Isotachophoretische Bestimmung der B-Vitamine im ng-Bereich unter Verwendung kationischer Spacerionen

Ohne Zusammenfassung

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Isotachophoretic determination of vitamins B in the ng-range using kationic spacer ions

     

The nonlinear programming method of Wilson,Han, and Powell with an augmented Lagrangian type line search function

Summary The paper represents an outcome of an extensive comparative study of nonlinear optimization algorithms. This study indicates that quadratic approximation methods which are characterized by solving a sequence of quadratic subproblems recursively, belong to the most efficient and reliable nonlinear programming algorithms available at present. The purpose of this paper is to analyse the theoretical convergence properties and to investigate the numerical performance in more detail. In Part 1, the exactL ₁-penalty function of Han and Powell is replaced by a differentiable augmented Lagrange function for the line search computation to be able to prove the global convergence and to show that the steplength one is chosen in the neighbourhood of a solution. In Part 2, the quadratic subproblem is exchanged by a linear least squares problem to improve the efficiency, and to test the dependence of the performance from different solution methods for the quadratic or least squares subproblem.     

Synthese von 3,3,3-trifluoralanin aus hexafluoraceton

A new synthesis of 3,3,3-trifluoroalanine — starting from hexafluoroacetone — is described.     

Minimal nicht überauflösbare,endliche Gruppen

Ohne Zusammenfassung     

Stochastic integrators with stationary independent increments

Summary Lipschitzian stochastic differential equations driven by a process with stationary independent increments permit a priori growth and stability estimates up to any sure time, and the solutions depend differentiably on parameters provided the Levy measure of the driving term has suitable moments.Research partially supported by NSF grant Nr. MCS 8001779