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Journal of Environmental Science and Engineering(B) 2012年第2期1卷 199-207页

作者： dinh Binh Phan Thanh Hai nguyen Faculty of Resources and Environmental Science Thai Nguyen University of Agriculture and Forestry Thai Nguyen City 280 Vietnam

The purpose of this paper is to apply ＂Soil and Water Assessment Tool （SWAT）＂ model to simulate the impacts of climate change and deforestation on nutrient （nitrogen and phosphorus） yield from Phu Luong watershed in Northern Viet Nam. Among the three climate change scenarios B1, B2 and A2, which represented low, medium, and high levels of greenhouse gas emission respectively, were set up for Viet Nam. The B2 scenario was selected for this study. Two land use scenarios （SI-2030 and S2-2050 which converted 4.43%. and 13.40% forest-mixed land into agricultural land, respectively） were formulated by combination with climatic change in SWAT simulation. In B2 climate change scenario, mean temperature increases 0.7 ℃ （2030） and 1.3 ℃（2050）; annual rainfall increases 2.1% （2030） and 3.80% （2050） with respect to baseline scenario. The results showed that monthly Nash-Sutcliffe coefficient of Efficiency （NSE） ranged from 0.81 to 0.96 and percent bias （PB1AS） ranged from -7.88 to 9.38. Additionally, SWAT simulation results also showed that climate change and deforestation caused significant percentage of changes in total N and P loads within Phu Luong watershed.

关键词： SWAT climate change deforestation nutrient yield.

Eye Strain Detection During Online Learning

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Intelligent Automation & Soft Computing 2023年第3期35卷 3517-3530页

作者： Le Quang Thao Duong Duc Cuong Vu Manh Hung Le Thanh Vinh Doan Trong Nghia dinh Ha Hai nguyen Nhan Nhi Faculty of Physics VNU University of ScienceHanoi100000Vietnam University of Science Vietnam National UniversityHanoi100000Vietnam VNU-HUS High School for Gifted StudentsHanoi100000Vietnam Hanoi-Amsterdam High School for the Gifted Hanoi100000Vietnam

The recent outbreak of the coronavirus disease of 2019(Covid-19)has been causing many disruptions among the education systems worldwide,most of them due to the abrupt transition to online *** sudden upsurge in digital electronic devices usage,namely personal computers,laptops,tablets and smart-phones is unprecedented,which leads to a new wave of both mental and physical health problems among students,for example eye-related *** overexpo-sure to electronic devices,extended screen time usage and lack of outdoor sun-light have put a consequential strain on the student’s ophthalmic health because of their young age and a relative lack of responsibility on their own *** to take appropriate external measures to mitigate the negative effects of this pro-cess could lead to common ophthalmic illnesses such as myopia or more serious *** remedy this situation,we propose a software solution that is able to track and capture images of its users’eyes to detect symptoms of eye illnesses while simultaneously giving them warnings and even offering *** meet the requirements of a small and light model that is operable on low-end devices without information loss,we optimized the original MobileNetV2 model with depth-wise separable convolutions by altering the parameters in the last layers with an aim to minimize the resizing of the input image and obtained a new model which we call *** with applying the knowledge distillation tech-nique and ResNet-18 as a teacher model to train the student model,we have suc-cessfully increased the accuracy of the EyeNet model up to 87.16%and support the development of a model compatible with embedded systems with limited computing power,accessible to all students.

关键词： Digital eye strain Covid-19 online study knowledge distillation eye care EyeNet

SOME PRELIMINARY RESULTS FROM STUDY OF CRUSTAL DEFORMATION IN VIETNAM

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大地测量与地球动力学 2003年第B12期23卷 114-118页

作者： Cao dinh Trieu Le Van Dung nguyen Huu Tuyen Pham Nam Hung Institute of Geophysics Institute of GeophysicsInstitute of GeophysicsInstitute of Geophysics 18 Hoang Quoc Viet Road Cau GiayHanoi18 Hoang Quoc Viet Road Cau GiayHanoi18 Hoang Quoc Viet Road Cau GiayHanoi18 Hoang Quoc Viet Road Cau GiayHanoi

In this work, the authors present some results of strain monitoring within the territory of Vietnam from 1984 to 2001. Data analysis shows that (1) the Phu Lien area is tectonically stable with low strain rate, 1×10\+\{-6\} /a; (2) the Hoa Binh area has indication of tectonic instability with relatively high strain rate of the earth crust: absolute value of the strain reaching 100×10\+\{-6\}, usual average strain amplitude of 60×10\+\{-6\}, whereas the monthly average strain intensity varies in a range from 30×10\+\{-6\} to 50×10\+\{-6\}; (3) there are clear indications of the strain state of the earth crust before occurrence of earthquakes of medium or higher magnitude. This is a very important indication in the research and short term prediction of earthquakes, especially for the areas with low seismic stability like the NW of Vietnam.

关键词：越南表层变形应变测量系统操作原则应变数据因变与地震相对关系地震活动特性

Local Existence of Solution to a Class of Stochastic Differential Equations with Finite Delay in Hilbert Spaces

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Applied Mathematics 2013年第1期4卷 97-101页

作者： Le Anh Minh Hoang Nam nguyen Xuan thuan Department of Natural Sciences Hong Duc University Thanh Hoa Vietnam

In this paper, we present a local Lipchitz condition for the local existence of solution to a class of stochastic differential equations with finite delay in a real separable Hilbert space which has the following form:

关键词： Stochastic Differential Equation Local Lipchitz Condition Strongly Semigroup

Preparation and Characterization of Reduced Graphene-P3HT Composite Thin Films for Use as Transparent Conducting Electrodes

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Materials Sciences and Applications 2018年第5期9卷 464-472页

作者： Lam Minh Long Dang dinh Long nguyen Phuong Hoai Nam nguyen Trong Tinh Sergei Antonovic Chizhik nguyen Nang dinh University of Engineering and Technology VNU in Hanoi Hanoi Vietnam Institute of Applied Physics and Scientific Instrument Vietnamese Academy of Science and Technology Hanoi Vietnam A.V. Luikov Heat and Mass Transfer Institute National Academy of Sciences of Belarus Minsk Belarus

With the aim of producing simple and effective transparent conducting electrodes, the conducting polymer poly(3-hexylthiophene) (P3HT) incorporated with reduced graphene oxide film (rGO) (called rGO-P3HT) was prepared by spin-coating method. Structural, electrical and optical characterization showed that rGO-P3HT films 9.0 wt% P3HT exhibited good stability when exposed to the ambient atmosphere. These composite films of 200 nm thickness possess a sheet resistance and transparency of R□~ 17Ω and T ~ 72%, respectively. Owing to containing conducting polymer, rGO-P3HT-coated glass could be efficiently used in photovoltaic applications, in organic solar cells in particular, with the replacement of the indium tin oxide (ITO) and fluorine tin oxide (FTO) electrodes.

关键词： Composite rGO-P3HT Thin Films Transparent Conducting Electrode Sheet Resistance Transmittance

Analysis of Storm Pattern for Design Urban Drainage System in the Monsoon Areas of Vietnam

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Journal of Environmental Science and Engineering(A) 2018年第2期7卷 49-68页

作者： Bui Thi Thu Trang nguyen Thi Hong Hanh nguyen Thi Hoai Thuong nguyen Van thuan Faculty of Environment Hanoi University of Natural Resources and EnvironmentHanoi 100000Vietnam Department of General Affairs State Audit Office of VietnamHanoi 100000Vietnam

In Vietnam,rainfall data usually received using daily rainfall at all hydrology stations with higher time resolution are ***,its analyses to achieve IDF(Intensity-Duration-Frequency)curves are often required at a finer scale such as ***,it needs to develop and apply methods to derive the IDF characteristics of short-duration events from daily rainfall statistics in *** recent years,the need for new insights into the rainfall process leading to new approaches to model the distribution of rainfall intensities in time and space was *** research aims to establish IDF curves for monsoon climate area in Vietnam based on scaling *** properties of extreme rainfall are examined in the Red River Delta of Vietnam in order to establish scaling behavior of statistical moments over different *** scaling or scale-invariant models enable us to scale data from one temporal resolution to another,and thus,help to overcome the lack of the extreme rainfall data of sub-daily *** disaggregation or downscaling techniques are used to obtain sub-daily rainfall data from daily rainfall data for the derivation of scaled IDF *** results show that most of rainfall amount(approximately 70%)received from rains occurring between 6:0 pm to 6:0 am of the day after that,the daytime usually less rainfall occurrence with only 30%.The peak rainfall is usually occurred during 0:0 am to 4:0 am having approximately 42.98%of rainfall amount over a *** peak rainfall likely happen earlier in the recent year(36%rainfall amount over a day occurrence from 6:00 pm to 10:00 pm in 2008).The analysis also illustrated that approximately 40%of rainfall events have duration less than 60 *** contrast,only approximately 9%of rainfall events have duration more than 6 hours but total rainfall depths of these events is approximately.

关键词： IDF(Intensity-Duration-Frequency)curves design rainfall for urban design rainfall in the Monsoon areas

Hydrodeoxygenation of Bio-Oil on Bimetallic Catalysts: From Model Compound to Real Feed

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Journal of Sustainable Bioenergy Systems 2015年第4期5卷 151-160页

作者： thuan Minh Huynh Udo Armbruster Luong Huu nguyen Duc Anh nguyen Andreas Martin Leibniz Institute for Catalysis at University of Rostock Rostock Germany Vietnam Petroleum Institute Hanoi Vietnam

Two series of bimetallic Ni-Co catalysts and corresponding monometallic catalysts with ca. 20 wt% metal loading were evaluated in hydrodeoxygenation (HDO) of phenol as a model compound for bio-oil. The bimetallic catalysts outperformed the corresponding monometallic catalyst in terms of conversion and cyclohexane selectivity. This could be attributed to the formation of Ni-Co alloy, which caused a decrease in metal particle size and stabilized Ni active sites in the near surface region. The balanced combination of formed Ni-Co alloy with acidity from supports allowed performing all individual steps in the reaction network toward desired products at high rate. Consequently, the two best-performing catalysts were tested in HDO of wood based bio-oil, showing that the bimetallic catalyst 10Ni10Co/HZSM-5 was more effective than 20Ni/HZSM-5 in terms of degree of deoxygenation and upgraded bio-oil yield. These findings might open an opportunity for development of a novel cheap but effective catalyst for a key step in the process chain from biomass to renewable liquid fuels.

关键词： Bimetallic Catalysts Hydrodeoxygenation Phenol Bio-Oil Ni-Co Alloy

Atomic Dispersion of Rh on Interconnected Mo_(2)C Nanosheet Network Intimately Embedded in 3D Ni_(x)MoO_(y) Nanorod Arrays for pH-Universal Hydrogen Evolution

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Energy & Environmental Materials 2023年第5期6卷 236-250页

作者： Thi Luu Luyen Doan dinh Chuong nguyen Patrick M.Bacirhonde Ahmed S.Yasin Abdelrahman I.Rezk Nelson Y.Dzade Cheol Sang Kim Chan Hee Park Department of Bionanotechnology and Bioconvergence Engineering Graduate SchoolJeonbuk National UniversityJeonju Jeollabuk-do 54896Korea Department of Nano Convergence Engineering Jeonbuk National UniversityJeonju Jeollabuk-doJeonbuk 54896Korea Graduate School of Energy Science and Technology Chungnam National UniversityDaejeon 34134Korea Department of Energy and Mineral Engineering The Pennsylvania State UniversityUniversity Park State CollegePA 16802USA Division of Mechanical Design Engineering School of EngineeringJeonbuk National UniversityJeonju Jeollabuk-do 54896Korea Department of Bionanosystem Engineering Graduate School Jeonbuk National UniversityJeonju Jeollabuk-do 54896Korea

Herein,a simple synthetic approach is employed for the atomic dispersion of Rh atoms(Rh SAs)over the surface of interconnected Mo_(2)C nanosheets intimately embedded in a three-dimensional Ni_(x)MoO_(y)nanorod arrays(Ni_(x)MoO_(y)NRs)framework;we found that the introduction of both isolated Rh SAs and Ni_(x)MoO_(y)NRs adjusts the electrocatalytic function of the host Mo_(2)C toward the direction of being an advanced and highly stable electrocatalyst for efficient hydrogen evolution at pH-universal *** a result,the proposed catalyst outperforms most recently reported transition metal-based catalysts,and its performance even rivals that of commercial Pt/C,as demonstrated by its ultralow overpotentials of 31.7,109.7,and 95.4 mV at a current density of 10 mA cm^(-2),along with its small Tafel slopes of 42.4,51.2,and 46.8 mV dec^(-1)in acidic,neutral,and alkaline conditions,*** addition,the catalyst shows remarkable long-term stability over all pH values with good maintenance of its catalytic activity and structural characteristics after continuous operation.

关键词： hydrogen evolution reaction Mo_(2)C nanosheets Ni_(x)MoO_(y)nanorod arrays pH-universal catalyst single Rh atoms

Facile Preparation, Characterization of Flexible Organic Solar Cells Using P3HT-MWCNTS Composite Photoactive Layer

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Journal of Materials Science and Chemical Engineering 2020年第10期8卷 1-10页

作者： Tran Si Trong Khanh nguyen Phuong Hoai Nam nguyen Nang dinh Advanced Research Group of Nano-Semiconducting Materials and Devices (ARGD) University of Engineering and Technology VNU in Hanoi Hanoi Vietnam

Multiwalled carbon nanotubes (MWCNTs) mixed in poly(3-hexylthiophene) (P3HT) were used as a photoactive layer for organic solar cells (OSC). The flexible OSCs of a structure of PET/rGO-P3HT/P3CT/PCBM/LiF-Al were prepared by spincoating. The UV-Vis absorption spectra of the photoactive films and current-voltage characteristics of the OSCs showed the advantage of the composite devices above the pristine-polymeric ones. Under illumination of light with a 100 mW/cm2-powerdensity, the photoelectrical conversion efficiency (PCE) of the OSCs with 3.0 wt% MWNCTs embedded in the photoactive layer possess a value as large as 2.35%. The obtained results suggest further useful applications of the flexible large-area solar cells.

关键词： P3HT-MWCNTs Composite Photovoltage UV-Vis Absorption Photoluminescence (PL) Quenching J-V Characteristics Photoelectrical Conversion Efficiency (PCE)

Stability Criteria of Solutions for Stochastic Set Differential Equations

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Applied Mathematics 2012年第4期3卷 354-359页

作者： Ho Vu nguyen Ngoc Phung Ngo Van Hoa nguyen dinh Phu Faculty of Basic Education University of Banking HCM City Vietnam Faculty of Mathematics and Computer Science Vietnam National University HCM City Vietnam

The existence and uniqueness results on solutions of set stochastic differential equation were studied in [1]. In this paper, we present the stability criteria for solutions of stochastic set differential equation.

关键词： Stochastic Set Differential Equation Stability Exponential Stability