Vol. XXXV (1969)
Fasc. 1, pages 3–199
Henryk Niewodniczański Obituary
Acta Phys. Pol. 35, 3 (1969)not a regular article
The Effect of Shift of Total Absorption Peaks on the Accuracy of Determination in Non-destructive Activation Analysis (the Case of Covell’s Digital Method)
Acta Phys. Pol. 35, 11 (1969)
abstract
The shift of a total absorption peak in the gamma spectrum of the sample relative to a corresponding peak in the gamma spectrum of the standard is considered to be an inevitable fact. The effect on the value of the systematic error has been discussed with reference to the case in which Covell’s method is applied. Suggestions have been made as regards the way of determining the channel zero, the number of channels to be covered in calculations and the position of the peak in a pulse height analyser.
The Initial Value Problem for a Plasma in an External Field
Acta Phys. Pol. 35, 19 (1969)
abstract
The longitudinal plasma oscillations in an external electric field are investigated by means of numerical solutions and an approximation technique. For weak external fields the phase integral approximation and multitimescales perturbation techniques are used. The approximate solutions in the form of damped oscillations with time-dependent frequencies are found. The mechanism of instability growth is discussed.
Temperature Dependence of Saturation Currents in the System: Anthracene–Liquid Redox Electrode
Acta Phys. Pol. 35, 33 (1969)
abstract
The saturation currents in the system: anthracene–redox electrode have been investigated. From the measurements of the temperature dependence of the currents the reorientation energy of the solvent molecules has been estimated.
Polarized Infrared Spectrum of \(p\)-Xylene–Carbon Tetrabromide Complex
Acta Phys. Pol. 35, 39 (1969)
abstract
Polarized infrared spectrum of \(p\)-xylene–carbon tetrabromide complex single crystals was investigated in the 400–3200 cm\(^{-1}\) region. Crystal structure of the compound is confirmed. Spectra of complex components are not affected by complex formation, the enhancement of \(A_{1u}\) forbidden transitions and suppression of \(A_{1g}\) and \(B_{2g}\) bands in the crystalline compound is explained by the crystal-field symmetry. Assignments of \(p\)-xylene infrared-active frequencies are discussed.
Green’s Functions for the Bose Superfluid and the Relations Between Kinetical Coefficients
Acta Phys. Pol. 35, 49 (1969)
abstract
The Green’s functions are obtained with the help of the hydrodynamic equations with viscous terms and from the formulae connecting average values of dynamical variables with retarded or advanced thermodynamical Green’s functions. From the relations between the advanced and retarded Green’s functions the relations for some kinetical coefficients are obtained.
On Some Identities for Green’s Functions in the Hydrodynamical Approximation. II. Superfluid
Acta Phys. Pol. 35, 57 (1969)
abstract
After the calculation of Green’s function, with the help of the hydrodynamical equations for the Bose-superfluid, it is demonstrated that they are connected by formulas, derived earlier by means of the gauge transformation.
Critical Magnetic Scattering of Neutrons in Antiferromagnets
Acta Phys. Pol. 35, 61 (1969)
abstract
The cross section for critical magnetic scattering of unpolarized neutrons in a two sublattice, spin \(s = \frac {1}{2} \). Heisenberg antiferromagnet, for temperatures above or at the Néel point, without external magnetic field has been calculated on the basis of the previously derived general cross section formula and the previously developed description of the spatial and temporal behaviour of thermodynamic fluctuations in antiferromagnetic order. The cross section has been derived in two forms connected with the Ormstein–Zernike and \(|\sin \chi _2r|/r\) spin correlations. In discussing these cross sections, emphasis has been laid upon the second one.
Ternary Fission of \(^{238}_{92}\)U and \(^{232}_{90}\)Th Nuclei Induced by 2.9 MeV Neutrons
Acta Phys. Pol. 35, 67 (1969)
see erratum: Acta Physica Polonica 36, 499 (1969)
abstract
The ternary fission mechanism of \(^{238}_{92}\)U and \(^{232}_{90}\)Th induced by 2.9 MeV neutrons was investigated. Two modes of ternary fission of \(^{239}_{92}\)U have been determined. The average total kinetic energy of fragments was found to be 174.5 MeV for ternary fission of \(^{239}_{92}\)U and 162 MeV for ternary fission of \(^{232}_{90}\)Th. The frequency of occurrence of ternary fission relative to binary fission was found to be \(8\times 10^{-4}\) for fission of \(^{238}_{92}\)U induced by 2.9 MeV neutrons and \(3\times 10^{-3}\) for fission of \(^{232}_{90}\)Th induced by 2.9 MeV neutrons.
Development of Partition Function in Boltzmann Distribution V. Exchange Corrections
Acta Phys. Pol. 35, 75 (1969)
abstract
Corrections from the exchange diagrams to the previously obtained formula for the partition function \(Z\) are found. These corrections influence neither the properties of the leading diagrams nor the general form of the expression for \(\ln Z\). The effect of retaining them results only in a renormalization of the value of the parameter \(A\) of the theory.
Development of Partition Function in Boltzmann Distribution VI. Formula for \(\ln Z\)
Acta Phys. Pol. 35, 83 (1969)
abstract
Summations of the previously obtained infinite series to a closed formula for the partition function \(Z\) in the quasi-ideal approximation are performed for some values of the parameters. It is proved that the formula for \(\ln Z\) as a function of temperature exhibits one point of discontinuity.
Specific Heat of Cementite in the Temperature Range 2–20°K
Acta Phys. Pol. 35, 91 (1969)
abstract
By using the results of our earlier measurements of the specific heat of six carbon steels containing from 0.10 to 2.50 percent of carbon, the lattice and the electronic specific heats and the Debye temperature of these steels have been estimated as well as the respective values for cementite. To about 15°K the specific heal of cementite may be represented by the formula: \(C = \alpha T^3 +\gamma T\). The change in the lattice specific heat coefficient and Debye temperature has been estimated within the temperature range 15°–20°K. The change in both the specific heat and thermodynamic functions of cementite has been calculated for the interval from 2°–20°K.
Emission Anisotropy of Fluorescence of Anthracene Solutions. I
Acta Phys. Pol. 35, 101 (1969)
abstract
The emission anisotropy (EA) and the mean duration of fluorescence of anthracene and d-anthracene in glycerol solutions have been measured. It was found that the limiting EA is higher than that reported in other papers. Using expressions given by Jabłoński and Perrin in their theories of fluorescence light depolarization by Brownian rotations and torsional vibrations of the luminescent molecules the limiting EA \(r_0\), the probability of depolarization by rotation per unit time \(\phi \), the volume of the anthracene molecule together with its solvation shell \(v\), as well as the frequency of its torsional vibrations and its moment of torsion were calculated. Taking into account the shortness of the mean duration and the high EA-value of the fluorescence and comparing the obtained parameters of the torsional vibrations of anthracene and d-anthracene molecules with those obtained for several different molecules by other authors, the conclusion is reached, that probably the only depolarization factor (after elimination of the Brownian rotations an the concentration depolarization) are torsional vibrations, while the admixture of the negatively polarized fluorescence produced by excitation to the electronic level \(L_b\) lying above the initial level \(L_a\) of emission of fluorescence is negligible.
Dependence of Domain Width on Crystal Thickness in the Remanent Honeycomb Domain Structure in Cobalt
Acta Phys. Pol. 35, 117 (1969)
abstract
The dependence of the domain width on the crystal thickness is examined experimentally for the remanent honeycomb domain structure in cobalt single crystals, in the thickness range where no closure domains are formed at the basal crystal surface. The experimental results confirm the half-power law following form theory, the domain width being however nearly five times larger than predicted by theory. Moreover, it is shown that for crystal thicknesses up to 50 \(\mu \)m no closure domains form at the crystal surface, contrary to theory according to which closure domains in cobalt should from if the crystal thickness is larger than 0.2 \(\mu \)m. A critique of similar experiments carried out by other authors on magnetoplumbite is given.
Influence of Domain Width on the Thickness and Energy of Symmetric Bloch Walls in Body-centred Cubic Ferromagnetic Lattices
Acta Phys. Pol. 35, 127 (1969)
abstract
The dependence of the thickness and energy of symmetric Bloch walls on the domain width is numerically examined for the case of the \(bcc\) ferromagnetic lattice, by utilizing the formulae derived for those quantities in an earlier paper (Wachniewski, Ziętek 1967 Acta Phys. Pol., 32, 93 (1967)), where the variational principles for the walls were solved under periodic boundary conditions. For each type of wall, the critical domain width is determined below which the departure of the examined quantities from their asymptotic values (as used in the conventional domain theory and in practical applications) becomes significant. As an example, specific data for Fe are provided.
Time Evolution of a System with a Stochastic Hamiltonian and a Given Initial State
Acta Phys. Pol. 35, 145 (1969)
abstract
The time evolution of a quantum system, which with a given Hamiltonian and an initial state is described by the Von Neumann equation, is discussed in the case of a stochastic Hamiltonian. The notion of a stochastic Hamiltonian is taken from the statistical theory of the energy levels of complex systems (cf. Porter 1965). Following the ideas of Ingarden (1965, independently also Porter 1965, Bronk 1966), the conventional statistical approach used in the statistical theory of energy levels is generalized by means of the variational principle of information thermodynamics (Ingarden 1963). The optimum density operator is introduced and its matrix elements are calculated in some special cases. The reversibility of the evolution of the system described by the optimum density operator is discussed. It is shown that in the cases considered this evolution is irreversible.
Artificial Zeolites Application in Vacuum Technology
Acta Phys. Pol. 35, 161 (1969)
abstract
Some sorptive properties of synthetic type \(A\) and \(X\) zeolites in various cationic forms are described. The measurements were limited to pressures below 1 Tr and were carried out for nitrogen by means of the volumetric and gravimetric methods at 78°K and for helium by means of the volumetric method at 4.2°K. Besides, the problem is discussed how to get rough vacuum by means of single or double stage sorption pumps filled with synthetic zeolites of different type. Some aspects of the behaviour of zeolite traps cooperating with oil diffusion pumps in laboratory vacuum equipment are also discussed.
Sensitive Automatic Method of Measuring Time Variations of Magnetization
Acta Phys. Pol. 35, 173 (1969)
abstract
The paper describes an arrangement for investigating the magnetization relaxation of weakly magnetic materials, being an adaptation of the coercive force meter with internal one core astatic fluxgate. In particular, a unit for rapid switch-off the field in the coil and a compensation unit are described. Given are the range of applicability of the method and its sensitivity.
Influence of Crystal Thickness on Remanent Domain Structures in Cobalt. II. Rectangular-prism-shaped Single Crystals
Acta Phys. Pol. 35, 179 (1969)
abstract
The dependence of the domain width \(D\) on the crystal thickness \(T\) in the magnetically preferred direction [0001] in cobalt is studied experimentally for the honeycomb (\(H\)) and Goodenough (\(G\)) remanent domain structures, on a set of single crystals in the form of rectangular prisms with square cross-sections (8 mm\(\times \) 8 mm) in the basal plane (0001), their thickness \(T\) ranging from 11500 \(\mu \)m to 3 \(\mu \)m. The dependence is found to be of the form \(D_{X;m} = T^{b_m}a_{X;m}\), where \(m =1\) for \(T\ll T_1\) and \(m \approx 2\) for \(T\gg T_1\), \(X = H\) or \(G\), \(b_1 = 0.5, b_2 = 0.57\), and \(T_1 = 50~\mu \)m is the critical thickness below which closure domains disappear. The results are in very good agreement with those obtained on a single wedge-shaped sample in Part I of this paper.
Low Energy Part of the \(\alpha \) Particle Spectrum from Tripartition of \(^{235}\)U
Acta Phys. Pol. 35, 187 (1969)
abstract
Measurement of the low-energy part of the spectrum of \(\alpha \) particles emitted in thermal neutron fission of \(^{235}\)U was performed with a telescope counter. The upper limit for the cross section of the \(^{235}\mathrm {U} (n, \alpha )^{232}\mathrm {Th}\) reaction, was estimated to be 3 mb for the transition to the ground state and 2 mb for the transition to the excited state up to 5 MeV.
Some Remarks on the Foundations of the Improved LCAO Theory
Acta Phys. Pol. 35, 191 (1969)
abstract
Basing on the properties of really effective correlation factors a critical review of the foundations of Julg’s improved LCAO method is presented.
Temperature Dependence of Field Emission of Since Crystal Planes of Tungsten
Acta Phys. Pol. 35, 195 (1969)
abstract
\(T\)–\(F\) emission (W.W. Dolan, W.P. Dyke, Phys. Rev. 95, 327 (1954)) of single crystal planes of tungsten as an emitter was investigated in Müller’s tube. A comparison of the experimental data with the theory of Murphy and Good is made. A new method of computing the geometrical factor \(\beta \) for any point of the tip is shown.ERRATA
Characteristics of Molecular Complexes in the Excited State
Acta Phys. Pol. 35, 199 (1969)
The Pyrene Excimer
Acta Phys. Pol. 35, 199 (1969)
Elektrophotoluminescence in Rigid Organic Solutions
Acta Phys. Pol. 35, 199 (1969)
Fasc. 2, pages 203–327
The Influence of Gravitational Fields on the Propagation of Light
Acta Phys. Pol. 35, 203 (1969)
abstract
The gravitational wave accompanying a light pulse is shown to interact with a stationary mass causing the mass to be displaced in the direction of the light path and endowing the mass with a constant velocity perpendicular to and toward the light path. Requiring the center of inertia of the mass plus light pulse to remain fixed, necessitates that the light pulse be delayed the amount predicted by Shapiro’s fourth test of general relativity; in addition, and for the same reason, the path of the light pulse is bent an amount predicted by the second test of general relativity.
Diffraction of Electromagnetic Quadrupole Radiation on Perfectly Conducting Wedge
Acta Phys. Pol. 35, 207 (1969)
abstract
The solution of the problem of diffraction of electromagnetic waves emitted by an electric dipole on a perfectly conducting wedge has been given in a previous paper. The present paper gives the solution of the electromagnetic diffraction problem for waves generated by an electric quadrupole. The method used has been proposed by Petykiewicz who has applied it for the first time in the problem of diffraction of scalar multipole radiation on a wedge.
Динамика решетки хлористого аммония
Acta Phys. Pol. 35, 223 (1969)
abstract
В работе приведен расчет дисперсионных кривых и спектров частот ионного кристалла хлористого аммония в приближении жестких ионов. Полученный спектр частот торсионных колебаний аммониевых ионов имеет форму очень узкого пика с шириной порядка 0,4 мэв.
Reorientation of the \(\mathrm {H}_3\mathrm {0}^+\) Ion in Polycrystalline Perchloric Acid Monohydrate Studied by NMR
Acta Phys. Pol. 35, 239 (1969)
abstract
The proton magnetic resonance absorption line in polycrystalline \(\mathrm {HClO}_4 \cdot \mathrm {H}_2\mathrm {O}\) was measured between \(-180\)°C and \(+50\)°C. Two distinct line width transitions were found. In the lowest temperature the line corresponds to an equilateral triangle of side \(r = 1.7\) Å formed by the protons in the OH\(_3^+\) group. Second moment considerations led to the conclusions that in the intermediate region (between \(-90\)° and \(-40\)°C) the triangle rotates about perpendicular axis and above \(+5\)°C it reorients isotropically. A thermal hysteresis of the line width found between \(-30\)°C and \(0\)°C corroborates the conclusions of Rosolowskij and Zinovjev concerning a first order phase transition in this region.
Determination of Magnetic Structures in hcp Crystals. Part I
Acta Phys. Pol. 35, 245 (1969)
abstract
The Landau and Lifshitz theory is applied to a single second-order magnetic phase transition from the paramagnetic to the magnetic state within the framework of the model of magnetic moments strictly attached to lattice points for the hcp crystal lattice. Knowing the magnetic space group in the disordered phase only, all magnetic orderings possible just below the transition temperature are found.
Decay and Depolarization of Fluorescence of Phtalimide Solutions
Acta Phys. Pol. 35, 259 (1969)
abstract
The position of the maximum of the fluorescence spectrum of phtalimide solutions depends strongly on their temperature. Phtalimide molecules, when excited, change their dipole moment considerable, causing a perturbance in the state of equilibrium existing between the solvent and dye molecules in the ground state. The degree of reorientation which the molecules of the solute have reached at the instant of fluorescence emission, and thus also their energy of interaction with the surrounding solvent molecules at this instant (responsible for the fluorescence spectrum shift), are both temperature dependent. At temperatures of the solution in which the relaxation time of reorientation \(\tau _r\) is of the same order as the mean duration \(\tau \) of fluorescence, we observe the biggest differences in the duration of fluorescence and in the emission anisotropy in the long- and short- wave regions of the fluorescence spectrum. These differences are due to the different luminescence centers with different degrees of reorientation and mean durations of fluorescence. Because of the differences in the mean durations, the emission anisotropy \(\bar {r}\) of fluorescence also becomes dependent on the wavelength of the emitted light. The strongest dependence was observed, however, at temperatures higher than those at which the largest fluorescence spectrum shift occurs. To find the reason for this effect, measurements of the mean duration and emission anisotropy of fluorescence of various phtalimide solutions were performed at different temperatures and wavelengths of emitted light. The results of these measurements show that the depolarization probability, as well as the dipole-dipole interaction, depends on the temperature of the solution (owing to the temperature dependence of the volume of the fluorescent molecule’s solvatation shell).
Coherence of Electromagnetic Field and the Radiation Source Structure
Acta Phys. Pol. 35, 271 (1969)
abstract
The coherence effects of optical fields have so far been related to the finite spectral width of radiation and to the source size. These two effects are called temporal coherence and spatial coherence effects, respectively. On the basis of earlier investigations on wide-angle interference we can however expect another effect related to the multipolarity of the source. This effect of multipole coherence, which plays a role both in vector and scalar formulation of the theory, is discussed in connexion with the effects mentioned above. The electromagnetic degree of coherence is evaluated for a simple model of the source. In the concluding part of this paper a generalization of the van Cittert–Zernike theorem for multipole radiation is derived. It is indicated that for the fields of narrow angular spread a scalar theory is applicable.
Virial Expansion of Maxwell–Boltzmann Distribution of a Real Gas
Acta Phys. Pol. 35, 285 (1969)
abstract
The Maxwell–Boltzmann distribution of a real gas, \(\langle N\)(p)\(\rangle \) i.e. , the probability of finding a particle with momentum \(\hbar \)p in a system of interacting particles, is calculated in the form of an expansion in powers of the pressure of the gas (the virial expansion). The expansion coefficients are related in a simple way with the usual virial coefficients of the expansion of the equation of state. It is found that the distribution of momentum remains the same as that for an ideal gas, but the temperature and pressure dependence is changed. The method of calculating \(\langle N\)(p)\(\rangle \), both for classical and quantum gases, by means of differentiation of a corresponding expression for the partition function of the system under consideration is used. This method is much simpler than direct calculation of the statistical average of the occupation number operator \(\langle N\)(p)\(\rangle \) of the momentum eigenstate \(\hbar \)p.
Low-energy Excited States of \(^{54}\)Mn
Acta Phys. Pol. 35, 295 (1969)
abstract
The low-energy excited states of \(^{54}\)Mn were investigated by means of the reaction \(^{54}\mathrm {Cr}(p, n)^{54}\mathrm {Mn}\) at a proton energy of 2.7 MeV. The energy of the first two excited states, being (\(54.34\pm 0.5\)) keV and (\(156.9\pm 1\)) keV, respectively, were determined from the internal conversion electron spectrum. The ratio of internal conversion coefficients, \(\alpha _K/(\alpha _L +\alpha _M)\), for the 54.3 keV transition was found to be \(7.1\pm 1\).
Low-energy Excited States of \(^{65}\)Zn From the Decay of \(^{65}\)Ga
Acta Phys. Pol. 35, 301 (1969)
abstract
The internal conversion electron spectrum of the gamma transitions following the 15.2-minute decay of \(^{65}\)Ga has been measured several times. The half-lives for the individual transitions and the relative internal conversion coefficients are determined. A spin value of \(3/2^+\) for the third excited state of \(^{65}\)Zn is suggested.
Influence of Domain Width on the Thickness and Energy of Symmetric Bloch Walls in Face-centred Cubic Ferromagnetic Lattices
Acta Phys. Pol. 35, 307 (1969)
abstract
The influence of the domain width on the thickness and energy of symmetric Bloch walls in the \(fcc\) ferromagnetic lattice is numerically examined, by utilizing the formulae derived for those quantities in an earlier paper (Wachniewski, Ziętek 1967) where the variational principles for the walls were solved under periodic boundary conditions. For each type of wall, the critical domain width is determined below which the departure of the examined quantities from their asymptotic values (as used in practice) becomes significant. As an example, specific results for Ni are provided.
Method of Measurement of Laser Beam Energy with “Black Horn” Calorimeter
Acta Phys. Pol. 35, 325 (1969)
abstract
The paper gives the description of a “rat’s nest” calorimeter. The absorbing element consists of wires laid in the shape of a bent cone (horn) and placed in a passage Dewar vessel. The reflection coefficient measured was 0.1%. Ventilation by mean of a fan makes the bolometer suitable for multiple measurements.
A New Theory of Quasars
Acta Phys. Pol. 35, 327 (1969)
Fasc. 3, pages 331–489
Transformation of Heat in Relativistic Thermodynamics
Acta Phys. Pol. 35, 331 (1969)
abstract
A system enclosed in impenetrable diathermic walls which perform work on and transfer heat to the system in a reversible or irreversible process is studied. Direct calculation of forces from the walls on the system, of work, and of energy leads to the conclusion that heat transferred to the system in all reversible and a number of irreversible processes transforms according to Planck’s formula. We ought to redefine the concept of force from the wall in order to get Ott’s transformation formula. However, the redefined force is no longer a time average of actual forges from the particles of the wall on the particles of the system and therefore does not have a good physical meaning.
Flux de neutrons lents dans les cavites des moderateurs de moniteurs
Acta Phys. Pol. 35, 359 (1969)
abstract
On a étudié l’influence de l’élargissement de la cavité, dans les modérateurs cylindriques de matériel hydrogénique sur le changement du flux de neutrons lents. On à constaté, que le flux de neutrons diminue considérablement quand le rayon de la cavité s’agrandit. Il est recommandé d’encastrer qu’cours de la fabrications les détecteurs dans les modérateurs et, présentant un ensemble, ils peuvent être inclus dans le système de moniteurs.
Static Maxwell–Einstein–Klein–Gordon Fields
Acta Phys. Pol. 35, 363 (1969)
abstract
This paper considers the existence of the stationary s state of matter field generating the most general statical metric and electrostatic fields. The system of equations are seen to be determinate, but if Weyl–Majumder condition between \(g_{44}\) and the electrostatic potential is assumed the system of equations becomes over determinate and it readily reduces to a determinate one if mass parameter equals the charge parameter in magnitude. Further, if the matter is at rest Weyl–Majumder condition is a necessary one and no solution exists unless the mass parameter in magnitude equals the charge parameter i.e. , matter cannot be at rest without the mass charge balance.
О выполнении законов сохранения в элементарном акте при расчетах внутриядерного каскада
Acta Phys. Pol. 35, 367 (1969)
abstract
Моделирование неупругих \(\pi N\) и \(NN\) взаимодействий при расчёте столкновений быстрых частиц с атомными ядрами ло каскадной модели связано с рядом трудностей. Одна из них — точный учёт законов сохранения энергии и импульса при розыгрыше характеристик элементарного акта по известным экспериментальным угловым и энергетическим распределениям рождающихся частиц. В данной работе исследован вопрос о том, в какой степени точный учёт только закона сохранения энергии в „эквивалентной“ системе влияет на характеристики элементарного акта и на результаты расчёта неупругих нуклон-ядерных взаимодействий.
Е-мезон и мезон-барионное рассеяние в нарушенной \(SU_W(6)\)
Acta Phys. Pol. 35, 373 (1969)
abstract
Изучаются следствия нарушения симметрии \(SU_W(6)\) в амплитудах мезонбарионных столкновений. Полученные соотношения между сечениями процессов не противоречат имеющимся экспериментальным данным. Нарушенная симметрия \(SU_W(6)\) приводит к заключению, что девятый псевдоскалярный мезон Е (1420) должен рождаться столь же часто, как и \(\eta \)-мезон.
Magnetization and the Spectrum of Elementary Excitations of the Uniaxial Anisotropic Ferromagnet
Acta Phys. Pol. 35, 381 (1969)
abstract
The expressions determining the magnetization and the spectrum of elementary excitations are derived for the uniaxial anisotropic ferromagnet. Their dependence on the temperature and the external magnetic field is discussed. The calculations were made using double-time temperature-dependent Green-functions.
Aging Time Dependence of Magnetic Hysteresis Parameters for Cu–Co Solid Solutions
Acta Phys. Pol. 35, 391 (1969)
abstract
This work gives the experimental results of \(H_c\), \(H_R\) and \(I_r\) measurements as a function of ageing time for Cu-1% Co solid solution aged at 600°C and 700°C. On the basis of an analysis of the results there have been distinguished in the ageing process: a superparamagnetic stage, stable single particles, stable agglomerations and multidomain particles or particles subject to incoherent rotation. Using the results of observations under an electron microscope and magnetic granulometry of the initial states we discuss the precipitation kinetics for long annealing times, and we assess the usefulness of the various granulometry techniques at different ageing stages.
Local Quantum Field Theory Without Divergences
Acta Phys. Pol. 35, 403 (1969)
abstract
The well known convergence difficulties within the framework of relativistic, local and microcausal quantum field theories may be avoided by introducing non-linear interactions represented by bounded operators. Such interactions mean infinite sets of many-body forces. The plural forces become more and more important for small distances and high concentrations of matter (strong fields). A general idea of how to perform approximative computations for such a theory is sketched.
On the Abelian Fields of Special Type
Acta Phys. Pol. 35, 407 (1969)
abstract
It is proved that the abelian Wightman field \(A(x)\) is a polynomial in \(x\) variables. Some natural conditions are indicated under which this polynomial is a constant or vanishes.
Excitation Curve for the Reaction \(^{181}\mathrm {Ta}(n, p) ^{181}\mathrm {Hf}\) in the 13 to 17.5 MeV Energy Range
Acta Phys. Pol. 35, 413 (1969)
abstract
The activation method was applied in measurements of cross-sections in the reactions \(^{181}\mathrm {Ta}(n, p) ^{181}\mathrm {Hf}\) in the 13 to 17.5 MeV neutron energy range. Experimental results were compared with those predicted theoretically by the statistical model. This comparison shows that the process of compound nucleus formation makes only a small contribution to the reaction in question.
Excitation Curve for the Reaction \(^{181}\mathrm {Ta}(n,\gamma ) ^{182}\mathrm {Ta}\) in the 0.03 to 5.1 MeV Neutron Energy Range
Acta Phys. Pol. 35, 417 (1969)
abstract
The activation method was applied in measurements of the cross-sections of the \(^{181}\mathrm {Ta}(n,\gamma ) ^{182}\mathrm {Ta}\) reaction in the neutron energy range from. 0.03 to 5.1 MeV. The agreement of the experimental results with those predicted theoretically by the statistical model was good on the assumption that the formula for the \(\gamma \)-ray emission probability depends on the \(\gamma \)-ray absorption cross-section. It was necessary to assume that a giant \(E1\) resonance and a “pigmy” resonance exist. The agreement was poor when the probability of \(\gamma \)-ray emission was assumed to be proportional to \(E_{\gamma }^3\) (\(E_{\gamma }\) being the energy of \(\gamma \) quanta).
Permeability Disaccommodation in \(\alpha \) Fe–C–N in the Temperature Range from \(-40\)° to \(+180\)°C
Acta Phys. Pol. 35, 421 (1969)
abstract
The disaccommodation of permeability in several samples of pure and very pure iron, containing carbon and nitrogen in the form of a solid solution, was studied in the range of temperatures from \(-40\)° to \(+180\)°C. Apart from time decrease of permeability associated with the carbon and nitrogen Snoek relaxation and with C–C pairs, a new disaccommodation effect was found to appear at temperatures over \(0\)°C. The effect of quenching, ageing and plastic working on this phenomenon was investigated.
The Effect of CO-Activator Concentration on the Photoluminescence of ZnS-Cu at Various Temperatures
Acta Phys. Pol. 35, 431 (1969)
abstract
ZnS–Cu luminophors were produced by sintering together the basic substance, activator and the flux, NaCl, whose concentration ranged from one to eight per cent. The co-activator for this group of luminophors is the chlorine ion. The spectral characteristics of the luminous emission of the samples illuminated by a mercury lamp with a Wood filter were studied with the use of a monochromator and electronic photomultiplier at temperatures of 100, 200, 300, 400, 500 and 600 degrees Kelvin. On the basis of the obtained results it was found that: (1) the co-activator concentration affects the spectral curves of the blue and green bands and their position in the spectrum; with higher concentrations both bands shift toward the shorter wavelengths, which points to a gradual change of the luminophor structure from sphalerite to wurtzite type with increased co-activator concentration; (2) the optimal concentration of introduced flux, at a fixed activator concentration, is between 4 and 5 per cent; (3) the co-activator concentration affects the temperature extinction of the photoluminescence; (4) the co-activator concentration does not bear any observable effect (within experimental error) on the half-widths of the bands at any of the temperatures, nor does it alter the ratio of the widths at higher temperatures to that at 100°K; (5) the most appropriate model for the photoluminescence of this type of luminophor is that proposed by G. Curie and D. Curie (J. Phys. 21, 127 (1960).
Vector Meson Production at High Energy and the Quark Model
Acta Phys. Pol. 35, 441 (1969)
abstract
A comparison of the predictions of the quark model with existing experimental data on the vector meson production is presented.
Large Angle Elastic Scattering at High Energies and the Quark Model
Acta Phys. Pol. 35, 447 (1969)
abstract
A quark model is proposed for the large angle elastic scattering of elementary particles. The model explains the main features of the baryon–baryon and baryon–antibaryon scattering.
Excited States of \(^{119}\mathrm {Sb}\)
Acta Phys. Pol. 35, 453 (1969)
abstract
A magnetic beta-spectrometer of high transmission was used to measure the energies and intensities of the internal conversion electron lines following the decay of \(^{119m}\mathrm {Te}\). The existence of the 116.4 keV and 871.2 keV transitions was confirmed. Several lines of very weak intensities, whose decay times are near the value of the \(^{119m}\mathrm {Te}\) life-time, were observed for the first time. The conversion coefficients were evaluated for most of the observed transitions. The following spin values for the excited states of \(^{119}\)Sb are suggested: \(0\) keV — \(5/2^-\), \(270.3\) keV — \(7/2^+\), \(1048.1\) keV — \(7/2^+\), \(1212.6\) keV — \(9/2^+\), \(1249\) keV — \(9/2^+\), \(1365.8\) keV — \(11/2^-\), \(1407\) keV — \(9/2^+, 11/2^+\), \(2129\) keV — \(9/2^-\), \(2226\) keV — \(9/2, 11/2^+\) and \(2278\) keV — \(9/2, 13/2^-\).
О конформной инвариантности уравнений, онисывающих частицы с произвольным спином
Acta Phys. Pol. 35, 459 (1969)
abstract
Изучается вопрос о конформной инвариантности волновых уравнений, описывающих частицы с произвольным спином.
An Improved Method of Preparation of Spherical Samples from Ferrites and Metallic Alloys Used in Some Magnetic Measurements
Acta Phys. Pol. 35, 467 (1969)
abstract
A very simple method is presented for the preparation of spherical samples from ceramic materials and metallic alloys. No use of compressors or specially shaped grindstones is required. The method permits simultaneous treatment of several samples of different chemical composition.
A Rotating Probe for Measurements of Field Strength Gradient of Laboratory Electromagnets
Acta Phys. Pol. 35, 471 (1969)
abstract
The construction of a probe for measurements of magnetic field strength gradient of laboratory electromagnets is described. The probe consists of two very small coaxial coils whose distance is constant. The windings of the coils are in series opposing connection. The coils are mounted on a spindle which is driven by a synchro-motor. When they are placed in a non-uniform magnetic field an e.m.f. is induced which is a measure of the magnetic field gradient at that particular place.
Exoelectron Emission During Phase Transformations of Magnetic Pyrites
Acta Phys. Pol. 35, 475 (1969)
abstract
In this communication we present the results of measurements of exoelectron emission from magnetic pyrites which in the temperature range from 300°K to 650°K undergo magnetic transitions as well as non-magnetic phase transitions.
Quantum Mechanics as a Quantum Markovian Process
Acta Phys. Pol. 35, 479 (1969)
abstract
A new mathematical notion of the quantum Markovian process is introduced and it is shown that it is adequate for the needs of quantum mechanics.
Valence Force Constants, Mean Amplitudes of Vibration, and Thermodynamic Functions of Carbonyl Sulphide
Acta Phys. Pol. 35, 483 (1969)
abstract
On the basis of the recent vibrational and structural data for carbonyl sulphide, four valence force constants as well as mean-square amplitudes of vibration and mean amplitudes of vibration at the room temperature have been computed by the symmetry considerations. In addition to these, molar thermodynamic functions, such as the enthalpy function, free enthalpy function, entropy, and heat capacity have also been computed for the temperature range 200–2000°K on the assumption of a rigid rotator, harmonic oscillator model. The results have been briefly discussed.
Feldemission aus \(\mathrm {CdP}_4\)
Acta Phys. Pol. 35, 487 (1969)
abstract
Im Temperaturbereich von 77°K bis 300°K ist der Feldemissionsstrom aus \(\mathrm {CdP}_4\) von der Belichtung und Temperatur unabhängig. Hieraus kann man bei Berücksichtigung der Eigenschaften des \(\mathrm {CdP}_4\) den Schluß ziehen, daß Emission aus einem an der Oberfläche entarteten Leitungsband vorliegt.ERRATA
A Perturbation Treatment of the Hartree–Fock Equation for \(2s^2\) \(^1S\) Weakly Quantized States of Helium-like Ions
Acta Phys. Pol. 35, 489 (1969)
Fasc. 4, pages 491–659
Electronic Interaction in the Free Electron Model Incorporating a Finite Number of Potential Discontinuities. Part I Theory
Acta Phys. Pol. 35, 491 (1969)
abstract
Two methods for approximating free electron wave functions in cases involving potential wells or barriers are discussed. These are further employed to generate expressions for evaluating the Coulomb exchange and repulsion integrals between free-electron molecular orbitals. The method is tested by application to the calculation of the electronic states of divinylborane.
Dynamic Magnetoconductivity for an Electron-impurity System Strong Coupling Case
Acta Phys. Pol. 35, 507 (1969)
abstract
The rigorous analysis of the contribution of one-electron-one-impurity interaction process to the dynamic magnetoconductivity \(\sigma (\omega , B)\) is carried out by means of correlation function formula (Kubo’s formula) and the connected diagram expansion. It is shown that this contribution is completely described in terms of the generalization of the transition matrix on- and off-energy shell.
A Generalization of Case’s Transformation of the Dirac Equation
Acta Phys. Pol. 35, 517 (1969)
abstract
A transformation of the inhomogeneous Dirac equation is proposed which: (1) gives insight into the kinematical and dynamical aspects of the problem of separating positive and negative energy states of the Dirac particle, (2) stresses the difference between the roles of the magnetic and electric stationary fields in such a procedure. The explicit formula for the transformed Hamiltonian is derived and interpreted. It is given in a finite form as well as in an expansion into a series. A simple geometrical interpretation follows the calculation.
A Revised Theory of General Relativity and Quantization of the Gravitational Field II
Acta Phys. Pol. 35, 523 (1969)
abstract
By modifying the Lagrangian and introducing some coordinate conditions the theory of gravitation can be modified (without spoiling its most beautiful feature: the connection between gravitation and geometry). In contradistinction to the traditional theory there exist solutions representing truly localized wave packets, energy-momentum is localized, and a linear approximation is meaningful. The modified theory is quantizable.
One-particle Operators for the Dirac Particle
Acta Phys. Pol. 35, 529 (1969)
abstract
Various schemes of one-particle operators (expressed in terms of the projection operators into the positive and negative energy states) have been defined and their properties investigated. The prominent role of the scheme of Foldy–Wouthuysen within this set has been confirmed.
Superconvergent Sum Rules for Meson–Baryon Scattering and \(j\)-plane Singularities
Acta Phys. Pol. 35, 535 (1969)
abstract
The possible superconvergent relations which correspond to the decouplet exchange in the ¢-channel are considered for meson–baryon scattering. The following combination of scattering amplitudes is used in the analysis of sum rules: \[T_{10} = T_{\pi ^{-}p} - T_{\pi ^{+}p} + T_{K^{+}p} - T_{K^{—}p} + T_{\bar {K}^{0}p} - T_{K^{0}p}\,.\] It is found that the superconvergence relations hold for nonspin-flip but fail for the spin-flip amplitudes. It is suggested that the failure of the latter may be due to the \(j\)-plane branch point singularity which protects the fixed singularity at the wrong signature nonsense point \(j = 0\). It is argued by means of the many channel unitarity condition that this branch point singularity is likely to be absent at \(t\)-channel partial wave helicity amplitudes, which are regular at \(j = 0\). Thus it does not prevent the sum rule for the nonspin-flip amplitude from holding.
Degeneration and Stability of Magnetohydrodynamic Modes in a Coaxial Channel with an Helical Field
Acta Phys. Pol. 35, 549 (1969)
abstract
The eigenfrequency spectrum and stability of perfectly conducting inviscid and incom, pressible fluids confined to cylindrical channels and permeated by twisted magnetic fields is investigated. It is found that even when we limit our investigations to axially symmetric instabilities, solutions can be found that are not stable. This happens for some azimuthal fields \(B_{\phi }(r)\) and for waves longer than a given critical length. In one particular case the flow fields are given, as well as the exact values of the critical wave lengths. In this case the instability is nonconvective and should therefore be easy to detect experimentally.
The Effect of Cathode Hydrogen on Relaxation Processes in Silicon Steel
Acta Phys. Pol. 35, 557 (1969)
abstract
Metals, including iron, form interstitial solid solutions as well as substitutional solutions. The interstitial sites can be occupied only by elements which have small atomic diameters, such as hydrogen, boron, nitrogen, carbon and oxygen. Owing to the appreciable mobility of these atoms, even at relatively low temperatures, they bear a large effect on the physical properties of metals. The elementary jumps of single atoms, clusters and atoms interacting with the impurity atoms forming the substitutional solution or with lattice imperfections, lead to the appearance of mechanical or magnetic after-effects, also known as relaxation effects. After-effects attributed to hydrogen have been found in samples of iron and its alloys of body-centered cubic structure in three temperature ranges: (1) near 50°K (relaxation I), (2) intermediate range above 100°K (relaxation II), and (3) high-temperature range over 1000°K (relaxation III, for a frequency of one cycle per second).
Broadening of Ferromagnetic Resonance Line by Dislocations
Acta Phys. Pol. 35, 565 (1969)
abstract
The relaxation time for uniform magnons scattered on dislocations is calculated. The semiphenomenological theory of magnons is adopted. It is assumed that magnons are coupled to the strain field of a dislocation by magnetostrictive effects, and the magnetoelastic energy is taken for the magnon interaction Hamiltonian. Only two-magnon relaxation processes are considered. The calculated relaxation time is used to estimate the influence of dislocations on the ferromagnetic resonance line-width. Results of numerical calculations of the line-width are presented.
Electronic Properties of [\(n\)]-radialenes and Their Methyl Derivatives
Acta Phys. Pol. 35, 585 (1969)
abstract
The structural and electronic properties of [\(n\)]-radialenes are considered with the following five methods: the Hückel method, the SC LCAO MO method with variation of resonance integrals, the SC—\(\omega \) LCAO MO method with variation of resonance integrals and Coulomb integrals, the SCF LCAO MO method within the PPP approximation scheme and the SCF LCAO MO CI method in the PPP approximation. Additionally the substituent effect of methyl groups on the spectrum of hexamethyl-[3]-radialene is discussed.
Spin Waves in Band Model of Ferromagnetic Thin Films
Acta Phys. Pol. 35, 595 (1969)
abstract
Magnetic properties of ferromagnetic thin films in the band model are calculated in a manner analogous to that used for bulk bodies. The formula for spin wave energy spectrum is obtained with respect to the boundary conditions. The spontaneous magnetization is calculated starting from the free energy. Some properties of spin waves are discussed.
A Modified Phase Space Model and Its Application in Fitting Effective Mass Distributions in Many-body Reactions
Acta Phys. Pol. 35, 603 (1969)
abstract
A modified phase space model with a matrix element depending on baryon momentum is presented for \(\pi p\) interactions. The predictions of the model are shown to agree with the experimental effective mass distributions of pionic subsystems in the reactions \(\pi ^+ p \to p\,5\,\pi \) and \(\pi ^+ p \to p\,6\,\pi \) at 8 GeV/\(c\). The production of mesonic resonances is estimated.
Investigation of the Reaction \(\pi ^- p\to \pi ^0n\) at 4.0 GeV/\(c\)
Acta Phys. Pol. 35, 625 (1969)
abstract
The reaction \(\pi ^- p\to \pi ^0n\) at 4.0 GeV/\(c\) was analysed using spark chamber technique. Crosssection was found to be: \[\sigma _{\pi ^{-}p\,\to \, \pi ^{0}n} =(0.130\pm 0.020)\, \mathrm {mb}\,.\] The ratio \(X = |\mathrm {Re}\, T(t = 0)/\mathrm {Im}\, T(t - 0)| = 0.89\pm 0.10\) corresponds, according to the Regge pole approach, to \(\alpha _{\rho }(t = 0) = 0.46\pm 0.06\). The comparison with theoretical prediction is presented.
Semiconductor Properties of \(\mathrm {Ni}_{1-x}\mathrm {Zn}_x\mathrm {Fe}_2\mathrm {O}_4\) Ferrimagnetics for \(0\leqslant x \leqslant 1\)
Acta Phys. Pol. 35, 631 (1969)
abstract
\(\mathrm {Ni}_{1-x}\mathrm {Zn}_x\mathrm {Fe}_2\mathrm {O}_4\) ferrimagnetics with \(0\leqslant x\leqslant 1\) are semiconductors in which \(3d\) electrons are carriers of electric charge as well as of spin magnetic moment, and participate in exchange interactions leading to ferrimagnetic type of ordering. The effect of magnetic structure of NiZn ferrites on the generation energy and mobility of the electric current was studied. To this aim, the temperature dependence of electric conductivity \(\sigma \) and Seebeck effect \(\theta \) in the temperature range from 500°K to 1000°K was determined. The results are interpreted on the basis of the crystal field theory and assuming the Verwey model for electric conductivity in \(3d\) oxides. Magnetic ordering is found to lower the generation energy of carriers, and their mobility is then independent of their density.
Matteucci (MS) Effect in Single Iron Crystals, Iron Whiskers and Thin Martensitic Steel Wires
Acta Phys. Pol. 35, 641 (1969)
abstract
Matteucei emf (MS) impulses in different ferromagnetic policrystalline metals and alloys and single crystals are presented. Different signs and amplitudes of the MS depend on chemical composition and crystallographic orientation of the examined ferromagnetic crystal. It has been found that in ferromagnetic wires an emf can be generated similar to the MS, but without the torsional twist. In order to distinguish it from the MS, it has been designated \(S\). The sign of the \(S\) depends on the section of the wire in the excitation coil. When the measurement is performed between the two ends of the wire located at the opposite ends of the excitation coil, it under goes a cancellation due to the summation of the \(S\) having opposite signs in the opposite halves of the wire.
Dielectric Saturation of Nitrobenzene in Some Dipolar and Nondipolar Solvents
Acta Phys. Pol. 35, 651 (1969)
abstract
Dielectric saturation \(\Delta \varepsilon = E_{\varepsilon -\varepsilon }\) (where \(E_{\varepsilon }\) and \(\varepsilon \) are, respectively, the dielectric permittivity of the medium in the presence and absence of an externally applied electric field \(E\)) is measured for solutions of nitrobenzene in the nondipolar solvents: benzene, cyklohexane, carbon, tetrachloride, and the dipolar solvents toluene, chlorobenzene, \(o\)-dichlorobenzene.
Scalar Mesons and the Breaking of SU(3)
Acta Phys. Pol. 35, 655 (1969)
abstract
An argument is given to support the theorem that the divergences of the strangeness-changing vector currents, if considered to the first order of magnitude in the medium strong interactions, are proportional to scalar fields belonging to \(8_D\) of SU(3).
Investigations of the \(n\)-type GaAs Monocrystals by \(R, \sigma \) and \(T\)-\(EP\) Measurements
Acta Phys. Pol. 35, 659 (1969)
abstract
In the letter the results of measurements of the Hall constant, conductivity and thermoelectric power are presented. Several monocrystallic GaAs samples produced in Poland and Czechoslovakia were investigated and \(n\)-type conductivity was found beginning at the lowest measured temperatures. The concentration and mobility of the electrons in the conductivity band were measured as well as the positions of the Fermi level. A degeneracy of the electron gas was established. The Fermi energies calculated from the thermoelectric power measurements differed significantly from those calculated using the Kane theory with known electron concentrations.Fasc. 5, pages 667–863
Dark Emission of Exoelectrons from Plastically Deformed Aluminium Covered with Oxide and Excited by Electrons
Acta Phys. Pol. 35, 667 (1969)
abstract
Exoelectron emission is observed during the plastic deformation of aluminium on the surface of which there is an oxide layer with thickness \(D \gt 70\) nm previously excited by electron bombardment. The emission intensity increases with strain until sample failure after which it decays slowly. The curve of intensity of dark emission of exoelectrons vs strain is to a certain extent similar to that in the case of photostimulated emission of exoelectrons. The following factors have been found to influence the investigated dark emission: oxide layer thickness — \(D\), time of bombardment with electrons — \(t_b\), bombarding electron current — \(i_e\), energy of bombarding electrons — \(U_b\). It is assumed that the observed dark emission of electrons during plastic deformation is due to a strong electric field in the oxide layer on the surface of the sample. This field is the resultant of the electric field in micro-fissures produced in the oxide and the internal field (“frozen’’) in the oxide which is due to previous bombardment with electrons. The observed phenomenon is not a classical Malter effect; it occurs only after exceeding a certain threshold value \(\varepsilon _{od}\) — which will be called initial strain.
Photostimulated Exoelectron Emission from Thin Layers of Nickel, Chromium and Their Oxides During Magnetic Phase Changes
Acta Phys. Pol. 35, 679 (1969)
abstract
Electron exoemission into air atmosphere from thin layers of nickel and chromium and their oxides formed on their surface has been studied. An air point counter and an air point counter with quenching vapour above the free liquid surface have been used as detectors. In both cases the occurrence of emission maxima was found at the Néel point for NiO, \(\mathrm {Cr}_2\mathrm {O}_3\), and pure chromium and at the Curie point pure nickel. It follows from the above-mentioned investigations that: (a) the intensity of emission depends on the thickness of the oxide film covering the investigated samples, (b) the dependence of the position of the maximum corresponding to the Néel point for NiO on oxide thickness is a parabolic one, (c) the positions of emission maxima from chromium samples correspond to phase transition points both for chromium and its oxides.
Covariant Formulation of the Cauchy Problem in Generalized Electrodynamics and General Relativity
Acta Phys. Pol. 35, 689 (1969)
abstract
The Cauchy problem in a manifold is formulated geometrically as the problem of the continuation of certain field variables off a rigged hypersurface of the manifold, given certain initial data on that hypersurface, and a system of covariant partial differential equations obeyed by the field variables. The Lie derivative is shown to lend itself naturally to such a formulation. The Cauchy problem for generalized electrodynamics and spacelike initial hypersurfaces in general relativity is formulated and discussed from this point of view. It is shown that without the constitutive equations the propagation characteristics of Maxwell’s equations are undefined. A Newtonian form for the field equations of general relativity is given, and a Hamiltonian form using Lie derivatives is developed from the Lagrangian for the field equations. All calculations are explicitly covariant, and the geometrical interpretation of the results thereby becomes obvious.
Thermoluminescence, Stimulation and Quenching by Infrared of the Luminescence of the ZnS–Cu, Pb Phosphors with Varying Pb Contents
Acta Phys. Pol. 35, 711 (1969)
abstract
Thermoluminescence and stimulation as well as quenching by infrared radiation (\(\lambda = 700\) nm of the luminescence of phosphors ZnS–Cu, Pb are studied for varying Pb concentration and constant concentration of Cu. The thermoluminescence curves of a series of ZnS–Cu, Pb phosphors samples indicate a decrease in the height of the low-temperature thermoluminescence peak with increasing Pb concentration. Investigations of quenching and stimulation with a weak beam of infrared radiation (\(\lambda = 700\) nm) indicate a systematically increasing stimulation and decreasing quenching with increasing Pb concentration. These results can be interpreted (in accordance with the suggestion of Kalmann) in terms of the influence of infrared radiation on the release of holes from excited Cu-centres and the existence in the ZnS–Cu, Pb phosphors of centres with greater cross-section for radiative transitions than the cross-section for such transitions in Cu-centres which absorb the excitation energy. The paper gives a concept of the structure of centres with large cross-section for radiative transitions in ZnS–Cu, Pb and ZnS–Cu. However the results of the study of stimulation by an intense IR beam (laser) with \(\lambda = 700\) nm could not be interpreted in terms of the previous model. They suggest in the case of the ZnS–Cu, Pb phosphors a participation of electrons which are held in local levels for a long time (several minutes) even at room temperatures.
Dependence of Domain Width on Crystal Thickness in Fe–Si Single Crystals
Acta Phys. Pol. 35, 731 (1969)
abstract
The dependence of the domain width \(D\) on the crystal thickness \(T\) in wedge-shaped single-crystalline Fe–Si samples is studied experimentally for the standard (\(SL\)) and modified (\(ML\)) Landau–Lifshitz domain structure, in the thickness range \(20\,\mu \mathrm {m} \lesssim T \lesssim 5\) mm. Similarly as in uniaxial Co (Wysłocki 1968), the thickness dependence is found to be of the form \(D_{X;m} = a_{X;m}T^{b_{m}}\), where \(m =1, b_1 = 0.5\) for \(T\leqslant T_0\) and \(m = 2, b_2 = 0.9\) for \(T\geqslant T\). The subscript \(X\) denotes the type of domain structure (\(X = SL\) or \(ML\)). The critical thickness \(T_0\) is determined experimentally (\(T_0 \cong 400\,\mu \mathrm {m}\) for Fe — 3.25% Si) and, for the \(ML\) domain structure, shown to correspond to an energy discontinuity. In the case of the \(SL\) domain structure, the failure of the standard Landau–Lifshitz theory is pointed out.
Level Crossing with Optical Pumping in Potassium
Acta Phys. Pol. 35, 745 (1969)
abstract
Level crossing in the first excited \(4^2P_{3/2}\) state of potassium (\(^{39}\mathrm {K}\)) is analysed. An improvement in measurements of level crossing signals using simultaneous optical pumping is discussed. The experimental results are demonstrated.
On the \(S\)-Matrix Unitarity Problem
Acta Phys. Pol. 35, 759 (1969)
abstract
The \(S\)-matrix unitary problem is discussed in the axiomatic framework of quantum field theory. The necessary and sufficient condition, in terms of the aperture of the asymptotic subspaces, for unitatiry of the \(S\)-matrix is proposed.
Higher Harmonics Generated by Free Carriers in Semiconductors
Acta Phys. Pol. 35, 765 (1969)
abstract
The third harmonic in the electric current density generated by free carriers in semiconductors is derived and numerical calculations are performed. The effects discussed in this paper are associated with the energy dependence of the relaxation time for a parabolic band and with the nonparabolicity of the band. It is shown that a large enhancement of nonlinear effects due to the energy dependence of the relaxation time at high magnetic fields can be observed.
О возможности аномально большой ширины распада Е(1420) \(\to 2\gamma \)
Acta Phys. Pol. 35, 777 (1969)
abstract
Оценена ширина распада Е(1420) \(\to 2\gamma \) в рамках нарушенной SU(6)\(_W\) симметрии. Значение ширины сильно зависит от схемы нарушения SU(6)\(_W\). Возможна аномально большая ширина \(\sim \) 1Мэб.
О микроскопической теории ротационных возбуждении ядер
Acta Phys. Pol. 35, 783 (1969)
see erratum: Acta Physica Polonica 36, 499 (1969)
abstract
В работе рассмотрены уравнения движения для одночастичных амплитуд в модели парных и квадруполь-квадрупольных остаточных взаимодействий между фермионами одного сорта на одной оболочке. Решены уравнения для энергии возбуждения, энергетической щели и элементов квадрупольного момента четного ярда во вторам порядке теории возмущений, что является хорощим приближением деформированных ядер. Получен ротационный спектр с моментом инерции Инглиса. Затем найдены энергии ротационных состояний нечетного ядра, каторые отличаются от энергий полученных в кранкинг модели.
Analysis of the Standard Long-wavelength Low-temperature Approximations in the Spin-Wave Theory of the Heisenberg Ferromagnet. Part I. Wallace’s Perturbation Methods
Acta Phys. Pol. 35, 799 (1969)
abstract
The adequacy of the standard long-wavelength low-temperature approximations in the spin-wave theory of the isotropic Heisenberg ferromagnet is analysed, by employing three different perturbation methods and comparing the results. The spin Hamiltonian is mapped on to the boson Hilbert space (ideal spin waves) according to Holstein’s and Primakoff’s mapping rules, and the first approximation in the power-series expansion for the square-root is used, which is equivalent to Dyson’s first Born approximation in calculating the leading correction to the free energy originating from dynamical spin-wave interactions. In Part I, Wallace’s Hamiltonian and statistical perturbation methods are applied to the boson Hamiltonian, and his results for unrenormalized spin waves are shown to be inaccurate and obtainable in a much simpler way. It is also shown that, in this approximation, Wallace’s, Dyson’s, and other authors’ thermodynamic results are recovered in the simplest way by applying to our Hamiltonian the standard statistical perturbation method. In Part II, the correct first-order corrections to the single-particle energies and to the system’s energy levels are derived, and the thermodynamic aspect of the magnon Hilbert space is studied. Part III is devoted to the refinement of the standard low-temperature thermodynamics of the Heisenberg ferromagnet.
Asymptotic Condition in Quantum Theory of a Field with a Parameter
Acta Phys. Pol. 35, 813 (1969)
abstract
Under usual axioms and some additional assumptions the asymptotic condition for a field \(A(x, s)\) with a parameter is proved. In addition to the results analogous to the one of Hepp in the Haag–Ruelle theory some new theorems are derived. The possibility of replacing the non-overlapping states by usual scattering states is discussed.
Modified CNDO Method. I. Calculation of the Stretching Force Constants for Diatomic Molecules
Acta Phys. Pol. 35, 829 (1969)
abstract
A modified semiempirical parametrization of the approximate SCF MO CNDO treatment is presented. The new parameters, different from those used by Pople and Segal, have been chosen from various atomic data. Moreover, the two centre Coulomb integrals were calculated with the aid of Ohno’s formula. The resonance integrals were approximated by using a semi-empirical relation similar to that proposed by Cusachs. The modified CNDO method has been tested on a series of diatomic molecules. Similarly as in the case of the original CNDO approach, the orbital energies are not yet adequate for the a priori calculations. However, the bond lengths and dipole moments are in reasonable agreement with experimental data. The main success of the modifications introduced seems to be in the calculation of the stretching force constants, In general, they are better than those reported previously by Segal.
The Overlap Functions for \(\pi p\) Inelastic Processes and Their Relation to Partial Inelastic Cross-sections
Acta Phys. Pol. 35, 839 (1969)
abstract
The overlap function formalism is extended to the spin (\(0,\frac {1}{2} \)) case. Two overlap functions for inelastic collisions — helicity non-flip and helicity flip — are introduced, the first corresponding to that from a spinless case. Their connection with partial cross-sections is derived. It is shown that the slope of the helicity non-flip overlap function practically does not depend on energy in the range from 1.5 to 8 GeV/\(c\).
Some Optical Properties of Crystalline LaB\(_6\)
Acta Phys. Pol. 35, 849 (1969)
abstract
The ultraviolet reflectivity and the plasma reflection edge in crystalline samples of LaB\(_6\) were investigated. The spectral dependences of the optical constants were calculated in the region 1.1 to 6.0 eV, using Kramers–Kronig method. The dielectric constant and carrier concentration to the effective mass ratio \(N/m^*\) were evaluated by application of the Drude’s theory.
On the Temperature Dependence of the Saturation Magnetization of Hardened Lithium Ferrites-Chromites
Acta Phys. Pol. 35, 857 (1969)
abstract
The paper presents results of a research on the effect of hardening on the temperature dependence of the saturation magnetization of lithium ferrites-chromites of the general chemical formula \(\mathrm {Li}_2\mathrm {O}(5\cdot 2a) \mathrm {Fe}_2\mathrm {O}_3 2a\mathrm {Cr}_2\mathrm {O}_3\) for \(a = 0.95, 1.00, 1.15, 1.25, 1.35, 1.55, 1.60, 1.70\) and 1.75. In the initial state this dependence is characterized by the existence of a compensation point which vanishes after hardening in water. The Curie point shifts towards lower temperatures, whereas the saturation magnetization, measured at the temperature of liquid nitrogen, rises relative to the value of the size of sample in the initial state.
A Note on the Nuclear Phenomena Recorded in Biological Material
Acta Phys. Pol. 35, 859 (1969)
Nonlinear Optical Activity in Liquids
Acta Phys. Pol. 35, 861 (1969)
abstract
Strong laser light induces a measurable nonlinear variation of the optical rotation. This variation is calculated, and is shown to provide information on the anisotropy of gyrotropic properties of molecules.
Bemerkungen zu Den Beobachteten Einfluss der Temperatur auf die Fluoreszenzpolarisation Fester Lösungen
Acta Phys. Pol. 35, 863 (1969)
abstract
In dieser Notiz wird der von uns beobachtete Einfluss der Temperatur auf die Fluoreszenzpolarisation fester Lösungen gedeutet.Fasc. 6, pages 867–1029
Potential Field and Force Constants of Cyanuric Fluoride
Acta Phys. Pol. 35, 867 (1969)
abstract
The Wilson group theoretical method has been employed for the evaluation of potential energy constants for the planar and nonplanar vibrations of the cyanuric fluoride molecule possessing a planar cyclie structure with the symmetry point group \(D_{3_{h}}\). An orthonormalized set of symmetry coordinates satisfying the transformation properties has been constructed. A modified valence force field consisting of only eleven force constants has been applied and the force constants have been evaluated from the vibrational and structural data. The values of these force constants have been compared with those of the molecules having similar environments and chemical bonds with nearly identical internuclear distances. A brief discussion of the results has been given with special reference to the carbon-nitrogen and carbon-fluorine bonds.
Generalised Mean Square Amplitudes and Coriolis Coupling Coefficients of Methylene Halides
Acta Phys. Pol. 35, 875 (1969)
abstract
The generalised mean square amplitudes of vibration for both bonded and nonbonded atom pairs and the Coriolis coupling coefficients have been evaluated for the molecules \(\mathrm {CH}_2\mathrm {F}_2, \mathrm {CH}_2\mathrm {Cl}_2, \mathrm {CH}_2\mathrm {Br}_2\) and \(\mathrm {CH}_2\mathrm {I}_2\). The \(\zeta \) values indicate that there is very strong Coriolis coupling between the \(\mathrm {CH}_2\) symmetric deformation and the D–H asymmetric stretching vibrations. The results are discussed in relation to the structure of the molecules.
Дипольные электрические переходы в \(L\)-серии Рентгеновского характеристического излучения
Acta Phys. Pol. 35, 883 (1969)
abstract
На основе полученного автором выражения для вероятности электрического мультипольного релятивистского радиационного перехода проведены вычисления сил осцилляторов и относительных интенсивностей дипольных электрических переходов для \(L\)-серии рентгеновского характеристического излучения. Получснные данные сравниваются с имеющимися экспериментальными результатами.
Квадрупольные электрические переходы в \(K\)- и \(L\)-cepuax рентгеновского характеристического излучения
Acta Phys. Pol. 35, 891 (1969)
abstract
На основе полученного автором выражения для вероятности электрического мультипольного релятивистского радиационного перехода проведены вычисления сил осцилляторов и относительных интенсивностей квадрупольных электрических переходов для \(K\)- и \(L\)-серий рентгеновского характеристического излучения. Полученные результаты сравниваются с имеющимися экспериментальными данными.
Anisotropy of the Diamagnetic Susceptibility in \(\alpha \) and \(\beta \) \(p\)-Nitrophenol Crystals
Acta Phys. Pol. 35, 897 (1969)
abstract
The \(\alpha \)-form of nitrophenol which is stable below 63°C, becomes coloured when illuminated with sunlight while the \(\beta \)-form, stable above 63° does not exhibit this property. To check the hypothesis that the reason for the difference in the properties of the two forms is a different distribution of the molecules in the unit cell, the diamagnetic anisotropy of the crystal has been measured, and the principal susceptibilities of the \(p\)-nitrophenol molecule, calculated from this anisotropy have been compared.
The Dependence of Electroluminescence on Temperature
Acta Phys. Pol. 35, 907 (1969)
abstract
The temperature dependence of the brightness of electroluminescence \(B = f(T)\) is studied for the Zn–S–Cu phosphor (\(2\cdot 10^{-2}\) gCu/gZnS) in insulating mounting without dielectric. The parameters were the voltage applied across the cell or the frequency. Both global electroluminescence and luminescence separated from both emission bands of this phosphor trough interference filters \(\lambda _1 = 450\) nm and \(\lambda _2 = 525\) nm were investigated. The difference in the curves for \(\lambda _1\) and \(\lambda _2\) consists mainly in the fact that sudden electroluminescence decay (temperature quenching) occurs in the case of blue emission at lover temperature than that in the case of green emission. The influence of voltage on the \(B = f(T)\) curves in the range up to about 450 V (for cell thickness \(10^{-2}\) cm) is the following: (a) the peaks shift towards lower temperatures with increasing voltage, (b) the low-temperature peak broadens with increasing voltage from the low-temperature side, (c) and a faster increase in the height of the low temperature peak with increasing voltage. For higher voltages (\(U \gt 450\) V) the increase in voltage results in a2 much faster growth of the high temperature peak than the growth of the low-temperature peak. The influence of previous illumination of the phosphor by Wood’s light on \(B = f(T)\) has also been investigated as well as the influence of ageing of the phosphor on the intensity ratio of the low- and high-temperature peaks of the \(B = f(T)\) curve.
Elements of the Aberration Matrix of a Thin Lens Limited by Two Spherical Surfaces
Acta Phys. Pol. 35, 921 (1969)
abstract
The translation and refraction matrices of a thin lens have been presented, and the corresponding aberration matrix calculated. Also the connection between the elements of the aberration matrix and the quantities specifying the optical properties of the thin lens has been given.
Analysis of the Results of Experiments on the Intermediate State of a Superconducting Cylinder with Current
Acta Phys. Pol. 35, 925 (1969)
abstract
An analysis is made of the experimentally discernible departures from the London model in a superconducting cylinder with current which arise due to Joule heat generated in the domains of normal phase, deformations of the superconducting domains caused by surface energy at the boundaries of the normal and superconducting phases, and shortening of the free path of conduction electrons because of scattering at the surface of the superconducting domains. It was proved that these perturbing factors can be eliminated by performing experiments with samples of sufficient purity, sufficiently large diameters and close enough to the critical temperature. On the basis of an analysis of the experimental material it was shown that despite refinements the results of experiments contradict the London theory. No analysis was made of the experiments performed with samples of small diameters (50 to 100 microns) or performed at temperatures much different than the critical temperatures. For under these conditions the thermal energy density due to the Joule effect is large, the super-conducting domains may become deformed, a Londonean structure cannot become fully formed, and the influence of the shortening of the free path of conduction electrons by scattering at the wire surface comes into play.
The Influence of the Temperature on the Bloch Wall Thickness
Acta Phys. Pol. 35, 939 (1969)
abstract
By applying the Heisenberg model and Bogolubov’s variational method in the molecular field approximation (MFA) to three-axial ferromagnets with (90°|90°) Bloch walls, a temperature dependent equation for the domain structure is derived and the dependence of the Bloch wall thickness on the temperature is examined. The results are illustrated by numerical calculations.
Interband Faraday Effect and Ellipticity in Silicon in Weak Magnetic Fields
Acta Phys. Pol. 35, 953 (1969)
abstract
The results of measurements of the Faraday rotation and ellipticity in silicon are presented. These effects are associated with indirect interband transitions. Comparison of the experimental results with theory gives rather qualitative than quantitative agreement.
Absorption of Infrared Radiation in \(n\)-type Germanium under High [111] Compression in a Weak Magnetic Field
Acta Phys. Pol. 35, 957 (1969)
abstract
The absorption of polarized electromagnetic waves at helium temperatures in the wavelength region from \(5\times 10^{-2}\) cm to 2 cm, in \(n\)-type Ge subjected to high uniaxial [111] compression and in a magnetic field from 8 kgauss to 12 kgauss, is investigated theoretically on the basis of a model of direct absorption process model. A formula is derived for the magnetic field-dependent correction to the absorption coefficient calculated by Blinowski and the numerical results are presented for waves polarized with the electric vector parallel and perpendicular to the [111] direction of the crystal with magnetic field parallel to this direction. Concentrations of donors up to \(6\times 10^{15}\) cm\(^{-3}\) and compensations up to 0.2 are considered. The range of validity of the results is discussed.
Emission Anisotropy of Fluorescence of Aromatic Hydrocarbons II
Acta Phys. Pol. 35, 975 (1969)
abstract
The absorption polarization spectra of tetracene, anthracene and 5-aminoacridine were measured. The depolarization of the fluorescence light of these solutions becomes more dependent on the frequency of the exciting light with higher dye concentration (except for 5-aminoacridine solutions). A certain relationship was found between the structure of absorption and emission spectra of these hydrocarbon solutions and the magnitude of the depolarization of fluorescence excited with light of frequencies higher than that of the \(0\)–\(0\) transition. The probability of electronic energy transfer between dye molecules from higher vibrational levels is larger when the vibrational structure of the spectra is more pronounced, i.e. when there is less coupling between the vibrational levels. This behaviour may be explained by assuming that tetracene and anthracene molecules are partly “weakly” coupled. At higher concentrations of the dye molecules and shorter mean distances between them a certain kind of complex is formed. Energy transfers between complexed molecules are more probable than between “very weakly” coupled ones. An assumption of weak coupling between the dye molecules explains the observed vibrational structure of the polarization spectrum of tetracene and anthracene solutions, because in this kind of coupling the energy transfer rate is proportional to the population of the vibrational levels in both excited and unexcited molecules.
Multipole Lines in the Spectrum of Te I
Acta Phys. Pol. 35, 989 (1969)
abstract
The wavelengths of multipole lines of Te I have been determined: \(E2: 4309.42\pm 0.01\) Å and \(M1: 5419.23\pm 0.02\) Å . The terms \(^1S_0\) and \(^3P_1\) of the ground state configuration of Te I obtained from these values are \(23198\pm 0.1\) cm\(^{-1}\) and \(4750.84\pm 0.2\) cm\(^{-1}\), respectively. The intensity ratio of the multipole lines of Te I has been measured and amounts to \(I_{5419}/I_{4309} = 14.6\pm 3\). This result has been compared with the theoretical predictions. Experimental results published so far, concerning the determination of relative multipole transition probabilities, are compared with the results of corresponding theoretical papers. The Zeeman pattern of the 5419.23 Å line has also been analyzed.
An Infra-red Study of Crystallo-hydrates
Acta Phys. Pol. 35, 997 (1969)
abstract
An infra-red study of the crystallohydrates: \(\mathrm {Li}_2\mathrm {SO}_4 \cdot \mathrm {H}_2\mathrm {O}, \mathrm {LiClO}_4 \cdot 3\mathrm {H}_2\mathrm {O}, \mathrm {NiSO}_4 \cdot 6\mathrm {H}_2\mathrm {O}, \mathrm {NiSO}_4 \cdot 7\mathrm {H}_2\mathrm {O}\) is presented, special attention being paid to the region 400–1000 cm\(^{-1}\). The results are compared with the neutron inelastic scattering study of the same substances. On the basis of this comparison it was possible to interpret certain peaks appearing in the region 400 cm\(^{-1}\) to 800 cm\(^{-1}\) as arising from vibrational motions of the \(\mathrm {H}_2\mathrm {O}\) molecules. Some qualitative statements concerning the seventh water in \(\mathrm {NiSO}_4 \cdot 7\mathrm {H}_2\mathrm {O}\) are also given.
A High Speed Photographic Shutter Based on the Kerr-cell Principle
Acta Phys. Pol. 35, 1009 (1969)
abstract
A new single frame Kerr-cell shutter is described. Its electrical system is based on the principle of a four pulse timer driving a high voltage square pulse generator. A sequence of pulses: scope driving, synchronizing, shutter opening and closing, is continuously adjustable and covers the region from 0.1 \(\mu \)sec to a few hundred \(\mu \)secs. The shutter may by positioned either in front of a spectrograph or furnished with a telephoto lens and used as a camera for photographing self luminous events. The shutter is efficient within the spectral range from 450 nm up to 770 nm. A nitrobenzene purification procedure is also described.
A Preliminary X-Ray Crystallographic Study of \(p\)-Nitro-Benzylimino Methyl Ether
Acta Phys. Pol. 35, 1019 (1969)
abstract
The crystal of \(p\)-nitro-benzylimino methyl ether were colorless needles elongated parallel to \(a\)-axis. The symmetry, space group and unit cell has been determined by X-ray diffraction. The monodinic unit cell contains 4 molecules and has the dimensions \(a = 4.31, b = 22.71, c = 9.40\) Å , \(\beta = 100°45'\). The space group is \(C^5_{2h}\)–\(P2_1/c\).
Holographic Method of Determining Temperature Distributions
Acta Phys. Pol. 35, 1021 (1969)
see erratum: Acta Physica Polonica 36, 1121 (1969)
abstract
The paper presents the results obtained in determinations of the temperature distribution around a heated wire by means of a double hologram.
Investigation of Photoelectric Work Function in GaAs \(n\)-type Monocrystals
Acta Phys. Pol. 35, 1025 (1969)
abstract
Photoemission of electrons from (111) and (110) surfaces of \(n\)-type GaAs was studied. The current-voltage characteristics were measured when samples were subjected to the illumination of incident photon energy, \(h\nu \), from 4.89 to 5.80 eV. The photoelectric work function, \(\phi _\mathrm {ph}\) increases lineary with \(h\nu \) for both types of surfaces. It was found that \(\phi _\mathrm {ph}^{111}\) increases quicker than \(\phi _\mathrm {ph}^{110}\).ERRATA
Recent Studies on Triplet–Singlet Transitions in Aromatic Molecules
Acta Phys. Pol. 35, 1029 (1969)
Theorie quantique relativiste des gaz parfaits de Fermi et de Bose
Acta Phys. Pol. 35, 1029 (1969)