The application of fibre optics to remote speckle metrology using incoherent light

Fibre optics can simplify optical measurement systems and suppress negative effects of hostile mechanical and thermal environments. In this study, fibre optic bundle is used to illuminate a test surface with white light. Two real images of artificially generated speckle patterns are transmitted through a second bundle to a photographic film or a vidicon camera. These patterns, corresponding to different positions of the object, are correlated using either an optical or a photoelectronic-numerical system to measure surface displacement in the region of interest.     

Selbstwechselwirkung von Gravitationsfeldern schnell bewegter Pol-Dipolquellen

We construct retarded solutions of the second order Lorentz-covariant approximation of Einstein's field equations for rapidly moving pole-dipole-like mass distributions. As the conventional Green's function method breaks down here, the integration is accomplished by a new regularization procedure based on analytic continuation of properly cut integrals. It is pointed out that there is no self-interaction for a pole-particle, in contradistinction to a spin-particle, where the self-interaction manifests itself in a back-scattering of gravitational radiation (producing a wave tail).     

Weitere Messungen zur Anisotropie der intermolekularen Wechselwirkung durch Streuung von Molekülen in definiertem Quantenzustand

Improved measurements of the ratio of scattering cross sections for various molecular rotational states are reported for scattering of TlF in rotational states ¦J, M〉=¦1, 0〉 and ¦1, 1〉, and CsF in rotational states ¦2, 0〉 and ¦2, 2〉 by rare gases. The results are interpreted in terms of an angle dependent attractive potentialV=?2ε(r _m /r) ⁶(1+q ₆ P ₂(cosΘ) in which the repulsive part of the interaction is neglected. The “high energy” approximation is used to calculate the cross section, which contains the velocity dependence and the state dependence as factors. The experiments show for all scattering partners with the exception of He and Ne, that the state dependence is velocity independent. In those cases this result provides a justification for the neglect of the repulsive potential term. The results for the anisotropy parameterq ₆, which to a good approximation depends only on properties of the moleculus, are:q ₆=0.23±0.01 for TlF,q ₆=0.28±0.02 for CsF.     

Approximation Numbers of Sobolev Embedding Operators on an Interval

Consider the Sobolev embedding operator from the space of functionsin W^1,p(I) with average zero into L^p, where I is a finite intervaland p>1. This operator plays an important role in recentwork. The operator norm and its approximation numbers in closedform are calculated. The closed form of the norm and approximationnumbers of several similar Sobolev embedding operators on afinite interval have recently been found. It is proved in thepaper that most of these operator norms and approximation numberson a finite interval are the same.     

Interaction potential and hopping dynamics governing sliding friction

The friction force on a nanometer-sized tip sliding on a surface is related to the thermally activated hopping of the contact atoms on an effective atomic interaction potential. A general analytical expression relates the height of this potential and the hopping attempt frequency to measurements of the velocity dependence of the friction force performed with an atomic force microscope. While the height of the potential is roughly proportional to the normal load, the attempt frequency falls in the range of mechanical eigenfrequencies of the probing tip in contact with the surface.     

Einzelteilchen-Berechnungen zur Kernspaltung

We use an axial symmetric, energy-, spin-, and isospin-dependent shell model Hamiltonian to describe heavy deformed nuclei, where the equipotential surfaces are taken to be spheroids, corrected towards a more realistic nuclear shape by means of Legendre polynomials of maximal order four, and the potential is assumed to depend on the modified radial coordinate like a Fermi function. The eigenvalue problem is solved by a perturbation treatment which starts with the eigensolutions for purely spheroidal deformations as a first approximation. By analysis of an expression which involves the single particle energies for a given deformation, the sets of deformation parameters for the ground state and the transition point of a fissioning nucleus are found, and from them the total energy at the transition point is obtained. For Th²³¹, Th²³³, U²³⁵, U²³⁶ and U²³⁷ we give our results and compare them with measurements and liquid drop model calculations.     

Potentiometrische p-Bestimmung

Ohne Zusammenfassung     

Contrast inversion in nc-AFM on Si(111)7×7 due to short-range electrostatic interactions

Contrast inversion in nc-AFM on Si(111)7ǻ is observed at positive sample bias. Corner holes appear as protrusions and adatoms as holes. The application of negative bias voltages causes drastic changes in the atomic constrast. Frequency shift vs distance curves show evidence of short-range, voltage-dependent forces. These observations indicate that short-range electrostatic forces are important for atomic-scale contrast in nc-AFM.     

Einfaches Verfahren zur pH-Bestimmung mittels Glaselektroden

Ohne Zusammenfassung