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Influence of different land-use types on selected soil properties related to soil fertility in A Luoi District,Thua thien Hue,Vietnam

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Soil Ecology letters 2024年第1期6卷 131-140页

作者： Khoa Phuc Nguyen Tan Trong Tran Huy Dinh le phuong Thuy Nguyen Hien thao thi Pham Dien Thanh Nguyen Ngu Huu Nguyen University of Agriculture and Forestry Hue UniversityHue CityThua Thien Hue 52000Vietnam School of Biotechnology Tan Tao UniversityTan Duc ECityDuc HoaLong An850000Vietnam

Land use type affects the physicochemical properties of *** value of OM and TN is high in acacia *** acidity of soil is considered a serious constraint for *** cash crops are acacia,cassava,banana,rice and *** fertility is affected by land-use types and land management,which exacerbates soil erosion and various other forms of soil degradation in the mountainous regions of *** study was conducted in A Luoi District,Thua thien Hue,Vietnam to identify the effects of land-use types on specific soil physicochemical characteristics related to soil *** physicochemical properties,such as organic matter(OM),total nitrogen(TN),total phosphorous(TP),and K+were significantly affected by land-use *** results showed that the soils were sandy in rice but clay loam for acacia and *** mean bulk density value of acacia soil was significantly greater than that of other *** were higher in the acacia soils than those in the rice,maize,and banana *** OM content was significantly higher in the acacia,cassava,and banana soils than those in the rice and maize *** mean of exchangeable K+in the rice soil was higher compared to those in other soils and was affected by land-use *** high exchangeable acidity content in the soils was probably due to intensive ***,both land use type and management did not affect the CEC ***,the inappropriate land use caused the disturbance of soil physicochemical properties,indicating that the conditions of rice and maize soils are becoming worse than acacia ***,lowering the intensity of cultivation,adopting incorporated soil fertility management,and applying organic fertilizer should preserve the existing conditions and enhance soil properties.

关键词： Land-use types soil characteristics soil frility suitable crop Vietnam

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越南初级非汉语专业学习者汉语口语自我效能与口语成绩的相关性研究

越南初级非汉语专业学习者汉语口语自我效能与口语成绩的相关性研...

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作者：陈氏芳草（TRAN thi phuong thao）广西大学

学位级别：硕士

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越南汉越词四字格成语与汉语四字格成语对比研究

越南汉越词四字格成语与汉语四字格成语对比研究

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作者： NGUYEN phuong thao（阮芳草）河北大学

学位级别：硕士

本研究致力于探索越南汉越词四字格成语与汉语四字格成语之间的相似性与差异性,并分析这些异同对越南学生学习汉语成语的影响。通过深入研究,本论文旨在为越南学生提供有效的学习参考,同时增进对中越文化交流与理解。研究的初衷源于对... 详细信息

本研究致力于探索越南汉越词四字格成语与汉语四字格成语之间的相似性与差异性,并分析这些异同对越南学生学习汉语成语的影响。通过深入研究,本论文旨在为越南学生提供有效的学习参考,同时增进对中越文化交流与理解。研究的初衷源于对当前学术界在汉越词四字格成语与汉语四字格成语对比研究领域的相对匮乏。现有研究大多集中于汉越成语的整体特征,而对四字格成语的细节和深入分析尚显不足。为填补这一空白,本研究梳理和统计《汉越成语词典》等越南语料库中的相关成语,力求提供全面且细致的分析视角。在对比分析方面,本文着重考察了越南语汉越四字格成语与汉语四字格成语在语素和语义上的异同。通过研究笔者发现,尽管许多成语在结构和语素上保持一致,但在语义上却常呈现出显著的差异。通过问卷调查,本研究探讨了汉越四字格成语对越南学生学习汉语四字格成语的影响。结果显示,虽然汉越成语在学习过程中具有积极作用,但也存在一定挑战。基于这些发现,本文进一步提出了针对越南汉语的学习及教学建议。这些建议旨在帮助学生克服学习过程中的困难,提高学习效率,并为教师提供了实用的教学策略。这一部分的研究不仅对理解汉越语言间的相互作用具有重要意义,也为汉语作为第二语言教学提供了新的视角。整体而言,本文有效填补了学术研究的空白,并结合理论与实践为越南汉语教育提供了实用指导。通过对比分析和问卷调查,本研究深入分析了汉越四字格成语与汉语四字格成语之间的相似性与差异性,探讨了越南学生在汉语学习中遇到的挑战,并提出了相应的解决策略。这些发现不仅具有学术价值,也为教学实践提供了重要的参考。

关键词：汉越词四字格成语汉语四字格成语对比分析

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Influence of Process Factors on Electrode Wear Rate when EDM 90CrSi Steel using Graphite Electrodes

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Journal of Environmental Science and Engineering(B) 2023年第5期12卷 230-235页

作者： Tran Huu Danh le thi phuong thao Nguyen thi Quoc Dung Vu Trung Tuyen Luu Anh Tung Vinh Long University of Technology Education Vinh Long City 85110Vietnam Thai Nguyen University of Technology Thai Nguyen city 251750Vietnam National Research Institute of Mechanical Engineering Hanoi City 511309Vietnam

The findings of a study on the optimization of Electric Discharge Machining(EDM)procedure for processing cylindrically shaped components with graphite electrodes are presented in this *** steel 90CrSi was the material of choice for the study’s ***,the Electrode Wear Rate(EWR)was chosen as the optimization problem’s objective *** experiment using the Taguchi design was conducted to address this ***,experiments were created and their outcomes were analyzed using the Minitab R19 *** impact of the input process factors on EWR was investigated,including the powder concentration,the pulse on and off times,the servo current,and the servo ***,the best process variables for a minimal EWR were provided.

关键词： EDM process factor EWR 90CrSi.

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Synthesis and characterization of NaYF4:Yb3+,Er3+@silica-N=folic acid nanocomplex for bioimaginable detecting MCF-7 breast cancer cells

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Journal of Rare Earths 2019年第11期37卷 1183-1187页

作者： Ha thi phuong Tran Thu Huong le thi Vinh Hoang thi Khuyen Do thi thao Nguyen Thanh Huong Pham thi Lien le Quoc Minh Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietCau GiayHanoiViet Nam Graduate University of Science and Technology-Vietnam Academy of Science and Technology 18 Hoang Quoc VietCau GiayHanoiViet Nam Department of Chemistry Hanoi Medical University1-Ton That TungDong DaHanoiViet Nam Department of Chemistry Hanoi University of Mining and Geology18-Pho LienBac Tu LiemHanoiViet Nam Institute of Biotechnology Vietnam Academy of Science and Technology18-Hoang Quoc VietCau GiayHanoiViet Nam Duy Tan University K7/25 Quang TrungDa NangViet Nam

Upconversion nanophosphors are new promising nanomaterials to be used as biolabels for detection and imaging of cancer *** nanophosphors absorb long-wavelength excitation radiation in the infrared or near infrared region and emit shorter wavelength,higher energy radiation from ultraviolet to *** this paper,we studied the hydrothermal method and optical properties of the functionalized NaYF4:Yb^3+,Er^3+for biomedical *** synthesis,these NaYF4:Yb^3+,Er^3+nanophosphors were functionalized with aminosilanes and folic *** acid binds to the folate receptor on the surface of MCF-7 breast cancer cells and this binding promotes internalization of the nanophosphors via *** sizes of the functionalized NaYF4:Yb^3+,Er^3+@silica-N=FA(folic acid)nanophosphors can be controlled with length of the rod about 300-800 nm and diameter of the rod about 100-200 *** structure of NaYF4:Yb^3+,Er^3+is in hexagonal crystal *** photo luminescence(PL)spectra of the functionalized NaYF4:Yb^3+,Er^3+@silica-N=FA nanophosphors were *** nanophosphors emit in red color with the strongest band at 650 nm under 980 nm *** result can provide NaYF4:Er^3+,Yb^3+@silica-N=FA complex for developing fluorescence label and image tool in cancer biology and medicine.

关键词： Upconversion luminescence NaYF4:Yb^3+,Er^3+ Nanophosphors Bioimaging Cancer cell Rare earths

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Polygonatum kingianum rhizome extract alleviates collagen antibody-induced arthritis by modulating proinflammatory cytokine production in mice

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Asian Pacific Journal of Tropical Biomedicine 2020年第11期10卷 490-495页

作者： Huyen Do thi Thanh phuong Ngo thi Hien Nguyen thi Thu Nga Nguyen thi Hung le Ngoc thao Dothi Ha le Minh Graduate University of Science and Technology Vietnam Academy of Science and Technology18 Hoang Quoc VietNghia DoCau GiayHanoiVietnam Institute of Natural Products Chemistry Vietnam Academy of Science and Technology18 Hoang Quoc VietNghia DoCau GiayHanoiVietnam Hanoi Open University101 Nguyen Hien str Hai Ba Trung Dist.HanoiVietnam Laboratory of Bioassay Institute of BiotechnologyVietnam Academy of Science and Technology18 Hoang Quoc VietNghia DoCau GiayHanoiVietnam Chemistry Lab Project Center for Research and Technology transferVietnam Academy of Science and Technology18 Hoang Quoc VietNghia DoCau GiayHanoiVietnam

Objective: To evaluate the anti-arthritic effects of Polygonatum kingianum rhizome extract using both in vitro and in vivo ***: Lipopolysaccharide-induced RAW 264.7 macrophages were treated with an ethanol extract of Polygonatum kingianum rhizomes at different concentrations to determine nitric oxide and prostaglandin E2(PGE2) production. For in vivo study, Polygonatum kingianum ethanol extract was further investigated for its antiinflammatory effect in a mouse model with collagen antibodyinduced arthritis. Phytochemical study of Polygonatum kingianum ethanol extract was also ***: Saponins(142 mg/g total yield) was the main component in the Polygonatum kingianum ethanol extract. 5α,8α-ergosterol peroxide,(E,E)-9-oxooctadeca-10,12-dienoic acid and 3-(2?-hydroxy-4?-methoxy-benzyl)-5,7-dihydroxy-8-methyl-chroman-4-one were isolated from the extract. Polygonatum kingianum ethanol extract exhibited potential anti-inflammatory effects by inhibiting nitric oxide and PGE2 production in RAW 264.7 cells in a dosedependent manner. The level of arthritis in mice with collagen antibody-induced arthritis was significantly reduced(Pleukin-6, and interleukin-10 in treated ***: Polygonatum kingianum ethanol extract has beneficial effects on inflammatory cytokine regulation and PGE2 inhibition in an experimental mouse model with collagen antibody-induced arthritis. The phytochemical screening reveals that the saponin, as the main component, and sterols(daucosterol and 5α,8α-ergosterol peroxide) from Polygonatum kingianum ethanol extract may contribute to its promising in vitro and in vivo anti-inflammatory activities.

关键词： inflammatory cytokine PGE2

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ALMA observations of the circumstellar envelope around EP Aqr

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Research in Astronomy and Astrophysics 2019年第3期19卷 97-110页

作者： Pham thi Tuyet Nhung Do thi Hoai Pham Tuan-Anh thibaut le Bertre Pierre Darriulat Pham Ngoc Diep Nguyen thi phuong Nguyen thi thao Jan Martin Winters Department of Astrophysics Vietnam National Space CenterVAST leRMA UMR 8112 CNRS and Observatoire de Paris PSL Research University Graduate University of Science and Technology VAST IRAM 300 rue de la Piscine Domaine Universitaire

Atacama Large Millimetre/sub-millimetre Array(ALMA) observations of CO(1–0) and CO(2–1) emissions from the circumstellar envelope of the asymptotic giant branch(AGB) star EP Aqr have been made with four times better spatial resolution than previously available. They are analysed with emphasis on the de-projection in space of the effective emissivity and flux of matter using as input a prescribed configuration of the velocity field, assumed to be radial. The data are found to display an intrinsic axisymmetry with respect to an axis making a small angle with respect to the line of sight. A broad range of wind configurations, from prolate(bipolar) to oblate(equatorial) has been studied and found to be accompanied by significant equatorial emission. Qualitatively, the effective emissivity is enhanced near the equator to produce the central narrow component observed in the Doppler velocity spectra and its dependence on star latitude generally follows that of the wind velocity with the exception of an omni-present depression near the poles. In particular, large equatorial expansion velocities produce a flared disc or a ring of effective emissivity and mass loss. The effect on the determination of the orientation of the star axis of radial velocity gradients, and possibly competing rotation and expansion in the equatorial disc, is discussed. In general,the flux of matter is found to reach a broad maximum at distances of the order of 500 AU from the *** are given that may be used to favour one wind velocity distribution over another. As a result of the improved quality of the data, a deeper understanding of the constraints imposed on morphology and kinematics has been obtained.

关键词： stars: AGB and post-AGB (stars:) circumstellar matter stars: individual: EP Aqr stars:mass-loss radio lines: stars

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Localized Exponential Time Differencing Method for Shallow Water Equations: Algorithms and Numerical Study

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Communications in Computational Physics 2021年第1期29卷 80-110页

作者： Xucheng Meng thi-thao-phuong Hoang Zhu Wang Lili Ju Department of Mathematics University of South CarolinaColumbiaSC 29208USA Department of Mathematics and Statistics Auburn UniversityAuburnAL 36849USA SUSTech International Center for Mathematics Southern University of Science and TechnologyShenzhenGuangdong 518055China Center for Mathematical studies Advanced Institute of Natural SciencesBeijing Normal University at ZhuhaiZhuhaiGuangdong 519087China

In this paper,we investigate the performance of the exponential time differencing(ETD)method applied to the rotating shallow water *** with explicit time stepping of the same order accuracy in time,the ETD algorithms could reduce the computational time in many cases by allowing the use of large time step sizes while still maintaining numerical *** accelerate the ETD simulations,we propose a localized approach that synthesizes the ETD method and overlapping domain *** dividing the original problem into many subdomain problems of smaller sizes and solving them locally,the proposed approach could speed up the calculation of matrix exponential vector *** standard test cases for shallow water equations of one or multiple layers are *** results show great potential of the localized ETD method for high-performance computing because each subdomain problem can be naturally solved in parallel at every time step.

关键词： Exponential time differencing domain decomposition rotating shallow water equa-tions finite volume discretization

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Operator Splitting and Local Time-Stepping Methods for Transport Problems in Fractured Porous Media

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Communications in Computational Physics 2023年第10期34卷 1215-1246页

作者： Phuoc-Toan Huynh Yanzhao Cao thi-thao-phuong Hoang Department of Mathematics and Statistics Auburn UniversityAuburn 36849AlabamaUSA

this paper is concerned with efficient numerical methods for the advectiondiffusion equation in a heterogeneous porous medium containing fractures.A dimensionally reduced fracture model is considered,in which the fracture is represented as an interface between subdomains and is assumed to have larger permeability than the surrounding *** develop three global-in-time domain decomposition methods coupled with operator splitting for the reduced fracture model,where the advection and the diffusion are treated separately by different numerical schemes and with different time ***,smaller time steps can be used in the fracture-interface than in the *** first two methods are based on the physical transmission conditions,while the third one is based on the optimized Schwarz waveform relaxation approach with Ventcel-Robin transmission conditions.A discrete space-time interface system is formulated for each method and is solved iteratively and globally in *** results for two-dimensional problems with various P′eclet numbers and different types of fracture are presented to illustrate and compare the convergence and accuracy in time of the proposed methods with local time stepping.

关键词： Domain decomposition reduced fracture model operator splitting nonconforming time grids time-dependent Steklov-Poincare operator optimized Schwarz waveform relaxation

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Morphology and kinematics of the gas envelope of the Mira binary W Aquilae

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Research in Astronomy and Astrophysics 2016年第7期16卷 47-54页

作者： Do thi Hoai Pham Tuyet Nhung Pham Ngoc Diep Nguyen thi phuong Pham Tuan-Anh Nguyen thi thao Pierre Darriulat Department of Astrophysics Vietnam National Satellite CenterVAST

We analyse ALMA observations of the12CO（3-2） emission of the circumstellar envelope（CSE）of the Mira variable binary star W Aql. These provide, for the first time, spatially resolved Doppler velocity spectra of the CSE up to angular distances to the central star ofy nature of the observations（only five minutes in each of～5′′（meaning some 2000 AU）. The explorator two different configurations） does not allow for a detailed modelling of the properties of the CSE but provides important qualitative information on its morphology and kinematics. Emission is found to be enhanced along an axis moving from east/west to north-east/south-west when the angular distance from the central star projected on the plane of the sky increases from zero to four arcseconds. In parallel, the Doppler velocity distribution displays asymmetry along an axis moving from east/west to north-west/south-east. The results are discussed in the context of earlier observations, in particular of the dust morphology.

关键词： stars AGB and post-AGB (stars ) circumstellar matter stars individual(W Aql) stars mass-loss radio lines stars

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