,facilitating the adsorption and activation of molecular NO and O_(2).This work not only promotes the utilization of natural mineral resources but also enriches the fields of environmental photochemistry and semiconductor photocatalysis.

关键词： sand dyes Rhodamine B Photo-oxidation of NO Visible light illumination

Experimental study of corner separation and unsteady characteristics in linear compressor cascades with and without sweeping jet actuator

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Propulsion and Power Research 2024年第3期13卷 360-374页

作者： s.W.chen W.H.li c.Xu Q.H.Meng school of Energy science and Engineering Harbin Institute of TechnologyHarbinHeilongjiang 150001China AVIc shenyang Aircraft Design and Research Institute Shenyang 110035China

sweeping jet actuator(sJA)has been widely applied for activeflow control in *** this paper,the sJA character in compressor cascade and its performance for separation control in innerflows are ***-averaged and transientflowfield measurement,together with visualization methods are *** is found that endwall effects are important for both sJA behaviors and sJA performance for separation control in compressor *** is a maximum of 12.7%total pressure loss reduction with sJA placed near the separation position,close to the endwall and under *** characteristic frequencies in theflowfield contribute to the capture of influence regions of vortices and excitation *** concentrated shedding vortices and sJA jets impact region helped to judge that sJA energizes low momentumfluids in a large region and matches the high loss core *** be concrete,theflow separation control mechanism of sJA lies on the interruption of the blade suction surface boundary layer development and the restriction of the lifting of the boundary layer from end-wall towards blade suction surface.

关键词： compressor cascade Activeflow control sweeping jet actuator corner separation Oilflow visualization

Editorial for the special Issue on Emerging Technology and Advanced Application of Nondestructive Detection for Power Equipment

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chinese Journal of Electrical Engineering 2024年第1期10卷 1-2页

作者： li J. Mei H. li s. Tianjin University China Tsinghua shenzhen International Graduate school China Lanzhou Jiaotong University China

The rapid development of clean and renewable energy technologies represented by wind and solar energy,as well as the continuous growth of load demand,have put forward higher requirements for the safe operation of the power *** performance of power equipment based on traditional dielectric materials is often limited by various defects generated during molding,transportation,assembly,and operation,which cannot meet the reliability requirements of power systems in the new *** detection is an essential technical method in industrial development,which can detect and evaluate the defect and damage status of in-service equipment,key components,and materials without damaging the object.

关键词： service Application operation

Effects of layer interactions on instantaneous stability of finite stokes flows

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 69-84页

作者： chen ZHAO Zhenli cHEN c.T.MUTAsA Dong li school of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

The stability analysis of a finite stokes layer is of practical importance in flow control. In the present work, the instantaneous stability of a finite stokes layer with layer interactions is studied via a linear stability analysis of the frozen phases of the base flow. The oscillations of two plates can have different velocity amplitudes, initial phases, and frequencies. The effects of the stokes-layer interactions on the stability when two plates oscillate synchronously are analyzed. The growth rates of two most unstable modes when δ st equal, and δ = δ*/h*, where δ*and h*are the stokes-layer thickness and the half height of the channel, respectively. However, their vorticities are different. The vorticity of the most unstable mode is symmetric, while the other is asymmetric. The stokes-layer interactions have a destabilizing effect on the most unstable mode when δ stabilizing effect when δ > 0.68. However, the interactions always have a stabilizing effect on the other unstable mode. It is explained that one of the two unstable modes has much higher dissipation than the other one when the stokes-layer interactions are strong. We also find that the stability of the stokes layer is closely related to the inflectional points of the base-flow velocity profile. The effects of inconsistent velocity-amplitude, initial phase, and frequency of the oscillations on the stability are analyzed. The energy of the most unstable eigenvector is mainly distributed near the plate of higher velocity amplitude or higher oscillation frequency. The effects of the initial phase difference are complicated because the base-flow velocity is extremely sensitive to the initial phase.

关键词： finite stokes layer instantaneous stability stokes-layer interaction asynchronous oscillation