排序方式: 共有30条查询结果,搜索用时 15 毫秒
11.
N. Gurker H. Ebel K. Zeiner K. Wechselberger J. Finster G. Leonhard 《Journal of Electron Spectroscopy and Related Phenomena》1982,25(2):219-229
The photoelectron energy corresponding to the Fermi level of an investigated specimen and the onset energy for detection of secondary electrons are two characteristic energy values that can be used for work-function evaluation. Secondary-electron onset measurements are usually carried out by applying an acceleration voltage between the specimen and the spectrometer entrance, giving a structured secondary-electron spectrum showing three types of secondary electrons: those from the specimen, those from the entrance-slit system, and those from the X-ray tube window. For the latter electrons the electrical field built up in the sample chamber acts as an energy analyzer, imaging a discrete energy interval onto the spectrometer entrance slit. The variation of energy and intensity of these “ghost-lines” is discussed as a function of the applied acceleration voltage and the specimen tilting angle, leading to optimized experimental parameters for recording of secondary-electron spectra. 相似文献
12.
Petra Lorenz J. Finster G. Wendt J.V. Salyn E.K. Žumadilov V.I. Nefedov 《Journal of Electron Spectroscopy and Related Phenomena》1979,16(3):267-276
The ESCA spectra of a series of NiO/SiO2 and NiO—Al2 O3/SiO2 catalysts are reported, together with those of some reference compounds. The positions and shapes of the lines, in conjunction with a quantitative surface analysis from relative intensities, allow the identification of different surface phases, e.g. an NiO-like phase in the impregnated catalysts with very low catalytic activity and an Ni talc-like phase in the precipitated catalysts which have higher activity. The addition of Al2O3 has a great influence on the surface structure (formation of alumosilicate). 相似文献
13.
A method is presented for obtaining rigorous error estimates for approximate solutions of the Riccati equation, with real or complex potentials. Our main tool is to derive invariant region estimates for complex solutions of the Riccati equation. We explain the general strategy for applying these estimates and illustrate the method in typical examples, where the approximate solutions are obtained by gluing together WKB and Airy solutions of corresponding one-dimensional Schrödinger equations. Our method is motivated by, and has applications to, the analysis of linear wave equations in the geometry of a rotating black hole. 相似文献
14.
15.
We introduce a lattice model for a static and isotropic system of relativistic fermions. An action principle is formulated, which describes a particle‐particle interaction of all fermions. The model is designed specifically for a numerical analysis of the nonlinear interaction, which is expected to lead to the formation of a Dirac sea structure. We discuss basic properties of the system. It is proved that the minimum of the variational principle is attained. First numerical results reveal an effect of spontaneous symmetry breaking. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
16.
F. Finster N. Kamran J. Smoller S.-T. Yau 《Communications in Mathematical Physics》2006,264(2):465-503
We consider the Cauchy problem for the massless scalar wave equation in the Kerr geometry for smooth initial data compactly
supported outside the event horizon. We prove that the solutions decay in time in L
∞
loc. The proof is based on a representation of the solution as an infinite sum over the angular momentum modes, each of which
is an integral of the energy variable ω on the real line. This integral representation involves solutions of the radial and angular ODEs which arise in the separation
of variables.
Research supported in part by the Deutsche Forschungsgemeinschaft.
Research supported by NSERC grant #RGPIN 105490-2004.
Research supported in part by the NSF, Grant No. DMS-010-3998.
Research supported in part by the NSF, Grant No. 33-585-7510-2-30.
An erratum to this article is available at . 相似文献
17.
Robert Musiol Barbara Podeszwa Jacek Finster Halina Niedbala Jaroslaw Polanski 《Monatshefte für Chemie / Chemical Monthly》2006,118(2):1211-1217
Aromatic aldehydes undergo condensation with quinaldines under microwave irradiation to afford structurally diverse styrylquinolines
in high yields under solvent-free conditions. A comparison with the conventional method clearly indicates the advantages of
the new protocol. 相似文献
18.
19.
E. Kurth A. Reif V. Gottschalch J. Finster E. Butter 《Crystal Research and Technology》1988,23(1):117-126
This paper describes possibilities of several chemical preparations for the selective cleaning of InP surfaces. The investigations of the surface states after the chemical treatment were carried out by means of XPS measurements. A pre-etching with (NH4)2S2O8:H2SO4:H2O and a polishing with 1% bromine in methanol produce optically smooth (100)- and (111) P surfaces free of oxides. 相似文献
20.
Myriam Finster 《Israel Journal of Mathematics》2016,214(2):885-930
We study Veech groups of covering surfaces of primitive translation surfaces. Therefore we define congruence subgroups in Veech groups of primitive translation surfaces using their action on the homology with entries in Z/aZ. We introduce a congruence level definition and a property of a primitive translation surface which we call property (★). It guarantees that partition stabilising congruence subgroups of this level occur as Veech groups of a translation covering. 相似文献