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Structure-from-Motion Photogrammetry and rare earth oxides can quantify diffuse and convergent soil loss and source apportionment

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International Soil and Water Conservation Research 2023年第4期11卷 633-648页

作者： Pia Benaud Karen Anderson Mike R.James Timothy A.Quine John N.Quinton Richard E.Brazier CREWW GeographyFaculty of EnvironmentScience and EconomyUniversity of ExeterExeterDevonEX44RJUnited Kingdom Environment and Sustainability Institute University of ExeterPenrynCornwallTR109FEUnited Kingdom Lancaster Environment Centre Lancaster UniversityBailriggLancasterLA14YQUnited Kingdom Geography Faculty of EnvironmentScience and Economy.University of ExeterExeterDevonEX44RJUnited Kingdom

Accurately quantifying rates of soil erosion requires capturing both the volumetric nature of the visible,convergent fluvial pathways(also known as rills)and the subtle nature of the less-visible,diffuse pathways(interrill areas).The aim of this study was to use rare earth Oxide(REO)tracers and Structure-from-Motion(SfM)photogrammetry to elucidate retrospective information about soil erosion rates and sediment sources during different soil erosion conditions,within a controlled laboratory *** experimental conditions created erosion events consistent with diffuse and convergent erosion *** tracers allowed the sediment transport distances of over 2 m to be described,and helped resolved the relative contribution of diffuse and convergent soil erosion;interrill areas were also iden-tified as a significant sediment sources soil loss under convergent erosion *** the potential for SfM photogrammetry to resolve sub-millimetre elevations changes was demonstrated,under some conditions non-erosional changes in surface elevation,such as compaction,exceeded volumes of soil loss via diffuse *** discrepancies between SfM Photogrammetry calculations and REO tagged sediment export were beneficial,identifying that during soil erosion events sediment in both aggregate and particle form is deposited within the convergent features,even when the rill extended the full length of the soil *** combination of SfM photogrammetry and REO tracers has provided a novel platform for building a spatial understanding of patterns of soil loss and source apportionment between rill and interrill erosion.

关键词： Soil erosion Structure-from-Motion Photogrammetry rare earth oxides Tracers Sediment Rainfall simulator Sheetwash Rilling Interrill

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Nano-preparation promoting effectively luminescent properties of one-dimensional rare earth oxides

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Journal of rare earths 2012年第11期30卷 1096-1101页

作者：李俊峰卢冠忠谢宝庚王艳芹郭耘郭杨龙 Key Laboratory for Advanced Materials and Research Institute of Industrial Catalysis East China University of Science and Technology

rare earth （La, Nd and Tb） oxides with one-dimensional micro/nanostmcatres were synthesized hydrothermally under facile and mild conditions with two surfactants, and characterized by X-ray diffraction （XRD）, thermal gravimetry （TG）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and photoluminescence. The results showed that the synthesized rare earth oxides behaved regular nano- and micro-scale structures. And the morphologies of samples depended on the radii of rare earth ions, with the help of two sur- factants of sodium dodecyl sulfonic and PEG 600. Nanocrystalline La2O3：Eu^3＋ possessed good photoluminescence （PL） property and might be used as a nanosized phosphor, its PL intensity was akered by the doping Eu^3＋ concentration and the optimum concentration of Eu^3＋ was 3 mol.%. In comparison with bulk Eu^3＋/La2O3, Eu^3＋/nano-La2O3 showed better photoluminescence property, nearly equal to that of nanocrtstalline La2O3：Eu^3＋. Tb4O7 microwires showed interesting photoluminescence properties.

关键词： rare earth oxides one-dimensional morphology hydrothermal synthesis luminescence property Eu^3+ dopant

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Effect of mixed rare earth oxides and CaCO_3 modification on the microstructure of an in-situ Mg_2Si/Al-Si composite

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rare Metals 2009年第2期28卷 169-174页

作者： Liu, Zheng Lin, Jixing Jing, Qingxiu Faculty of Material and Chemical Engineering Jiangxi University of Science and Technology Ganzhou 341000 China

The effects of mixed rare earth oxides and CaCO3 on the microstructure of an in-situ Mg2Si/Al-Si hypereutectic alloy composite were investigated by optical microscope,scanning electron microscope,and energy dispersive spectrum analysis. The results showed that the morphol-ogy of the primary Mg2Si phase particles changed from irregular or crosses to polygonal shape,their sizes decreased from 75 μm to about 25 μm,and the compound of both the oxide and CaCO3 was better than either the single mixed rare earth o...

关键词： hypereutectic alloys Al-Si alloys composite rare earth oxides modification

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Synthesis and thermoluminescence properties of rare earth oxides (Y, Ce-Lu) doped lithium triborate

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Journal of rare earths 2011年第6期29卷 618-622页

作者： Tolga Depci Gulhan Ozbayoglu Aysen Yilmaz Department of Mining Engineering Faculty of Engineering and Architecture Yuzuncu Yil University Faculty of Engineering Atilim University Department of Chemistry Middle East Technical University

Lithium triborate （LiB3O5） was synthesized by high temperature solid-state reaction method, and then rare earth oxides were doped into LiB3O5 to enhance its thermoluminescent （TL） properties. The identification and characteristics of the obtained compounds were determined by X-ray diffraction （XRD）, Fourier transform infrared （FTIR） analyses, differential thermal analyses （DTA） and scanning electron microscopy （SEM）. The glow curves were obtained using a thermoluminescent （TL） reader. The results revealed that all the rare earth oxides were not good activators for lithium triborate and the obtained compounds could not be used for dosimetric applications.

关键词： lithium triborate solid state thermoluminescent rare earth oxides

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Effects of rare earth oxides on dielectric properties of Y_2Ti_2O_7 series ceramics

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Journal of rare earths 2010年第5期28卷 765-768页

作者：丁佳钰肖瑗韩朋德张其土 College of Materials Science and Engineering Nanjing University of Technology Jiangsu Provincial Key Laboratory of New Materials of Inorganic and its Composites Nanjing University of Technology

A series of Y2Ti2O7 microwave dielectric ceramics were synthesized by conventional solid-state method. The effects of rare earth oxide (La2O3, CeO2, Nd2O3, Sm2O3, Eu2O3, Gd2O3 and Dy2O3) and Nd2O3 doping content on the microstructure and dielectric properties of Y2Ti2O7 ceramics were investigated. The experimental results showed that the rare earth ions were considered to dissolve in Y-sites of the pyrochlore structure, different rare earth oxides and concentration had different influences on Y2Ti2O7 cerami...

关键词： microwave dielectric ceramics rare earth oxides Y2Ti2O7 pyrochlore structure doping modification rare earths

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Effect of rare earth oxides on the morphology of carbides in hardfacing metal of high chromium cast iron

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Journal of rare earths 2011年第2期29卷 168-172页

作者：郝飞飞李达淡婷任学军廖波杨庆祥 State Key Laboratory of Metastable Materials Science and Technology College of Materials Science and EngineeringYanshan University School of Materials Science and Engineering Southwest Jiaotong University School of Engineering Liverpool John Moores University

The flux cored wires with different amounts of rare earth （RE） oxides additions for hardfacing （harden-face-welding） the workpieces of high chromium cast iron were studied in this *** morphology of carbides in hardfacing metal was observed,and the type of the carbides was determined by optical microscopy,scanning electron microscopy （SEM）,energy dispersive spectrometer （EDS） and X-ray diffraction （XRD）.Based on the data of effect of RE on carbides morphology,the refined reason for carbide by RE oxide was discussed with the misfit *** results showed that,the microstructure of hardfacing metal was composed of martensite,residual austenite and M7C3 *** the increasing amount of RE oxide additions,the volume fraction and roundness of the carbides were increased,however,the area and perimeter of carbides were *** indicated that carbides in hardfacing metal could be refined and spheroidized by adding RE oxides in flux cored wires.

关键词： high-chromium cast iron flux cored wires carbides rare earth oxides

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Effects of rare earth oxides on Viscosity,Thermal Expansion,and Structure of Alkali-Free Boro-Aluminosilicate Glass

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Journal of Wuhan University of Technology(Materials Science) 2017年第1期32卷 58-62页

作者：侯延升 YUAN Jian 康俊峰 CUI Jingjing CHENG Jinshu CUI Jing State Key Laborato-ry of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China Hebei Shahe Glass Technology Research Institute Shahe 054100China Shanxi Industry Vocational College Xianyang 712000China

Effects of rare earth oxides（Y2O3,La2O3,and Er2O3） on the viscosity,thermal expansion,and structure of alkali-free boro-aluminosilicate glasses were investigated by the rotating crucible viscometer,dilatometry and FT-IR absorption *** results showed that the melting temperature of alkali-free boroaluminosilicate glasses decreased from 1 697.55 to 1 662.59,1 674.37 and 1 640.87 ℃ with the introduction of 1 mol%La2O3,Y2O3 and Er2O3,***,the glass transition temperature Tg,dilatometric softening temperature T_d and coefficient of thermal expansion of alkali-free boro-aluminosilicate glasses increased when adding the rare-earth *** high temperatures,incorporating rare earth oxides into glass resulted in the peak at about 1 085 cm^-1 towards lower wavenumber and the absorption band in the region of 850-1 260 cm^-1 broader,which indicated that rare earths acted as network modifiers and increased the numbers of non-bridging oxygen in the glass ***,the rare earths had an opposite effect and accumulated the glass structure at low temperatures near Tg.

关键词： viscosity structure boro-aluminosilicate rare earth oxides

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Effect of rare earth oxides on Catalysts Mo-Te System

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Journal of rare earths 1991年第2期9卷 116-120页

作者：贺仁近江洪波钟邦克王祥珍 Department of Chemistry Jinan UniversityGuangzhou 510632China South China Sea Institute of Oceanology Academia SinicaGuangzhou 510275China

Surface compositions,structures,and acidities of the Mo-Te-Fe-Ni catalysts added with La_2O_3,CeO_2, Pr_6O_(12),Nd_2O_3 and Sm_2O_3 were measured and related with the activities of the catalysts for selective oxidation of *** was found that adding rare earth elements to the Mo-Te catalysts increases obviously their selectivities to methacrolein(MAL),and the yield percentage of MAL changes periodically with the increase of atomic numbers of rare earth elements added,and the highest yield was obtained with the catalyst containing CeO_*** addition of CeO_2 to 9-component Mo-Te catalyst increases not only the activity of the catalyst, but also its thermostability *** mechanism of rare earth elements in the catalysts was discussed.

关键词： Mo-Te catalysts rare earth oxides Oxidation Isobutene Methacroiein

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Studies on Gas Sensitive Materials of γ-Fe_2O_3 Doped with rare earth oxides

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Journal of rare earths 1992年第2期10卷 125-129页

作者：徐甲强曾桓兴沈瑜生王弘 Department of Chemical Engineering Zhengzhou Institute of Light IndustryZhengzhou 450002China Department of Material Science and Engineering University of Science and Technology of ChinaHefei 230026China

Fine powders of γ-Fe_2O_3,doped with Y_2O_3,CeO_2,Eu_2O_3 or Tb_2O_3 have been prepared by the chemical co-precipitation *** sensitivity of gas sensation has been measured with respect to the relative resist- ance change in the ceramic matrix upon introduction of inflammable *** structure of the materials has been studied with X-ray diffraction spectroscopy(XRD),electron diffraction spectroscopy( ED) and transmis- sion electron microscopy(TEM).The addition of rare earth oxides,which improves ceramic microstructure of γ-Fe_2O_3,improves gas sensitivity of γ-Fe_2O_*** stability can be increased because of the increase of phase transition *** addition,the selectivity of gas sensation of γ-Fe_2O_3 can be improved because of the variation of rare earth oxides.

关键词： Gamma hematite(γ-Fe_2O_3) Ceramic microstructure rare earth oxides Gas sensitive materials

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EFFECTS OF rare earth oxides ON PERFORMANCES OF Ni/Al2O3 CATALYSTS FOR METHANE STEAM REFORMING REACTION

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Journal of Energy Chemistry 1995年第2期 186-201页

作者： SU Bao-Lian* GUO Shen-DuChengdu Institute of Organic Chemistry, Acaderma Siiaca Chengdu, Sichuan 610015

The Catalytic performances for methane steam reforming reaction ofNi/AlO（commercial）, Ni/AlO（developed surface ）and Ni/AlO-RO（R israre earth oxide） Catalysts were investigated by means of X-ray diffraction,TG, SEM/ X-ray analysis, pulse gas chromatography,BET and Mercuryporsiniter techniques. The distribution of rear earth oxides on the supports,themetal-support （additives） interaction and the influence of rare earth oxideadditives on the dispersion of active components,catulytic activities,variationof nickel crystallites size,CO chemisorption,formation of NiAlOas well asthe reducibility of the catalysts were *** presence of rare earthoxides in the Ni/AlO（developed surface） results in great improvement ofstubility through suppressing the growth of Ni crystallites,the oxidation of themetallic Ni and the formation of NiAlO. The effect of heavy rare earth oxidesis more distinct than that of the light *** metal support interaction（SMSI） exists in Ni/AlO- R

关键词： rare earth oxides Ni/Al2O3catalysts methane steam reforming

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