Zur Gerbmaterialanalyse (Richtigstellung)

Ohne Zusammenfassung     

Acetylene chemistry. Part 23 . N-vinylation on acridinones

The vinylation of 9(10H)-acridinones 1a-1d with propiolic acid ethylester resulting in acridinonyl-N-acrylic esters is reported.     

On the Exponential Convergence of Spline Approximation Methods for Wiener-Hopf Equations

This paper deals with the study of some new multidimensional operators of fractional calculus. These operators are considered in certain spaces of test and generalized functions. Some mapping properties and product rules are obtained.     

Destruction of26Al in explosive nucleosynthesis

The²⁶Al(n, p)²⁶Mg reaction has been studied using neutron spectra which closely resembled Maxwell-Boltzmann (M.-B.) distributions with thermal energies ofkT=40 ×10^?6, 31 and 71 keV and also forE _n =270–350 keV. These energies correspond to stellar temperaturesT ₉=4.6×10^?7, 0.36, 0.82 and 3.1–4.1, whereT ₉ is in units of 10⁹ K. The partial cross sections for thep ₀-(p ₁-)transition are found to equal 26±10(1,850 ±150), 13±6(124±17), 16±13(84±14) and 21±8(72±15) mb for the above neutron spectra, respectively. The astrophysical reaction rate is determined for the combinedp ₀- andp ₁-transitions to beN _A 〈σν〉=(0.324±0.026, 20.5±2.7, 22.6±4.3 and 38.7±11.1) ×10⁶ cm³ mole^?1 s^?1. The results are compared with previous investigations and with statistical model calculations.     

Second-kind integral formulations of the capacitance problem

The standard approach to calculating electrostatic forces and capacitances involves solving a surface integral equation of the first kind. However, discretizations of this problem lead to ill-conditioned linear systems and second-kind integral equations usually solve for the dipole density, which can not be directly related to electrostatic forces. This paper describes a second-kind equation for the monopole or charge density and investigates different discretization schemes for this integral formulation. Numerical experiments, using multipole accelerated matrix–vector multiplications, demonstrate the efficiency and accuracy of the new approach. This revised version was published online in June 2006 with corrections to the Cover Date.