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Effect of land use change on water discharge in Srepok watershed,Central Highland,Viet Nam

International Soil and Water Conservation Research 2014年第3期2卷 74-86页

作者： nguyen thi Ngoc quyen nguyen Duy Liem nguyen Kim Loi Tay nguyen University Viet Nam.567 Le Duan streetBuon Ma Thuot CityDak Lak Province Nong Lam University Viet Nam.Linh Trung WardThu Duc districtHo Chi Minh City

Srepok watershed plays an important role in Central Highland in Viet *** impacts to developing social-economic ***,it is necessary to research elements which impact to natural resources in this *** Soil and Water Assessment Tool(SWAT)model and Geography Information System(GIS)were used to simulate water discharge in the Srepok *** objectives of the research were to apply GIS and SWAT model for simulation water discharge and then,we assessed land use change which impacted on water discharge in the *** observed stream flow data from Ban Don Stream gauge station was used to calibrate for the period from 1981 to 2000 and then validate for the period from 2001 to *** using SWAT-CUP software to calibration,NSI reached 0.63 and R square value achieved 0.64 from 2004 to 2008 in calibration and NSI gained good level at 0.74 and R square got 0.75 from 2009 to 2012 in validation step at Ban Don *** that,land cover in 2010 was processed like land cover in 2000 and set up SWAT model *** simulated water discharge in scenario 1(land use 2000)was compared with scenario 2(land use 2010),the simulation result was not significant difference between two scenarios because the change of area of land use was not much enough to affect the fluctuation of water ***,the effect of land cover on water resource could be seen clearly via total water *** percentage of surface flow in 2000 was twice times more than in 2010;retard and base flow in 2000 was slightly more than in ***,decreased surface flow,increased infiltration capacity of water and enriched base flow resulted in the growth of land cover.

关键词： Water discharge Land use change GIS SWAT model Simulations

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The Power of Change-Point Test for Two-Phase Regression

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Applied Mathematics 2014年第19期5卷 2994-3000页

作者： To Van Ban nguyen thi quyen Department of Mathematics Haiphong University Haiphong Vietnam

In this paper, the roughness of the model function to the basis functions and its properties have been considered. We also consider some conditions to take the limit of the roughness when the observations are i.i.d. An explicit formula to calculate the power of change-point test for the two phases regression through the roughness was obtained.

关键词： Change-Point Test The Power The Roughness Random Design

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The Roughness of Model Function to the Basis Functions

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Journal of Mathematics and System Science 2013年第8期3卷 385-390页

作者： To Van Ban nguyen thi quyen Phan Thu Ha Department of mathematics IT faculty Le Quy Don Technical University 100 Hoang Quoc Viet Cau Giay District Hanoi Vietnam Faculty of Mathematics Hai Phong University 1 71 Phan Dang Luu Kien An District Hai Phong Vietnam

The roughness of the model function f（x） to the basis functions has been identified. When the model function is continuous segment, its roughness does not depend on the behavior of the first segment, but depends on ＂h＂, the shift in the slope of two consecutive segments. If the distribution of design is uniform, f（x） is continuous segment function, and h is constant, then the maximum roughness is h2/192 obtained at the midpoint of the observations. Suppose that we have a sequence of designs {Pn（x）} then its corresponding distribution {Fn （x）} converges weakly to some distribution F（x）. Let D（f） be a set of discontinuous points off（x）, it is possible to take the limit of the roughness if D（f） has zero （dF）-measure. The behavior of maximum roughness of the discontinuous segment function has been studied by using grid points.

关键词： The roughness segment function model function design converge.

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胃食管反流病中医证型分布与精神心理状态的相关性研究

胃食管反流病中医证型分布与精神心理状态的相关性研究

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作者：阮氏权（nguyen thi quyen）广州中医药大学

学位级别：硕士

目的:分析不同中医证型下胃食管反流病(GERD)患者的精神心理状态,并探讨GERD中医证型与患者抑郁,焦虑心理可能存在的相关性,以了解情志因素在GERD发病中所起的作用,为临床治疗提供理论依据,更好地指导临床用药。方法:研究采用横断面调... 详细信息

目的:分析不同中医证型下胃食管反流病(GERD)患者的精神心理状态,并探讨GERD中医证型与患者抑郁,焦虑心理可能存在的相关性,以了解情志因素在GERD发病中所起的作用,为临床治疗提供理论依据,更好地指导临床用药。方法:研究采用横断面调查研究方法,通过对门诊就诊的GERD患者收集临床研究调查表、状态—特质焦虑量表(STAI)、医院焦虑抑郁量表(HADS)以及患者健康量表(PHQ-15)的信息,并对收集的数据用SPSS 19.0软件进行统计分析,探讨GERD中医证型分布和GERD中医证型与精神因素的相关性。结果:本研究收回问卷104份,有效问卷96份。男性53例,女性43例。年龄范24-67岁,平均年龄48.66±11.73岁。NERD有63例,RE有27例,BE有6例。中虚气逆型有14例,气郁痰阻型有36例,肝胃郁热型16例,胆热犯胃型22例,瘀血阻络型有8例。中医症候的分布情况为:有反酸症状的患者有60例,烧心症状出现的有58例,嗳气者有68例,呕吐者4例,恶心者30例,胃脘疼痛者62例,胃脘疼痛因情绪加重者有18例,胃脘胀闷者66例,腹部胀满者44例,腹部疼痛者38例,腹部疼痛因情绪而加重者10例,咽喉部有异物感者有32例,口苦者28例,口干者54例,心烦易怒者38例,潮热者10例,乏力者44例,怕冷者42例,身体困重者30例,嘈杂不适者28例,纳差者32例。前5位的中医症候分别有反酸、烧心、嗳气、胃脘疼痛和胃脘胀闷。在S-AI、STAI和HAD-A评分上,5个证型之间不存在统计学差异(P>0.05),而在T-AI、HAD-D和HADS评分上,5个证型之间存在统计学差异(P<0.05)。进一步对T-AI、HAD-D和HADS评分中组内每两个证型分析,发现在T-AI评分中,瘀血阻络型评分明显高于气郁痰阻型、中虚气逆型的(P<0.05),肝胃郁热型高于气郁痰阻型、中虚气逆型的(P<0.05)。在HAD-D评分中,瘀血阻络型、肝胃郁热型、胆热犯胃型的评分均明显高于气郁痰阻型和中虚气逆型的(P<0.05)。在HADS评分中,瘀血阻络型与中虚气逆型和气郁痰阻型均有统计学差异(P<0.05)。在各证型的躯体化症状的评估中,瘀血阻络型GERD患者的躯体化症状比其他4个证型患者的更为严重,但中医证型与躯体化症状等级不存在关联性。结论:本研究初步揭示在GERD中,中医证型的分布主要以肝胃不和多见,其中气郁痰阻型、肝胃郁热型及胆热犯胃型为常见证型。中虚气逆型和气郁痰阻型是GERD的基本病机,也是本病的早期,本期患者的焦虑抑郁状态相对较轻,随着病情进展,当发展至肝胃郁热型或胆热犯胃型时,患者的焦虑抑郁状态会出现加重的趋势,躯体化症状也有随之加重的趋势,当疾病进入后期,即瘀血阻络型时,焦虑抑郁状态最为严重。但中医证型与躯体化症状等级不存在关联性。

关键词：胃食管反流病中医证型分布精神心理状态量表相关性

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Scouring of a granular bed by dam break: Experimental study and numerical simulation by a VOF-LPT coupling

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International Journal of Sediment Research 2023年第3期38卷 432-445页

作者： quyen thi Le nguyen Viet Dung nguyen Patrice Coorevits EPROAD Research Unit University of Picardie Jules Verne IUT of Aisne Hanoi University of Civil Engineering

The first part of the research reported here consists of an experimental campaign to study the scouring of a granular bed(glass beads, sand) induced by a dam break in an open channel. Two configurations are considered: with and without cylinders. In the second part of this study, the volume of fluid method coupled with the shear stress transport turbulent model and the lagrangian particle tracking method is used to simulate the local scour processes. The four-way coupling is realized by considering the drag force and collisions between particles. Using a vortex map and velocity profiles, the flow dynamics and scour pattern can be studied. The current research also focuses on the profiles of the erodible particle bed and the sediment transport rate to study the effects of a cylinder on local scour. The presence of the cylinder increases the experimental erosion depth by up to 42%. It was found that for relatively close particle diameters(2 and 3 mm), a granular bed with larger porosity(larger diameter) erodes the *** and numerically it was found that the center of the granular bed experiences more erosion compared to the channel sides. In the last part of the research, comparisons between the numerical results and the experimental data allowed risk areas to be identified and the roles of porosity,sediment density, and flow dynamics on erosion to be identified.

关键词： Volume of fluid Lagrangian particle tracking Scour Granular bed Cylinder Dam break

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Development of deep neural network model to predict the compressive strength of FRCM confined columns

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Frontiers of Structural and Civil Engineering 2022年第10期16卷 1213-1232页

作者： Khuong LE-nguyen quyen Cao MINH Afaq AHMAD Lanh Si HO Department of Civil Engineering University of Transport TechnologyHanoi 100000Vietnam Faculty of Arts and Design University of CanberraBruce ACT 2617Australia Department of Civil Engineering University of Engineering and TechnologyTaxila 47080Pakistan Graduate School of Advanced Science and Engineering Hiroshima UniversityHiroshima 739-8527Japan

The present study describes a reliability analysis of the strength model for predicting concrete columns confinement influence with Fabric-Reinforced Cementitious Matrix(FRCM).through both physical models and Deep Neural Network model(artificial neural network(ANN)with double and triple hidden layers).The database of 330 samples collected for the training model contains many important parameters,i.e.,section type(circle or square),corner radius rc,unconfined concrete strength fco,thickness nt,the elastic modulus of fiber Ef,the elastic modulus of mortar *** results revealed that the proposed ANN models well predicted the compressive strength of FRCM with high prediction *** ANN model with double hidden layers(APDL-1)was shown to be the best to predict the compressive strength of FRCM confined columns compared with the ACI design code and five physical ***,the results also reveal that the unconfined compressive strength of concrete,type of fiber mesh for FRCM,type of section,and the corner radius ratio,are the most significant input variables in the efficiency of FRCM confinement *** performance of the proposed ANN models(including double and triple hidden layers)had high precision with R higher than 0.93 and RMSE smaller than 0.13,as compared with other models from the literature available.

关键词： FRCM deep neural networks confinement effect strength model confined concrete

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Data driven discovery of conjugated polyelectrolytes for optoelectronic and photocatalytic applications

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npj Computational Materials 2021年第1期7卷 641-649页

作者： Yangyang Wan Fernando Ramirez Xu Zhang Thuc-quyen nguyen Guillermo C.Bazan Gang Lu Department of Physics and Astronomy California State University NorthridgeNorthridgeCaliforniaUSA Department of Chemistry and Biochemistry University of CaliforniaSanta BarbaraCaliforniaUSA

Conjugated polyelectrolytes(CPEs),comprised of conjugated backbones and pendant ionic functionalities,are versatile organic materials with diverse ***,the myriad of possible molecular structures of CPEs render traditional,trial-and-error materials discovery strategy ***,we tackle this problem using a data-centric approach by incorporating machine learning with high-throughput first-principles *** systematically examine how key materials properties depend on individual structural components of CPEs and from which the structure–property relationships are *** means of machine learning,we uncover structural features crucial to the CPE properties,and these features are then used as descriptors in the machine learning to predict the properties of unknown ***,we discover promising CPEs as hole transport materials in halide perovskite-based optoelectronic devices and as photocatalysts for water *** work could accelerate the discovery of CPEs for optoelectronic and photocatalytic applications.

关键词： conjugated backbone photocatalytic

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Spectral contrast optical coherence tomography angiography enables single-scan vessel imaging

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Light(Science & Applications) 2019年第1期8卷 1108-1116页

作者： James A.Winkelmann Aya Eid Graham Spicer Luay M.Almassalha The-quyen nguyen Vadim Backman Department of Biomedical Engineering Northwestern UniversityEvanstonIL 60208USA Department of Chemical and Biological Engineering Northwestern UniversityEvanstonIL 60208USA

Optical coherence tomography angiography relies on motion for contrast and requires at least two data acquisitions per pointwise scanning *** present a method termed spectral contrast optical coherence tomography angiography using visible light that relies on the spectral signatures of blood for angiography from a single scan using endogenous *** demonstrate the molecular sensitivity of this method,which enables lymphatic vessel,blood,and tissue discrimination.

关键词： enable signature spectral

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Facile synthesis of FeFe2O4 magnetic nanomaterial for removing methylene blue from aqueous solution

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Progress in Natural Science:Materials International 2019年第6期29卷 648-654页

作者： Van-Phuc Dinh Ngoc quyen Tran nguyen-Que-Tran Le Quang-Huy Tran Trinh Duy nguyen Gr EEN), nguyen Tat Thanh University Van Tan Le Future Materials and Devices Laboratory Institute of Fundamental and Applied Sciences Duy Tan University Institute of Applied Materials Science VAST Graduate University of Science and Technology VAST Le Quy Don–LBT Highschool Bien Hoa City Dong Nai province Center of Excellence for Green Energy and Environmental Nanomaterials (CE Industrial University of Ho Chi Minh City

A facile and simple chemical precipitation method was utilized to synthesize FeFe2O4magnetic nanomaterial for removing methylene blue（MB） from aqueous solution. Characterizations of this material were examined by using XRD, SEM, FT-IR, TGA-DTG and BET methods. Factors affecting the uptake of methylene blue, including p H, adsorption time, and MB initial concentration were also studied. The measured data were fitted by using four isotherm models including Langmuir, Freundlich, Sips and Temkin. Results showed that the Sips model offers the best fit to the data. In addition, the monolayer MB adsorption capacity obtained from the Langmuir model was 42.35 mg g-1under the optimal conditions of p H = 10 and adsorption time = 80 min. In particular, the uptake of MB onto FeFe2O4magnetic nanomaterial obtained from the kinetic and mechanism studies of the adsorption was in good agreement with prediction of the pseudo-first-order model, whereas the electrostatic interaction was found to play a primary mechanism.

关键词： FeFe2O4 magnetic nanomaterial Adsorption Methylene blue Adsorption mechanism

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A Cell-Based Smoothed Finite Element Method for Modal Analysis of Non-Woven Fabrics

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Computers, Materials & Continua 2021年第6期67卷 2765-2795页

作者： nguyen T.quyen N.Dourado A.J.P.Gomes F.B.N.Ferreira C2T—Centro de Ciência e Tecnologia Têxtil Departamento de Engenharia TêxtilUniversidade do MinhoCampus de AzurémGuimarães4804-533Portugal CMEMS-UMinho Departamento de Engenharia MecânicaUniversidade do MinhoCampus de AzurémGuimarães4804-533Portugal Department of Computer Science Universidade da Beira InteriorConvento de Sto.AntónioCovilhã6201-001Portugal Instituto de Telecomunicações R.Marquês deÁvila e BolamaCovilhã6201-001Portugal

The combination of a 4-node quadrilateral mixed interpolation of tensorial components element(MITC4)and the cell-based smoothed finite element method(CSFEM)was formulated and implemented in this work for the analysis of free vibration and unidirectional buckling of shell *** formulation was applied to numerous numerical examples of non-woven *** CSFEM schemes do not require coordinate transformation,spurious modes and numerical instabilities are prevented using bilinear quadrilateral element subdivided into two,three and four smoothing *** improvement of the original CSFEM formulation was made regarding the calculation of outward unit normal vectors,which allowed to remove the integral operator in the strain smoothing *** procedure conducted both to the simplification of the developed formulation and the reduction of computational cost.A wide range of values for the thickness-to-length ratio and edge boundary conditions were *** developed numerical model proved to overcome the shear locking phenomenon with success,revealing both reduced implementation effort and computational cost in comparison to the conventional FEM *** cell-based strain smoothing technique used in this work yields accurate results and generally attains higher convergence rate in energy at low computational cost.

关键词： Mindlin-Reissner theory of plates shear-locking gradient/strain smoothing technique non-woven fabric

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