Showing papers by "University of Warsaw published in 1972"
TL;DR: In this paper, the problem of a spherically-symmetric gravitational field produced by spinning dust is solved in the framework of the Einstein-Cartan theory, and a two-parameter family of world-models without singularities of the Friedmann type is presented.
138 citations
TL;DR: Analyses of published NMR spectra for uridine, β-pseudouridine and their 3′-monophosphates, together with the deshielding effect of a phosphate group, have made possible specific assignments of the signals of the two 5′ protons, allowing of a more accurate evaluation of the relative populations of the three CH 2 OH conformers.
125 citations
Abstract: Electron microscopic studies of skeletal periderm of 450 million year old graptolites (Hemichordata) reveal a morphologically well-preserved fibrous material which resembles collagen in association with polysaccharide. The cortical fibrils, organized into lamellar plies, show a rough periodicity, a central “core” and helical structure, all of which can be related to extant collagens.
82 citations
TL;DR: In this article, a new solution of the Einstein field equations depending on four arbitrary constants was obtained by the method of complex coordinate transformations, which is of type II and possesses a wire-like singularity.
73 citations
TL;DR: In this article, the Poisson bracket definition in the multisymplectic formulation of an arbitrary non-linear classical field theory is dealt with, and the physical quantities related to a given space-like 3-dimensional surface are defined.
49 citations
TL;DR: In this article, the absorption spectra of divalent impurities in cadmium telluride were derived from the spectra values of the crystal field parameter Δ and Racah parameters B and C.
Abstract: The absorption spectra of divalent impurities Ti(d2), V(d3), and Cr(d4) in cadmium telluride are presented. From the spectra values of the crystal field parameter Δ and Racah parameters B and C are derived and discussed.
Es werden Absorptionsspektren fur zweiwertige Ti(d2)-, V(d3)- und Cr(d4)-Storstellen in Kadmiumtellurid mitgeteilt. Aus den Spektren werden die Werte des Kristallfeldparameters Δ und der Racahparameter B und C bestimmt und diskutiert.
43 citations
01 Dec 1972
TL;DR: The fine structure of the „germinal cytoplasm“ of the dividing egg of Xenopus laevis has been studied and the organization of the electron-dense bodies is strongly reminiscent of that of the polar granules in Drosophila.
Abstract: 1. The fine structure of the "germinal cytoplasm" of the dividing egg ofXenopus laevis has been studied. Mitochondria which occur in great numbers and electron-dense bodies associated with them are the two characteristic components of the so-called "germinal cytoplasm". 2. The electron-dense bodies are composed of granular and fibrillar elements and often contain an internal light area. Long fibrillar elements have been found within the light area. The organization of the electron-dense bodies is strongly reminiscent of that of the polar granules inDrosophila.
41 citations
TL;DR: In this article, it was shown that any factor state ω of a C*-algebra can be extended to a pure exactj-positive state of ω→\(tilde \omega) of a ω √ √ ⊗\(mathfrak{A}\) if and only if their purifications ω1 and ω2 are quasi-equivalent.
Abstract: Let\(\mathfrak{A}\) be aC*-algebra and\(\mathfrak{A}^ \circ \) be an opposite algebra. Notions of exact andj-positive states of\(\mathfrak{A}^ \circ \) ⊗\(\mathfrak{A}\) are introduced. It is shown, that any factor state ω of\(\mathfrak{A}\) can be extended to a pure exactj-positive state\(\tilde \omega \) of\(\mathfrak{A}^ \circ \) ⊗\(\mathfrak{A}\). The correspondence ω→\(\tilde \omega \) generalizes the notion of the purifications map introduced by Powers and Stormer. The factor states ω1 and ω2 are quasi-equivalent if and only if their purifications\(\tilde \omega _1 \) and\(\tilde \omega _2 \) are equivalent.
37 citations
TL;DR: In this article, the authors considered the homogeneous, anisotropic cosmological model with three physically reasonable conditions: it is space homogeneous and possesses flat space like sections and is filled with expanding, rotating and shearing matter.
Abstract: The homogeneous, anisotropic cosmological model is considered. It satisfies three physically reasonable conditions: it is space homogeneous, possesses flat space like sections and is filled with expanding, rotating and shearing matter. The asymptotic solution is presented and general properties are discussed. The question how the rotation influences the behaviour of matter near the singularity is investigated.
33 citations
TL;DR: The spin and isospin dependent parts of the single-particle potential in nuclear matter are calculated at the Fermi surface with the Brueckner-Gammel-Thaler and the Reid soft core potential as discussed by the authors.
32 citations
TL;DR: In this paper, a new approach based on the application of Glauber's (or coherent-state) representation is proposed to formulate the theory of many-boson systems in terms of hydrodynamical quantities, i.e., particle density and velocity fields.
TL;DR: In this article, first-order three-and four-body contributions to the interaction energy of 3 and 4 hydrogen atoms in their repulsive states of highest multiplicity have been calculated.
TL;DR: In this paper, positive definiteness of matter density and pressure, adiabatic stability etc are presented in the form of inequalities relating certain functions which appear in the general formal solution; the latter solution has been derived recently by the same author in isotropic coordinates for spherically symmetric matter distributions.
TL;DR: In this paper, the adsorption of Cl− ions on mercury from aqueous HCl solutions was studied as a function of concentration (0.1 − 1.4 M) and temperature (25, 40 and 60°C).
TL;DR: The dimer reduction product has been identified as a component of some photoproducts of nucleic acid constituents and, possibly, ofucleic acids and its photobiological significance is discussed.
TL;DR: The connection between statistical independence of von Neumann algebras and their commutation is studied in this article, where it is shown that a stronger condition, similar to the condition of statistical independence, implies commutation.
TL;DR: The relation between the effect of ABA and the stage of stratification is closer in the case of GA4 than GA7, and it is assumed ABA to inhibit the gibberellin biosynthesis.
Abstract: The content of endogenous GA4 and GA7 was determined in apple embryos cultured either on water or in the presence of ABA solution. The embryos were isolated from dormant seeds and from seeds removed from stratification which was effected either in water or in the presence of ABA. The influence of ABA on the decrease of two GAs levels was proved. The relation between the effect of ABA and the stage of stratification is closer in the case of GA4 than GA7. It is assumed ABA to inhibit the gibberellin biosynthesis.
01 Aug 1972
TL;DR: In this paper, the authors considered a method of determining the electromagnetic field and power losses in ferromagnetic materials, using data from measured hysteresis loops, with the help of a GIER digital computer, and calculated the distribution of electromagnetic waves in solid iron and in steel sheets.
Abstract: The authors consider a method of determining the electromagnetic field and power losses in ferromagnetic materials, using data from measured hysteresis loops. With the help of a GIER digital computer, the distribution of electromagnetic waves in solid iron and in steel sheets has been calculated. The results of these calculations are compared with measurements obtained from tests on samples.
01 Jan 1972
TL;DR: The exchange splitting observed in excitons depends exponentially on the interatomic distance of the cation and anion of the compound as discussed by the authors, and the distance depends on the cross-correlation of the two components.
TL;DR: The interpretation of this experiment has been questioned, however, for the following reasons: the recipient animal was intact and therefore in possession of a complete neuro-endocrine system whose clock may simply have been re-started by the shock of the operation.
Abstract: FIFTEEN years of research on the hormonal control of insect circadian rhythms has been founded on the original report that rhythms could be transmitted in the blood between para-biosed cockroaches1. The interpretation of this experiment has been questioned, however, for the following reasons, (a) No control parabioses were performed using animals with unconnected haemocoels2. (b) The lower (recipient) animal was supposedly made arrhythmic by keeping it in constant light (LL), whereas it is now known that cockroaches can remain rhythmic for weeks in LL3 and that such rhythms may not necessarily be apparent in the locomotor activity4, (c) No cognizance was taken of the phase of the recipient animal, which may therefore have been close to that of the donor5. (d) The recipient animal was intact and therefore in possession of a complete neuro-endocrine system whose clock may simply have been re-started by the shock of the operation6.
TL;DR: A formal model for diagnostic problem solving is proposed which comprises a goal block and an operational block in short-term memory, together with an environment information block and a psychoinformation block in long- term memory.
TL;DR: Both CCC and cold (5°C) treatment gave rise to an increased content of the water-soluble proteins in leaf tissue of the winter rape, irrespective of the day length as discussed by the authors.
Abstract: Both CCC and cold (5°C) treatment gave rise to an increased content of the water-soluble proteins in leaf tissue of the winter rape, irrespective of the day length This effect was accompanied by a decrease of the insoluble nitrogen compounds content, mainly under theLD (the 16 hour day) The applied retardant also stimulated the consumption of the structural compounds induced by low temperature
TL;DR: In this paper, the Hall coefficient in CdxHg1−xTe under hydrostatic pressure over the temperature range 77 to 300 K was investigated and it was shown that within the experimental error, the energy gap is linear with x in the range 0 < x < 0.2.
Abstract: The investigation of the Hall coefficient in CdxHg1−xTe under hydrostatic pressure over the temperature range 77 to 300 K is reported. It is shown that within the experimental error, the energy gap is linear with x in the range 0 < x < 0.2. The pressure coefficient (dE0/dp)T and temperature coefficient (dE0/dT)p have been determined. The temperature coefficient of E0 has been found to be positive and to decrease with x. From the behaviour of RH = f(p) it has been established that the cross over Γ6, Γ8 is continuous.
Es wird uber Untersuchungen des Hallkoeffizienten in CdxHg1−xTe unter hydrostatischem Druck im Temperaturbereich 77 bis 300 K berichtet. Es wird gezeigt, das sich die Energielucke innerhalb des experimentellen Fehlers linear mit x im Bereich 0 < x < 0,2 andert. Der Druckkoeffizient (dE0/dp)T und der Temperaturkoeffizient (dE0/dT)p wurden bestimmt. Es wurde gefunden, das der Temperaturkoeffizient von E0 positiv ist und mit x abnimmt. Aus dem Verhalten von RH = f(p) wurde festgestellt, das die Uberschneidung Γ6, Γ8 kontinuierlich ist.
TL;DR: In this article, the absorption due to optical transitions from the valence band to empty cobalt acceptor states in GaAs has been investigated and the results are well explained in terms of Lucovsky's model, and the hole ionization energy of 0.14 eV was determined.
Abstract: The absorption due to optical transitions from the valence band to empty cobalt-acceptor states in GaAs has been investigated. The results are well explained in terms of Lucovsky's model, and the hole ionization energy of 0.14 eV was determined. The crystal-field spectrum of the 3d7 configuration is observed when the acceptor states are filled by electrons from shallow donors. The experimental results indicate that the acceptor state is due to hole in 3d-shell of the cobalt impurity on substitutional gallium sites.
Es wurde die Absorption von optischen ubergangen vom Valenzband zu leeren Kobalt-Akzeptorzustanden in GaAs untersucht. Die Ergebnisse lassen sich gut mit dem Modell von Lucovsky erklaren; eine Locherionisierungsenergie von 0,14 eV wurde bestimmt. Wenn die Akzeptorzustande durch Elektronen aus flachen Donatoren gefullt sind, wird das Kri-stallfeldspektrum der 3d7-Konfiguration beobachtet,. Die experimentellen Ergebnisse zei-gen, das der Akzeptorzustand durch ein Loch in der 3d-Schale des Kobaltdefekts auf Gal-liumsubstitutionsplatzen verursacht wird.
TL;DR: In this article, the double-layer capacitance of a mercury electrode in the solutions containing pyridine at different pH was measured and the dependence of capacitance on pH was determined.
TL;DR: Among restriction-deficient mutants isolated from strain Ra, seven of the eight possible phenotypes for these two systems were obtained after either one or two mutational steps.
Abstract: Rough R strains of Haemophilus influenzae derived from the smooth (S) serotypes Sa, Sb, Sd, Se and Sf each carry DNA restriction and modification systems. The DNA host specificity determined by Re and Rf may be the same but is different from that for Ra, Rb and Rd all of which can be distinguished from one another.
TL;DR: In this paper, the 14 C incorporation from 14 CO 2 into photosynthesis products in either normal (21 %) or high (approximately 100%) O 2 concentration was investigated, and it was associated with a decrease of 14 C in PGA, alanine and sugars but with an increase of radioactivity in glycine and serine.