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221.
Th. Seyller K.V. Emtsev F. Speck A. Tadich J.D. Riley O. Rader A.M. Shikin 《Surface science》2006,600(18):3906-3911
Photoelectron spectroscopy, low-energy electron diffraction, and scanning probe microscopy were used to investigate the electronic and structural properties of graphite layers grown by solid state graphitization of SiC(0 0 0 1) surfaces. The process leads to well-ordered graphite layers which are rotated against the substrate lattice by 30°. On on-axis 6H-SiC(0 0 0 1) substrates we observe graphitic layers with up to several 100 nm wide terraces. ARUPS spectra of the graphite layers grown on on-axis 6H-SiC(0 0 0 1) surfaces are indicative of a well-developed band structure. For the graphite/n-type 6H-SiC(0 0 0 1) layer system we observe a Schottky barrier height of ?B,n = 0.3 ± 0.1 eV. ARUPS spectra of graphite layers grown on 8° off-axis oriented 4H-SiC(0 0 0 1) show unique replicas which are explained by a carpet-like growth mode combined with a step bunching of the substrate. 相似文献
222.
Benjamin J. K. Evans Susan M. Scott Antony C. Searle 《General Relativity and Gravitation》2002,34(10):1675-1684
We have developed a new tool for numerical work in General Relativity: GRworkbench. We discuss how GRworkbench's implementation of a numerically-amenable analogue to Differential Geometry facilitates the development of robust and chart-independent numerical algorithms. We consider, as an example, geodesic tracing on two charts covering the exterior Schwarzschild space-time. 相似文献
223.
J. M. Bernard 《Mathematical Methods in the Applied Sciences》2002,25(8):627-661
This paper is devoted to Stokes and Navier–Stokes problems with non‐standard boundary conditions: we consider, in particular, the case where the pressure is given on a part of the boundary. These problems were studied by Bégue, Conca, Murat and Pironneau. They proved the existence of variational solutions, indicating that these were solutions of the initial non‐standard problems, if they are regular enough, but without specifying the conditions on the data which would imply this regularity. In this paper, first we show that the variational solutions, on supposing pressure on the boundary Γ2 of regularity H1/2 instead of H?1/2, have their Laplacians in L2 and, therefore, are solutions of non‐standard Stokes problem. Next, we give a result of regularity H2, which we generalize, obtaining regularities Wm, r, m∈?, m?2, r?2. Finally, by a fixed‐point argument, we prove analogous results for the Navier–Stokes problem, in the case where the viscosity νis large compared to the data. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
224.
A graph is called supereulerian if it has a spanning closed trail. Let G be a 2-edge-connected graph of order n such that each minimal edge cut SE(G) with |S|3 satisfies the property that each component of G−S has order at least (n−2)/5. We prove that either G is supereulerian or G belongs to one of two classes of exceptional graphs. Our results slightly improve earlier results of Catlin and Li. Furthermore, our main result implies the following strengthening of a theorem of Lai within the class of graphs with minimum degree δ4: If G is a 2-edge-connected graph of order n with δ(G)4 such that for every edge xyE(G) , we have max{d(x),d(y)}(n−2)/5−1, then either G is supereulerian or G belongs to one of two classes of exceptional graphs. We show that the condition δ(G)4 cannot be relaxed. 相似文献
225.
The structural evolution in amorphous silicon and germanium thin films has been investigated by high-resolution transmission electron microscopy (HRTEM) in conjunction with autocorrelation function (ACF) analysis. The results established that the structure of as-deposited semiconductor films is of a high density of nanocrystallites embedded in the amorphous matrix. In addition, from ACF analysis, the structure of a-Ge is more ordered than that of a-Si. The density of embedded nanocrystallites in amorphous films was found to diminish with annealing temperature first, then to increase. The conclusions also corroborate well with the results of diminished medium-range order in annealed amorphous films determined previously by a variable coherence microscopy method. 相似文献
226.
227.
J. Kalliongis 《Mathematische Zeitschrift》2002,241(4):801-828
For compact irreducible sufficiently large 3-manifolds containing 2-sided projective planes, we consider the following Realization
Problem: Given a finite subgroup of the outer automorphism group of the fundamental group, is there a finite group of homeomorphisms,
which induces this subgroup?
Received: 16 November 1999; in final form: 18 January 2001 / Published online: 8 November 2002 相似文献
228.
We call a one-way infinite word w over a finite alphabet (ρ,l)-repetitive if all long enough prefixes of w contain as a suffix a ρth power (or more generally a repetition of order ρ) of a word of length at most l. We show that each (2,4)-repetitive word is ultimately periodic, as well as that there exist continuum many, and hence also nonultimately periodic, (2,5)-repetitive words. Further, we characterize nonultimately periodic (2,5)-repetitive words both structurally and algebraically. 相似文献
229.
Michael K. Kinyon Kenneth Kunen J. D. Phillips 《Proceedings of the American Mathematical Society》2002,130(3):619-624
An A-loop is a loop in which every inner mapping is an automorphism. A problem which had been open since 1956 is settled by showing that every diassociative A-loop is Moufang.
230.
K. Yatsu T. Cho H. Higaki M. Ichimura K. Ishii Y. Ishimoto M. K. Islam A. Itakura I. Katanuma J. Kohagura Y. Nakashima T. Saito Y. Takemura Y. Tatematsu M. Yoshida M. Yoshikawa 《Czechoslovak Journal of Physics》2002,52(10):1143-1148
GAMMA 10 experiments have advanced in high density experiments after the last EPS Workshop where we reported high density
plasma production by using an ion cyclotron range of frequency heating at a high harmonic frequency and neutral beam injection
in the central cell. Recently a high density plasma was obtained with much improved reproducibility than before and without
degradation of diamagnetic signal. The high density plasma was attained by adjusting the spacing of the conducting plates
installed in the anchor transition regions. Dependencies of particle confinement time, ion energy confinement time and plasma
confining potential on plasma density were obtained for the first time in the high density region.
Presented at 5th Workshop “Role of Electric Fields in Plasma Confinement and Exhaust”, Montreus, Switzerland, June 23–24,
2002. 相似文献