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Inferences on the Difference of Two Proportions: A Bayesian Approach

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Open Journal of Statistics 2017年第1期7卷 1-15页

作者： Thu Pham-Gia nguyen van thin Phan Phuc Doan Department of Mathematics and Statistics Université de Moncton New Brunswick Canada Faculty of Mathematics and Computer Science Hochiminh University of Science Ho Chi Minh Vietnam

Let π=π1-π2 be the difference of two independent proportions related to two populations. We study the test H0:π≥0 against different alternatives, in the Bayesian context. The various Bayesian approaches use standard beta distributions, and are simple to derive and compute. But the more general test H0:π≥η, with η>0, requires more advanced mathematical tools to carry out the computations. These tools, which include the density of the difference of two general beta variables, are presented in the article, with numerical examples for illustrations to facilitate comprehension of results.

关键词： Proportion Convolution Normal Beta Bayesian Critical Value Appell’s Function

An Analytical Approach for Nonlinear Buckling Analysis of Torsionally Loaded Sandwich Carbon Nanotube Reinforced Cylindrical Shells with Auxetic Core

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Advances in Applied Mathematics and Mechanics 2023年第2期15卷 468-484页

作者： Dang Thuy Dong nguyen Thi Phuong Vu Hoai Nam Le Ngoc Ly nguyen van Tien Vu Minh Duc Tran Quang Minh Vu Tho Hung nguyen Thi Huong Giang Faculty of Civil Engineering University of Transport TechnologyHanoi 100000Vietnam Graduate School of Advanced Science and Engineering Hiroshima University1-4-1 KagamiyamaHigashi-HiroshimaHiroshima 739-8527Japan Faculty of Fundamental Science for Engineering University of Transport TechnologyHanoi 100000Vietnam

The main aim of this paper is to present an analytical approach on the postbuckling for torsionally loaded sandwich carbon nanotube(CNT)reinforced cylindrical shells with the auxetic *** considered shells consist of three layers,external and internal CNT reinforced layers,and the auxetic lattice core made by isotropic *** homogenization model for honeycomb auxetic lattice core is utilized,and the equilibrium equations are formulated based on the nonlinear Donnell’s thin shell theory with von Karman geometrical *** three terms of deflection are considered,the Airy’s stress function and Galerkin’s method are utilized,the explicit expression of critical buckling of torsionally loaded shells and load-deflection expression of postbuckling states are *** effects of two carbon nanotube reinforced layers,the auxetic core layer,the volume fraction of carbon nanotube on the torsional buckling behavior are examined and remarked.

关键词： Nonlinear postbuckling carbon nanotube reinforced composite cylindrical shell torsion auxetic core

Hydrogen roles approaching ideal electrical and optical properties for undoped and Al doped ZnO thin films

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Journal of Materiomics 2022年第1期8卷 123-135页

作者： Dung van Hoang Nam Hoang Vu Nga Thi Do Anh Tuan Thanh Pham Truong Huu nguyen Jer-Lai Kuo Thang Bach Phan Vinh Cao Tran Laboratory of Advanced Materials University of ScienceHoChiMinh City700000Viet Nam Vietnam National University HoChiMinh City700000Viet Nam HoChiMinh City Institute of Physics HoChiMinh City700000Viet Nam Institute of Atomic and Molecular Sciences Academia SinicaTaipei10617Taiwan Center for Innovative Materials and Architectures(INOMAR) HoChiMinh City700000Viet Nam Faculty of Materials Science&Technology University of ScienceHoChiMinh City700000Viet Nam

This paper distinguished hydrogen roles to improve electron mobility and carrier concentration in ZnO and Al doped ZnO sputtered *** combining experimental evidences and theoretical results,we find out that hydrogen located at oxygen vacancy sites(H_(O))is the main factor gives rise to increase simultaneously mobility and carrier concentration which has not been mentioned *** appropriate hydrogen content during sputtering not only results in crystalline relaxation but also supports doping Al into ZnO,increasing carrier concentration and electron mobility in the *** principles calculations confirmed hydrogen substitutional stability for oxygen vacancy,significantly reducing electron conductivity effective mass and hence increasing electron *** particular,0.8%hydrogen partial pressure ratio achieved 61 cm^(2)V^(-1)s^(-1)maximum electron mobility,optical transmittance above 82%in visible and near-infrared regions,and 2×10^(20) cm^(-3)carrier concentrations for H-Al co-doped ZnO *** values approach ideal electrical and optical properties for transparent conducting oxide *** presence of one maximum electron mobility was attributed to competition between increasing mobility due to restoring effective electron mass and hydrogen passivation of native defects,and decreased electron mobility due to electron-phonon scattering.

关键词： High electron mobility Hydrogen roles Passivation effects Effective electron mass DFT calculations Doped ZnO thin Film

Engineering a light–matter strong coupling regime in perovskite-based plasmonic metasurface: quasi-bound state in the continuum and exceptional points

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Photonics Research 2020年第12期8卷 I0005-I0014页

作者： LERAN LU QUYNH LE-van LYDIE FERRIER EMMANUEL DROUARD CHRISTIAN SEASSAL HAI SON nguyen Universitéde Lyon Institut des Nanotechnologies de LyonINL/CNRSEcole Centrale de Lyon36 avenue Guy de Collongue69130 EcullyFrance College of Engineering and Computer Science VinUniversityHanoi 14000Vietnam Universitéde Lyon Institut des Nanotechnologies de LyonINL/CNRSINSA-Lyon7 avenue Jean Capelle69621 VilleurbanneFrance Institut Universitaire de France(IUF) ParisFrance

We present theoretically the formation of exciton–photon polaritons and exciton-surface plasmon polaritons in a perovskite-based subwavelength lattice on the metallic *** is shown that the later polaritons will be achieved as the perovskite layer is ultra-thin(<50 nm),while the co-existence of both polaritons will dominate,as the thickness of the perovskite metasurface approaches *** the two cases,the lower polaritonic branches consist of dark and bright modes corresponding to infinite and finite radiative quality factors,*** salient property in this work is that it allows one to obtain exceptional points(EPs)in momentum space with a four-fold enhancement of local density of states through engineering the perovskite *** findings show that the perovskite metasurface is an attractive and rich platform to make polaritonic devices,even with the presence of a lossy metallic layer.

关键词： surface. perovskite exceptional

Two-Dimensional Aerodynamic Models of Insect Flight for Robotic Flapping Wing Mechanisms of Maximum Efficiency

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Journal of Bionic Engineering 2008年第1期5卷 1-11页

作者： Thien-Tong nguyen Doyoung Byun Department of Aeronautical Engineering Hochiminh City University of Technology Hochiminh City Vietnam Department of Aerospace Engineering Konkuk University Seoul 143-701 Korea

In the ＂modified quasi-steady＂ approach, two-dimensional （2D） aerodynamic models of flapping wing motions are analyzed with focus on different types of wing rotation and different positions of rotation axis to explain the force peak at the end of each half stroke. In this model, an additional velocity of the mid chord position due to rotation is superimposed on the translational relative velocity of air with respect to the wing. This modification produces augmented forces around the end of each stroke. For each case of the flapping wing motions with various combination of controlled translational and rotational velocities of the wing along inclined stroke planes with thin figure-of-eight trajectory, discussions focus on lift-drag evolution during one stroke cycle and efficiency of types of wing rotation. This ＂modified quasi-steady＂ approach provides a systematic analysis of various parameters and their effects on efficiency of flapping wing mechanism. Flapping mechanism with delayed rotation around quarter-chord axis is an efficient one and can be made simple by a passive rotation mechanism so that it can be useful for robotic application.

关键词： bionics modified quasi-steady approach insect flight hovering forward flight

Inner crust of neutron stars in a relativistic mean field approach

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Inner crust of neutron stars in a relativistic mean field ap...

Fabrication and Characterization of Multi-layer Heat Mirror with Photocatalytic Properties

International Workshop on Nuclear Dynamics in Heavy-ion Reactions and Neutron Stars

作者： nguyen van Giai Institut de Physique Nucleaire Universite Paris-Sud OrsayFrance

＜正＞In the physics of neutron stars the inner crust deserves a special attention for the role it plays in the cooling *** cooling time depends very much indeed on the specific heat of that particular region of the neutron star,and it is therefore interesting to have microscopic models of the inner crust so as to evaluate this specific *** inner crust is a relatively thin layer containing a lattice of nucleus-like clusters immersed in a dilute gas of neutrons and relativistic *** density of the crust varies from the neutron drip density to about half of the saturation *** is usually modelized an isolated and spherical Wigner-Seitz（W-S）cell,where neutron-rich nuclei immersed in a sea of dilute, inhomogeneous neutron gas.

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Chinese Physics Letters 2009年第11期26卷 152-155页

作者： Tran Le Tuan Tran Huu Chi nguyen Dac Ngoc Son Luu Minh Nam Hoang Dinh Quan nguyen Department of Applied Physics College of Natural Science National University of He Chi Mirth City 227 Nguyen Van Cu District 5 Ward 4 He Chi Minh City Vietnam Department of Chemical Engineering College of Technology National University of He Chi Minh City 168 Ly Thuong Kiet District 10 Ho chi Minh City Vietnam

A novel TiO2（5）/TiO2（buffer）/Ti（4）/Ag（3）/Ti（2）/TiO2（1） multi-layer film coating with corning glass is designed and fabricated by a dc magnetron sputtering method as a renovation of the well-known TiO2/Ti/Ag/Ti/TiO2 system in order to obtain a heat mirror system with photocatalytic properties due to sufficient thickness of the Ti02 layer. The outer TiO2 layer is fabricated in two steps, possibly claimed as two layers TiO2（5） and TiO2（buuer）, among which TiO2（buffer） the 70-nm-thick layer deposited in poor oxygen effectively minimizes the oxidation toward its neighbor Ti（4） layer. The optimal total thickness of the TiO2（5） and TiO（buffer） di-layer is found to be 300nm to yield a highly photo-catalytic property of the film without affecting the optical properties considerably. This multi-layer film can transmit light of above 75-85% in the visible spectrum （380 ≤ λ≤ 760 nm） and reflect radiation of above 90% in the infrared spectrum （ λ≥760 nm）. Such multi-layer coatings are strongly recommended not only as promising transparent heat mirrors but also as photo-catalytic films for architectural window coatings.

关键词： Condensed matter: electrical magnetic and optical Surfaces interfaces and thin films Chemical physics and physical chemistry

越南蒲马特国家自然保护区植物区系特征(英文)

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广西植物 2008年第5期28卷 620-626页

作者：陈春强阮青闲阮义辰朱华中国科学院西双版纳热带植物园云南勐腊666303 越南蒲马特国家公园越南义安越南河内大学生物系越南河内

蒲马特国家公园位于越南中部的义安省,国际著名的生物多样性极为丰富的Annamite山系的核心地区。基于植物标本鉴定,在蒲马特国家公园保护区内记录有维管束植物184科,771属,2018种(包括变种和亚种)。该植物区系占整个越南植物区系的21 %... 详细信息

蒲马特国家公园位于越南中部的义安省,国际著名的生物多样性极为丰富的Annamite山系的核心地区。基于植物标本鉴定,在蒲马特国家公园保护区内记录有维管束植物184科,771属,2018种(包括变种和亚种)。该植物区系占整个越南植物区系的21 %,其中的木兰亚纲植物占该植物区系总种数的90 .98 %,总属数的90 .4 %及总科数的83 .7 %。含种数最多的科包括茜草科(37属/129种) ,大戟科(36/99) ,兰科(34/73) ,樟科(11/66) ,桑科(10/54) ,蝶形花科(24/51) ,壳斗科(4/50) ,紫金牛科(5/48)及芸香科(14/45)等。在种子植物地理成分组成上,有11个科的分布区类型及14属分布区类型,其中,热带分布型分别占总科数的85 .6 %和总属数的90 .1 %,并且在其热带分布属中,热带亚洲成分占总属数的31 .4 %。这些特征显示,蒲马特国家公园植物区系是典型热带性质的植物区系,属于热带亚洲植物区系的一部分。

关键词：蒲马特国家公园植物区系组成地理成分越南

Effect of initial precursor concentration on TiO_2 thin film nanostructures prepared by PCVD system

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Journal of Energy Chemistry 2013年第3期22卷 375-381页

作者： Hoang Hai nguyen Dong-Joo Kim Dong-Wha Park Kyo-Seon Kim Department of Chemical Engineering Kangwon National UniversityChuncheonKangwon-Do200-701Republic of Korea Department of Chemical Engineering and RIC-ETTP(Regional Innovation Center for Environmental Technology of Thermal Plasma) Inha University253 Yonghyun-dongNam-guIncheon402-751Republic of Korea

TiO2 thin film was prepared on Si substrate by plasma chemical vapor deposition （PCVD） system and the morphologies of ZiO2 thin film were controlled by adjusting the initial precursor concentration. As the initial titanium tetra-isopropoxide （TTIP） concentration increases in PCVD reactor, the shapes of TiO2 particles generated in PCVD reactor change from the spherical small-sized particles around 20 nm and spherical large-sized particles around 60 nm to aggregate particles around 100 nm. The TiO2 particles with different shapes deposit on the substrate and become the main building blocks of resulting TiO2 thin film. We observed the TiO2 thin film with smooth morphology at low initial TTIP concentration, granular morphology at medium initial TTIP concentration, and columnar morphology at high initial TTIP concentration. It is proposed that we can prepare the TiO2 thin film with controlled morphologies in one-step process just by adjusting the initial precursor concentration in PCVD .

关键词： plasma chemical vapor deposition thin film growth morphology of TiO2 thin film shape of TiO2 particles