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A tree-based intelligence ensemble approach for spatial prediction of potential groundwater

international Journal of Digital Earth 2020年第12期13卷 1408-1429页

作者： Mohammadtaghi Avand Saeid Janizadeh Dieu tien Bui Viet Hoa pham Phuong thao t.Ngo Viet-Ha Nhu Faculty of Natural Resources and Marine Sciences Tarbiat Modares UniversityTehranIran Geographic information Science Research Group Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Environment and Labour Safety Ton Duc Thang UniversityHo Chi Minh CityVietnam Ho Chi Minh City institute of Resources Geography Vietnam Academy of Science and TechnologyHo Chi Minh CityVietnam institute of Research and Development Duy Tan UniversityDa NangVietnam Department of Geological-Geotechnical Engineering Hanoi University of Mining and GeologyHanoiVietnam

the objective of t.is research is to propose and confirm a new machine learning approach of Best-First tree(BFtree),AdaBoost(AB),MultiBoosting(MB),and Bagging(Bag)ensembles for potential groundwater mapping and assessing role of influencing *** Yasuj-Dena area(iran)is selected as a case *** t.is regard,a Yasuj-Dena database was established with 362 springs locations and 12 groundwater-influencing factors(slope,aspect,elevation,stream power index(SPi),length of slope(LS),topographic wetness index(t.i),topographic position index(t.i),land use,lithology,distance from fault,distance from river,and rainfall).the database was employed to train and validate the proposed groundwater *** area under the curve(AUC)and statistical met.ics were employed to check and confirm the quality of the *** result shows that the BFtree-Bag model(AUC=0.810,kappa=0.495)has the highest prediction performance,followed by the BFtree-MB model(AUC=0.785,kappa=0.477),and the BFtree-MB model(AUC=0.745,kappa=0.422).Compared to the benchmark of Random Forests,the BFtree-Bag model performs better;therefore,we conclude that the BFtree-Bag is a new tool should be used for modeling of groundwater potential.

关键词： Environmental modeling groundwater potential GiS ensemble model decision tree

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High-performance carbon fiber/gold/copper composite wires for lightweight elect.ical cables

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Journal of Materials Science & technology 2020年第7期42卷 46-53页

作者： thang Q.tran Jeremy Kong Yoong Lee Amutha Chinnappan Nguyen Huu Loc Long t.tran Dongxiao Ji W.A.D.M.Jayat.ilaka Vishnu Vijay Kumar Seeram Ramakrishna Department of Mechanical Engineering National University of Singapore9 Engineering Drive 1EA-07-05Singapore 117575Singapore Faculty of Mechanical Engineering Ho Chi Minh City University of TechnologyVNUHCM268 Ly Thuong KietDistrict 10Ho Chi Minh City 740400Viet Nam

in t.is study,we synthesized high-performance Carbon Fiber/Gold/Copper(CF/Au/Cu)composite wires by using a 2-step deposition method via sputtering and *** Au was sputtered on PANbased CFs as a pre-treatment,the wettability and surface reactivity of the CFs were improved,resulting in a homogeneous deposition of Cu on their *** different Cu electrodeposition time,the resulting CF/Au/Cu composite wires could possess a high strength of up to 3.27 GPa(~10 times stronger than copper wires)while their elect.ical conductivity could be as high as 4.4×10^5 S/cm(~75%of that for copper).More importantly,since the composite wires were lightweight(up to 70%lower than Cu mass density),they are a promising candidate to substitute conventional heavy metal wires in the future elect.ical applications.

关键词： Carbon fiber Copper composite wires Strength Elect.ical properties

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气垫车辆土壤参数估值算法

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上海交通大学学报 2011年第4期45卷 451-456页

作者：许烁喻凡罗哲 pham D t 纪赜上海交通大学机械与动力工程学院上海200240 卡迪夫大学制造工程中心

针对气垫车辆具有附加的垂向力控制自由度的特点,提出了基于g函数和扩展卡尔曼滤波器(EKF)联合算法的土壤参数估值方案.g函数通过解耦土壤参数解决了多解问题,EKF通过减小测量不确定度提高了估值准确性.通过不同噪声水平下算法准确性和... 详细信息

针对气垫车辆具有附加的垂向力控制自由度的特点,提出了基于g函数和扩展卡尔曼滤波器(EKF)联合算法的土壤参数估值方案.g函数通过解耦土壤参数解决了多解问题,EKF通过减小测量不确定度提高了估值准确性.通过不同噪声水平下算法准确性和大噪声重复实验下算法稳定性的实验表明:g-EKF联合算法在各种噪声水平下具有应用鲁棒性,特别是在大噪声工况下,其估值准确性、精确性和稳定性具有明显优势.

关键词：土壤参数估值 g—EKF算法气垫车状态噪声测量噪声

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Ethyl acetate extract of Smilax glabra Roxb roots and its major active compound astilbin promote osteoblastogenesis in vitro by upregulating bone cell differentiation-associated genes

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Asian Pacific Journal of tropical Biomedicine 2021年第12期11卷 553-560页

作者： Huyen t.t.Nguyen Minh t.H.Nguyen thu X.Nguyen Quan M.pham Ha X.Nguyen Phuong t.M.Nguyen University of Science and technology of Hanoi Vietnam Academy of Science and TechnologyHanoiVietnam institute of Biotechnology Vietnam Academy of Science and TechnologyHanoiVietnam institute of Natural Products Chemistry Vietnam Academy of Science and TechnologyHanoiVietnam Graduate University of Science and technology Vietnam Academy of Science and TechnologyHanoiVietnam

Objective:to investigate the osteoblastogenic activity of the ethyl acetate(EtOAc)extract of Smilax glabra Roxb roots and its major active compound ***:Astilbin was isolated from EtOAc extract using silica gel chromatography combined with fraction *** structure of astilbin was determined by analysis of the spectroscopic data in comparison with the *** method was used to detect the *** phosphatase(ALP)activity was determined by the spectrophotomet.ic method at 405 nm using p-nitrophenyl phosphate as a *** deposition was st.ined with alizarin red-S,dist.ined with cetylpyridium chloride,and quantified at 562 *** silico model for astilbin-ALP interaction was analyzed using AutoDock *** changes in expression of osteoblast differentiation related genes were determined using quantitative real-time ***:Both the EtOAc extract and astilbin had no toxicity toward osteoblast MC3t3-E1 cells at 5.0,10,25,and 50μg/*** 25μg/mL,they enhanced ALP activity and mineralization of osteoblasts up to 30%and 55%for the EtOAc extract and 22%and 41%for astilbin,*** docking analysis of astilbin-ALP interaction revealed Arg167,Asp320,His324,and His437 were key residues participating in hydrophobic interaction;meanwhile,His434 and thr436 residues were involved in hydrogen bond formation in the active site of human tissue-nonspecific ***,the expression level of genes opn,col1,osx,and runx2 were up-regulated in astilbin treated samples with the fold changes as 2.2;3.7;4.1;2.3,respectively at 10μg/mL(Pions:the EtOAc extract and its major compound astilbin exhibit osteoblastogenic activity by up-regulating important markers for bone cell *** could be a new and promising osteogenic agent with dual actions for therapeutic applications.

关键词： Smilax glabra Roxb Astilbin Cytotoxicity Osteogenesis Osteoblast Ethyl acetate extract

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Performance evaluation of a two-way relay network with energy harvesting^and hardware noises

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Digital Communications and Networks 2021年第1期7卷 45-54页

作者： Nguyen tien tung pham Minh Nam Phu tran tin Faculty of Electronics technology Industrial University of Ho Chi Minh CityHo Chi Minh CityVietnam Wireless Communcations Research Group Faculy of Electrical and Electronics EngineeringTon Duc Thang UniversityHo Chi Minh CityVietnam

in t.is paper,we propose a two-Way Cognitive Relay Network(tWCRN)where the secondary users operate on an underlay mode to access the licensed *** the proposed protocols,two secondary sources transmit their data to a relay in the first time slot,and then the relay would forward the received information to both sources in the remaining ***,the relay is self-powered by harvesting energy from ambient Radio Frequency(RF)signals,using the time Switching(tS)and the Power Switching(PS)*** paper concentrates on eval-uating the performance of the secondary networks under the impact of hardware impairments and co-channel interference from the primary *** particular,based on the secondary transmitters'constraint power,we derive the closed-form expressions of the outage probability and the throughput over Rayleigh fading channels in two cases:tS and *** also investigate the energy efficiency issue and the locally optimal position of the relay to maximize the system throughput,which provides much information to install the relay ***,our derivations are verified by Monte Carlo simulation.

关键词： Energy harvesting two-way relay Energy efficiency Hardware impairments Cognitive network

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integrated universal soil loss equation (USLE) and Geographical information System (GiS) for soil erosion estimation in A Sap basin:Central Vietnam

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international Soil and Water Conservation Research 2018年第2期6卷 99-110页

作者： tung Gia pham Jan Degener Martin Kappas Cartography GIS and Remote Sensing DepartmentGottingen UniversityGermany University of Agriculture and Forestry Hue UniversityVietnam

Central Vietnam is very susceptible to soil erosion due to its complicated terrain and heavy rainfall. the objective of t.is study was to quantify soil erosion in the A Sap river basin, A Luoi dist.ict, thua t.ien Hue Province, Vietnam, using the Universal Soil Loss Equation (USLE) and Geographical informa-tion System (GiS). the results showed that 34% of land area lost accumulated to 10 t ha-1 year-1 while 47% of the total area lost less than 1 t ha-1 year-1. Natural forest land lost the most with an average of about 19 t ha-1 year-1, followed by plantation forest with approximately 7 t ha-1 year-1 and other agricultural lands at 3.70 and 1.45 t ha-1 year-1 for yearly crops and paddy rice, respectively. Soil erosion was most sensitive to the topographic factor (LS), followed by the practice support factor (P), soil erodibility factor (K), cropping management (C), and the rainfall erosivity factor (R). implications are that changes to the cultivated calendar and implementing intercropping are effective ways to prevent soil erosion in cultivated lands. Furthermore, introducing broad leaves trees for mount.inous areas in A Sap basin was the most effective practice in reducing soil erosion. the study also pointed out that the combination of available data sources used with the USLE and GiS technology is a viable option to cal-culate soil erosion in Central Vietnam, which would allow targeted attention toward a solution is to reduce future soil erosion.

关键词： Central Vietnam GiS Soil erosion USLE

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Surface Mapping of Resistive Switching CrO_x t.in Films

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Advances in Materials Physics and Chemistry 2016年第3期6卷 21-27页

作者： Kim Ngoc pham Kieu Hanh t.i ta Lien thuong t.i Nguyen Vinh Cao tran Bach thang Phan Faculty of Materials Science University of Science Vietnam National University Ho Chi Minh City Vietnam Faculty of Resources and Environment Thu Dau Mot University Binh Duong City Vietnam Laboratory of Advanced Materials University of Science Vietnam National University Ho Chi Minh City Vietnam

in t.is work, we investigated resistive switching behavior of CrOx t.in films grown by using sputtering technique. Conventional i-V measurements obt.ined from Ag/CrOx/Pt/ti/SiO2/Si structures depict the bipolar switching behavior, which is controlled by formation/dissolution processes of Ag conducting filaments through electrochemical redox reaction under external elect.ic field driven. Conductive atomic force microscopy (C-AFM) technique provides the valuable mapping images of existing Ag filaments at low resistance state as well as the characteristics of filament dist.ibutions and diameters. t.is study also reveals that where the higher amplitude of topography is, the easier possibility of forming conducting filament paths is on CrOx surface films.

关键词： Resistive Switching Chromium Oxide C-AFM Surface Mapping Metal Filament

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isogeomet.ic analysis for free vibration of bidirectional functionally graded plates in the fluid medium

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Defence technology（防务技术） 2022年第8期18卷 1311-1329页

作者： Quoc-Hoa pham Phu-Cuong Nguyen Van Ke tran trung Nguyen-thoi Faculty of Civil Engineering Ho Chi Minh City Open UniversityHo Chi Minh CityViet Nam Faculty of Mechanical Engineering Le Quy Don Technical UniversityHanoiViet Nam Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Duc Thang UniversityHo Chi Minh CityViet Nam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityViet Nam

t.is paper for first time proposes an isogeomet.ic analysis (iGA) for free vibration response of bi-directional functionally graded (BDFG) rectangular plates in the fluid medium. Material properties of the BDFG plate change in both the t.ickness and length directions via power-law dist.ibutions and Mori-tanaka model. the governing equation of motion of BDFG plate in the fluid-plate system is formulated basing on Hamilton's principle and the refined quasi three-dimensional (3D) plate theory with improved function f(z). the fluid velocity potential is derived from the boundary conditions of the fluid-plate system and is used to determine the added mass. the discrete system of equations is derived from the Galerkin weak form and numerically analyzed by iGA. the accuracy and reliability of the proposed solutions are verified by comparing the obt.ined results with those published in the literature. Moreover, the effects of the various parameters such as the interaction boundary condition, geomet.ic parameter, submerged depth of plate, fluid density, fluid level, and the material volume control coefficients on the free vibration behavior of BDFG plate in the fluid medium are investigated in det.il. Some major findings regarding the numerical results are withdrawn in conclusions.

关键词： Contact plate-fluid Refined quasi 3D plate theory Mori-tanaka model isogeomet.ic analysis Bidirectional functionally graded plate

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Gamma Cascade transition of 51V(nth, &lt.i>g )52V Reaction

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World Journal of Nuclear Science and technology 2014年第1期4卷 40-45页

作者： pham Dinh Khang Nguyen Xuan Hai Ho Huu thang Vuong Huu tan Nguyen An Son Nguyen Duc Hoa Nuclear Research institute Dalat Vietnam Nuclear training Center Hanoi Vietnam University of Dalat Dalat Vietnam Vietnam Agency for Radiation and Nuclear Safety Hanoi Vietnam

the thermal neutron capture gamma radiations for 51V(n, g)52V reaction have been studied at Dalat Nuclear Research Reactor (DNRR). the gamma two-step cascade transition was measured by event-event coincidence spectrometer. the added-neutron binding energy in 52V was measured as 7.31 MeV. Energy and the intensity transition of cascades were consistent with prediction of single particle model. Furthermore, the spin and the parity of levels were confined.

关键词： Gamma two-Step Cascade Neutron Capture Reaction Coincidence

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基于tGF-β1/Smads信号通路探讨2-十二烷基-6-甲氧基-2,5-二烯-1,4-环己二酮抗肝纤维化的作用机制

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中国药理学通报 2024年第3期40卷 545-551页

作者：黄湘方坤凤范氏泰和梁杏梅黄仁彬李学政广西卫生职业技术学院广西南宁530023 广西平南县妇幼保健院广西平南537300 广西中医药大学附属国际壮医医院广西南宁530001 广西医科大学药学院广西南宁530021

目的探讨2-十二烷基-6-甲氧基-2,5-二烯-1,4-环己二酮(2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione,DMDD)对CCl_(4)致大鼠肝纤维化的影响及潜在作用机制。方法采用50%CCl_(4)复制肝纤维化模型,检测血液中门冬氨酸转移酶(aspartate transferase,ASt)、丙氨酸转移酶(alanine transferase,ALt)、白蛋白/球蛋白(albumin/globulin,A/G)、总蛋白(total prot.in,tP)、总胆红素(total bilirubin,t-BiL)、大鼠透明质酸(hyaluronic acid,HA)、层黏连蛋白(laminin,LN)、Ⅲ型胶原(collagen typeⅢ,ColⅢ)和Ⅳ型胶原(collagen typeⅣ,ColⅣ)。HE和Masson染色观察肝脏组织病变和纤维形成情况。免疫组织化学法检测肝脏组织中α平滑肌肌动蛋白(αsmooth muscle actin,α-SMA)、Ⅰ型胶原(collagen typeⅠ,Coli)、转化生长因子β1(transformed growth factor-β1,tGF-β1)、Smad2、Smad7蛋白表达水平。Rt-PCR法检测肝脏组织中α-SMA、Coli、tGF-β1、Smad7mRNA水平。Western blot法检测肝脏组织中tGF-β1、Smad4、Smad7蛋白表达水平。结果与正常对照组相比,模型组血清ASt、ALt、tP、t-BiL、HA、LN、ColⅢ、ColⅣ水平明显升高,A/G水平明显降低,肝脏HE和Masson染色显示有大量纤维形成,说明造模成功。与模型组相比,DMDD给药组大鼠ASt、ALt、tP、t-BiL、HA、LN、ColⅢ、ColⅣ含量和α-SMA、Coli、tGF-β1、Smad2、Smad4mRNA及蛋白水平显著下调,A/G、Smad7水平上调。肝脏HE和Masson染色结果显示纤维增生明显减少。结论DMDD对CCl_(4)诱导的肝纤维化具有保护作用,其机制可能与tGF-β1/Smads信号通路有关。

关键词： DMDD CCl_(4) 大鼠肝纤维化作用机制 tGF-β1/Smads信号通路

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