排序方式: 共有133条查询结果,搜索用时 31 毫秒
31.
Our goal is to experimentally investigate whether or not the effective Schottky barrier heights (SBHs) and ideality factors obtained from the current-voltage (I-V) and capacitance-voltage (C-V) characteristics differ from diode to diode even if the samples were identically prepared. For this purpose, we prepared Cd/n-Si (33 dots) and Cd/p-Si (15 dots) diodes. The SBH for the Cd/n-Si diodes ranged from 0.701 to 0.605 eV, and ideality factor n from 1.913 to 1.213. Φb value for the Cd/p-Si diodes ranged from 0.688 to 0.730 eV, and ideality factor n value from 1.473 to 1.040. The experimental SBH distributions obtained from the C−2-V and I-V characteristics were fitted by a Gaussian function and their mean SBH values were calculated. Furthermore, the laterally homogeneous barrier heights were also computed from the extrapolation of the linear plot of experimental barrier heights versus ideality factors. 相似文献
32.
T. Taniguchi G. P. Morriss 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(1-2):305-309
The relation between the Lyapunov modes (delocalized
Lyapunov vectors) and the momentum autocorrelation function
is discussed in two-dimensional hard-disk systems.
We show numerical evidence that
the smallest time-oscillating period of the Lyapunov modes
is twice as long as the time-oscillating period of
momentum autocorrelation function for
both square and rectangular two-dimensional systems
with hard-wall boundary conditions. 相似文献
33.
34.
An efficient and versatile synthesis of acylpolyamine spider toxins of all structural types classified by extensive MS analysis has been achieved. By using 2-nitrobenzenesulfonamide as an effective activating and/or protecting group (the Nosyl strategy), the naturally occurring toxins 1-8 corresponding to Types A-F were concisely synthesized in high overall yield. 相似文献
35.
Chuan-bing Rong Hong-wei ZhangJi-rong Sun Bao-gen Shen 《Journal of magnetism and magnetic materials》2006
The effects of geometry and material parameters on the extraordinary magnetoresistance (EMR) of the rectangular semiconductor–metal hybrid structure have been studied systematically using the finite-element method (FEM). We find that the EMR depends sensitively on the placement of the voltage probes and explain the origin of the EMR enhancement in the asymmetric voltage probe configuration. The width of the metal is important for the EMR effect as well as the width of the semiconductor. The low-field EMR shows an approximate quadratic with the mobility of semiconductor, while the high-field EMR gradually saturates with the increase of mobility due to the little change of hall angle. To obtain significant EMR effect, the ration of conductivity of metal and semiconductor should be larger than 104. 相似文献
36.
Dorothée Dorner Stefan Zaefferer Ludger Lahn Dierk Raabe 《Journal of magnetism and magnetic materials》2006
This paper outlines the development of the microstructure and microtexture of grain-oriented silicon steel during the industrial production process. In particular the evolution of the Goss orientation was studied in industrial material as well as in single crystal experiments. 相似文献
37.
Surface Brillouin spectroscopy (SBS) has been widely used for elastic property characterization of thin films. For films thicker than 500 nm, however, the wavelength of surface acoustic wave in the frequency range available for SBS is smaller than film thickness, and the SBS measures only the Rayleigh wave of the film. The laser-SAW technique, on the other hand, measures only the low-frequency portion of the surface acoustic wave dispersion and can estimate only one elastic modulus of the film (typically Young's modulus). In this work, we have combined the two methods to determine both Young's modulus and Poisson's ratio of a diamond-like carbon (DLC) film. It was found that reasonable estimates can be obtained for the longitudinal wave velocity, shear wave velocity, and Young's modulus of the film. The Poisson's ratio, however, still has a relatively large measurement error. 相似文献
38.
Núñez A Darias R Pinto R Paredes V R Medina E 《The European physical journal. E, Soft matter》2002,9(4):327-334
We study a model of concentrated suspensions under shear in two dimensions. Interactions between suspended particles are dominated
by direct-contact viscoelastic forces and the particles are neutrally bouyant. The bimodal suspensions consist of a variable
proportion between large and small droplets, with a fixed global suspended fraction. Going beyond the assumptions of the classical
theory of Farris (R.J. Farris, Trans. Soc. Rheol. 12, 281 (1968)), we discuss a shear viscosity minimum, as a function of the small-to-large-particle ratio, in shear geometries
imposed by external body forces and boundaries. Within a linear-response scheme, we find the dependence of the viscosity minimum
on the imposed shear and the microscopic drop friction parameters. We also discuss the viscosity minimum under dynamically
imposed shear applied by boundaries. We find a reduction of macroscopic viscosity with the increase of the microscopic friction
parameters that is understood using a simple two-drop model. Our simulation results are qualitatively consistent with recent
experiments in concentrated bimodal emulsions with a highly viscous or rigid suspended component.
Received 28 June 2002
RID="a"
ID="a"e-mail: ernesto@pion.ivic.ve 相似文献
39.
J. Horbach W. Kob K. Binder 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,19(4):531-543
We present the results of extensive molecular dynamics computer simulations in which the high frequency dynamics of silica,
i.e. for frequencies ν > 0.5 THz, is investigated in the viscous liquid state as well as in the glass state. We characterize the
properties of high frequency sound modes by analyzing J
l(q,ν) and J
t(q,ν), the longitudinal and transverse current correlation function, respectively. For wave-vectors q > 0.4 ?-1 the spectra are sitting on top of a flat background. The dynamic structure factor S(q,ν) exhibits for q > 0.23 ?-1 a boson peak which is located nearly independent of q around 1.7 THz and for which the intensity scales approximately linearly with temperature. We show that the low frequency
part of the boson peak is mainly due to the elastic scattering of transverse acoustic modes with frequencies around 1 THz.
The strength of this scattering depends on q and is largest around q = 1.7 ?-1, the location of the first sharp diffraction peak in the static structure factor. By studying S(q,ν) for different system sizes we show that strong finite size effects are present in the low frequency part of the boson
peak in that for small systems part of its intensity is missing. We discuss the consequences of these finite size effects
for the structural relaxation.
Received 27 June 2000 and Received in final form 9 January 2001 相似文献
40.
D. Conrad K. Scheerschmidt U. Gösele 《Applied Physics A: Materials Science & Processing》1996,62(1):7-12
Molecular dynamics simulations based on a modified Stillinger-Weber potential are used to investigate the elementary steps of bonding two Si(001) wafers. The energy dissipation and thus the dynamic bonding behaviour are controlled by the transfer rates for the kinetic energy. The applicability of the method is demonstrated by studying the interaction of perfect wafer surfaces (UHV conditions). First calculations covering the influence of surface steps, rotational misorientations and adsorbates are presented. 相似文献