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International Journal of Digital Earth 2019年第10期12卷 1118-1132页

作者： Quang-Thanh Bui Manh Pham Van nguyen Thi Thuy Hang Quoc-Huy nguyen nguyen xuan Linh Pham Minh Hai Tran Anh Tuan Pham Van Cu Center for Applied Research in Remote sensing and GIS(CARGIS) VNU University of ScienceHa NoiViet Nam VNU University of Science Ha NoiViet Nam Vietnam Institute of Geodesy and Cartography Ha NoiViet Nam Ministry of Education and Training Ha NoiViet Nam

This study proposed a novel object-based hybrid classification model named GMNN that combines Grasshopper Optimization Algorithm(GOA)and the multiple-class Neural network(MNN)for urban pattern detection in Hanoi,*** bands of SPOT 7 image and derivable NDVI,NDWI were used to generate image segments with associated attributes by PCI Geomatics *** segments were classified into four urban surface types(namely water,impervious surface,vegetation and bare soil)by the proposed ***,three training and validation datasets of different sizes were used to verify the robustness of this *** all tests,the overall accuracies of the classification were approximately 87%,and the Area under Receiver Operating Characteristic curves for each land cover type was ***,the performance of this model was examined by comparing several statistical indicators with common benchmark *** results showed that GMNN out-performed established methods in all comparable *** results suggested that our hybrid model was successfully deployed in the study area and could be used as an alternative classification method for urban land cover *** a broader sense,classification methods will be enriched with the active and fast-growing contribution of metaheuristic algorithms.

关键词： Urban remote sensing object-based classification neural network grasshopper optimization algorithm

One-step hydrothermal synthesis of Sn-doped α-Fe_(2)O_(3) nanoparticles for enhanced photocatalytic degradation of Congo red

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Journal of Semiconductors 2022年第12期43卷 22-31页

作者： Van Nang Lam Thi Bich Vu Quang Dat Do Thi Thanh xuan Le Tien Dai nguyen T-Thanh-Bao nguyen hoang Tung Do Thi Tu Oanh nguyen Department of Natural Sciences Hoa Lu UniversityNinh NhatNinh Binh CityViet Nam Institute of Theoretical and Applied Research Duy Tan UniversityHanoi 100000Viet Nam Faculty of Natural Sciences Duy Tan UniversityDa Nang 550000Vietnam Institute of Physics Vietnam Academy of Science and Technology10 Dao TanBa DinhHanoiVietnam Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietCaugiayHanoiVietnam

We report on the synthesis of Sn-doped hematite nanoparticles(Sn-α-Fe_(2)O_(3) NPs)by the hydrothermal *** prepared Sn-α-Fe_(2)O_(3) NPs had a highly pure and well crystalline rhombohedral phase with an average particle size of 41.4 *** optical properties of as-synthesizedα-Fe_(2)O_(3) NPs show a higher bandgap energy(2.40-2.57 eV)than that of pure bulkα-Fe_(2)O_(3)(2.1 eV).By doping Sn intoα-Fe_(2)O_(3) NPs,the Sn-doped hematite was observed a redshift toward a long wavelength with in-creasing Sn concentration from 0%to 4.0%.The photocatalytic activity of Sn-dopedα-Fe_(2)O_(3) NPs was evaluated by Congo red(CR)dye *** degradation efficiency of CR dye using Sn-α-Fe_(2)O_(3) NPs catalyst is higher than that of pureα-Fe_(2)O_(3) *** highest degradation efficiency of CR dye was 97.8%using 2.5%Sn-dopedα-Fe_(2)O_(3) NPs catalyst under visible-light *** results suggest that the synthesized Sn-dopedα-Fe_(2)O_(3) nanoparticles might be a suitable approach to develop a photocatalytic degradation of toxic inorganic dye in wastewater.

关键词： α-Fe_(2)O_(3)nanoparticles Sn Congo red photocatalytic properties photodegradation

The Effect of Different Levels of Sesame Oil on Productive Performance, Egg Yolk and Blood Serum Lipid Profile in Laying Hens

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Open Journal of Animal Sciences 2016年第1期6卷 85-93页

作者： nguyen Duy hoan Mai Anh Khoa Faculty of Animal Husbandry—Veterinary Thai Nguyen University of Agriculture and Forestry Thai Nguyen City Vietnam

Addition of sesame oil into layer diets has been proved to enrich the proportion of polyunsatu-rated fatty acids in animal’s products. In this study, the effects of different levels of sesame oil in the diets on the performance, egg yolk and blood serum lipid profile of Isa Brown laying hens were investigated. A total of 96 layers were assigned into 4 groups to receive either 1 of 4 different diets contained 0.0%, 1.5%, 3.0% and 4.5% sesame oil, respectively. Sample of 12 eggs obtained from each groups were assessed for egg quality. The egg yolk fatty acid profile was determined with gas chromatography. Results revealed that the higher levels of sesame oil in the diet decreased egg production, egg weight, and egg yolk color except feed conversion ratio. In addition, supplementation of sesame oil increased the flow index of the eggs and the Haugh unite. The egg yolk lipid profile was not significantly different in the sesame oil fed groups, whereas, compare to control, it decreased the level of cholesterol. The blood serum lipid profile decreased in the sesame oil groups compare to control group. Meanwhile, monoacildigliserol also decreased in the sesame addition groups. In parallel with increasing levels of sesame oil, monounsaturated fatty acid (oleic acid) in the egg yolks significantly increased compared to the control (37.00%, 42.89%, 42.20% and 43.48%, respectively). It can be implied that sesame oil supplementation into the laying hens diet is necessary to produce monounsaturated fatty acid (MUFA) enriched eggs.

关键词： Sesame Oil Egg Yolk Lipid Profile Performance Laying Hens

Estimation of Land Use Changes in Tan Rai Bauxite Mine by Multi-Variants Change Vector Analysis (MCVA) on Multi-Temporal Remote Sensing Data

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Journal of Geoscience and Environment Protection 2020年第3期8卷 70-84页

作者： nguyen Thanh hoan Hoa Thuy Quynh Le Minh Hang nguyen Manh Ha hoang Thi Huyen Ngoc Dang xuan Phong Institute of Geography Vietnam Academy of Science and Technology Hanoi Vietnam Graduate University of Science and Technology Vietnam Academy of Science and Technology Hanoi Vietnam Le Quy Don Technical University Hanoi Vietnam

The Tan Rai Bauxite Project, which exploits a large bauxite mine in Lam Dong province, Vietnam has been in operation since 2012. In addition to the economic efficiency of the project, bauxite mining and processing uses a large area arable land and affect the regional environment. Remote sensing technology is increasingly widely used in many purposes in monitoring the changes of environment and resources, including land use change with high accuracy, giving managers more information to monitor the exploitation and use process of land resource. This study used a Change Vector Analysis (CVA) method of analysis on various remote sensing data sources to monitor the process of land exploitation and restoration of the Tan Rai Bauxite project. High-resolution remote sensing images were used as diverse as SPOT-5, VNREDSat-1, Google Earth from 2013 to 2019 to demonstrate the ability of the MCVA method to combine many other types of remote sensing images together. The results of fluctuation analysis were validated by 200 random points in the study area, and the accuracy of result is more than 90%. The results of land use change statistics were also compared with the annual data of Tan Rai Bauxite Factory. From this study, it can be concluded that the MCVA analysis method can quickly detect land use change areas and can combine many different image sources with a high accuracy. In addition, it also provides statistics of mining areas and restored areas, thereby assisting managers in monitoring the operation of the mine.

关键词： Bauxite Tan Rai MCVA Land Use Change Monitoring Multi-Sensors

Concentrations of Heavy Metals in Muscle with Relation to the Growth of Two Marine Fish Species

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生态毒理学报 2015年第3期10卷 304-310页

作者： Le Quang Dung nguyen Viet Linh nguyen xuan Thanh nguyen Duc Cu Vu Van Tu3 Takaomi Arai Institute of Marine Environment and Resources Vietnam Academic of Science and Technology Haiphong Vietnam Institute of Oceanography and Environment Universiti Malaysia Terengganu Kuala Terengganu Malaysia Institute of Environmental Technology Vietnam Academic of Science and Technology Hanoi Vietnam

Heavy metal concentrations in muscle and their relation to thegrowth of two marine fish species,including tonguefish( Cynoglossus arel) and mullet( Mugil cephalus),were studied. The samples were collected in Bach Dang estuary andconcentrations of heavy metals( As,Cd,Co,Mn,Cu,Zn,Pb,and V) in muscle of the fisheswere determined. The result showed that the accumulated trend of heavy metal is different between fish species. The concentration of As,Zn,Mn,V,Cu,Pb,Co and Cd in tonguefish were 73. 7 ± 30. 6,22. 82 ± 4.87,3. 44 ± 2. 13,1. 61 ± 0. 15,0. 71 ± 0. 13,0. 45 ± 0. 24,0. 03 ± 0. 02 and 0. 02 ± 0. 02 mg·g-1,respectively. Meanwhile the concentration of Zn,As,V,Mn,Cu,Pb,Co and Cd in mullet were 83. 41 ±19. 68,9. 78 ± 1. 92,1. 36 ± 0. 54,1. 29 ± 0. 51,0. 65 ± 0. 12,0. 42 ± 0. 20,0. 06 ± 0. 03 and0. 03 ± 0. 01mg·g-1,respectively. Comparison of metal levels among thesespecies indicated that the concentrations of As and Mn in tonguefish were significantly higher than those in mullet,whereas Zn levels in mullet were found to be higher than that in tonguefish. There is no significant differences of Cd,Co,Cu,Pb and V levels in muscle between two species. Significant inversed relationshipsbetween concentration levels of metals and lengths of tonguefish were found for Mn,Cu and Zn,butnot for As,Cd,Pb,and V. There were no significant relationships between the heavy metal concentrations and the length of mullet. In general,decreasesof the heavy metal concentrations corresponded to the increases of fish body lengths,particularly for As,Co,Cu,Mn and V and the exception for Cd. Terefore reduced risks were associated with consuming biggermullet fish,and increased risks of As and Cd were associated with consuming bigger tonguefish in Bach Dang river mouth.

关键词： heavy metals concentration levels marine fish health risk Vietnam

Genetic diversity in two threatened species in Vietnam:Taxus chinensis and Taxus wallichiana

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Journal of Forestry Research 2017年第2期28卷 265-272页

作者： Dinh Duy Vu Thi Tuyet xuan Bui Minh Tam nguyen Dinh Giap Vu Minh Duc nguyen Van Thang Bui Xiaohua Huang Yi Zhang College of Forestry Northwest A&F UniversityYangling 712100ShaanxiPeople's Republic of China Vietnam National Museum of Nature Vietnam Academy of Science and Technology(VAST)18 Hoang Quoc VietCau GiayHanoiVietnam Institute of Ecology and Biological Resource(VAST) 18 Hoang Quoc VietCau GiayHanoiVietnam Institute of Natural Products Chemistry(VAST) 18 Hoang Quoc VietCau GiayHanoiVietnam Institute of Forest Biotechnology Vietnam Forestry UniversityXuan MaiChuong MyHanoiVietnam

Taxus chinensis and T. wallichiana in have been threatened in their distribution areas in recent decades because of their over-exploitation and reduction and destruction of native habitats. Determining the genetic diversity in populations of the two species will provide guidelines for their protection and preservation. Two hundred and fifteen trees from six populations of T. chinensis and150 sampled trees of T. wallichiana were sampled. Six microsatellite primer pairs selected from 16 primer pairs were used to investigate genetic variation at the population and species levels. Five yielded polymorphic alleles, and among the 13 putative alleles amplified, 11 were polymorphic（accounting for 76.33 %）.Shannon＇s information index（I） and percentage of polymorphic bands（PPB）（I = 0.202 and PPB = 67.22 % for T. chinensis; I = 0.217 and PPB = 65.03 % for T. wallichiana）. Both species had low levels of genetic diversity（mean Ho= 0.107, He= 0.121 for T. chinensis; Ho= 0.095, He= 0.109 for T. wallichiana）. Genetic differentiation among populations was higher（FST= 0.189） for T. chinensis and lower（0.156） for ***, indicating limited gene flow（Nm） among populations for T. chinensis（0.68） and T. wallichiana（0.65）.Variation among individuals of T. chinensis was 63.59 and73.12 % for T. wallichiana. Thus, the threatened status of the two conifers is related to a lack of genetic diversity. All populations are isolated in small forest remnants. An ex situ conservation site should be established with a new population for these species that comprises all the genetic groups for the best chance to improve their fitness under environmental stresses.

关键词： Taxus populations alleles polymorphic microsatellite Vietnam primer accounting putative destruction

Polygonal Finite Element for Two-Dimensional Lid-Driven Cavity Flow

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Computers, Materials & Continua 2022年第3期70卷 4217-4239页

作者： T.Vu-Huu C.Le-Thanh H.nguyen-xuan M.Abdel-Wahab Faculty of Civil Engineering Vietnam Maritime University484 Lach Tray Str.Hai PhongVietnam Faculty of Civil Engineering and Electricity Ho Chi Minh City Open UniversityVietnam CIRTech Institute Ho ChiMinh City University of Technology(HUTECH)Ho Chi Minh CityVietnam Department of Architectural Engineering Sejong University209 NeungdongroGwangjinguSeoul05006Republic of Korea Soete Laboratory Faculty of Engineering and ArchitectureGhent UniversityTechnologiepark Zwijnaarde903B-9052ZwijnaardeBelgium

This paper investigates a polygonal finite element(PFE)to solve a two-dimensional(2D)incompressible steady fluid problem in a cavity *** is a well-known standard benchmark(i.e.,lid-driven cavity flow)-to evaluate the numerical methods in solving fluid problems controlled by the Navier-Stokes(N-S)equation *** approximation solutions provided in this research are based on our developed equal-order mixed PFE,called *** is an exciting development based on constructing the mixed scheme method of two equal-order discretisation spaces for both fluid pressure and velocity fields of flows and our proposed stabilisation *** this research,to handle the nonlinear problem of N-S,the Picard iteration scheme is *** proposed method’s performance and convergence are validated by several simulations coded by commercial software,i.e.,*** this research,the benchmark is executed with variousReynolds numbers up to the maximum Re=*** results then numerously compared to available sources in the literature.

关键词： Lid-driven cavity incompressible steady Navier-Stokes equations polygonal finite element method

Stabilization for Equal-Order Polygonal Finite Element Method for High Fluid Velocity and Pressure Gradient

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Computers, Materials & Continua 2020年第3期62卷 1109-1123页

作者： T.Vu-Huu C.Le-Thanh H.nguyen-xuan M.Abdel-Wahab Department of Electrical energy MetalsMechanical Constructions and SystemsFaculty of Engineering and ArchitectureGhent UniversityGhentBelgium Faculty of Civil Engineering Vietnam Maritime UniversityHai PhongVietnam Faculty of Civil Engineering and Electricity Ho Chi Minh City Open UniversityHo Chi MinhVietnam CIRTech Institute Ho Chi Minh City University of Technology(HUTECH)Ho Chi MinhVietnam Division of Computational Mechanics Ton Duc Thang UniversityHo Chi MinhVietnam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi MinhVietnam

This paper presents an adapted stabilisation method for the equal-order mixed scheme of finite elements on convex polygonal meshes to analyse the high velocity and pressure gradient of incompressible fluid flows that are governed by Stokes equations *** technique is constructed by a local pressure projection which is extremely simple,yet effective,to eliminate the poor or even non-convergence as well as the instability of equal-order mixed polygonal *** this research,some numerical examples of incompressible Stokes fluid flow that is coded and programmed by MATLAB will be presented to examine the effectiveness of the proposed stabilised method.

关键词： Polygonal finite element method fluid computation stokes equation mixed method local projection

Genetic diversity and conservation of two threatened dipterocarps(Dipterocarpaceae) in southeast Vietnam

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Journal of Forestry Research 2019年第5期30卷 1823-1831页

作者： Dinh-Duy Vu Thi Tuyet-xuan Bui Minh-Duc nguyen Syed Noor Muhammad Shah Dinh-Giap Vu Yi Zhang Minh-Tam nguyen Xiao-Hua Huang College of Forestry Northwest A&F UniversityYanglingShaanxi 712100People’s Republic of China Vietnam National Museum of Nature Vietnam Academy of Science and Technology(VAST)18 Hoang Quoc VietCau GiayHanoiVietnam Institute of Ecology and Biological Resource Vietnam Academy of Science and Technology(VAST)18 Hoang Quoc VietCau GiayHanoiVietnam Department of Horticulture Faculty of AgricultureGomal UniversityDera Ismail KhanPakistan Institute of Natural Products Chemistry Vietnam Academy of Science and Technology(VAST)18 Hoang Quoc VietCau GiayHanoiVietnam

Two threatened dipterocarp species,Dipterocarpus costatus and Dipterocarpus alatus are well-known endangered species in lowland forests of southeastern Vietnam,primarily from habitat loss and over-exploitation of their *** develop conservation strategies for these species,we analyzed 242 samples using nine microsatellite markers to determine the genetic variability within and among five populations of *** and three of ***,representing the natural range of dipterocarps in Southeast *** indicated low levels of genetic variability within populations with an average gene diversity of 0.223 for *** and 0.152 for *** of bottleneck tests indicated a reduction in population size of both species(P>0.05).Genetic differentiation among populations was high(FST=0.347 for *** and 0.274 for ***),indicating limited gene flow(Nm=0.662 for *** and 0.47 for ***)and isolated populations related to geographical *** of molecular variance showed high genetic variation within populations(72.92%for *** and 60.81%for ***)compared to among *** analysis and UPGMA tree also indicated the two optimal genetic clusters related to geographical *** results will provide a platform for the conservation,management and restoration of these species.

关键词： Dipterocarps Genetic conservation Gene diversity SSR primers

Fuzzy Feedback Control for Electro-Hydraulic Actuators

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Intelligent Automation & Soft Computing 2023年第5期36卷 2441-2456页

作者： Tan nguyen Van Huy Q.Tran Vinh xuan Ha Cheolkeun Ha Phu Huynh Minh School of Engineering-Technology Thu Dau Mot UniversityThu Dau Mot City590000Vietnam Faculty of Engineering-Technology Nguyen Tat Thanh UniversityHo Chi Minh City754000Vietnam Hue Industrial College Hue City530000Vietnam Robotics and Mechatronics Lab University of UlsanUlsan City44610Korea

Electro-hydraulic actuators(EHA)have recently played a signiﬁcant role in modern industrial applications,especially in systems requiring extremely high *** can be explained by EHA’s ability to precisely control the position and force through advanced sensors and innovative control *** of the promising approaches to improve control accuracy for EHA systems is applying classical to modern control algorithms,in which the proportional–inte-gral–derivative(PID)algorithm,fuzzy logic controller,and a hybrid of these methods are popular *** this paper,we developed a novel version of the fuzzy control algorithm and linear feedback control method,namely fuzzy lin-ear feedback control,to improve the control *** achieve the highest performance,weﬁrst designed a mathematical EHA model based on the Matlab/Simulink software packages thanks to the selected parameters,which are similar to a real EHA ***,we respectively applied PID,fuzzy PID(FPID),and fuzzy linear feedback control(FLFC)before comparing them to have a full view of the outstanding advantages of the proposed *** simulation results showed that the proposed FLFC algorithm is approximately 99%and 77%super-ior in performance to the PID and feedback control algorithms,respectively.

关键词： Electro-hydraulic actuator fuzzy PID feedback control