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Transport mechanism of eroded sediment particles under freeze-thaw and runoff conditions

Journal of Arid Land 2022年第5期14卷 490-501页

作者： WANG Tian LI Peng HOU Jingming TONG Yu LI Jing WANG Feng LI Zhanbin State Key Laboratory of Eco-hydraulics in Northwest Arid Region Xi'an University of TechnologyXi'an 710048China Key Laboratory of National Forestry Administration on Ecological Hydrology and Disaster Prevention in Arid Regions Xi'an University of TechnologyXi'an 710048China

Hydraulic erosion associated with seasonal freeze-thaw cycles is one of the most predominant factors,which drives soil stripping and transportation.In this study,indoor simulated meltwater erosion experiments were used to investigate the sorting characteristics and Transport mechanism of sediment particles under different freeze-thaw conditions(unfrozen,shallow-thawed,and frozen slopes)and runoff rates(1,2,and 4 L/min).Results showed that the order of sediment particle contents was silt>sand>clay during erosion process on unfrozen,shallow-thawed,and frozen slopes.Compared with original soils,clay and silt were lost,and sand was deposited.On unfrozen and shallow-thawed slopes,the change of runoff rate had a significant impact on the enrichment of clay,silt,and sand particles.In this study,the sediment particles transported in the form of suspension/saltation were 83.58%–86.54%on unfrozen slopes,69.24%–84.89%on shallow-thawed slopes,and 83.75%–87.44%on frozen slopes.Moreover,sediment particles smaller than 0.027 mm were preferentially transported.On shallow-thawed slope,relative contribution percentage of suspension/saltation sediment particles gradually increased with the increase in runoff rate,and an opposite trend occurred on unfrozen and frozen slopes.At the same runoff rate,freeze-thaw process had a significant impact on the relative contribution percentage of sediment particle transport via suspension/saltation and rolling during erosion process.The research results provide an improved Transport mechanism under freeze-thaw condition for steep loessal slopes.

关键词： freeze-thaw runoff conditions erosion process sediment particles Transport mechanism

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Plant pleiotropic drug resistance transporters:Transport mechanism, gene expression,and function

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Journal of Integrative Plant Biology 2014年第8期56卷 729-740页

作者： Mohammed Nuruzzaman Ru Zhang Hong-Zhe Cao Zhi-Yong Luo Molecular Biology Research Center School of Life Sciences Central South University State Key Laboratory of Medical Genetics Xiangya School of Medicine Central South University

Pleiotropic drug resistance （PDR） transporters belonging to the ABCG subfamily of ATP-binding cassette （ABC） transporters are identified only in fungi and plants. Members of this family are expressed in plants in response to various biotic and abiotic stresses and transport a diverse array of moleculesacross membranes, Although their detailed Transport mechanism is largely unknown, they play important roles in detoxification processes, preventing water loss, transport of phytohormones, and secondary metabolites. This review provides insights into Transport mechanisms of plant PDR transporters, their expression profiles, and multitude functions in plants.

关键词： ABC transporters expression pattern plant defense pleiotropic drug resistance Transport mechanism

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Transport mechanism of reverse surface leakage current in AlGaN/GaN high-electron mobility transistor with SiN passivation

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Chinese Physics B 2015年第2期24卷 376-381页

作者：郑雪峰范爽陈永和康迪张建坤王冲默江辉李亮马晓华张进成郝跃 School of Microelectronics Xidian University Key Laboratory of Wide Bandgap Semiconductor Materials and Devices Xidian University National Key Laboratory of Application Specific Integrated Circuit(ASIC) Hebei Semiconductor Research Institute

The Transport mechanism of reverse surface leakage current in the AlGaN/GaN high-electron mobility transistor（HEMT） becomes one of the most important reliability issues with the downscaling of feature size.In this paper,the research results show that the reverse surface leakage current in AlGaN/GaN HEMT with SiN passivation increases with the enhancement of temperature in the range from 298 K to 423 K.Three possible Transport mechanisms are proposed and examined to explain the generation of reverse surface leakage current.By comparing the experimental data with the numerical transport models,it is found that neither Fowler-Nordheim tunneling nor Frenkel-Poole emission can describe the transport of reverse surface leakage current.However,good agreement is found between the experimental data and the two-dimensional variable range hopping（2D-VRH） model.Therefore,it is concluded that the reverse surface leakage current is dominated by the electron hopping through the surface states at the barrier layer.Moreover,the activation energy of surface leakage current is extracted,which is around 0.083 eV.Finally,the SiN passivated HEMT with a high Al composition and a thin AlGaN barrier layer is also studied.It is observed that 2D-VRH still dominates the reverse surface leakage current and the activation energy is around 0.10 eV,which demonstrates that the alteration of the AlGaN barrier layer does not affect the Transport mechanism of reverse surface leakage current in this paper.

关键词： AlGaN/GaN HEMTs reverse surface leakage current Transport mechanism 2D-VRH

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Design and experimentation of the Transport mechanism for mulberry leaf harvesting machine in hilly terrain

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Journal of Chinese Agricultural Mechanization 2024年第3期45卷 133-139页

作者： Lu L. Li L. Lu S. Tang H. College of Engineering and Technology Southwest University Chongqing Key Laboratory of Agricultural Equipment for Hilly and Mountainous Regions Chongqing 400715 China Yibin Academy of Southwest University Yibin 644000 China

Aiming at the lack of mulberry leaf harvesting machinery in hilly and mountainous areas, the difficulty of mulberry leaf harvesting and collection, and the labor intensity of manual harvesting, developing a mulberry leaf harvesting machine for hilly and mountainous terrains. and mountainous areas, and focused on the design and test of the transfer device. Firstly, analyze the working environment of the mulberry leaf harvester and the mulberry leaf harvesting process, and complete the analysis of the working principle and structural design and calculation of the receiving mechanism, guiding mechanism and bag feeding mechanism of the transfer device. Secondly, according to the design parameters, the prototype of mulberry leaf harvester is made, and the test of the transfer device is carried out in the hilly and mountainous mulberry gardens. Finally, according to the test to get the conclusion: mulberry leaf harvester transfer device toggle speed for 80 r/min, automatic decoupling length size b1=25 mm, width size b2=25mm, depth size b3= 15 mm, when hook thickness h3= 8 mm, the receiving mechanism transfer process mulberry leaves average transfer rate of 95.78%, the guide mechanism mulberry leaves into the bag of the average rate of 97.88%, the bag feeding mechanism bag drop rate of 1.25%, the success rate of automatic bag removal is 98.75%. The field test in mulberry orchard shows that the mulberry leaf harvester transfer device can meet the functional requirements of mulberry leaf harvesting, which verifies the correctness and feasibility of the design. © 2024 Journal of Chinese Agricultural Mechanization Editorial Office. All rights reserved.

关键词： bag feeding mechanism guide mechanism mulberry leaf harvesting machine receiving mechanism Transport mechanism

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Research Advance on the mechanism of Cadmium transport in Rice

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Meteorological and Environmental Research 2014年第5期5卷 48-52页

作者： Liu Zhongqi Agro-Environmental Protection Institute Ministry of Agriculture

Soils in part of rice production areas have been seriously contaminated by cadmium （Cd）. Rice with high Cd content over allowable limit produced in these areas is widely concerned. Low accumulation varieties can remarkably decrease the Cd content in rice as well as the risk of food safety. The translocation of Cd either from soil to root system or from roots to aboveground parts is identified by a lot of ion transport proteins. transport efficiency of Cd in some rice varieties is regulated by special metal ionic transporters. However, most varieties transport Cd by cation transporters or universal ionic transporters. Both the expression levels and time of gens controlling ionic transporters directly influence the Cd transport rates inside rice plant and the accumulation amount in different organs. Screening and utilizing specific Cd transport genes are the genetic basis of breeding low accumulation varieties.

关键词： Rice Cadium Ionic channel Transport mechanism Low accumulation China

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Stability and transepithelial transport of oligopeptide(KRQKYD)with hepatocyte-protective activity from Jinhua ham in human intestinal Caco-2 monolayer cells

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Food Science and Human Wellness 2024年第3期13卷 1503-1512页

作者： Wen Nie Feiran Xu Kai Zhou Jieying Deng Ying Wang Baocai Xu Engineering Research Center of Bio-process Ministry of EducationSchool of Food and Biological EngineeringHefei University of TechnologyHefei 230601China School of Biological and Food Engineering Chuzhou UniversityChuzhou 239001China

The study evaluated the stability of an oligopeptide(Lys-Arg-Gln-Lys-Tyr-Asp,KRQKYD)and its Transport mechanism by simulating gastrointestinal digestion and a model of human intestinal Caco-2 monolayer cells in vitro.In this study,the effects of environmental factors(temperature,pH and NaCl concentration)and simulated gastrointestinal digestion on the stability of KRQKYD were evaluated by indicators of the levels of alanine transaminase(ALT),aspartate transaminase(AST)and malondialdehyde(MDA)in an alcoholinduced hepatocyte injury model.The results showed that KRQKYD still maintained satisfactory hepatocyteprotective activity after treatment with different temperatures(20-80℃),pH(3.0-9.0),NaCl concentration(1%-7%)and simulated gastrointestinal digestion,which indicated that KRQKYD showed good stability to environmental factors and simulated gastrointestinal digestion.Furthermore,the intact KRQKYD could be absorbed in a model of Caco-2 monolayer cells with a P_(app)value of(9.70±0.53)×10^(-7)cm/s.Pretreatment with an energy inhibitor(sodium azide),a competitive peptide transporter inhibitor(Gly-Pro)and a transcytosis inhibitor wortmannin did not decrease the level of transepithelial KRQKYD transport,indicating that the Transport mechanism of KRQKYD was not associated with energy dependent,vector mediated and endocytosis.The tight junction disruptor cytochalasin D significantly increased the level of transepithelial KRQKYD transport(Ptransport.

关键词： Jinhua ham KRQKYD(Lys-Arg-Gln-Lys-Tyr-Asp) Environmental stability Gastrointestinal digestive Transport mechanism

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Sr-doping effects on conductivity,charge transport,and ferroelectricity of Ba_(0.7)La_(0.3)TiO_(3) epitaxial thin films

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Chinese Physics B 2021年第2期30卷 514-519页

作者：李强王岛张岩李育珊张爱华陶瑞强樊贞曾敏周国富陆旭兵刘俊明 Institute for Advanced Materials South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou 510006China Guangdong Provincial Key Laboratory of Optical Information Materials South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou 510006China National Center for International Research on Green Optoelectronics South China Normal UniversityGuangzhou 510006China Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210009China

Sr-doped Ba_(0.7)La_(0.3)TiO_(3)(BSLTO)thin films are deposited by pulsed laser deposition,and their microstructure,conductivity,carrier Transport mechanism,and ferroelectricity are systematically investigated.The x-ray diffraction measurements demonstrate that Sr-doping reduces the lattice constant of BSLTO thin films,resulting in the enhanced phonon energy in the films as evidenced by the Raman measurements.Resistivity-temperature and Hall effect measurements demonstrate that Sr can gradually reduce electrical resistivity while the electron concentration remains almost unchanged at high temperatures.For the films with semiconducting behavior,the charge transport model transforms from variable range hopping to small polaron hopping as the measurement temperature increases.The metalic conductive behaviors in the films with Sr=0.30,0.40 conform to thermal phonon scattering mode.The difference in charge transport behavior dependent on the A-site cation doping,is clarified.It is revealed that the increasing of phonon energy by Sr doping is responsible for lower activation energy of small polaron hopping,higher carrier mobility,and lower electrical resistivity.Interestingly,the piezoelectric force microscopy(PFM)results demonstrate that all the BSLTO films can exhibit ferroelectricity,especially for the room temperature metallic conduction film with Sr=0.40.These results imply that Sr-doping could be a potential way to explore ferroelectric metal materials for other perovskite oxides.

关键词： Sr-doping Transport mechanism BSLTO thin film ferroelectric metal

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First-principles calculations on spin-polarized transport properties of Mn_4O_4 cluster

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Rare Metals 2015年第1期34卷 45-50页

作者： Zhen-Xiang Dai Gan-Hong Zheng Bing Wang Wei-Wei Wang Yong-Qing Ma Zhi Zeng School of Physics and Materials Science Anhui University Key Laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences

Taking the Mn404 cluster as a model system, the spin-polarized transport properties of the small cluster system were systematically probed. The theoretical inves- tigations are based on density-functional theory and non- equilibrium Green＇s functional method. The equilibrium Transport mechanism is illustrated by the band structure of the electrode, the electronic structure of the Mn404 cluster and the coupling between the cluster and the electrodes. To well understand the non-equilibrium mechanisms, one straightforward and simple band-matching model was proposed. Moreover, such a band-matching model can be extended to well illustrate the transport properties of other nano-scale systems.

关键词： Cluster First-principles Band-matchingmodel Transport mechanism

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transport of Propylene Carbonate-LiTFSI Electrolytes in P(VDF-HFP)Using Time-resolved ATR-FTIR Spectroscopy:Diffusion Coefficients and Molecular Interactions

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Chinese Journal of Polymer Science 2021年第8期39卷 975-983,I0005页

作者： Hui-Xian Li Lei Hou Pei-Yi Wu National Engineering Research Center for Dyeing and Finishing of Textiles College of ChemistryChemical Engineering and BiotechnologyDonghua UniversityShanghai 201620China

The time-resolved attenuated total reflectance-Fourier transform infrared(ATR-FTIR)spectroscopy is employed to investigate the Transport mechanism of gel electrolytes by monitoring the diffusion behavior of propylene carbonate-lithium bis(trifluoromethylsulfonyl)imide(PC-LiTFSI)solution through poly(vinylidene fluoride-co-hexafluoropropylene)(P(VDF-HFP))films.Fickian behavior has been observed for both TFSr and PC.Higher temperature leads to faster diffusion of TFSI'and PC,which could be related to the increased free volume in P(VDF-HFP)matrix and rapid molecular movements upon heating.Various molecular interactions among LiTFSI,PC and P(VDF-HFP)have been recognized.During the diffusion process,PC molecules,in the form of small clusters,can firstly diffuse through the P(VDF-HFP)film and interact with P(VDF-HFP)by dipole-dipole interaction,acting as the plasticizer.Then,Li+diffuses into P(VDF-HFP)with the help of ion-dipole interactions between Li+and C=0 of PC.Meanwhile,TFSI-diffuses through the polymer matrix in solvation states.In addition,slight ion-dipole interactions between Li+and P(VDF-HFP)have been observed as well.Results in this work contribute to a better understanding of transport process in gel polymer electrolytes for lithium-ion batteries and support the development of improved gel polymer electrolytes by rationally regulating molecular interactions.

关键词： ATR-FTIR spectroscopy Gel polymer electrolyte Transport mechanism Molecular interaction Diffusion coefficient

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Synthesis of novel PANI-based Ti(IV)phosphosulphosalicylate composite cation exchanger-structural,electrical,and impedance properties

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Journal of Advanced Dielectrics 2021年第1期11卷 55-65页

作者： T.Amutha K.Jacinth Mispa Aditanar College of Arts and Science Tiruchendur-628216 Affiliating to Manonmaniam Sundaranar UniversityAbishekapatti Tirunelveli-627012Tamil NaduIndia Department of Chemistry Aditanar College of Arts and Science Tiruchendur-628216Affiliating to Manonmaniam Sundaranar University AbishekapattiTirunelveli-627012Tamil NaduIndia

In order to combine the properties of inorganic ion exchanger and conducting organic polymer,a new class of organic-inorganic composite cation exchanger PANI-Ti(IV)phosphosulphosalicylate(PTPSS)was synthesized by intercalating polyaniline(PANI)into Ti(IV)phosphosulphosalicylate(Ti(IV)PSS)using sol-gel chemical route with enhanced properties.PTPSS has been characterized by using Fourier Transform Infrared Spectroscopy(FT-IR),X-ray diffraction(XRD),Scanning Electron Microscopy(SEM),Energy dispersive X-ray(EDAX),thermo gravimetric analysis(TGA-DTG),and Transmission Electron Microscopy(TEM).Ac electrical conductivity studies were also performed.This material possessed electrical conductivity of 10^(−3)-10^(−6)Scm^(−1) which falls in the semiconducting range.The frequency(2×10^(5)-1×10^(6)Hz)dependent Ac conductivity at room temperature suggests the evidence for the Transport mechanism for the conductivity in PTPSS.The structure of the composite cation exchanger extremely supports its conducting behavior.

关键词： Polyaniline-Ti(IV)phosphosulphosalicylate composite cation exchanger electrical conductivity Transport mechanism impedance studies

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