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A comparative analysis of weight-based machine learning methods for landslide susceptibility mapping in Ha Giang area

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Big Earth Data 2023年第4期7卷 1005-1034页

作者： Thanh Trinh Binh Thanh Luu Trang Ha thi Le Duong Huy nguyen Trong Van Tran thi Hai Van nguyen Khanh Quoc nguyen Lien thi nguyen Faculty of Computer Science Phenikaa UniversityYen NghiaHa DongHanoi 12116Vietnam Phenikaa Research and Technology Institute(PRATI) A&A Green Phoenix Group JSCNo.167 Hoang NganTrung HoaCau GiayHanoi 11313Vietnam Northwestern Geological Division General Department of Geology and Minerals of VietnamHanoiVietnam Youth union office Thuyloi University175 Tay SonDong DaHanoiVietnam Center of Remote Sensing and Geohazards Vietnam Institute of Geosciences and Mineral ResourcesHanoiVietnam

Landslide susceptibility maps (LSMs) are very crucial for planningpolicies in hazardous areas. However, the accuracy and reliability ofLSMs depend on available data and the selection of suitable *** study is conducted to produce LSMs by combinations of machinelearning methods and weighting techniques for Ha Giang province,Vietnam, where has limited data. In study area, we gather 11 landslideconditioning factors and establish a landslide inventory *** the weights of classes (or factors) is very important toprepare data for machine learning methods to generate LSMs. Wefrst use frequency ratio (FR) and analytic hierarchy process (AHP)techniques to generate the weights. Then, random forest (RF), supportvector machine (SVM), logistic regression (LR), and AHP methods arecombined with FR and AHP weights to yield accurate and reliableLSMs. Finally, the performance of these methods is evaluated by fivestatistical metrics, ROC and R-index. The empirical results have shownthat RF is the best method in terms of R-index and the five metrics, *** rate (0.9661), FP rate (0.0), ACC (0.9835), MAE (0.0046), and RMSE(0.0350) for this study area. this study opens the perspective of weightbasedmachine learning methods for landslide susceptibility mapping.

关键词： Landslide logistic regression random forest SvM Vietnam

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Electrochemical Immunosensor for Detection of Atrazine Based on Polyaniline/Graphene

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Journal of Materials Science & Technology 2016年第6期32卷 539-544页

作者： nguyen Van Chu nguyen Hai Binh Cao thi Thanh nguyen Van Tu nguyen Le Huy nguyen Tuan Dzung Phan Ngoc Minh Vu thi Thu Tran Dai Lam Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietCau Giay.HanoiViet Nam School of Chemical Engineering.Hanoi University of Science and Technology 1 Dai Co VietHanoiViet Ham Institute for Tropical Technology.Vietnam Academy of Science and Technology 18 Hoang Quoc VietHanoiViet Nam Center for High Technology Development Vietnam Academy of Science and Technology18 Hoang Quoc VietHanoiViet Nam University of Science and Technology of Hanoi.18 Hoang Quoc Viet HanoiViet Ham Graduate University of Science and Technology.Vietnam Academy of Science and Technology 18 Hoang Quoc Viet.HanoiViet Nam

In this study, a novel layer-by-layer polyaniline/graphene （PANi/Gr） structure for electrochemical detec- tion of atrazine was developed. Gr film was synthesized by thermal chemical vapor deposition （CVD） method and transferred onto the PANi-predeposited microelectrode. The properties of PANi/Gr film were thoroughly investigated by high-resolution transmission electron microscopy and Raman techniques. The most attractive feature of this system is a suitable microenvironment, which could provide an amplifi- cation of the conductive signal, thus may contribute to enhancing electron transfer and subsequently improve the sensitivity in electrochemical measurements. With low detection limit （- 43 × 10 -12 g/L）, ac-ceptable stability and good reproducibility, the proposed electrochemical immunosensor could be advantageously extended for multiplexed detection of other agents of environmental pollution.

关键词： Electrochemical immunosensor Polyaniline Graphene Atrazine

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Effect of heating time on structural,morphology,optical,and photocatalytic properties of g-C3N4 nanosheets

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Chinese Physics B 2020年第5期29卷 504-508页

作者： nguyen Manh Hung Le thi Mai Oanh Lam thi Hang Pham Do Chung Pham thi Duyen Dao Viet Thang nguyen Van Minh Center for Nano Science and Technology Hanoi National University of Education136 Xuan Thuy RoadCau Giay DistrictHanoi100000Vietnam Department of Physics Hanoi National University of Education136 Xuan Thuy RoadCau Giay DistrictHanoi100000Vietnam Faculty of Basic Sciences Hanoi University of Natural Resources and Environment41A Phu Dien RoadNorth Tu LiemHanoi100000Vietnam Hanoi University of Mining and Geology Duc Thang wardNorth Tu Liem DistrictHanoi100000Vietnam Military science Academy 322 Le Trong Tan streetDinh CongHoang MaiHanoi100000Vietnam

Effect of heating time on the structural,morphology,optical,and photocatalytic properties of graphitic carbon nitride(g-C3N4)nanosheets prepared at 550℃in Ar atmosphere is *** investigations are carried out by using x-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier-transform infrared spectroscopy(FTIR),UV-vis absorption,and photoluminescence(PL).At a heating temperature of 550℃,g-C3N4 nanocrystals are formed after 0.5 h and become more orderly as the heating time *** surface area of the g-C3N4 nanosheets significantly increases as the preparation time *** g-C3N4 prepared in 2.5 h shows the highest photocatalytic performance,decomposing completely 10 ppm RhB solution under xenon lamp irradiation for 2.0 h.

关键词： nanosheets photocatalytic heating time Ar atmosphere

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Multiparticle^(nat)Sr(γ,xny p)reactions induced with bremsstrahlung end-point energies of 55,60,and 65 MeV

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Chinese Physics C 2022年第9期46卷 185-196页

作者： nguyen Van Do nguyen Thanh Luan nguyen thi Xuan Kim Tien Thanh nguyen thi Hien Guinyun Kim Institute of Theoretical and Applied Research Duy Tan UniversityHanoi 100000Vietnam Faculty of Natural Sciences Duy Tan UniversityDa Nang 550000Vietnam Institute of Physics Vietnam Academy of Science and Technology10 Dao TanHanoi 10000Vietnam Department of Physics Kyungpook National UniversityDaegu 415661Republic of Korea Graduate School of Science and Technology Vietnam Academy of Science and Technology18 Hoang Quoc VietHanoiVietnam

this study measured the yields of the radionuclides^(82)Sr,^(83(m+g))Sr,^(85m)Sr,^(85g)Sr,^(87m)Sr,^(81(g+0.976m))Rb,^(82m)Rb,^(83g)Rb,^(84(m+g))Rb,and^(86(m+g))Rb produced in^(nat)Sr(γ,xnyp)multiparticle reactions with bremsstrahlung end-point energies of 55,60,and 65 *** bremsstrahlung radiation was generated using the 100-MeV electron linear accelerator at the Pohang Accelerator Laboratory,Korea,and the reaction yields were derived from the induced activitiesmeasured using off-lineγ-ray *** obtain accurate experimental results,we performed the necessaryγ-ray interference *** experimental results were compared with the theoretical predictions obtained using the TALYS-1.95 statistical nuclear model *** calculations were performed using six different level-density models to ascertain which model best fitted the experimental *** dependence of the reaction yield on the incident bremsstrahlung energy and on the number of nucleons emitted by the photonuclear reactions was also investigated.

关键词： reaction yield activation method ^(nat)Sr(γ xnyp)reactions γ-ray spectrometry 55- 60- and 65-MeV bremsstrahlung.

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Luminescent and magnetic properties of multifunctional europium(Ⅲ) complex based nanocomposite

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Journal of Rare Earths 2019年第11期37卷 1237-1241页

作者： Hoang thi Khuyen nguyen Thanh Huong Tran Thu Huong Pham thi Lien Do thi Anh Thu nguyen thi Anh Huong Wieslaw Strek Le Quoc Minh Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietCau CiayHanoiViet Nam Graduate University of Science and Technology Vietnam Academy of Science and Technology18 Hoang Quoc VietCau GiayHanoiViet Nam Department of Chemistry University of Natural SciencesHanoi National University19 Le Thanh TongHoan KiemHanoiViet Nam Institute of Low Temperature and Structure Research PASOkolna 2Wroclaw 50-422Poland Duy Tan University K7/25 Quang TrungDa DangViet Nam

The luminescent rare earth(RE)complex based multifunctional nanocomposites offer new potential applications of multimodal imaging(magnetic resonance imaging(MRI),fluorescent bioimaging,etc.)that can be associated with therapeutic *** this study,we report some results obtained with novel multifunctional Fe3O4/Si-amine/Eu(NTA)3 nanocomposites that are composed of europium(Ⅲ)complex with 1-(2-naphthoyl)-3,3,3-trifluoroacetone ligands(NTA)(Eu(NTA)3)and superparamagnetic Fe3O4 *** nanocomposites were functionalized with an amine group for biomedicine *** multifunctional Fe3O4/Si-amine/Eu(NTA)3 nanocomposites exhibit both good magnetic behavior of Fe3O4 nanoparticles as a core and strong fluorescent property of europium(Ⅲ)*** characterizations were analyzed by XRD,SEM,EDX and FTIR *** optical properties were studied in detail by UV-VIS spectra and luminescent emission *** magnetic property was estimated by *** effect of concentrations of luminescent Eu(NTA)3 complex on luminescent and magnetic properties is discussed.

关键词： Multifunctional nanocomposite Luminescence Magnetic Europium(Ⅲ)complex Fe3O4 Rare earths

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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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^(12)CO emission from the Red Rectangle

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Research in Astronomy and Astrophysics 2015年第12期15卷 2213-2228页

作者： Pham Tuan Anh Pham Ngoc Diep Do thi Hoai Pham Tuyet Nhung nguyen thi Phuong nguyen thi Thao Pierre Darriulat Department of Astrophysics Vietnam National Satellite CenterVAST

Observations of an unprecedented quality made by ALMA on the Red Rectangle of CO（3-2） and CO（6-5） emissions are analysed jointly with the aim of obtaining as simple as possible a description of the gas morphology and kinematics. Evidence is found for polar conical outflows and for a broad equatorial torus in rotation and expansion. Simple models of both are proposed. Comparing CO（6-5） and CO（3-2） emissions provides evidence for a strong temperature enhancement over the polar outflows. Continuum emission （dust） is seen to be enhanced in the equatorial region. Observed asymmetries are briefly discussed.

关键词： stars: AGB and post-AGB -- circumstellar matter -- radio-lines: stars-- planetary nebulae: individual (Red Rectangle)

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Antidiabetic and antioxidant activities of red seaweed Laurencia dendroidea

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Asian Pacific Journal of Tropical Biomedicine 2019年第12期9卷 501-509页

作者： The Han nguyen thi Huyen nguyen Van Minh nguyen thi Lan Phuong nguyen thi Van Anh Tran Anh Duy Do Sang Moo Kim Faculty of Food Technology Nha Trang University02 Nguyen Dinh Chieu StreetNha Trang CityKhanh HoaVietnam Quality Control Department Institute of Vaccines and Medical BiologicalsNha Trang CityKhanh HoaVietnam Faculty of Pharmacy University of Medicine and Pharmacy of Ho Chi Minh City41 Dinh Tien Hoang StreetHo Chi Minh CityVietnam Research Department of Marine Conservation Research Institute for Marine Fisheries224 Le Lai StreetHai Phong CityVietnam Department of Marine Food Science and Technology Gangneung-Wonju National University7 Jukheon-gilGangneung 25457Republic of Korea

Objective:To investigate antidiabetic and antioxidant activities of the extract and fractions from Vietnamese red seaweed Laurencia ***:The seaweed Laurencia dendroidea was extracted by using microwave-assisted extraction method in 80%*** seaweed extract was then fractionated using different solvents(n-hexane,chloroform,ethyl acetate,butanol and water).These obtained fractions were evaluated forα-glucosidase inhibitory and antioxidant *** activities were tested using DPPH,nitric oxide radical scavenging and metal chelating *** enzyme inhibition mode was determined using Lineweaver-Burk *** acidic and thermal stabilities,the ethyl acetate fraction was treated at pH 2.0 and 100℃,*** residual inhibitory activity of the fraction was calculated based on the initial inhibitory *** in vivo antidiabetic activity,mice were divided into four groups,including normal control,diabetic control,diabetic mice treated with ethyl acetate fraction and diabetic mice treated with *** glucose level of treated mice during acute and prolonged treatments was *** evaluate the toxicity of the ethyl acetate fraction,the body weight changes and activities of liver function enzymes(aspartate transaminase,alanine transaminase and gammaglutamyl transferase)were carried ***:The extract of Laurencia dendroidea showed strongα-glucosidase inhibitory and DPPH radical scavenging *** concentrations affected bothα-glucosidase inhibitory and antioxidant activities.A 80%aqueous methanol was the suitable solvent for extraction of enzyme inhibitors and *** solvent fractions,ethyl acetate fraction had the highest inhibitory activities againstα-glucosidase with a mixed type of inhibition and the strongest antioxidant activities,and was stable under acidic and thermal *** ethyl acetate fraction treated diabetic mice significantly reduced blood glucose level compare

关键词： α-Glucosidase inhibitor Antidiabetic Antioxidant Red seaweeds Vietnam

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Morphology and kinematics of the gas envelope of the variable AGB star π^1 Gruis

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Research in Astronomy and Astrophysics 2016年第7期16卷 97-104页

作者： Pham Tuyet Nhung Do thi Hoai Pham Ngoc Diep nguyen thi Phuong nguyen thi Thao Pham Tuan Anh Pierre Darriulat Department of Astrophysics Vietnam National Satellite CenterVAST

Observations of the ^12CO（3–2） emission from the circumstellar envelope（CSE） of the variable star π1Gru using the compact array of the ALMA observatory have been recently made accessible to the public. An analysis of the morphology and kinematics of the CSE is presented with a result very similar to that obtained earlier for ^12CO（2–1） emission using the Submillimeter Array. A quantitative comparison is made using their flared disk model. A new model is presented that provides a significantly better description of the data, using radial winds and smooth evolutions of the radio emission and wind velocity from the stellar equator to the poles.

关键词： stars AGB and post-AGB circumstellar matter star individual(π1Gru) stars massloss radio lines stars

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Evaluation of five gridded rainfall datasets in simulating streamflow in the upper Dong Nai river basin,Vietnam

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International Journal of Digital Earth 2019年第3期12卷 311-327页

作者： Pham thi Thao Nhi Dao nguyen Khoi nguyen Xuan Hoan Institute of Research and Development Duy Tan UniversityDa NangVietnam Institute for Computational Science and Technology Tan Hiep Chanh WardDistrict 12Ho Chi Minh CityVietnam Faculty of Environment University of ScienceVietnam National University Ho Chi Minh City227 Nguyen Van Cu StreetDistrict 5Ho Chi Minh CityVietnam Ho Chi Minh City University of Food Industry 140 Le Trong Tan StreetTan Phu DistrictHo Chi Minh CityVietnam

Rainfall data with an appropriate spatial resolution is a key input to hydrological ***,networks of rain gauges are often sparsely and unevenly distributed in large catchments,especially in developing ***-resolution rainfall datasets,such as the Asian Precipitation Highly Resolved Observational Data Integration Towards Evaluation of Water Resources(APHRODITE),the Climate Forecast System Reanalysis(CFSR),the Climatic Research Unit Time Series(CRUTS),the Global Precipitation Climatology Centre(GPCC)and the Tropical Rainfall Measuring Mission(TRMM),have become available to overcome such *** objective of this study was to evaluate the impacts of four land-based rainfall products(APHRODITE,CFSR,CRU-TS,and GPCC)and a satellite-based rainfall product(TRMM)on streamflow of the upper catchment of Tri An reservoir in Vietnam using the Hydrological Modeling System(HEC-HMS).In addition,the available rain gauges data were used for comparison *** indicates that the TRMM and GPCC data show their best match to rain gauges data in simulating the streamflow in the period 1999–***,the results indicate that the TRMM and GPCC data could be alternative solutions.

关键词： APHRODITE CFSR CRU-TS GPCC TRMM rainfall streamflow HEC-HMS model

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