Le pouvoir résolvant du système „objectif-émulsion“

Sans résumé

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Der Einfluss der Plastischen Verformung durch Kaltwalzen auf die Koerzitivkraft

Zusammenfassung Es werden die Ergebnisse der Messungen der Koerzitivkraft von Eisen, Nickel und einiger Fe-Ni-Legierungen in Abhängigkeit von der plastischen Verformung durch Kaltwalzen angegeben. Gemessen wurde in Richtung parallel und senkrecht zur Walzrichtung. Die Ergebnisse werden insbesondere vom Gesichtspunkt des Einflusses der Versetzungen und der einachsigen induzierten Anisotropie diskutiert.

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Für die wertvollen Diskussionen und das Durchlesen der Arbeit danken wir den Kollegen J. Kaczér und V. Janovec, für die wirkungsvolle Hilfe bei den Messungen Koll. J. Grolmus.     

Anmerkung zur Lösung der Temperaturänderung in der Positiven Säule

Ohne Zusammenfassung

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The interaction of foils activated by thermal neutrons

The interaction of foils lying in a plane during their activation by thermal neutrons has been calculated. Numerical values of functions are listed, which can be used in calculations, especially for graphite. The interaction was measured in the graphite column of the VVR-S reactor.

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, , . , , . VVR-S.

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We thank J. Frytacký, T. Kania and V. ervenka for their help in the numerical calculations and measurements.     

Graphische Bestimmung der optischen Konstanten aus Zwei DurchlÄssigkeiten

Ohne Zusammenfassung

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Double cascade transitions of gamma rays from radiative capture on Co59

Pairs of gamma quanta, giving a sum equal to the binding energy of the last neutron in a Co⁶⁰ isotope, were studied during radiation capture on a Co⁵⁹ nucleus. The energies of the gamma quanta giving such cascades were determined and an attempt was made to determine the relative intensities of the different cascades.

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- Co⁵⁹

Co⁵⁹ -, Co⁶⁰. -, , .

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In conclusion the authors thank J. Vávra for cooperation in the measurements.     

The propagation of excitation energy in perturbed crystals

The process of the propagation of excitation energy in perturbed dielectric crystals with a weak bond between the atoms having zero permanent dipole moment is studied. It is shown that on certain assumptions this process of propagation can be regarded as the motion of a Frenkel exciton in the electrostatic field of the defect. Frenkel's exciton can be characterized in this case as a neutral polarizable particle having induced dipole moment equal to the change in the induced dipole moment of the crystal during the excitation of one of its atoms.

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Photo-piezoelectric effect in semiconductors

A new photo-voltaic effect was observed which is caused by inhomogeneous distribution of the pressure in a semiconductor. Its production can be explained by the dependence of the energy gap on the pressure.

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Influence of manganese and oxygen content on tetragonal deformation of copper ferrite

Pure copper ferrite and solid solutions of 0.9 parts of copper ferrite CuFe₂ and 0.1 part of hausmannite Mn₃ were heated in air or in oxygen at various temperatures and either cooled slowly or quenched. All samples with cubic spinel structure contained less oxygen than required by the ideal spinel formula Me²⁺Me ₂ ³⁺ O ₄ ^2– . The addition of hausmannite promotes the formation and/or stabilization of the cubic structure. The lower the heating temperature, the higher the oxygen deficiency necessary for the preparation of cubic samples.

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CuFe₂O_4– Cu_0,88Mn_0,30Fe_1,82O_4± Cu_0,91Mn_0,31Fe_1,82O_4± . , <0; , , (4±) ( ) . Cu-Mn ( –) ó, . , CuFe₂O_4– . ; .

     

Spectral composition of thermoluminescence of coloured NaCl crystals

The paper gives the experimental results of studying the spectral composition of thermoluminescence in the different maxima in photo-chemically coloured pure NaCl crystals or NaCl-crystals containing Cu in different concentrations.

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NaCl

NaCl .

     

To the question of electron angular distribution at Μ-meson decay

The paper describes the measurement of the angular distribution of electrons at the decay of-mesons in a longitudinal magnetic field. The results of measurement indicate that electrons are emitted with preference not only in the direction parallel to the spin orientation of -meson but also in the antiparallel direction in disagreement with the angular distribution predicted by theory.

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- . , -, , , .

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The authors thank N. V. Rabin for irradiating the nuclear emulsions, Prof. Dr. V. Petrílka and M. Suk for mediating relations with the Joint Institute of Nuclear Research in Dubna and Dr. J. Pernegr for valuable discussions and remarks. Thanks also go to H. Koutová and H. Slámová for carefully scanning the nuclear emulsions.     

Beitrag zum problem der Exo-Emission von festkörpern

Zusammenfassung Es sind die Versuchsergebnisse des Studiums der Photoerscheinungen bei verschieden bearbeiteten Metallen (Au, Al, Pt) angeführt. Die Metallfolien wurden an der Luft mit UV-Licht bestrahlt und gleichmä\ig erwärmt. Die Ergebnisse wurden vom Gesichtspunkt der neueren Kenntnisse über Adsorption, Katalyse und Oxydation diskutiert. Daraus sind Folgerungen gezogen worden, die in manchen Fällen zu Bedenken über die Klärung der Exo-Emissions-Glow-Kurven zu führen scheinen.

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Au, Al, Pt . , . , . , .

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Ich möchte auch an dieser Stelle meinen besten Dank Frau K. Listoová aussprechen für die mit gro\er Sorgfältigkeit durchgeführten Versuchsreihen und K. Huml für die Hilfe bei der Bearbeitung der Versuchsergebnisse.     

Zur Frage derZ-Zentren bei der Exoelektronenemission aus Alkalihalogeniden

Zusammenfassung Es wurde das Maximum des Exoelektronenemissionsstroms untersucht, das an NaCl infolge Verunreinigung durch Kalzium auftritt, und die Möglichkeit, dieses Maximum denZ-Zentren zuzuordnen, diskutiert.

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Z-

, NaCl . Z-.

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Wir danken herzlichst Herrn Dr. A. Bohun für das gefällige überlassen des NaCl: Ca-Materials.     

The classical theory of nuclear spin interaction in a ferromagnet

The Hamiltonian of nuclear spin interaction in a ferromagnet is derived by the classical method, which introduces the precession of nuclear spin into the equation of motion for magnetization. From this it is shown that the interaction Hamiltonian also depends on the magnitude and sign of nuclear precession frequency _N and the damping constant of ferromagnetic resonance A. The calculation of these parameters makes the Suhl [1] quantum mechanical derivation of the Hamiltonian of nuclear spin interaction in a ferromagnet more accurate. The influence of these parameters on the relaxation timeT ₂ is also discussed and is applied to the case of cubic cobalt.

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. , _N . , [1] - . ₂ .

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In conclusion the author thanks Dr. L. Valenta for significant remarks and valuable advice on this work. He also thanks J. Kvasnica and Z. roubek for suggestive discussions.     

Some applications of the discrete fourier transform to problems of crystal lattice deformation II

The method elaborated in [1] is applied to the solution of some problems for a plane lattice and the linear chain. The method can be used to investigate deformations around crystal lattice defects.

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, [1] . .

     

Der Einfluss verschiedener Beimischungen auf die Entstehung der Leinen und Baumstruktur in der Glimmentladung in der Atmosphere Luft-Quecksilberdampf

Ohne Zusammenfassung

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Magnetization coils without iron core for high field intensities

A new theory of rectangular coils without an iron core is described which amends the old one of Fabry and Bitter. It enables us to compute field intensities in coils having very small openings, which the old theory could not do.

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Nochmals Zur Arbeit Über Reines Eisen

Ohne Zusammenfassung

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The application of the thermodynamics of irreversible processes to welding arcs

The self-regulation of an inert gas shielded metal welding arc is dealt with briefly. A thermodynamic equation is derived for the self-regulation of such an arc.

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