Showing papers in "Annalen der Physik in 1971"
TL;DR: Echo attenuation due to both diffusion and relaxation in two phase systems is investigated theoretically for the pulsed field gradient experiment in this article, and it is found that the general formulae are rather complicated.
Abstract: Echo attenuation due to both diffusion and relaxation in two phase systems is investigated theoretically for the pulsed field gradient experiment. It is found that the general formulae are rather complicated. In some special cases however a separation of relaxation and diffusion terms is possible. The practical importance of these cases is discussed.
75 citations
TL;DR: In this article, the Dirichlet boundary value problem for the Helmholtz equation is solved rigorously by function-theoretic techniques for an infinite plane grating formed by strips and gaps of equal width.
Abstract: For an infinite plane grating formed by strips and gaps of equal width, a Dirichlet boundary value problem for the Helmholtz equation is solved rigorously by function-theoretic techniques. Plane wave excitation with an arbitrary angle of incidence is considered. The high frequency asymptotics of the solution is completely evaluated and compared with Kirchhoff's diffraction theory as well as with the asymptotics for a single strip. Extensive numerical data are laid down graphically.
42 citations
TL;DR: In this paper, the universal form of Gyarmati's variational principle of thermodynamics is derived from the differential equations governing the internal energy and impulse transport of one component hydro-thermodynamic systems.
Abstract: From the universal form of Gyarmati's variational principle of thermodynamics the differential equations governing the internal energy and impulse transport of one component hydro-thermodynamic systems are derived. In our particular case Gyarmati's “supplementary theorem” is confirmed, by which the validity of the universal form of Gyarmati's variational principle is guaranted also in non-linear cases. Finally some problems of the Gyarmati principle and of non-linear thermodynamics are discussed.
29 citations
TL;DR: In this paper, it is shown that non-relativistic quantum mechanics can be treated as a kind of relativistic statistical theory which describes a random motion of a classical particle.
Abstract: It is shown that non-relativistic quantum mechanics can be treated as a kind of relativistic statistical theory which describes a random motion of a classical particle. The theory is relativistic in the sense that for the description of the particle behaviour the relativistic notion of the state is used. This is very important because a statistics is a state calculus and the result depends on the definition of the notion of state.
19 citations
TL;DR: In this article, the influence of reemission of electrons on the characteristic of a probe is calculated and compared with measurements of the primary electrons in a low pressure discharge Structures due to the energy dependence of the Reemission coefficient which are predicted by the calculations are confirmed by the measurements.
Abstract: Der Einflus der Elektronenreemission auf die Anlaufkennlinie wird berechnet und mit Messungen an den Primarelektronen in einer Niederdruckentladung verglichen Die Messungen zeigen die von der Rechnung vorhergesagten Strukturen, die auf der Energieabhangigkeit des Reemissionskoeffizienten beruhen Aus der Materialabhangigkeit des Reemissionskoeffizienten lassen sich Ruckschlusse auf den Zustand der Sondenoberflache, insbesondere auf Kontaminationen und die Effektivitat von Verfahren zur Reinigung der Oberflache, ziehen
The influence of reemission of electrons on the characteristic of a probe is calculated and compared with measurements of the primary electrons in a low pressure discharge Structures due to the energy dependence of the reemission coefficient which are predicted by the calculations are confirmed by the measurements Thus it is possible – considering the dependence of the coefficient of reemission on the material of the probe surface – to investigate by this effect the state of the probe surface i e contamination and the effect of cleaning methods
18 citations
TL;DR: In this paper, experimentelle Ergebnisse uber das Verhalten des Feldemissionsstroms aus Wolfram bei gleichzeitiger Belichtung des Emitters mitgeteilt.
Abstract: Es werden experimentelle Ergebnisse uber das Verhalten des Feldemissionsstroms aus Wolfram bei gleichzeitiger Belichtung des Emitters mitgeteilt. Die Mesmethodik wird ausfuhrlich beschrieben. Die Versuchsergebnisse lassen sich nur deuten, wenn man die Bandstruktur des Emittermaterials berucksichtigt. Die aus den Photostrom-Feldstarke-Kennlinien fur unterschiedliche spektrale Zusammensetzung der auf den Emitter treffenden Strahlung gewonnenen Aussagen uber die Bandstruktur stimmen qualitativ gut mit der theoretisch berechneten Bandstruktur des Wolframs uberein.
15 citations
TL;DR: In this paper, the interference between two independent single mode He-Ne laser beams was observed and recorded on a photographic film for low intensities, and the results of the experiments were in agreement with the statement of the quantummechanical description: the interference pattern down to very small intensities of the superposed beams.
Abstract: We have observed the interference between two independent single mode He-Ne laser beams. Our special equipment allowed us to record many times the interference pattern, when it was standing for a short time at the same position on the recorder. In this way we have obtained an interference picture of two independent light beams, which was (a) visible directly for the unaided eye for large intensities, (b) recorded on a photographic film for low intensities. The result of the experiments were in agreement with the statement of the quantummechanical description: We found a classical interference pattern down to very small intensities of the superposed beams. This result is discussed with regard to the quantum structure of light.
14 citations
TL;DR: In this article, an invariance transformation of the Lagrangian was used to obtain a class of exact static solutions of the Einstein-Maxwell equations including perfect fluid, and the boundary conditions of the resulting metric were automatically fulfilled.
Abstract: With the aid of an invariance transformation of the Lagrangian we obtain a class of exact static solutions of the Einstein-Maxwell equations including perfect fluid. Application of the method to the interior and exterior Schwarzschild solution yields a corresponding solution with electromagnetic field (Reissner-Weyl solution). The boundary conditions of the resulting metric are automatically fulfilled.
14 citations
TL;DR: In this paper, a generalization of the Bloch matrix, valid for arbitrary degrees of degeneracy, is used to handle quantum corrections to the Thomas-Fermi approximation, and the results of a treatment of optical transitions in high-doped semiconductors with this method are given.
Abstract: To treat fluctuating perturbation potentials in semiconductors, it is necessary to take quantum corrections to the Thomas-Fermi approximation into account. A generalization of the Bloch matrix, valid for arbitrary degrees of degeneracy, is used to handle these quantum corrections. The generalized Bloch equation and the results of a treatment of optical transitions in high-doped semiconductors with this method are given. The concept of effective band edges is shown to be useful for the problem on hand.
12 citations
TL;DR: In this paper, the adaption von Sauerstoff an polykristallinem Wolfram wurde bei SauerStoffpartialdrucken pO2 zwischen einigen 10−10 Torr und 10−6 Torr and Temperaturen T zwich between 1000 K and 2800 K with einem Massenspektrometer untersucht.
Abstract: Die Adsorption von Sauerstoff an polykristallinem Wolfram wurde bei Sauerstoffpartialdrucken pO2 zwischen einigen 10−10 Torr und 10−6 Torr und Temperaturen T zwischen 1000 K und 2800 K mit einem Massenspektrometer untersucht. Aus der zeitlichen Anderung des Partialdrucks wahrend der Adsorption an einem vorher reinen Wolframband erhielten wir bei vernachlassigbarer Desorption (T = 950 K) fur die Oberflachenkonzentration cM bei monoatomarer Bedeckung und den Haftkoeffizienten H als Funktion der Bedeckung Θ: cM = (1,1 ± 0,1). 1015 O-Atome/cm2 bzw. HΘ = (0,7 ± 0,05). (1–Θ)2. Bei Konkurrenz zwischen Adsorption und Desorption wurde Θ aus der Messung der Austrittsarbeitsanderung Δϕ bestimmt; dazu wurden zwei Verfahren benutzt, die beide auf der Oberflachenionisation eines als Sonde dienenden Metall-Atomstrahls (bei uns: Indium) beruhen. Aus den fur verschiedene pO2 erhaltenen stationaren Werten von Δϕ(T) konnte mit H(Θ) die Verweilzeit Θ der adsorbierten Sauerstoffatome berechnet und aus deren Temperaturabhangigkeit die Desorptionsenergie Q(Θ) als Funktion der Bedeckung bestimmt werden. Sie betragt bei reiner Oberflache (6,05 ± 0,1) eV und nimmt mit wachsendem Θ bis auf etwa 3, 25 eV bei Θ = 1 ab. Der praexponentielle Faktor Θ0 der Frenkel-Gleichung nimmt dagegen mit Θ zu (Kompensationseffekt).
9 citations
TL;DR: In this article, the decay problem of two atoms with various initial states was solved using the many-centers-quantization (MQ) method, and the angular distributions and angular correlations were given.
Abstract: The method of “many-centers-quantization” developed in a foregoing paper [1] is used to solve the decay problem of two atoms with various initial states. Especially the angular distributions and angular correlations are given.
TL;DR: In this article, two Greensche Dyads are hergeleitet, die die Beugung elektromagnetischer Wellen, herruhrend von einem beliebig orientierten elektrischen bzw, magnetischen Elementardipol, am unendlich gut leitenden Kegel elliptischen Querschnitts beschreiben.
Abstract: Es werden zwei Greensche Dyaden hergeleitet, die die Beugung elektromagnetischer Wellen, herruhrend von einem beliebig orientierten elektrischen bzw, magnetischen Elementardipol, am unendlich gut leitenden Kegel elliptischen Querschnitts beschreiben. Die Losungen des Beugungsproblems fur den Halbraum, den Keil, die Halbebene, den sektorformigen ebenen Schirm und den rotationssymmetrischen Kegel werden mit erfast. Die Greenschen Dyaden werden wesentlich bestimmt durch zwei Greensche Funktionen, die das skalare akustische Beugungsproblem fur den schallharten bzw. schallweichen Kegel elliptischen Querschnitts losen.
TL;DR: In this article, the interference of intramolecular dipole-dipole interaction and anisotropy of electronic screening in nuclear magnetic relaxation is taken into account for systems containing four identical nuclei of spin 1/2 located at the corners of a tetrahedral, a square and a rectangle.
Abstract: The interference of intramolecular dipole-dipole interaction and anisotropy of electronic screening in nuclear magnetic relaxation is taken into account for systems containing four identical nuclei of spin 1/2 located at the corners of a tetrahedral, a square and a rectangle The influence of spinrotational interaction is also considered The results, presented in the paper show that, due to the interference effect, a significant deviation of a pure exponential time dependence of nuclear magnetization in some special cases may appear
TL;DR: In this paper, the optical parametric oscillator is investigated theoretically for the general case of resonant pump, signal and idler waves, and mean photon numbers, threshold energies and conversion rates are calculated explicitly for different types of the waves (standing and running ones).
Abstract: The optical parametric oscillator is investigated theoretically for the general case of resonant pump, signal and idler waves. Mean photon numbers, threshold energies and conversion rates are calculated explicitly for different types of the waves (standing and running ones), where in the case of both signal and idler being standing waves the appearance of an oppositely running (“reflected”) pump wave is properly taken into account. In addition, from the equations of motion for the photon creation operators approximately valid rate equations are deduced which in certain cases predict a damped oscillating transition (analogous to the relaxation oscillations of a ruby laser) to the stationary state.
TL;DR: The influence of stimulated Raman scattering (SRS) on refractive index due to excitation of vibrational levels of molecules has been estimated for Hydrogen and carbon disulphide.
Abstract: Der Einflus der stimulierten Raman-Streuung (SRS) auf die Brechzahl infolge Schwingungsanregung von Molekulen wird fur Wasserstoff und Schwefelkohlenstoff abgeschatzt. Die durch SRS hervorgerufenen Anderungen des Brechungsindex werden mit den aus Molekulorientierung und Elektrostriktion resultierenden Beitragen verglichen. Es werden Bedingungen angegeben, unter denen derartige Brechzahlanderungen und damit Polarisierbarkeiten in angeregten Zustanden beobachtbar sein musten.
The influence of stimulated Raman scattering (SRS) on refractive index due to excitation of vibrational levels of molecules has been estimated for Hydrogen and carbon disulphide. A comparison is given between the changes of refractive index caused by SRS, orientation of molecules and electrostriction. There are shown conditions under which it should be possible to observe such changes and therefore polarizabilities of excited levels.
TL;DR: In this paper, the limits of resolution dependent on defocusing and spherical aberration were calculated and the partial coherence in connection with the aberrations of the electron lenses limits the possible resolution.
Abstract: Enhancement of resolution in electron microscopy can be achieved by use of electron image holography. In order to compensate for the aberrations of the electron lenses the reconstruction is performed with laser light in an optical system with suitably adapted aberrations. The partial coherence in connection with the aberrations of the electron lenses limits the possible resolution. The limits of resolution dependent on defocusing and spherical aberration are calculated.
TL;DR: With level crossing technique, the states 4d5s5p y2D3/2,5/2/2.5 2.5/1.7/2 in the Yttrium I spectrum were investigated and the magnetic hyperfine structure splitting A factors and the lifetimes determined.
Abstract: With level crossing technique the states 4d5s5p y2D3/2,5/2 and 4d5s5p y2F5/2,7/2 in the Yttrium I spectrum were investigated and the magnetic hyperfine structure splitting A factors and the lifetimes determined. The experimental values are discussed and compared with theoretical results.
TL;DR: In this article, die Greenschen Funktionen des elliptischen Kegels in Form einer Reihenentwicklung nach geeigneten Partikularlosungen der homogenen Wellengleichung angegeben.
Abstract: Es werden die Greenschen Funktionen des elliptischen Kegels in Form einer Reihenentwicklung nach geeigneten Partikularlosungen der homogenen Wellengleichung angegeben. Das erste Glied dieser Entwicklung wird numerisch ausgewertet.
TL;DR: In this paper, the amplitude fluctuations of the signal wave of an optical parametric oscillator are evaluated for the case of nonresonant pumping by calculating the decrease of a random deviation e of signal amplitude from its stationary value during a round trip through the (ring) resonator.
Abstract: Amplitude fluctuations of the signal wave of an optical parametric oscillator are evaluated for the case of nonresonant pumping by calculating the decrease of a random deviation e of the signal amplitude from its stationary value during a round trip through the (ring) resonator. From this, a damping term governing the temporal behaviour of e is deduced which, together with a Langevin force connected with the spontaneous decay of pump photons into both signal and idler photons, determines the amplitude fluctuations of the signal wave. In addition, it is shown that the same results may be obtained from a mode formalism for signal and idler waves taking into account the spatial variation of the pump wave following from Maxwell's equations.
TL;DR: In this paper, the coupling coefficients, which describe the interaction between the different waves, were derived in a comparatively simple way by means of coupled mode theory even if dissipative effects are taken into account.
Abstract: Longitudinal waves in a spatially uniform magnetized plasma are studied. It is demonstrated that the coupling coefficients, which describe the interaction between the different waves, can be derived in a comparatively simple way by means of coupled mode theory even if dissipative effects are taken into account.
TL;DR: In the Newtonian theory of gravitation only negative sources of gravity are existent as mentioned in this paper, and for an infinite universe with a mean density of matter ϱ ≠ 0 consistent states are only possible if the mean densities of positive and negative sources are balanced.
Abstract: In the Newtonian theory of gravitation only negative sources of gravity are existent. However, for an infinite universe with a mean density of matter ϱ ≠ 0 consistent states are only possible if the mean densities of positive and negative sources are balanced. - The general relativistic cosmology gives possibilities for physical interpretations of the positive sources.
TL;DR: In this paper, allgemein Beziehungen fur den Feldemissionsstrom aus einem Metall bei gleichzeitig vorhandener optischer Anregung hergeleitet are discussed.
Abstract: Es werden allgemein Beziehungen fur den Feldemissionsstrom aus einem Metall bei gleichzeitig vorhandener optischer Anregung hergeleitet. Der Einflus der Bandstruktur auf die Energieverteilung der emittierten Elektronen und den Emissionsstrom wird diskutiert. Fur Wolfram gefundene experimentelle Ergebnisse lassen sich qualitativ richtig deuten.
TL;DR: In this article, the correlation functions for the Langevin forces connected with the spontaneous decay of pump photons into both signal and idler photons as well as the loss mechanism for the radiation are calculated.
Abstract: In a heuristic manner – analogous to the procedure known from laser theory – the correlation functions for the fluctuation operators (Langevin forces) connected with the spontaneous decay of pump photons into both signal and idler photons as well as the loss mechanism for the radiation are calculated.
TL;DR: In this article, it was shown that the spontaneous creation of matter in strong gravitation fields may be a result of an inconsistent approximation for the simultaneous systems of Einstein field equations and of matter field equations.
Abstract: This paper suggests that the “spontaneous creation of matter in strong gravitation fields” – which is asserted in some papers – may be a result of an inconsistent approximation for the simultaneous systems of Einstein field equations and of matter field equations.
Firstly we shall remark that Einstein's dynamical equation is not only the consequence of the Einstein field equations (via Bianchi identity) but also the consequence of the relativistic matter field equations and of the weak principle of equivalence. Therefore, for all discussions we must start from the dynamical equation and from the conservation laws of charges.
Secondly, we find a formal inhomogeneous dynamical equation for the matter tensor by working in a background-field approximation. But, this inhomogenity vanishes according to the matter field equations.
Thirdly, we discuss the properties in an evolution-cosmos. In such cosmos a law of conformal conservation of energy is fulfilled. From this conservation law results that the energy is a continuous function of the gauge of time. Such continuous dependence involves the constance of discrete numbers according to the well known argument of Planck.
TL;DR: In this article, the kinematics and dynamics of classical and quantum mechanical systems are discussed, and canonical transformations are introduced and the time development of quantum mechanical system as well as the Schrodinger and Heisenberg picture are considered.
Abstract: The kinematics and dynamics of classical and quantum mechanical systems are discussed. In a mathematical strict way canonical transformations are introduced and the time development of quantum mechanical systems as well as the Schrodinger and Heisenberg picture are considered.
TL;DR: In this article, the authors studied the possibility to separate functional equations in the static pion-nucleon theory into a set of uncoupled ones by means of a finite-order Cremona transformation.
Abstract: Certain mathematical aspects of the static pion-nucleon theory are investigated. We start from the fact that the theory in its uniformized form (cuts transformed away) leads to a system of functional equations for the S-matrix. The nonlinear mapping involved in the functional equations is a second-order Cremona transformation. After a summary of the general properties of Cremona transformations, the special transformations are studied which arise in the symmetric scalar and the Chew-Low theory respectively. The emphasis is on the possibility to separate, by means of a finite-order Cremona transformation, the functional equations into a set of uncoupled ones. For the symmetric scalar theory, the separation is trivial. For the Chew-Low theory, a proof of nonseparability is given.
TL;DR: In this article, a microscopic model of BaTiO3 was treated to describe static phenomena near the ferroelectric phase transition, where changes of the lattice constant at fixed pressure were considered.
Abstract: A microscopic model of BaTiO3 is treated to describe static phenomena near the ferroelectric phase transition. In addition to the polarization, changes of the lattice constant at fixed pressure are also considered. That leads to a new explanation of the first order character of the transition, which is carried out not only qualitatively but also quantitatively. We investigate the dependence on pressure and external field. Agreement with the experiment through the adjustment of the parameters of the theory is obtained.