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Upconversion luminescence of Gd2O3:Er3+and Gd2O3:Er3+/silica nanophosphors fabricated by EDTA combustion method

Journal of Rare Earths 2019年第11期37卷 1126-1131页

作者： Le Quoc Minh Tran Kim Anh nguyen Duy Hung Pham thi Minh Chau nguyen thi Quy Hai Ho van Tuyen Vu thi Thai Ha Vu Duc Tu Wieslaw Strek Institute of Theoretical and Applied Research Duy Tan UniversityDa Nang 55000Viet Nam Advanced Institute for Science and Technology Hanoi University of Science and Technology1 Dai Co VietHai Ba TrungHanoiViet Nam Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc Viet RoadCau Giay DistrictHanoiViet Nam Institute of Low Temperature and Structure Research Polish Academy of Science 2 OkolnaWroclawPoland

Gd2O3:Er^3+nanophosphors were fabricated by the combustion method in presence of Na2 ethylene diamine tetra acetic acid(EDTA-Na2)as fuel at not high temperature(≤350℃)within a very short time of 5 *** added concentration of Er^3+ions in Gd2O3 matrix was changed from 0.5 mol%to 5.0 mol%.The X-ray diffraction pattern of samples indicates the monoclinic structure of Gd2O3:Er^3+.The morphology and chemical composition analysis of the Gd2O3:Er^3+samples are characterized by a field emission scanning electron microscope(FESEM)and a Fourier-transform infrared spectrometer(FTIR).The photoluminescence(PL),photo luminescence excitation(PLE)and upconversion(UC)at room temperature of the prepared materials with different concentrations of Er^3+were *** PL of Gd2O3:Er^3+nanomaterials are shown in visible at 545,594,623,648,688 nm under excitation at 275 *** emission bands from transitions of Er^3+from 2P3/2 to 4F9/2 are observed,UC luminescent spectra of the Gd2O3:Er^3+/silica nanocomposites under 976 nm excitation show the bands at 548 and 670 *** influence of excitation power at 980 nm for transitions were measured and *** results indicate that the upconversion process of Gd2O3:Er^3+/silica is two photons absorption *** low temperature dependence of UC luminescent intensities of the main bands of Gd2O3:Er^3+was investigated towards development of a nanotemperature sensor in the range of 10-300 K.

关键词： Upconversion luminescence Gd2O3:Er3+ Gd2O3:Er3+/silica Nanophosphors EDTA combustion Rare earths

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Successful containment of a COVID-19 outbreak in Bach Mai Hospital by prompt and decisive responses

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Asian Pacific Journal of Tropical Medicine 2021年第5期14卷 234-235页

作者： van Minh Hoang thi Phuong Thao Tran thi Ngoc Phuong nguyen thi Hai Yen nguyen Quang Tuan nguyen Hanoi University of Public Health HanoiVietnam Bach Mai Hospital HanoiVietnam

In low-and middle-income countries,tertiary care hospitals frequently face an extremely heavy workload and shoulder an even heavier burden during the COVID-19 *** Mai Hospital(BMH),one of the leading tertiary hospitals in Vietnam,is on the frontline in the fierce battle against *** letter aims to describe how BMH tackles the COVID-19 outbreak in the hospitallevel battle,which could support policymakers in time-management and well-preparation for this unpredictable pandemic.

关键词： prompt income policy

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Optimization, equilibrium, adsorption behavior and role of surface functional groups on graphene oxide-based nanocomposite towards diclofenac drug

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Journal of Environmental Sciences 2020年第7期32卷 137-150页

作者： Thuan van Tran Duyen thi Cam nguyen Hanh TNLe Dai-Viet NVo Sonil Nanda Trinh Duy nguyen nguyen Tat Thanh Hi-Tech Institute Nguyen Tat Thanh UniversityHo Chi Minh City 755414Viet Nam Center of Excellence for Green Energy and Environmental Nanomaterials(CE@GrEEN) Nguyen Tat Thanh UniversityHo Chi Minh City 755414Viet Nam Institute of Hygiene and Public Health Ho Chi Minh City 700000Viet Nam Department of Chemical and Biochemical Engineering University of Western OntarioLondonOntarioCanada

Aquatic contamination of diclofenac(DCF),an emergent non-steroidal anti-inflammatory drug(NSAIDs),can result in adverse effects to many ecosystems through ***,introducing effective remediation techniques to sequester the pharmaceutical wastes is highly fundamental to prevent their accumulation in the ***,adsorption has been presented as a green and efficient ***,we report the characterization and application of the novel magnetic nanocomposite(GO@CoFe2O4)derived from cobalt-based ferrite(CoFe2O4)and graphene oxide(GO)for DCF *** the optimization procedure,the response surface methodology(RSM)was adopted to investigate the impacts of DCF concentration(1.6-18.4 mg/L),DCF dosage(0.08-0.92 g/L),and solution pH(2.6-9.4)to find the optimum conditions for DCF removal,at 10.5 mg/L,0.74 g/L,and pH 4,*** the adsorption experiments,the kinetic,isotherm,thermodynamic,and intraparticle diffusion models were systematically ***,we have elucidated the role of functional groups on the surface of GO@CoFe2O4 in enhancing the adsorption of DCF *** good removal efficiency(up to 86.1%),high maximum adsorption capacity(32.4 mg/g),GO@CoFe2O4 can be a potential candidate to eliminate DCF drug from water.

关键词： Diclofenac sodium Graphene oxide Magnetic nanocomposite Response surface methodology Pharmaceuticals adsorption

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A crate of Pandora:do amyloids from bacteria promote Alzheimer’s disease?

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Neural Regeneration Research 2021年第5期16卷 988-989页

作者： Vu Thu thuy nguyen Kristina Endres Department of Psychiatry and Psychotherapy University Medical Center Johannes Gutenberg-University MainzMainzGermany

Incidence for microbes as drivers of Alzheimer’s disease(AD)pathology:AD is the predominant neurodegenerative disease within the *** 50 million patients suffer from dementia currently world-wide and an estimated tripling of numbers within the next 30 years is *** one to maximally five percent of all cases of AD are based on mutations in the amyloid precursor protein(APP)gene or within the presenilin genes(PS1/PS2)and therefore are called familial(FAD).The majority of cases has to be designated as sporadic,which frankly only means that the origin of these cases is still enigmatic.

关键词： amyloid Alzheimer pathology

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A hybrid machine learning model to estimate self-compacting concrete compressive strength

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Frontiers of Structural and Civil Engineering 2022年第8期16卷 990-1002页

作者： Hai-Bang LY thuy-Anh nguyen Binh Thai PHAM May Huu nguyen Civil Engineering Department University of Transport TechnologyHanoi 100000Vietnam Civil and Environmental Engineering Program Graduate School of Advanced Science and EngineeringHiroshima UniversityHiroshima 739-8527Japan

this study examined the feasibility of using the grey wolf optimizer(GWO)and artificial neural network(ANN)to predict the compressive strength(CS)of self-compacting concrete(SCC).The ANN-GWO model was created using 115 samples from different sources,taking into account nine key SCC *** validation of the proposed model was evaluated via six indices,including correlation coefficient(R),mean squared error,mean absolute error(MAE),IA,Slope,and mean absolute percentage *** addition,the importance of the parameters affecting the CS of SCC was investigated utilizing partial dependence *** results proved that the proposed ANN-GWO algorithm is a reliable predictor for SCC’s *** that,an examination of the parameters impacting the CS of SCC was provided.

关键词： artificial neural network grey wolf optimize algorithm compressive strength self-compacting concrete

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A Remark on the Topology at Infinity of a Polynomial Mapping F: Cⁿ→Cⁿ via Intersection Homology

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Advances in Pure Mathematics 2016年第13期6卷 1037-1052页

作者： nguyen thi Bich thuy UNESP Universidade Estadual Paulista “Júlio de Mesquita Filho” S&atilde o José do Rio Preto Brazil

In [1], Guillaume and Anna Valette associate singular varieties VF to a polynomial mapping . In the case , if the set K0(F) of critical values of F is empty, then F is not proper if and only if the 2-dimensional homology or intersection homology (with any perversity) of VF is not trivial. In [2], the results of [1] are generalized in the case where n≥3, with an additional condition. In this paper, we prove that for a class of non-proper generic dominant polynomial mappings, the results in [1] and [2] hold also for the case that the set K0(F) is not empty.

关键词： Polynomial Mappings Intersection Homology Singularities

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A Remark on Polynomial Mappings from Cⁿ to C^n-1 and an Application of the Software Maple in Research

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Applied Mathematics 2016年第15期7卷 1868-1881页

作者： thi Bich thuy nguyen UNESP Universidade Estadual Paulista “Júlio de Mesquita Filho” S&atilde o José do Rio Preto Brasil

In [1], we construct singular varieties associated to a polynomial mapping where such that if G is a local submersion but is not a fibration, then the 2-dimensional homology and intersection homology (with total perversity) of the variety are not trivial. In [2], the authors prove that if there exists a so-called very good projection with respect to the regular value of a polynomial mapping , then this value is an atypical value of G if and only if the Euler characteristic of the fibers is not constant. this paper provides relations of the results obtained in the articles [1] and [2]. Moreover, we provide some examples to illustrate these relations, using the software Maple to complete the calculations of the examples. We provide some discussions on these relations. this paper is an example for graduate students to apply a software that they study in the graduate program in advanced researches.

关键词： Singularities Intersection Homology Polynomial Mappings Bifurcation

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高速铁路重力式路肩挡墙抗倾覆稳定性对路基面动变形影响

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铁道学报 2024年第4期46卷 167-176页

作者：吕鹏举罗强周成冯桂帅阮文德付航西南交通大学土木工程学院四川成都610031 西南交通大学高速铁路线路工程教育部重点实验室四川成都610031 中铁二院工程集团有限责任公司四川成都610031

路肩挡墙支护能力对路基面动变形有重要影响。构建高速铁路无砟轨道-路肩挡墙路基的空间结构有限差分模型,针对以倾覆破坏为主导模式的岩质地基重力式挡墙,基于正交试验方案,分析路堤高度、墙胸坡度、墙背倾斜、墙土摩擦、墙体位置、抗... 详细信息

路肩挡墙支护能力对路基面动变形有重要影响。构建高速铁路无砟轨道-路肩挡墙路基的空间结构有限差分模型,针对以倾覆破坏为主导模式的岩质地基重力式挡墙,基于正交试验方案,分析路堤高度、墙胸坡度、墙背倾斜、墙土摩擦、墙体位置、抗倾覆稳定系数共6个因素对路基承受列车荷载的动变形影响效应。通过引入反映路肩挡土墙约束路基能力的动变形指数R_ω,建立路基面动变形与显著影响因素之间的关系式。研究表明:列车荷载下路基面动变形以压缩变形为主,跟随变形与墙顶水平动位移近似呈线性正相关;挡墙抗倾覆稳定系数K_0和墙背倾斜tanα是影响路基面动变形的2个显著因素,R_ω与K_0和tanα之间服从二元三次曲面关系;以路肩挡墙路基面动变形ω不大于标准断面路堤相应值δ,即R_ω=δ/ω≥1.0为控制条件,墙背由俯斜渐变为仰斜,路肩挡墙抗倾覆稳定系数限值[K_0]非线性增大。研究成果对优化高速铁路路肩挡墙设计具有参考价值。

关键词：路肩挡墙抗倾覆稳定性路基面动变形有限差分法正交试验

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Morphological Change in the Northern Red River Delta,Vietnam

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Journal of Ocean University of China 2018年第6期17卷 1272-1280页

作者： BUI Vuong van FAN Daidu nguyen Dac Ve TRAN Dinh Lan TRAN Duc Thanh HOANG van Long nguyen thi Hong Hanh Institute of Marine Environment and Resources Vietnam Academy of Science and TechnologyHaiphong 18000Vietnam State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China Hanoi University of Mining and Geology Hanoi 10000Vietnam Graduate University of Science and Technology Vietnam Academy of Science and TechnologyHanoi 10000Vietnam

Coastal erosion has become a worldwide concern, typically in the densely populated Asian mega-river deltas. Severe coastal erosion in the southern Red River Delta(RRD) has been intensively studied. Coastal morphological change in the northern RRD was examined in detail through DEM(Digital Elevation Model) analysis based on time series of bathymetrical maps(1965–2004) and Landsat images(1975–2015) in this study. The results show that the northern RRD is featured by rapid coastal accretion in the past few decades, although suspended sediment flux has dropped by roughly 60% after the completeness of Hoa Binh Dam(HBD) in 1988 and relative sea level rose at 1.9 mm yr^(-1). However, accretion at the outer part of subtidal shoals and platforms was observed to slow down quickly or even turned into erosion in the last two decades. The resuspended sediments from the erosion zone can be transported landward to replenish the inner coastal zone, keeping the latter accretion in the near future to compensate for the sediment discharge decrease from the river. However, this lag effect should be terminated soon if other adverse effects go worse, e.g., damming rivers, sea-level rising, strengthening storms, land reclamation and other poor-designed coastal engineering. Coastal planners and managers should pay full attention to these changes.

关键词： Morphological change DEM coastal erosion coastal engineering coastal management tide-dominated Red River Delta

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An Algorithm to Classify the Asymptotic Set Associated to a Polynomial Mapping

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American Journal of Computational Mathematics 2017年第1期7卷 109-126页

作者： nguyen thi Bich thuy IBILCE UNESPUniversidade Estadual Paulista"Julio de Mesquita"Sao Josedo Rio PretoSao PauloBrazil

We provide an algorithm to classify the asymptotic sets of the dominant polynomial mappingsof degree 2, using the definition of the so-called “fa?ons” in [2]. We obtain a classification theorem for the asymptotic sets of dominant polynomial mappingsof degree 2. this algorithm can be generalized for the dominant polynomial mappingsof degree d, with any (n,d)∈(N*)2.

关键词： Algorithms Polynomial Mappings Asymptotic Sets Facons

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