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In Silicon and Germanium one finds three types of characteristic energy losses: the plasma loss at 17 eV in transmission of electrons through thin films, the 10 eV loss in reflection at cleavage surfaces, and the 5 eV loss in transmission through extremely thin films. The present paper is concerned with the 5 eV loss. It is found that the intensity of the 5 eV loss does not depend on variation of thickness of the foils. Thus, it is concluded that the 5 eV loss is due to surface plasma oscillations. In fact, measuring the angular distribution, there is found a dependence of ∼ ϑ in good agreement with that given by the theory. In the case of non-normally incident electrons it is found that the intensity of this loss is not symmetric about the direction of the incident electrons. This is in agreement with the theoretical considerations of Stern and Ferrell, and represents a further typical feature of surface plasma losses. [ABSTRACT FROM AUTHOR]

The specific heat for constant pressure, constant volume and their ratio behind a strong shock wave in helium with initial pressures of p=0·1 and 1·0 mm Hg have been calculated. At shock-velocities up to Mach 150 both ionizations have to be considered. Lowering of ionization potential and exitation energy can be neglected for this range. The specific heats show typical maxima as first found by Möglich, Riewe und Rompe for c of hydrogen. The second part of this paper deals with a method of iteration applied to the Rankine-Hugoniot equations. Hence they can be evaluated continuously over the range of both ionizations including the lowering of ioniziation potential. [ABSTRACT FROM AUTHOR]

Using results of a preceding paper, the wavefunctions of nuclear vibrations in muon molecules have been calculated by numerical integration, especially at small nuclear distances. These functions have then been used to determine reaction rates of nuclear fusion. The effect of nuclear forces on the wavefunction at very small distances has been estimated and taken account of. The numerical results reasonably agree with ( pμd) experiments. [ABSTRACT FROM AUTHOR]

This paper deals with exterior solutions of the field equations of Jordans x-theory. The Bianchi identities are set up and brought into a simple form. All solutions with vanishing conform tensor are determined. There are three classes of solutions characterized by a timelike, spacelike, or lightlike gradient of the gravitational scalar x. [ABSTRACT FROM AUTHOR]

In the presented paper the behaviour of mixtures of ionizing atomic gases in the direction of electric current as a function of space and perpendicular to the current as a function of temperature is studied. The ionization energies of the 'constituents' being either extremely different from each other or equal (isotopes), simple solutions of the problem can be given which may be useful for the understanding of effects of mass separation being found in such mixtures. [ABSTRACT FROM AUTHOR]

The radiative decay of the charged π-meson π→ e+ ν+ γ is calculated using dispersion relation techniques. It is assumed that the weak interaction producing the decay has a V-A structure. The decay through the vector variant has been reinvestigated and found to be different from the result of Vaks and Ioffe. The theoretical prediction of this paper is in agreement with a preliminary experiment recently performed at CERN. [ABSTRACT FROM AUTHOR]

The quantum theory of relativistic particles is developed in close analogy with that of nonrelativistic ones. In §1 we show how the Hilbert-space for the states of a physical system can be derived immediaty from experience. It turns out that both theories, the relativistic as well as the nonrelativistic one belong to the same Hilbert space. Lorentz invariance does not enter until we consider the transformations induced in the Hilbert space by the motion of the particles. These are formulated in §2. They form a representation of the inhomogeneous Lorentz-group or even of the Klein-group of conformai transformations in space-time. In §3 we develop the Hilbert-space from the so called 'basic space'. This space is spanned by simultaneously observable quantities of specific single particles which we call 'simple particles'. The characteristics of these single particles are: particle type (mass), momentum, spin, isotopic spin, etc. The configuration-space of a many particle system is taken as a set of all occupation numbers in the basic space. The Hilbert space is then the manifold of all square-integrable functions in the configuration space. In this paper the simple particles are considered to have zero rest-mass. Those having finite mass require the assumption of internal interactions and thus lead to complex structures. Mereover, particles of mass zero are distinguished by a higher degree of symmetry, i.e. by their invariance under transformations of the Klein-group. Taking into account further group-theoretical properties of the Klein-group, we assume that all aprticles are built up from neutrinos of two types. Only these we consider as simple particles. To begin with, we consider the simple case of a world with one kind of simple particles having no internal degrees of freedom. In §4 operators are given representing the inhomogeneous Lorentz-group and the Klein-group. For particles without any interaction these can easily be determined. In the case of particles with interaction it is possible to derive all operators of the inhomogeneous Lorentz-group from the interaction energy operator. This operator must satisfy certain conditions, one of which is quite involved and leads to a nonlinear operator equation. A special and rather simple approximate solution is given in §5. The resulting two-body-equation given in §6 leads to some interesting features concerning scattering and virtual and bound states. The cross-section and the wave function of the virtual state of the particle-pair, as well as the mass of a resonant state are finite. There is no bound state after a limiting process. The whole is strictly Lorentz-invariant, although we started from an expression only approximately Lorentz-invariant. Finally we state the corresponding field equations in §7. Our specific expression for the interaction energy leads to a strictly local coupling between the particles. However, the kinetic terms (which are bilinear in creation- and annihilation-operators) are of a non-local type, perhaps describing something like an interaction between the particles and the vacuum. [ABSTRACT FROM AUTHOR]

An apparatus to measure differential scattering cross sections using crossed molecular beams is described and results for the scattering of potassium atoms by different heavy atoms and molecules are presented. The experimental data are compared with theoretical calculations for a Buckingham-(exp-six)-potential and the parameters of this potential are determined. To carry out this comparison, it was necessary to average the existing calculations of E. A. Mason over the Maxwellian velocity distribution in the potassium beam. These averaged differential cross sections are tabulated for various angles and temperatures in the appendix of the present paper. Using crossed beams of molecules containing halogens, we can observe chemical reactions. Methods to determine total and differential reaction cross sections are discussed. [ABSTRACT FROM AUTHOR]

This paper is concerned with the analysis of quantum-mechanical modes of description for extremely complex systems such as found in biology. Starting from Max Born's recent statistical approach to classical mechanics we proceed to a discussion of the limits of measurement and prediction in the corresponding quantum-theoretical problems. A main concept here is that of temporary constants of the motion, long-lived parameters of the system which have the property that they can be measured without appreciable perturbation. Knowing these, microscopic structure can only be estimated by means of inductive inferences which are intrinsically indefinite. The part played by such inferences can be diminished only by more thoroughgoing measurements which, however, perturb the system and thereby prevent it from being representative of a class of similar systems that have not been so perturbed. This may be taken as a quantitative expression of Bohr's concept of generalized complementarity. The pragmatic value of an effective description lies in its forming the basis for prediction. In quantum mechanics there are limits of prediction engendered by the indefinite nature of certain elements of the description. The importance of these limitations of predictability for theoretical biology is outlined. [ABSTRACT FROM AUTHOR]

In strong electric fields the acceleration of the electrons by the field exceeds the deceleration by collisions with neutral molecules. Thus run-away or beam electrons are produced. This paper investigates the motion of the beam electrons in a neutral gas considering ionization processes by electron-molecule-impacts. We start with a time independent current of primary electrons (case a) and a space independant density of primary electrons (case b). The further development of the velocity distribution is calculated. For a molecular hydrogen gas the amplification of the initial electrons, the average ionization, and the velocity distribution of the electrons as a function of space or time respectively is given. The average ionization has an asymptotic solution, which becomes valid, when one primary electron has produced by ionization an avalanche of approximately 100 electrons. The Townsend coefficient α for high values of the field strength is independant of space only in the region of this asymptotic solution. [ABSTRACT FROM AUTHOR]

This paper gives a report on measurements of the coefficient of absorption and intensities of a gas-ionizing radiation, which is emitted by a gas discharge. Earlier measurements in oxygen with a discharge in a cylindrical electrical field had yielded components of radiation with values of μ≈550, μ≈250, and μ= 38 cm according to 760 mm Hg. By new measurements using a spark discharge an additional component with a value of μ=2,5 has been found, which already has been measured by other authors. Measurements with mixtures of oxygen and nitrogen are compared with results of measurements in air. From this it may be deduced that the gas-ionizing radiation effective in air is essentially emitted by nitrogen and ionizes oxygen, the coefficient of absorption being about μ≈5 cm. The number of ionizing quantums emitted per ionizing collision of electrons in the discharge tube is about 10 for oxygen, nitrogen, and air. In oxygen this figure proves to be essentially independent of E/p. In air, however, this figure is reduced with increasing values of E/p. The absorption of the ionizing radiation in air is increased by the addition of methane ( μ=960 cm for 760 mm Hg of methane). In carbon dioxyde several components of ionizing radiation are found, with coefficients of absorption in the range 200< μ<800. [ABSTRACT FROM AUTHOR]

In a device described in a previous paper the angular dependence of the 14.7 eV energy loss of aluminum has been measured. - The dispersion coefficient and the angular dependence of the intensity of this energy loss are in good agreement with the plasma theory. The cut-off angle was found somewhat smaller than expected. [ABSTRACT FROM AUTHOR]

The interaction of the nuclear electric quadrupolemoment with an electric field gradient at the position of the nucleus changes the angular correlation of two successive γ-rays and should also produce a circular polarization of the γ-rays. By measuring this polarization it should be possible to distinguish between electric and magnetic attenuation of the γ-cascade. In the electric case this measurement leads to determine not only the absolute value of the interaction product $$Q \cdot \frac{{\partial E}}{{\partial z}}$$ but also the sign of it and therefore the sign of the nuclear quadrupolemoment. In the following paper the measurement of the circular polarization of the 247 kev γ-ray of Cadmium-111 is described. A polarization of P=(0.8±0.2)% leads to the determination of the quadrupolemoment of the first excited state to Q=+0·9·10cm. [ABSTRACT FROM AUTHOR]

The behaviour of mixtures of reacting gases can be described by means of different principles. In this paper the thermodynamics of irreversible processes is confronted by a method based on the mechanics of particles. Here the conception of the 'constituents' as the building elements, composing the several components of the mixture, can be used profitably. Taking into consideration the thermal diffusion and the terms due to reactions in the equations of force, when the mechanical or 'dynamical' method is used, and formulating the kinetic quantities more precisely, when the thermodynamics of irreversible processes is regarded, the forces of inertia, hitherto missed, appear in the phenomenological equations, and the two systems can be proved to be equivalent. [ABSTRACT FROM AUTHOR]

In lattices, in which the Fermi surface is simply closed, the saturation values of the electrical resistivities in longitudinal/ transversal magnetic fields are equal to the approximate values for the resistivities, obtained from the variational method of Kohler using rotation symetrical trial functions/ constant relaxion times. - Depending upon the magnetic field direction the changes of the longitudinal and transversal resistance and of the Hall coefficient are proportional to the anisotropies in k-space perpendicular to the magnetic field direction. Depending upon the current direction the change of the transversal resistance is larger in the direction perpendicular to the smaller anisotropy. - By generalization of the results of part II of this paper (concerning special elliptic models) one can conclude, that the saturation of the transversal resistance vanishes in the direction of the axis in presence of cylindrical dispersion surfaces and perpendicular to the open orbits in presense of open oblate Fermi surfaces. [ABSTRACT FROM AUTHOR]

Work already published under the above topic by W. Ludwig and the author was limited to crystal temperatures above the Debye temperature, as it treated the lattice vibrations by classical statistics. In this paper, a complete quantum-statistical treatment is presented. The essential features of the high temperature results remain unchanged: New, temperature dependent dispersion curves may be introduced which, for long waves, are determined by the isothermal elastic constants. [ABSTRACT FROM AUTHOR]

Single crystals of anthracene and trans-stilbene when irradiated by α-particles show a strong dependence of their scintillation light yield on the impact direction of the α-particles with respect to the crystal orientation. This having been established in earlier papers, further investigations of 11 other compounds confirm this effect which now seems to be a common feature of monocrystalline organic scintillators. For explanation a possible relation between the anisotropy of the scintillation light yield and that of the electronic conductivity is proposed. [ABSTRACT FROM AUTHOR]

The internal field emission (Zener-tunneling) is examined from two directions, using a onedimensional model. In section I the transition probability is calculated using the Houston expansion, but without perturbation theory, as has been used in previous papers by other authors. The calculation permits an examination of the various perturbation approximations. It is found, that the validity of the first approximation depends critically upon the residue of the interband coupling function. This residue contains the Keldysh factor, which is determined here. In section II the transition probability is calculated using free electron functions, again without perturbation theory. The same transition probability is obtained in both cases. [ABSTRACT FROM AUTHOR]

The β-spectrum of Na was measured with a scintillation spectrometer. To avoid source absorption and scattering troubles the Na source was built in in the lattice of NaJ(Tl)-crystals. The observed β-spectrum of Na has a statistical shape. The Fierz term b is obviously zero the value obtained in this paper is (+0,8±6,0)·10 m c. [ABSTRACT FROM AUTHOR]

The process of deceleration of electrons by the field of neutral atoms is investigated by the aid of a model approximating the neutral atom by a constant potential U in the interior of a sphere of radius γ. The free-free emission coefficient is determined in the general case for an isothermal plasma; in the special case of an impenetrable sphere it is compared with the emission coefficient of the ion bremsstrahlung as obtained by the 'soft' approximation. The results show that electron-atom radiation may not be neglegible as compared with electron-ion radiation, and this fact may be used to explain the experimentally observed increase of the emission coefficient with pressure which is more rapid than linear. This is verified numerically in the limiting case of an impenetrable sphere. In addition the bound-free absorption coefficient is determined both in general and in the special case of the H ion; a comparison is made with the absorption coefficient as obtained by Chandrasekhar. By the aid of the method of 'best approximation' given in the concluding part of the present paper the quantities U and γ may be determined for any neutral atom. [ABSTRACT FROM AUTHOR]

The procedure of quantum mechanical treatment of a three-body problem described in the preceding paper by Diehl, Flügge, Schröder, Völkel and Weiguny has been specialized to the ground state in which the eigenfunction only depends upon the three distances between the particles. The solution of the Schrödinger equation has been approximated by variational methods, using the electronic functions of Finkelstein and Horowitz, and of Guillemin and Zener, but including the nuclear vibration in the trial function. [ABSTRACT FROM AUTHOR]

A simple method of measuring the degree of polarization achieved by optical pumping has been described recently for the case of sodium vapor, illuminated with the single circularly polarized D line. The assumption had to be made, however, that the atomic absorption cross section Q, depending on the degree of polarization P and the frequency of light ν, may be approximated by Q( P, ν)=(1− P)· Q( P=O, ν). The purpose of this paper is to discuss the qualification of this assumption. A theoretical analysis of the pumping process is tried, showing that the measured polarization corresponds in good approximation to the degree of the valence electron spin polarization. - For the case of weak absorption and equal intensity of the two hyperfine components of the D line a diagramm is given, relating the measured polarization to the polarization of the nuclear spin. [ABSTRACT FROM AUTHOR]

The orbital and spin energy of a Fermi or Bose gas with different orbital and spin temperature depend on both temperatures. This new thermodynamic behaviour demands a new formulation of the foundations of thermodynamics for such systems. In the present paper the fundamental thermodynamic notions (variables of state, work, adiabatic processes) are formulated and the definition of an empirical orbital and spin temperature is given. The first law of thermodynamics, the definition of orbital and spin heat, and resulting conditions of integrability are discussed. There are four heat capacities (instead of the one for normal systems), the relations of which are stated. [ABSTRACT FROM AUTHOR]

A Dehmelt type experiment is performed in which sodium vapor and argon as a buffer are employed. The pumping radiation consists of the circularly polarized D line. Since the strongly absorbing magnetic sublevels are depopulated, the vapor becomes more transparent to the pumping radiation with growing polarization. The transparency of the vapor is measured with and without optical pumping as a function of the sodium vapor density. The degree of polarization is determined in simulating the increase in transparency due to polarization by decreasing the sodium vapor density of the unpumped sample. This method requires the knowledge of the exact sodium vapor density in the temperature range of interest (100 to 200° C). The determination of the degree of polarization is based on the assumption, that the atomic absorption cross section Q, which depends on the degree of polarization P and the frequency of light ν, can be written in the form Q(P,ν)=A(P) · B(ν), where A(P) is a linear function of P, while B (ν) must not be changed by optical pumping. As will be shown in a following paper, the degree of polarization determined under this assumptions, describes in good approximation the polarization of the sodium valence electrons. [ABSTRACT FROM AUTHOR]

Using the variational method developped in the preceding paper of Diehl and Flügge, the binding energy and molecular parameters of the muon molecule ppΜ have been calculated. The vibrational amplitudes of the protons turn out to be much larger in comparison to their equilibrium distance than in the electronic molecule H. The equilibrium distance is about 40% larger than it would have come out from a simple two-center calculation with fixed nuclei. A dissociation energy of 211 ev has been found; this value may be enlarged by something between 10 and 20 ev in consequence of plausible corrections. [ABSTRACT FROM AUTHOR]

The elastic scattering of deuterons in deuterium has so far only been treated in Born approximation, at rather high energies. In the present paper the authors derive integro-differential equations to deal with the scattering phenomenon at low energies of a few MeV. The mutual distortion of the two deuterons at close distance turns out to have a large influence on the angular distribution. A simple and plausible assumption has been made, concerning this distortion, and the results have been compared with experiment for two energies. [ABSTRACT FROM AUTHOR]

This paper concernes the problem of development of plaine waves in a gas plasma without external fields. The question has been recently treated by Landau, v. Kampen, Berz and o. m. The equation of Boltzmann is discussed and solved for the case with initial conditions (Anfangswertproblem) explicitly. With the usual expression for the collision term exist no 'Eigenlösungen'. Nevertheless in a short time long waves develop with λ>30 l ( Debye-Length) from the initial distribution; the statistical damping cancels down the development of shorter waves. Changing the collision term, one finds true Eigenlösungen too. This different behaviour of the solutions seems to be less a physical problem than a question of the used mathematical formalism. [ABSTRACT FROM AUTHOR]

Electron avalanches in uniform fields are studied by means of a short duration spark light source. Electron drift velocities ν are measured in hydrogen, nitrogen, oxygen, and some vapours. It is shown, that in hydrogen and nitrogen the number of electrons increases exponentially by gas amplification with a time constant 1/αν, in accordance with a conventional assumption and with previous measurements in methane, α is the first Townsend coefficient. In oxygen and air it is, however, demonstrated that the number of electrons increases considerably less than exp (αυ·t), and the multiplication process takes longer time. This is evidently due to time losses of the electrons on their paths across the gap. Thus the mean time interval for successors, started by photons at the cathode, is increased. - In addition, this paper gives details of some measurements of the first Townsend coefficient α, the electron diffusion coefficient, and ionic drift velocities for certain gases. [ABSTRACT FROM AUTHOR]

The nucleons liberated in a ( d, p)- or ( d, n)-stripping-reaction are generally polarized even if unpolarized deuterons are used. In this paper however these reactions are examined for polarized deuterons in order to provide more detailed information concerning the interactions between the reaction products. [ABSTRACT FROM AUTHOR]

An excited nuclear state can decay by three different modes of double quantum emission, namely double γ-emission, γ-electron emission and double conversion electron emission. The emission of two γ-quanta has been considered in an earlier paper. The purpose of the present work is to treat all three processes together in a systematic manner. It is shown that the connection between the transition rates for γ-electron emission T and double γ-quantum emission T is more complicated than in the case of single quantum processes. However, T can still be expressed in terms of the usual conversion coefficients. This is also true for the transition rate T for the emission of two K-shell electrons, although only approximately. For the emission of electrons from different atomic shells the formulas become rather complicated, because of interference effects. The electron and γ-quantum spectra in all of the three second order processes are discussed in detail for the decay of the isomeric level in Xe. [ABSTRACT FROM AUTHOR]

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Parametric amplifiers have been developed during the last years to get a low noise amplification of weak electromagnetic signals. This paper describes simple experiments to demonstrate the basic principles by an electrical arrangement with variable capacity and by a mechanical set-up with capillary-gravity waves on a water surface. An explanation of the parametric oscillation and amplification is given in connection with these experiments. [ABSTRACT FROM AUTHOR]

This paper describes the measurement of ionization and charge exchange cross-sections for hydrogen atoms (H), Protons (H) and molecular hydrogen ions H and H in hydrogen gas in the energy range 9 to 60 keV. Further, the emission of secondary electrons from copper-beryllium by impact of these particles was measured. A beam of monoenergetic neutral hydrogen atoms was produced by charge exchange of a beam of protons in a gas chamber. Separation of the charged and uncharged components was accomplished by a magnetic field. The pressure in the chamber in which the cross-sections were measured was so low, that only a few particles of the incident beam suffered an effective collision. The positive and negative charges, which were produced by ionization and charge exchange along the path of the beam, were extracted by a transverse electric field and the saturation current was measured. The intensity of the neutral beam was determined at the same time by repeated charge exchange in an 80 mμ thick foil of aluminiumoxide. [ABSTRACT FROM AUTHOR]

By condensation of metals from the vapour onto a cooled substrate an especially high degree of disorder can be frozen in. Such strongly disordered films show essential changes of their properties. This paper deals with optical studies of such films of Bi, Ga, Sn and Ag. Reflectivity and transmission and their changes during annealing are measured in the spectral range from 0,25 to 4 microns. There is reasonable agreement with results of other measurements e.g. Hall-voltage, electrical resistance and electron diffraction. Optical constants and their changes during annealing are calculated in the range from 0,8 to 4 microns by approximation formulas. The high disorder produces similar anomalies of the optical constants as observed so far at extremely thin films. Concentrations and collision frequencies of free electrons are determined by means of the Drude theory. These values, obtained by a purely optical method are compared to results of electrical measurements and show satisfactory agreement. [ABSTRACT FROM AUTHOR]

A strong-coupling approximation method for the Chew-Low meson-nucleon scattering formalism is developed, considering, for simplicity, the case of charged scalar mesons. As a starting point, the Low equation formulated for the case of strong coupling is stated. This formulation explicitly takes into account the formation of excited compound-nucleon states which arise in the case of strong coupling. The data concerning the zero-meson part and the compound-nucleon excitation energies, necessary to specify this Low equation, are introduced approcimatly by means of the field-splitting transformation developed in a previous paper. The one-meson approximation is constructed; this corresponds to a certain kind of many-meson approximation of the usual Low equation whose limit as g→∞ holds exactly. It is hoped that these considerations will serve to guide an analogous investigation using the pseudoscalar theory. [ABSTRACT FROM AUTHOR]

The paper investigates the possibility of obtaining improved eigenfunctions of the reduced Bardeen-Cooper-Schrieffer-Hamiltonian by forming linear combinations of the approximative BCS-functions. For the groundstate an admixture of states with two excited pairs is considered. This leads to a lowering of the ground-state by an amount δW which is independent of the volume and of the same order of magnitude as the energy-gap 2 ɛ. The same shift is produced for the states with excited single-pairs. Superposition of states with one excited pair leads to an additional discrete level within the energy-gap. [ABSTRACT FROM AUTHOR]

Papers from Ekertowa and Dember show contradicting results concerning the additivity of photoelectric current and secondary electron current. We found, upon investigation, that additivity exists between photoelectric current and secondary electron current for metals in agreement with Ekertowa. The large departures from additivity, observed by Dember, receive reasonable interpretation in terms of an internal photoelectric effect in the oxide layer of his target. [ABSTRACT FROM AUTHOR]

The paper gives a simplified treatment of the thermodynamics of the Bardeen-Cooper-Schrieffer-theory. It is shown, that all functions can be represented with the help of a function a ( x) and its derivatives. Newly calculated tables of thermo-dynamical functions are given. [ABSTRACT FROM AUTHOR]

It is shown in this paper, that it is possible to construct parity conserving baryonpion interactions which are γ-invariant in exactly the same manner as electromagnetic and weak interactions. [ABSTRACT FROM AUTHOR]

In a previous letter a generalized γ-invariance for strong interactions has been proposed and some consequences of this invariance have been outlined. The present paper contains the detailed proof and discussion of these consequences. For the baryon-pion interactions one obtains two possible forms for the coupling: The K-meson couplings themselves should violate the invariance against space reflections. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Physik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The equations derived in a previous paper are discussed in some greater detail, in order to correct an erroneous impression, to which this paper may have given rise. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Physik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Completing a former paper about scattering experiments with electrons a new foil containing an element of high atomic number (lead) has been produced, which shows a very equal and fine distribution of lead. [ABSTRACT FROM AUTHOR]

In the electric field as has been shown theoretically by Franz and Keldysh there is in crystals an absorption edge shift towards longer wave-lenghts. This effect has been studied and verified on CdS by Böer and co-workers and has led to a more profound understanding of many problems of CdS single crystals conductivity. This paper is a first report on the absorption edge shift of ZnS single crystals in the electric field. [ABSTRACT FROM AUTHOR]

The paper is based on the non-relativistic three quark model of the baryons including mass differences depending on the electromagnetic as well on the hypercharge. Assuming that the binding energies between two quarks in the baryons are the well known linear combinations of the binding energies we verify different mass formulas between the baryons. Some ones can be verified without additional assumptions, other ones only by supposing relations between the binding energies. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Physik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The application of high gain image intensifier and image converter streak shutter techniques to investigations of faintly luminous early stages of gaseous discharges discloses in some detail the development of electron avalanches into anode- and cathode-directed streamers as soon as the critical amplification ( n≈10) is attained in the gap. The velocities of both of the streamer branches were measured quantitatively as to the dependence on pressure ( p), field ( E/p) and gas (Nitrogen and various mixtures), typical values being 0.5 ... 1 · 10 cm/sec. We find that streamer propagation is suitably described in a coordinate-system drifting with the electrons (driftvelocity v ≈ 1 · 10 cm/sec) and that the way it depends on the discharge parameters suggests that ionization by electron impact (in the eigen-spacecharge distorted field) and photoionization are the determining effects. - The cathode-directed streamers show a considerable intensification and acceleration as soon as they are encountered by cathodic secondary avalanches, which however are obviously not essential for the initiation of the process in itself. - The streak images give also an impression of persisting excitation and ionization processes in the region of the streamer-paths and of the transition into the beginning of the bright spark, correlated with several ionizing fronts observed moving towards anode or cathode with velocities even >10 cm/sec. (The paper includes also details of the gaseous near UV-radiation which was utilized for registration with image intensifier or converter, especially with respect to the decaytime of the excited states.) The results obtained are essentially a verification and to some extend completion of predictions made on the basis of early cloud chamber investigations. [ABSTRACT FROM AUTHOR]

The superconducting transition of thin films of Al, In, Tl, Pb, Sn, and Ga is investigated by resistance measurements before and after the low temperature oxidation of the surface. The films are condensed onto a crystalline quartz plate to a thickness of about 100 Å or less at a temperature of mostly 105 °K. The oxidation process below 40 °K was described in a previous paper. After a theory of Mott, it may be understood by the tunneling of electrons from the metal to some acceptor levels of the oxygen molecules at the outside of the oxide layer. This way, a strong electric field arises which, on the one hand, facilitates the motion of metal ions outwards to form oxide molecules and, on the other hand, is suspected to affect the transition temperature. The experimental results show a shift of the transition to higher temperatures with the metals Al, In, and Tl, however, with the metals Sn, Pb, and Ga to lower temperatures. These results agree qualitatively very well with direct measurements of the influence of surface charges on the superconducting transition of Sn and In by Glover and Sherrill. The T-shift depends clearly upon the film thickness and amounts to about 0.3 to 0.4 °K for the thinnest films used. Some experiments are undertaken in order to prove the existence of the electric field. Removing the residual oxygen molecules on top of the oxide layer destroys the acceptor levels and causes a reduction of the transition temperature to the value observed with the oxygen free film. As expected, the thickness of the oxide layer is not important for the magnitude of the T shift. [ABSTRACT FROM AUTHOR]