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Atomistic simulation of free transverse vibration of graphene,hexagonal SiC, and BN nanosheets

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Acta Mechanica Sinica 2017年第1期33卷 132-147页

作者： Danh-Truong nguyen minh-Quy Le Thanh-Lam Bui Hai-Le Bui School of Mechanical Engineering Hanoi University of Science and Technology Hanoi 10000 Vietnam International Institute for Computational Science and Engineering Hanoi University of Science and TechnologyHanoi 10000 Vietnam Faculty of Mechanical Engineering Hanoi University of Industry Hanoi 10000 Vietnam

Free transverse vibration of monolayer graphene, boron nitride (BN), and silicon carbide (SiC) sheets is investigated by using molecular dynamics finite element method. Eigenfrequencies and eigenmodes of these three sheets in rectangular shape are studied with different aspect ratios with respect to various boundary conditions. It is found that aspect ratios and boundary conditions affect in a similar way on natural frequencies of graphene, BN, and SiC sheets. Natural frequencies in all modes decrease with an increase of the sheet’s size. Graphene exhibits the highest natural frequencies, and SiC sheet possesses the lowest ones. Missing atoms have minor effects on natural frequencies in this study.

关键词： Atomistic simulation Hexagonal sheet Transverse vibration Molecular dynamics finite element method

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

Factors Affecting Community-Based Tourism Development and Environmental Protection: Practical Study in Vietnam

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Journal of Environmental Protection 2020年第2期11卷 124-151页

作者： nguyen Thi minh Phuong nguyen Van Song Tran Xuan quang Vinh University (VU) Vinh Vietnam Vietnam National University of Agriculture (VNUA) Hanoi Vietnam Academy of Social Sciences Vietnam Academy of Social Sciences Hanoi Vietnam

Community-based tourism (CBT) is considered as one of the typical types of tourism towards sustainable development with three important goals such as bringing back economic benefits, protecting natural environment and preserving indigenous cultural values. Therefore, this paper analyzes the factors that affect community ecotourism development associated with environmental protection in emerging economies, including Vietnam, by the method of key and community tourism potential value assessment with 721 sample surveys. In this paper, we have applied to assess the key factors of tourism in Vietnam and other key points to have more comprehensive solutions to promote the development of community-based tourism with environmental protection. The article has used guest-based approach and method of assessing the key success factors. The results of researching factors to develop community tourist (impacting tourist community needs of tourists) by running Logit function have shown the great influence of factors such as: environmental protection (influence factor +3.585780, with a statistical significance of 99%), security and safety (+3.024816—statistical significance 99%) followed by infrastructure conditions & facilities for the community based tourism, the level of information etc… for your community based tourism needs. From the research results, we propose the following policy groups: 1) Developing guidelines for CBT, the first step as a basis for the development of community based tourism laws later;2) Policies related to the implementation of planning, development of key community tourist areas and destinations;3) Policies related to the development of community-based tourism associated with the protection of natural and cultural environments;4) Policies related to tourism management;coordinating monitoring of community tourism resource points;policies related to the local community in community tourism development;5) Policies related to human resource development;promo

关键词： Community Tourism Development of Community-Based Tourism Environment Protection Vietnam

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

Effectiveness on post-stroke hemiplegia in patients:electroacupuncture plus cycling vs electroacupuncture alone

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Journal of Traditional Chinese Medicine 2023年第2期43卷 352-358页

作者： minh Duc nguyen Thanh Van Tran Quoc Vinh nguyen Ninh Khac nguyen Son Truong Vu Luu Trong nguyen Linh Vu Phuong Dang Senior Specialist Clinic National Hospital of AcupunctureHanoi 1000Vietnam Department of Senior Specialist National Hospital of Acupuncture Hanoi 1000Vietnam Department of Senior Specialist Military Institute of Traditional MedicineHanoi 1000Vietnam Department of Training and Science National Hospital of AcupunctureHanoi 1000Vietnam Department of Senior Specialist National Hospital of AcupunctureHanoi 1000Vietnam Department of Rehabilitation 108 Military Central HospitalHanoi 1000Vietnam Department of Medicine Dai Nam UniversityHanoi 1000Vietnam

OBJECTIVE:To evaluate the effectiveness of cycling in combination with electroacupuncture in treatment of poststroke hemiplegia patients at National Hospital of Acupuncture,***:The study was designed as a single-centre,outcome-assessor-blinded parallel randomised controlled trial with 120 post-stroke hemiplegia patients randomly assigned into two groups:electroacupuncture plus cycling(CT group) and electroacupuncture(AT group).Patients were assessed before and after the treatment(using muscle grading,modified Rankin,Barthel,Orgorozo scores and electromyography).Statistical Man–Whitney U test,and Fisher’s exact tests were used to compare between CT and AT ***:The results reported statistically significant improvement in motor function in patients suffering from hemiplegia following ischemic stroke in both CT and AT *** in CT group experienced a greater improvement compared to those in AT group including better muscle contraction(increased frequency and amplitude of electromyography and increased muscle grading scale);increased recovery(Orgogozo scale),increased independency(Barthel scale) and decreased disability(Modified Rankin scale)(P < 0.01).CONCLUSIONS:Combination with cycling training significantly improves the recovery of post-stroke patients treated with electroacupuncture.

关键词： electroacupuncture cycle training post-stroke hemiplegia

Prediction of BRIC Stock Price Using ARIMA,SutteARIMA,and Holt-Winters

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Computers, Materials & Continua 2022年第1期70卷 523-534页

作者： Ansari Saleh Ahmar Pawan Kumar Singh nguyen Van Thanh nguyen Viet Tinh Vo minh Hieu Department of Statistics Faculty of Mathematics and Natural ScienccesUniversitas Negeri MakassarMakassar90223Indonesia School of Humanities and Social Sciences Thapar Institute of Engineering and TechnologyPatiala147004India Faculty of Commerce Van Lang UniversityHo Chi Minh City70000Vietnam

The novel coronavirus has played a disastrous role in many countries *** outbreak became a major epidemic,engulfing the entire world in lockdown and it is now speculated that its economic impact might be worse than economic deceleration and *** paper identifies two different models to capture the trend of closing stock prices in Brazil(BVSP),Russia(***),India(BSESN),and China(SSE),i.e.,(BRIC)*** predict the stock prices for three daily time periods,so appropriate preparations can be undertaken to solve these ***,we compared the ARIMA,SutteARIMA and Holt-Winters(H-W)methods to determine the most effective model for predicting *** stock closing price of BRIC country data was obtained from Yahoo *** data dates from 01 November 2019 to 11 December 2020,then divided into two categories-training data and test *** data covers 01 November 2019 to 02 December *** days(03December 2020 to 11December 2020)of datawas tested to determine the accuracy of the models using training data as a *** measure the accuracy of the models,we obtained the means absolute percentage error(MAPE)and mean square error(MSE).Prediction model Holt-Winters was found to be the most suitable for forecasting the Brazil stock price(BVSP)while MAPE(0.50)and MSE(579272.65)with Holt-Winters(smaller than ARIMA and SutteARIMA),model SutteARIMA was found most appropriate to predict the stock prices of Russia(***),India(BSESN),and China(SSE)when compared to ARIMA and *** andMSE with SutteARIMA:Russia(MAPE:0.7;MSE:940.20),India(MAPE:0.90;MSE:207271.16),and China(MAPE:0.72;MSE:786.28).Finally,Holt-Winters predicted the daily forecast values for the Brazil stock price(BVSP)(12 December to 14 December 2020 i.e.,115757.6,116150.9 and 116544.1),while SutteARIMA predicted the daily forecast values of Russia stock prices(***)(12 December to 14 December 2020 i.e.,3238.06,3241.54 and 3245.01),India stock price(BSESN)(

关键词： SutteARIMA Holt-Winters ARIMA stock price COVID-19

Mathematical modeling and numerical computation of the effective interfacial conditions for Stokes flow on an arbitrarily rough solid surface

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Applied Mathematics and Mechanics(English Edition) 2021年第5期42卷 721-746页

作者： A.T.TRAN H.LE quang Q.C.HE D.H.nguyen Research and Application Center for Technology in Civil Engineering University of Transport and CommunicationsHanoi 10000Vietnam Laboratoire Modelisation et Simulation Multi-Echelle Unite Mixte de Recherche 8208Centre National de la Recherche ScientifiqueUniversite Gustave EiffelMarne-la-Vallee F-77454France School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China

The present work is concerned with a two-dimensional(2D)Stokes flow through a channel bounded by two parallel solid *** distance between the walls may be arbitrary,and the surface of one of the walls can be arbitrarily *** main objective of this work consists in homogenizing the heterogeneous interface between the rough wall and fluid so as to obtain an equivalent smooth slippery fluid/solid interface characterized by an effective slip *** solve the corresponding problem,two efficient numerical approaches are elaborated on the basis of the method of fundamental solution(MFS)and the boundary element methods(BEMs).They are applied to different cases where the fluid/solid interface is periodically or randomly *** results obtained by the proposed two methods are compared with those given by the finite element method and some relevant ones reported in the *** comparison shows that the two proposed methods are particularly efficient and accurate.

关键词： effective slip length method of fundamental solution(MFS) boundary element method(BEM) Stokeslet micro-channel fluid/solid interface

Effectiveness of bee venom acupuncture for patients suffering from periarthritis humeroscapularis

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中医杂志:英文版 2023年第4期43卷 795-800页

作者： minh Duc nguyen Thanh Van Tran Quoc Vinh nguyen Cay Doan Ha Linh Vu Phuong Dang Senior Specialist Clinic National Hospital of AcupunctureHanoi 1000Vietnam Department of Senior Specialist National Hospital of Acupuncture Hanoi 1000Vietnam Department of Senior Specialist Military Institute of Traditional MedicineHanoi 1000Vietnam Department of minimally invasive spine National Hospital of AcupunctureHanoi 1000Vietnam Department of Medicine Dai Nam UniversityHanoi 1000Vietnam

OBJECTIVE:To evaluate the efficacy of bee venom acupuncture in humeroscapularis(PHS)***:One hundred and twenty patients diagnosed with PHS were assigned into four groups:BV1(0.01 mg/kg),BV2(0.005 mg/kg),BV3(0.0025 mg/kg),and control group(vitamin B1 plus novocain 3%injection)with 15 d of *** outcomes of the study including visual analogue scale(VAS)score andβ-endorphin,inflammatory cytokines including interleukin-10(IL-10),IL-1βand tumor necrosis factorα(TNF-α)and shoulder function score were assessed at baseline,after 10 and 15 d of ***:All four groups reported statistically significant improvement in VAS score,motion range,and shoulder function score(P<0.01),only the BV3 group showed significant increase of anti-inflammatory(IL-10)and decrease of pro-inflammatory(IL-1β,TNF-α)cytokines after treatment(P<0.05).The BV3 group presented a significant difference between all outcomes compared to the control and other ***:BV3 groups showed better recovery including reduced pain,improved motor function and normalized inflammatory cytokines than current therapy used in Vietnam and other groups.

关键词： periarthritis humeroscapularis bee venom acupuncture visual analogue scale range of motion articular shoulder function score inflammatory cytokines

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

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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