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Fabrication of Silicon Quantum Wires by Conventional Silicon Processing

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high Technology Letters 1995年第1期1卷 25-27页

作者： Yi, Sh. Jianlin, L. Feng, W. Rong, zh. Ping, h. Shulin, G. Shunming, zh. Baohua, M. Youdou, zh. Nanjing Univ Nanjing China

Ultra fine silicon quantum wires with the Si/SiO2 heterointerface have been fabricated successfully by using reactive ion etching, anisotropic wet chemical etching and subsequent thermal oxidation. The cross-sectional image of scanning electron microscope shows the silicon quantum wires of high quality with the linewidth down to 20nm. The present method has many remarkable advantages, which is important to the study of low-dimension quantum physics and devices.

关键词： Quantum wire Silicon Silicon dioxide Silicon technique

Co-substitution of zirconium and neodymium on hyperfine interactions and AC susceptibility of SrFe12O19 nanohexaferrites

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Journal of Rare Earths 2020年第3期38卷 265-273页

作者： M.A.Almessere Y.Slimani h.Güngünes A.Baykal Department of Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 198231441DammamSaudi Arabia Department of Biophysics Institute for Research&Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.O.Box 198231441DammamSaudi Arabia Department of Physics Hitit University19030Cevre Yolu Bulvan-CorumTurkey Department of Nano-Medicine Research Institute for Research&Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.O.Box 198231441DammamSaudi Arabia

This study presents the influence of Zn and Nd co-substitution on structure,morphology,AC susceptibility and ZFC-FC magnetizations of Sr nanohexaferrites(NhFs),SrFe12-x(Zn,Nd)xO19(0.0≤x≤1.0),which was produced by sol-gel *** powder patterns,scanning electron microscopy(SEM) and high-resolution transmission electron spectroscopy(hR-TEM) approve the synthesis of Sr M-type *** spectra show that Zn^2+ions occupy 2 b and 4f1 sites while Nd3+ions locate at 2 a,4f2 and 12 k *** magnetic properties of the produced Sr-NhFs were investigated also by ZFC-FC magnetizations and AC *** to the MFC-MZFC results(between 2 and 400 K),no blocking temperature was detected which indicates the ferromagnetic(FM) behavior of *** lower temperatures,a super-spin glass like behavior is *** AC susceptibility indicates that the magnetic interactions are improved due to the inclusion of low content(x=0.1) of Nd^3+and Zn^2+ions into the ***,with further increasing the Nd^3+and Zn^2+contents(x=0.9),the magnetic interactions are weakened.

关键词： Sr hexaferrites Rare earths Mossbauer spectroscopy AC susceptibility ZFC-FC

Constructive proof on the existence of periodic solution of Duffing equation

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Chinese Science Bulletin 1997年第22期42卷 1870-1874页

作者： Li, WG Shen, zh Nanjing Univ Dept Math Nanjing 210093 Peoples R China

CONSIDER the following boundary value problem of Duffing equation:{x(t)+Cx’(t)+g(t,x)=e(t), x(0)-x’(zπ)=x’(0)-x’(2π)=0,} (1)where g: R×R→R is continuous and continuously differentiable with respect to x, continu-ous and 2π-periodic with respect to t. C is a constant. e: R→R is continuous and 2π-period-ic. If there exist two almost everywhere continuous functions a(t), b(t)

关键词： Duffing equation periodic solution continuation.

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从消费税的设置目的谈我国消费税改革

消费经济 2005年第2期21卷 31-33页

作者：何志静暨南大学经济学院广东广州510632

我国现行的消费税是1994年税改设置的税种,设置目的是为调节产品结构、引导消费方向、保证国家收入。经过十多年的经济发展,我国的现行消费税制在一些方面已经与其设置目的不相符,这就要求我们对现行的消费税制进行改革,更好的发挥消费... 详细信息

我国现行的消费税是1994年税改设置的税种,设置目的是为调节产品结构、引导消费方向、保证国家收入。经过十多年的经济发展,我国的现行消费税制在一些方面已经与其设置目的不相符,这就要求我们对现行的消费税制进行改革,更好的发挥消费税的特殊调节作用。

关键词：消费税设置目的改革中国课税范围税率

Interaction of oblique waves with an array of long horizontal circular cylinders

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Science China(Technological Sciences) 2007年第4期50卷 490-509页

作者： ng Chiu-On Department of Mechanical Engineering the University of Hong Kong Pokfulam Road Hong Kong China

The scattering and radiations of linear oblique waves by multiple long horizontal circular cylinders submerged in water of finite depth are investigated using the multipole expansion method. Analytical expressions for the diffracted and radiated potentials are given as a linear combination of infinite multipoles. The unknown coefficients in the expressions are determined by using the addition theorem of the Bessel function and the cylinder boundary conditions. Also analytical expressions for wave forces, hydrodynamic coefficients and reflection and transmission coeffi-cients are derived. The present analytical solution is verified through the boundary element method and applied to investigate three different cases of the interaction of oblique waves with multiple submerged horizontal circular cylinders. The results show that the number of cylinders, the arrangement and spacing between cylinders play an important role in wave forces, hydrodynamic coefficients and reflection and transmission coefficients. Some interesting and important phenomena are ob-served in numerical experiments.

关键词： scattering and radiation water waves analytical technique hydrodynamic characteristics

Composition Dependence of Surface Phonon Polariton Mode in Wurtzite InxGa1-xN （0 ≤ x ≤ 1） Ternary Alloy

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Chinese Physics Letters 2008年第12期25卷 4378-4380页

作者： S. S. ng Z. hassan h. Abu hassan Nano-Optoelectronics Research and Technology Laboratory School of Physics Universiti Sains Malaysia 11800 Minden Pulau Pinang Malaysia

We present a theoretical study on the composition dependence of the surface phonon polariton （SPP） mode in wurtzite structure α-InxGa1-xN ternary alloy over the whole composition range. The SPP modes are obtained by the theoretical simulations by means of an anisotropy model. The results reveal that the SPP mode of α-InxGa1-xN semiconductors exhibits one-mode behaviour. From these data, composition dependence of the SPP mode with bowing parameter of-28.9 cm^-1 is theoretically obtained.

关键词： field emission molybdenum dioxide enhancement factor

Incorporating geotechnical and geophysical investigations for underground obstruction detection:A case study

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Underground Space 2023年第4期11卷 116-129页

作者： Yaohui Liu Yannick C.h.ng Yunhuo zh.ng Ping Yang Taeseo Ku School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhou 221000China Department of Civil and Environmental Engineering National University of Singapore117576Singapore Geotechnical&Tunnel Division Land Transport Authority Singapore219428Singapore Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Department of Civil and Environmental Engineering Konkuk UniversitySeoul 05029South Korea

Determining the location and boundary of underground obstructions and/or anomalies is a common problem and often a great chal-lenge for tunneling and underground *** this study,geotechnical investigations(penetration tests and borehole drilling/sam-pling)and geophysical investigations(surface wave method and cross-hole seismic method)were conducted with the aim of identifying the location and boundary of rock obstructions in Changi East,*** surface wave method is frequently used in the sites with lateral homogeneity in previous studies,but its application in the sites with rock obstructions is *** experimental results of this study indicate that the surface wave method is also able to determine the upper surface of rock obstructions,but difficult to identify the lateral and bottom boundaries of rock *** improve the precision of detection,the full waveform inversion(FWI)method was used to process the data from the cross-hole seismic *** results indicate that the inversion precision of P-wave is higher than that of *** horizontal and vertical ranges of rock obstructions in the P-wave inversion results are 14–26 m and 7.5–11.0 m respectively,roughly consistent with the results of penetration tests(about 15–25 m)and borehole log(8.85–10.80 m).This result proves that the sequential application of first-arrival time analysis and FWI can effectively delineate the boundary of rock ***,the results of various detection methods were analyzed and compared in this *** the advantages of various methods,we propose a cost-effective and high-precision workflow containing both geotechnical and geophysical investigations.

关键词： FWI Geotechnical and geophysical investigations Cross-hole seismic method Surface wave method Obstruction detection

Nonlinear dynamical characteristics of bed load motion

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Science China(Technological Sciences) 2006年第3期49卷 365-384页

作者： Chiu-On ng Department of Mechanical Engineering the University of Hong Kong Hong Kong China

Bed forms of various kinds that evolve naturally on the bottom of sandy coasts and rivers are a result of the kinematics of bed load transport. Based on the group motion of particles in the bed load within the bottom layer, a study on the nonlinear dy- namics of bed load transport is presented in this paper. It is found that some development stages, such as the initiation, the equilibrium sediment transport, and the transition from a smooth bed to sand dunes, can be accounted for by different states in the nonlinear sys- tem of the bed load transport. It is verified by comparison with experimental data reported by Laboratoire Nationae D’hydraulique, Chatou, France, that the evolution from a smooth bed to sand dunes is determined by mutation in the bed load transport. This paper pre- sents results that may offer theoretical explanations to the experimental observations. It is also an attempt to apply the state-of-the-art nonlinear science to the classical sediment transport mechanics.

关键词： bed load, bed form, nonlinear dynamics.

Study on Single-fiber Pull-out Method for Evaluating Interfacial Strength in CFRP

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high Technology Letters 1995年第1期1卷 105-108页

作者： Yudong, h. zhiqian, zh. Lixun, L. Qiwei, L. harbin Inst of Technology Harbin China

Single-fiber pull-out testing (SFPOT) methods are frequently used to evaluate the interfacial adhesion between fiber and matrix in composite materials. To make such pull-out measurements, however, the length of embedded fiber must be small enough so that the fiber does not break before it is pulled freely. This is difficult to achieve by conventional methods with fibers of small diameter, such as the carbon fibers. In this paper, a fiber pull-out experiment is described. Specialized apparatus in our laboratory, as well as this technique for sample preparation are discussed in detail. The interfacial shear strength of carbon fiber/resin matrix composites is analyzed quantitatively by using the finite-element method. The SFPOT system has been proved to be an available means for the study of interfacial properties for carbon fiber/resin matrix composites.

关键词： Carbon fiber Composite materials Interfacial shear strength Single-fiber pull-out