Massenspektroskopische Untersuchung von substituierten Steroidsapogeninen

Zusammenfassung Der Einfluß von Substituenten in Ring D und F auf das Fragmentierungsverhalten von Spirostan-Derivaten wird diskutiert.

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Mass spectrometric investigation of substituted steroid sapogenins

The influence of substitutents in ring D and F on the fragmentation behavior of spirostane derivatives is discussed.

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Mit 10 Abbildungen     

Generalized mean-square amplitudes of vibration in some XY4 type ions (II)

The generalized mean-square amplitudes of vibration and mean amplitudes of vibration have been computed for CrO^3-₄, Mn¹⁸O^-₄, MoSe^2-₄ and WSe^2-₄ ions at three temperatures, T = 0°K, T = 298°K, T = 500°K, employing Cyvin's method. The results have been discussed in the light of atomic weight and electronegativity of the atom in the ionic system.     

Molecular and absolute crystal structure of pindolol-1-(1H-indol-4-yloxy)-3-[(1-methylethyl)amino]-2-propanol: A specific beta-adrenoreceptor antagonist with partial agonist activity

The crystal and molecular structure of pindolol, 1-(1H indol-4-yloxy)-3-[(1-methylethyl)amino]-2-propanol, has been determined by direct methods. Crystals are tetragonal, ,a=b=15.809(4),c=11.246(2) Å,Z=8,D _c=1.174 mg m^–3. The finalR-factor for 2271 reflections withI>2(I) is 0.038. Refinement by full-matrix least-squares on F² also enabled the absolute configuration of the structure to be established. The molecule is essentially planar, including much of the side-chain which is stabilized by the existence of two intramolecular H-bonds, between the ethyl oxygen and OH group, and between the OH and side-chain amide groups, respectively. The crystal structure is formed by three intermolecular hydrogen bonds including two side-chain-side-chain interactions, between ethyl oxygen to amide and OH to amide, and an interaction between the side-chain OH to indole NH.     

Category equivalences of clones

This note was inspired by McKenzie's recent paper [8] whose main result is a characterization of categorical equivalence (for short category equivalence) between varieties. Here we use this result to define category equivalent clones and to describe all clones category equivalent to maximal clones. If one is interested in maximal clones only up to category equivalence it is sufficient to consider very simple maximal clones, essentially the same as considered in Jablonski's early papers about maximal clones [6]. The results we have found encourage us in our feeling that category equivalence could be a useful tool in clone theory.Dedicated to the memory of Alan Day.Presented by J. Sichler.     

Local structure of graphs with λ=μ=2,a 2=4

Several properties of graphs with ==2,a ₂=4 are studied. It is proved that such graphs are locally unions of triangles, hexagons or heptagons. As a consequence, a distance regular graph with intersection array (13,10,7;1,2,7) does not exist.     

Onn-widths of bounded periodic holomorphic functions

The even-dimensional Kolmogorov widthsd _2n , Gel'fand widthsd ²ⁿ , and linear widths _2n ofà inL _q andC are determined exactly. We show that all threen-widths are equal and give a characterization of the widths in terms of Blaschke products.Published in Ukrainskii Matematicheskii Zhurnal, Vol. 47, No. 9, pp. 1170–1175, September, 1995.     

Elimination of the energy from interactions that depend on it as a resolvent

A study is made of the spectral problem (A+V(z)=z, in which the main HamiltonianA is a self-adjoint operator of fairly general nature, while the perturbationV(z)=–B(A–z)^–1 B* depends on the energyz as the resolvent of some other self-adjoint operatorA. It is assumed that the operatorB has a finite Hilbert—Schmidt norm and, in addition, that the spectra of the operatorsA andA are separated. Conditions are formulated under which it is possible to replace the perturbationV(z) by an energy-independent potentialW such that the HamiltonianH=A+W has the same spectrum (more precisely, part of the spectrum) and the same eigenfunctions as the original spectral problem. Completeness and orthogonality theorems are proved for the systems of eigenfunctions of the operatorH=A+W. A scattering theory is constructed for the HamiltonianH in the case when the operatorA has a continuous spectrum. Applications of the results to the few-body problem are discussed.Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 104, No. 2, pp. 281–303, August, 1995.     

Orthogonal Algebraic Polynomial Schauder Bases of Optimal Degree

For any fixed we construct an orthonormal Schauder basis for C[-1,1] consisting of algebraic polynomials with The orthogonality is with respect to the Chebyshev weight.     

Determination of the atmospheric neutrino spectra with the Fréjus detector

The combined analysis of the final event set of data on neutrino interactions inside the detector, upward going stopping muons and horizontal muons recorded in the Fréjus experiment is presented. The absolute atmospheric neutrino spectra in the energy range for electron neutrinos and for muon neutrinos are determined. Based on the parameterization of Volkova for thev ^µ a spectral index of =2.66±0.05 is obtained from the ratio of horizontal muons over upward going stopping muons and from the measurement of the energy loss of horizontal muons inside the detector. The neutrino spectra are compared with various flux calculations. They do not show any evidence for neutrino oscillations in agreement with earlier analyses of the Fréjus data.Now atUniversity of Michigan, Ann Arbor, USA