Showing papers by "Johannes Kepler University of Linz published in 1986"
TL;DR: In this paper, experimental K-shell ionization cross sections using a data file containing about 7800 total X-ray or Auger production cross sections taken from the literature for which Z1/Z2 <-03, where Z1 and Z2 are the atomic numbers of the projectile and target.
109 citations
TL;DR: This paper describes a language interface for an extended NF2 model, i.e. a model which covers a much broader range of data structures than the original [17] NF’ model, and does not appropriately match further vital needs of new database applications.
90 citations
TL;DR: In this article, an estimator for the pair-potential with finite range was derived for a homogeneous Gibbsian point process with a step-fimction pair-to-finite-range.
Abstract: A pointconfiguration is supposed to be from a homogeneous Gibbsian point process with a pair–potential with finite range. The pair–potential is of the form of a step–fimction. An estimator for this pair–potential is derived
56 citations
TL;DR: In this article, it was shown that locally finite entropy holds under some growth and locality conditions on the forward drift which are close to the usual conditions for existence and uniqueness of strong solutions.
49 citations
TL;DR: In this article, the Radon-Nikodym property of Banach spaces has been shown to be equivalent to Bourgain's theorem of Bourgain in terms of optimization results, and some old ideas of Smulian can be used to give another proof of a theorem.
48 citations
TL;DR: In this article, the authors propose modeles theoriques des defauts a niveaux profonds dans les semiconducteurs a bande interdite etroite de type IV-VI and II-VI.
Abstract: Mise au point. Methodes experimentales. Modeles theoriques des defauts a niveaux profonds dans les semiconducteurs a bande interdite etroite de type IV-VI et II-VI
40 citations
TL;DR: In this paper, the authors made use of experimental data for complex moduli of melts of narrow molar mass distribution polystyrenes and their homogeneous blends and found that after the application of the required modifications, they could successfully obtain the complex modulus of the blend at circular frequencies characteristic for the flow and rubber transition regions.
Abstract: In the search for a workable mixing rule, use was made of experimental data for complex moduli of melts of narrow molar mass distribution polystyrenes and their homogeneous blends. In the course of this work two basic observations were made as to the nature of the relaxation time spectra of these blends:
For both processes approximate empirical equations could be found. It turned out that, after the application of the required modifications, the complex moduli of the components could successfully be added in order to obtain the complex moduli of the blend at circular frequencies characteristic for the flow and rubber transition regions. On the basis of these results one may expect that for the melt of any linear polymer the linear viscoelastic properties can be evaluated with reasonable accuracy from the knowledge of the molar mass distribution.
32 citations
TL;DR: In this paper, two methods for the estimation of pair-potential of Gibbsian point processes are described, which are applied to a point pattern of ant's nests to obtain information on the degree of interaction of two different species.
Abstract: In this paper two methods for the estimation of pair-potentials of Gibbsian point processes are described. These are applied to a point pattern of ant's nests to obtain information on the degree of interaction of two different species. Furthermore an estimation method of mark-point potentials is demonstrated and applied to the same example.
29 citations
TL;DR: In this article, the extremal structure of the dual unit balls of various operator spaces is studied and applications to the duality of operator spaces and differentiability properties of the norm in operator spaces are given.
Abstract: We study the extremal structure of the dual unit balls of various operator spaces. Mainly, we show that the classes of [w*-] strongly exposed, [w*-] exposed, and denting points in the dual unit balls of spaces of compact operators between Banach spacesX andY are completely — and in a canonical way — determined by the corresponding classes of points in the unit balls of the (bi-)duals of the factor spacesX andY. Applications to the duality of operator spaces and differentiability properties of the norm in operator spaces are given.
25 citations
01 Apr 1986-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this paper, the absolute values of the stopping cross sections of Al, Ni, Cu, Ag and Au were determined by different methods in two laboratories, and an analytical function depending on four parameters was fitted to these data.
Abstract: Absolute values of the proton stopping cross sections of Al, Ni, Cu, Ag and Au are presented which have been carefully determined by different methods in two laboratories. An analytical function depending on four parameters is fitted to these data. As the chosen range from 30 to 700 keV covers the energies where the stopping powers reach their maxima, values for the position E m and the height s m of these maxima are deduced. These data are compared to available theories: on the one hand to theories which predict a smooth dependence of s m × E m on E m , and on the other hand to theories which show how these maxima arise from the contributions of the individual subshells of the target atom.
24 citations
TL;DR: In this article, the laser-induced etching of PbTi1−xZrxO3 in a hydrogen atmosphere and in air has been investigated, where visible Ar+ and Kr+ laser radiation was employed in most of the experiments.
Abstract: The laser-induced etching of ceramic PbTi1−xZrxO3 in a hydrogen atmosphere and in air has been investigated. Visible Ar+ and Kr+ laser radiation was employed in most of the experiments. In H2 atmosphere, regular patterning of the ceramic is possible. Average etch rates reach up to about 250 μm/s.
08 Aug 1986
TL;DR: The algorithm for storage reclamation is presented, more general than existing ones as far as operations, system architecture, and communication are concerned, and the advantage with the longer retention of disposed objects is taken.
Abstract: ~ algorithm for storage reclamation In d is t r ibuted l t s t processing systems ts presented. The algorithm ts more general than exist ing ones as far as I t s t operations, system architecture, and communication are concerned. Thts advantage ts patd with the longer retention of disposed objects. Hethods are described to Intermit tent ly reclatm objects on a local basis, reduce the amount of objects retained needlessly, and to operate tn "real time".
TL;DR: It is found that the introduction of an energy threshold reduces at low energies the stopping cross section by a large factor and hence leads to an appreciable deviation from v/sub 1/ proportionality.
Abstract: We show how the electronic stopping power for slow protons is influenced by the deceleration and deflection of the projectile in the field of the target nucleus (Coulomb effect) and by the fact that in insulators a finite energy is also required for excitation of the outermost electrons (threshold effect). Estimates are derived from the Fermi-Teller description of the stopping process, from a modified local-density approximation, and from measured inner-shell ionization cross sections. It is found that the introduction of an energy threshold reduces at low energies the stopping cross section by a large factor and hence leads to an appreciable deviation from ${v}_{1}$ proportionality.
TL;DR: Alex is a scanner generator which translates the lexical description of a programming language into a scanner for that language using the scanner description language, which is intentionally small and simple.
Abstract: Alex is a scanner generator which translates the lexical description of a programming language into a scanner for that language. The scanner description language is easy to use, as it is intentionally small and simple. Alex as well as the generated scanners are written in Modula-2 and implemented on several microcomputers. The scanner generator may be used in conjunction with a compiler-compiler. As an example we show how to describe the lexical structure of Modula-2 with our tool. The scanner generated from that description is only about 20 percent slower than a hand-coded scanner.
TL;DR: In this paper, optically transparent ferroelectric ceramics of lanthanum modified lead zirconate titanate (PLZT) have been locally reduced and metallized by means of ultraviolet Kr+ laser irradiation in a hydrogen atmosphere.
Abstract: Hot pressed, optically transparent ferroelectric ceramics of lanthanum modified lead zirconate titanate (PLZT) have been locally reduced and metallized by means of ultraviolet Kr+ laser irradiation in a hydrogen atmosphere. The technique allows maskless single-step metallic patterning of the material.
TL;DR: In this paper, the shape of the peaks on the skew diagonal of the spectrum is determined by longitudinal and transverse relaxation functions along the ω 1 and ω 2 axes, respectively.
TL;DR: In this article, new types of periodic structures that occur in laser-induced chemical vapor deposition have been investigated, mainly for polycrystalline Si deposited on glass substrates covered with a thin amorphous Si layer.
Abstract: New types of periodic structures that occur in laser-induced chemical vapor deposition have been investigated, mainly for polycrystalline Si deposited on glass substrates covered with a thin amorphous Si layer. These periodic structures, which are believed to be a general phenomenon in pyrolytic laser-induced processing, limit the resolution obtainable in direct writing of patterns.
TL;DR: In this article, transmission and reflectivity measurements on thin epitaxial samples of Pb1-xMnxTe (x
Abstract: Transmission and reflectivity measurements on thin epitaxial samples of Pb1-xMnxTe (x
TL;DR: In this paper, the methine positions of the 10,15-dihydroderivative of the title compound of 1.1 were investigated and the results showed that it exhibits a very pronounced reactivity for nucleophiles at methine position "10" and "15" and that the adduct formation is irreversible.
Abstract: The title compound1 is found to be protonated corresponding topKa's of 2.5 and 0.5, thereby being two orders of magnitude less basic than bilatrienes-abc. Its deprotonation (pKa=17.1) is found to be less easy than in case of the bilatrienes.1 is shown to exhibit a very pronounced reactivity for nucleophiles at the methine positions “10” and “15”—a thiole adduct and the 10,15-dihydroderivative of1 are isolated and characterised. In contrast to the bilatrienes the adduct formation is irreversible. Accordingly, no diastereomers at exocyclic double bonds could be produced photochemically. Complexation of the lactam oxygens is achieved in case ofLewis acids (eg. AlCl3), chelation after addition of a proton acceptor is observed in a few cases only (Zn++, Hg++, In+++).
TL;DR: This deviation increases with increasing Z-italic/sub 1//Z/sub 2/; it cannot be explained by electron transfer to the projectile or by ionization due to target recoil atoms, and the ECPSSR provides best overall agreement for protons.
Abstract: Absolute K-italic-shell ionization cross sections have been measured for thin targets of Al, Ti, and Cu for protons in the energy range 0.3--2.0 MeV and for thin targets of Ti, V, Cr, Fe, Ni, Cu, and Ag for oxygen ions in the energy range 1.36--6.4 Mev. The experimental results are compared to the perturbed-stationary-state (PSS) approximation with energy-loss (E), Coulomb (C), and relativistic (R) corrections, i.e., the ECPSSR approximation (Brandt and Lapicki), to the semiclassical approximation (Laegsgaard, Andersen, and Lund), and to a theory for direct Coulomb ionization of the 1s-italicsigma molecular orbital (Montenegro and Sigaud (MS)). The proton results agree within 3% with empirical reference cross sections. Also, the ECPSSR provides best overall agreement for protons. For oxygen ions, ECPSSR and MS predict experimental results satisfactorily for scaled velocities xi> or =0.4. For lower scaled velocities, the experimental cross sections become considerably higher than theoretical predictions for Coulomb ionization. This deviation increases with increasing Z-italic/sub 1//Z/sub 2/; it cannot be explained by electron transfer to the projectile or by ionization due to target recoil atoms.
01 Jan 1986
TL;DR: In this article, the authors present an algorithmischen (d.h.m. mit dem Computer realisierbaren) Verfahren fur the Behandlung von Problemen, deren Angaben (Gleitkomma-) Zahlen sind and deren Losungen wieder (gleit komma)- Zahlensind.
Abstract: Numerische Mathematik befast sich mit algorithmischen (d.h. mit dem Computer realisierbaren) Verfahren fur die Behandlung von Problemen, deren Angaben (Gleitkomma-) Zahlen sind und deren Losungen wieder (Gleitkomma-) Zahlen sind.
TL;DR: In this paper, the linear dichroism of several pyrromethene derivatives embedded in a polyethylene film and oriented by stretching is investigated, and no changes in their conformations are observed, as compared to solutions in apolar solvents.
Abstract: The linear dichroism of several pyrromethene, pyrromethenone and bilatriene-abc derivatives embedded in a polyethylene film and oriented by stretching is investigated. On dissolving these pigments in the polymer matrix no changes in their conformations are observed, as compared to solutions in apolar solvents. Polarisation of the absorption bands of the pigments is deduced from the polarisation spectra. To enhance the solubility and orientation in the polymer, a pyrromethenone and a bilatriene-abc bearing a C18-alkyl chain were synthesised for the first time.
01 Apr 1986-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this article, a comparative study of measurements of electronic stopping cross sections was performed using a surface barrier detector and foil transmission with an electrostatic spectrometer, for 30-600 keV protons and deuterons equivalent and identical targets of Al, Ni, Cu, Ag and Au.
Abstract: Rutherford backscattering using a surface barrier detector and foil transmission with an electrostatic spectrometer were used for a comparative study of measurements of electronic stopping cross sections. The study is primarily devoted to the circumstances, under which these almost complementary methods deliver the same results for the film and foil targets analyzed. For 30–600 keV protons and deuterons equivalent and identical targets of Al, Ni, Cu, Ag, and Au were utilized.
TL;DR: Schneider and Hofreither as mentioned in this paper examined the methods used to analyse the underground or "shadow" economy in many Western countries, focusing mainly on the UK and the US.
Abstract: Early issues of Economic Affairs contained an exchange of views on the size and development of the black economy, concentrating chiefly on the UK. Friedrich Schneider and Markus Hofreither, of the University of Linz, continue the debate with an examination of the methods used to analyse the underground or ‘shadow’ economy in many Western countries.
TL;DR: The crystal structure of the (15E)-configurated 2,3-dihydrobilatriene-abc2, representing a model compound for the active form of the phytochrome chromophore, was determined at room temperature and at 97 K.
Abstract: The crystal structure of the (15E)-configurated 2,3-dihydrobilatriene-abc2, representing a model compound for the active form of the phytochrome chromophore, was determined at room temperature and at 97 K. Compared to the crystal structure of the corresponding (15Z)-derivative1, the molecule of2 shows a similar helix conformation, but with considerably larger helix pitch. The azide hydrogen atoms are localized at the nitrogen atoms of rings A, C and D. The distribution of bond lengths and bond angles is compatible with previous crystal structures and with the canonical formula. Tautomeric form, conformation and crystal packing are understandable on the basis of the observed intra- and intermolecular hydrogen bonds.
TL;DR: In this article, a method is described for the simultaneous quantitative determination of atrazine, pyrazon and lindane in potable water at the (sub-)ppb level using an adsorption column filled with Amberlite XAD-2 microporous resin advantageously replaces other preconcentration techniques.
Abstract: When groundwater reservoirs situated in agriculturally used areas are assigned as future potable water supplies, it has to be provided that traces of plant protection agents used in this area can be monitored in this groundwater. A method is described for the simultaneous quantitative determination of atrazine, pyrazon and lindane in potable water at the (sub-)ppb level. An adsorption column filled with Amberlite XAD-2 microporous resin advantageously replaces other preconcentration techniques. The concentrated eluate is analyzed by capillary gas chromatography without further purification. The recovery is 80% for atrazine and lindane at the 0.1 ppb level and 40% for pyrazon (1 ppb). The method was tested using tap water from the public water supply network. The complete procedure including sample preparation, preconcentration by adsorption on a macroporous resin, elution with diethyl ether, evaporation to dryness, addition of internal standard solution and capillary gas Chromatographic analysis is carried out in less than three hours (sample volume: 11).
01 Jan 1986
TL;DR: In this paper, various experimental techniques of band-offset determinations in semiconductor heterojunctions are discussed and a possible connection between band-edge offsets, deep impurities and Schottky barriers is made.
Abstract: The various experimental techniques of band-offset determinations in semiconductor heterojunctions are discussed. Special reference is made to their application to (Ga, Al)As/GaAs. We then review heuristic procedures for the band-offset prediction: i) band-edge alignment according to energy-level position of transition metal deep impurities and ii) using differences in Schottky-barrier heights. Finally, we comment on a possible threefold connection between band-edge offsets, deep impurities and Schottky barriers.
TL;DR: In this article, a new rheometer suitable for the region of very high viscosities is presented to measure at reasonable time and avoid degradation of the polymer, gravitational forces on iron spheres are replaced by magnetic ones.
Abstract: A new rheometer suitable for the region of very high viscosities is presented. To measure at reasonable time and avoid degradation of the polymer, gravitational forces on iron spheres are replaced by magnetic ones. The extent of the region depends on the strength of the magnetic field available. The velocity of the falling sphere is measured by interrupting the beam of a He-Ne-Laser which is registrated by a photoresistor. Results are analysed with the help of Stokes' law for falling spheres. By measuring the magnetic forces on the sphere with a special device based on glass springs absolute values of the viscosity are obtained and liquids for calibration are not needed.