Showing papers by "University of Warsaw published in 1989"
TL;DR: In this paper, a general theory of non-commutative differential geometry on quantum groups is developed, where bicovariant bimodules as objects analogous to tensor bundles over Lie groups are studied.
Abstract: The paper deals with non-commutative differential geometry. The general theory of differential calculus on quantum groups is developed. Bicovariant bimodules as objects analogous to tensor bundles over Lie groups are studied. Tensor algebra and external algebra constructions are described. It is shown that any bicovariant first order differential calculus admits a natural lifting to the external algebra, so the external derivative of higher order differential forms is well defined and obeys the usual properties. The proper form of the Cartan Maurer formula is found. The vector space dual to the space of left-invariant differential forms is endowed with a bilinear operation playing the role of the Lie bracket (commutator). Generalized antisymmetry relation and Jacobi identity are proved.
1,248 citations
University of Sheffield1, University of Warsaw2, Yale University3, CERN4, University of Liverpool5, Lancaster University6, University of Oxford7, Laboratoire d'Annecy-le-Vieux de physique des particules8, RWTH Aachen University9, University of Freiburg10, University of Turin11, Uppsala University12, Max Planck Society13
TL;DR: An investigation of the spin structure of the proton in deep inelastic scattering of polarised muons on polarised protons was performed in this article, where the spin was investigated in the context of the deep scattering process of polarized muons.
813 citations
420 citations
TL;DR: In this article, a formalism of second quatization procedure based upon the twisted SU (N) group is constructed and the related twisted canonical commutation relations (TCCR) are investigated.
341 citations
01 Jan 1989
TL;DR: For the last two decades predation has been considered to be a major driving force in shaping zooplankton communities and in determining their density and structure as mentioned in this paper, and predation was considered the major factor responsible for successional events.
Abstract: For the last two decades predation has been considered to be a major driving force in shaping zooplankton communities and in determining their density and structure. In early studies, species succession was usually considered to be the result of differences in ecological tolerance to various abiotic environmental factors, such as light intensity and water density or viscosity (Hutchinson, 1967). By the early 1960s, the time of worldwide “productivity” research, the competition for resources was usually considered to be the primary driving force. Later, after the pioneering papers by Hrbacek (Hrbacek, 1962; Hrbacek et al., 1961) were cited by Brooks and Dodson (1965) and Hall et al. (1976), predation was considered to be the major factor responsible for successional events.
272 citations
260 citations
TL;DR: Depending on the type of activating stimulus, oocytes exhibit the capacity for full activation at different ages, and the oocyte arrest in M III is similar to M II and can be released by subsequent activation.
223 citations
TL;DR: The pH is one of the most important parameters for char-acterizing the chemical properties of an aqueous solution, and among alternatives to the hydrogen-selective glass electrode group of sensors, potentiometric metal-metal oxide pH sensors respond to pH, ideally due to an equilibrium involving the metal and its oxide.
Abstract: The pH is one of the most important parameters for char-acterizing the chemical properties of an aqueous solution. The glass eiectrode is by far the most commonly used pH sensor. The determination of pH in special situations, e.g., in vivo applications where the fragility of the glass electrode is a draw-back, requires pH sensors that can easily be miniaturized and built into physically rugged sleeves. Also, for other applications where the volume of solution is very restricted miniaturization of pH sensors is very important. The glass electrode does not respond properly to pH in some corrosive environments (e.g., in hydrogen fluoride [HF] solutions). At present, among alternatives to the hydrogen-selective glass electrode group of sensors, potentiometric metal-metal oxide pH sensors respond to pH, ideally due to an equilibrium involving the metal and its oxide. In the case of metal oxide electrodes, the metal is not involved in the potential-determining reaction. This distinction is of course not clear in many cases because the mechanism giving the pH response is not always unequivocal.
152 citations
TL;DR: The first measurements of the mass and width of the Z 0 at the DELPHI Collaboration at the LEP Collider were presented in this article, where the authors derived the measurements from the multihadronic final states produced in e + e − annihilations at several energies around the 0 mass.
147 citations
TL;DR: In this paper, a jet cascading mechanism is used to reproduce the effect of the hadronization effect in π + p and K + p collisions at 250 GeV/c.
130 citations
TL;DR: In this article, a three-dimensional differential calculus on quantum spheres is introduced and investigated, and the classical limits of these objects are obtained and a simple approach to quantum mechanics on a quantum sphere is presented.
Abstract: Three-dimensional differential calculus on quantum spheres S
infμc
sup2
,μ∈]−1, 1[∖{0}, c∈[0, ∞], is introduced and investigated. Spectra of generalized Laplacians are found. These operators are expressed by generalized directional derivatives. Classical limits of these objects are obtained and a simple approach to quantum mechanics on a quantum sphere is presented.
TL;DR: In this paper, the electrocatalytic properties of composite films containing Pt microparticles dispersed in W(VI,V) oxide supports were described, and the coatings were prepared electrochemically on graphite.
TL;DR: In this paper, the existence of an invariant measure for a bounded region in R N is shown to be absolute invariant under the assumption that the angle subtended by tangents to these segments at the point of contact is bounded away from 0.
Abstract: LetS be a bounded region inR
N and let ℊ={S
i}
=1/
be a partition ofS into a finite number of subsets having piecewiseC
2 boundaries. We assume that whereC
2 segments of the boundaries meet, the angle subtended by tangents to these segments at the point of contact is bounded away from 0. Letτ:S →S be piecewiseC
2 on ℊ and expanding in the sense that there exists 0<σ< 1 such that for anyi=1, 2, ...,m, ‖Dτ
−1
‖<σ, whereDτ
−1
is the derivative matrix ofτ
−1
and ‖ ‖ is the euclidean matrix norm. The main result provides an upper bound onσ which guarantees the existence of an absolutely continuous invariant measure forτ.
TL;DR: The existence of the H particle, the dihyperon predicted by Jaffe, would bring into question the existence of double hypernuclei as mentioned in this paper, which would be a major blow to double hyper-nucleus theory.
Abstract: The existence of the H particle, the dihyperon predicted by Jaffe, would bring into question the existence of double hypernuclei. We review the two double hypernucleus events published in the literature. We include an independent report, hitherto unpublished, which was made on the $\Lambda\Lambda^{10}$Be event in 1963 and clarifies the salient features of the event; this report reaffirms its published interpretation. We have made a simple calculation of the energy spectrum for $\Xi^-$ hyperons produced with K$^-$ beams in past emulsion experiments, with a result which accounts adequately for the paucity of reported double hypernucleus events. We outline a hybrid emulsion experiment that would locate $\Xi^-$ hyperon interactions efficiently and could thereby greatly improve our knowledge of double hypernuclei.
TL;DR: In this paper, the classical dynamics of the gravitational field in the Poincare gauge theory is studied and the most general Lagrangian quadratic in curvature and torsion is considered.
Abstract: The classical dynamics of the gravitational field in the Poincare gauge theory is studied. The most general Lagrangian quadratic in curvature and torsion is considered. The relevant field equations and their solutions are analyzed in detail, with particular emphasis on the comparison of the Poincare gauge models with the general relativity theory. We investigate correspondence between the spaces of exact solutions of these theories, both in the presence and absence of material sources, and with or without torsion. Some new exact solutions are obtained without the use of the double duality ansatz. The weak-field approximation is discussed, and gravitational radiation is considered.
TL;DR: In this article, the authors applied organic geochemical analyses to sixteen extracts obtained from Kupferschiefer samples collected in the Konrad and Rudna mines, southwest Poland, and found that saturated hydrocarbons in the extracts are reduced relative to the content of aromatic and hetero-aromatic compounds.
TL;DR: In this article, the first in the series addressing the h-p version of the finite element method for parabolic equations is presented, where the p-version with one single time element is used.
Abstract: The paper is the first in the series addressing the h-p version of the finite element method for parabolic equations. The h-p version is applied to both time and space variables. The present paper addresses the case when in time the p-version with one single time element is used. Error estimation is given and numerical computations are presented.
TL;DR: In this paper, a comparison between the measured and predicted solubilities and the heats of dissolution has been made, and the experimental diffusion coefficients have been analyzed according to the simple Sutherland-Einstein equation.
Abstract: Experimental data on solubility, heat and kinetics of dissolution, diffusion and standard potentials of metals in mercury as well as the rate of the electrode process with an amalgam formation, have been collected and selected. A comparison has been made between the measured and predicted solubilities and heats of dissolution. The experimental diffusion coefficients have been analysed according to the simple Sutherland-Einstein equation; the average composition of diffusing particles in diluted amalgams have been estimated. The linear dependence between the logarithm of the rate constant of aquo-ion electroreduction on mercury and the metal solubility in mercury has been confirmed. No correlation of the dissolution rate of metals in mercury has been found.
TL;DR: In this article, twisted canonical anticommutation relations (TCAR) are connected with a formalism of a second quantization procedure based upon the twisted SU(N) group.
TL;DR: In this paper, basic relationships and algorithms for numerical simulation of non-linear, self-excited vibrations in single degree-of-freedom cutting systems were presented, where nonlinearities due to the tool leaving the cut, as well as interference between the cutting tool clearance face and cutting surface waviness, were taken into consideration.
Abstract: In this paper, basic relationships and algorithms for numerical simulation of non-linear, self-excited vibrations in single degree-of-freedom cutting systems are presented. Non-linearities due to the tool leaving the cut, as well as interference between the cutting tool clearance face and cutting surface waviness, were taken into consideration. Examples of vibration simulation results are shown.
TL;DR: In this paper, an analysis and experimental results are given for a class E switchingmode tuned power amplifier with an antiparallel diode or a series diode at any loaded Q and any switched duty cycle D. The experimental switch current and voltage waveforms were in agreement with theoretical predictions.
Abstract: An analysis and experimental results are given for a class E switching-mode tuned power amplifier with an antiparallel diode or a series diode at any loaded Q and any switched duty cycle D. The load resistance and the operating frequency of the amplifier can vary over a wide range while maintaining high efficiency. Using equations derived by the authors in a previous publication (ibid., vol.CAS-34, no.2, p.149-59, 1987), the analysis of the amplifier is performed at any values of the derivative of the switch voltage, load resistance, and operating frequency. The experimental switch current and voltage waveforms were in agreement with theoretical predictions. The measured efficiencies were 91 and 88% at 2 MHz in the amplifier with an antiparallel diode and a series diode, respectively. >
TL;DR: In this paper, the authors discuss possible experiments which allow determination of the valence and strange-sea quark spin distributions in the nucleon through measurement of various asymmetries in semi-inclusive polarised deep-inelastic muon-proton (deuteron) scattering.
TL;DR: In this paper, the membrane properties of the Prussian Blue [iron(III, II)hexacyanoferrate(II, III)] system, deposited as thin films onto electrodes, were studied with conventional electrochemical techniques and with Volta-potential measurements conducted on the emersed coated electrodes.
TL;DR: In this paper, similarities and differences between the single-particle orbitals of the Nilsson and Woods-Saxon average potentials are investigated in detail for deformed nuclei in the rare-earth and actinide regions.
Abstract: Similarities and differences between the single-particle orbitals of the Nilsson and Woods-Saxon average potentials are investigated in detail for deformed nuclei in the rare-earth and actinide regions. The neutron single-particle orbitals are found to be similar in the two potentials in the rare earth region, while in the actinide region large differences are found. These differences can, however, be significantly reduced by changing the Nilsson model parameters κ and μ. The proton single-particle orbitals show small but systematic differences both in the rare earth and actinide region. The origin of these differences can be traced back to the Coulomb interaction, which is not explicitly considered in the Nilsson potential.
TL;DR: In a study conducted in Sweden and the United States, subjects judged their own driving skills in relation to other drivers and showed that a majority of subjects regarded themselves as more skillful than the average driver.
TL;DR: In this paper, the results from the NA35 Collaboration were presented for the reactions of 60 and 200 GeV/nucleon p and 16 O, with various targets ranging from S to Au.
University of Turin1, University of Liverpool2, Max Planck Society3, University of Freiburg4, CERN5, RWTH Aachen University6, University of Hamburg7, Laboratoire d'Annecy-le-Vieux de physique des particules8, Uppsala University9, University of Sheffield10, University of Oxford11, University of Warsaw12, Lancaster University13, University of Paris14, University of Kiel15
TL;DR: In this article, a new determination of the u valence quark distribution function in the proton was obtained from the analysis of identified charged pions, kaons, protons and antiprotons produced in muon-proton and muon deuteron scattering.