Scattering theory for Stark Hamiltonians

We give an introduction to the spectral and scattering theory for Schr?dinger operators. An abstract short range scattering theory is developed. It is applied to perturbations of the Laplacian. Particular attention is paid to the study of Stark Hamiltonians. The main result is an explanation of the discrepancy between the classical and the quantum scattering theory for one-dimensional Stark Hamiltonians.     

Faecal lipid chromatography. I. Quantitative determination with chromarods

A new and original method is proposed for the qualitative and quantitative analysis of faecal lipids by thin-layer chromatography and detection through the flame ionization detector of an analyser (the Iatroscan TH 10). This method enables the rapid quantification of the different faecal lipid classes, including cholesterol, with great accuracy and reproducibility. In-series operations are possible with easy manipulation.     

Electron-beam-induced fracture of polymers

When a notched polymeric material is stressed, the notch opens into a wide crack tip, exposing a region of high stress concentration. The consequences of electron bombardment of the tip of such a stressed material under vacuum are explored here for the first time. Evidence is presented for electron-induced crack growth at stress far below that needed for crack growth due to stress alone. The electron current densities used in these experiments are sufficiently small that thermal heating of the zone near the crack tip is minimal. To provide information on the phenomena involved, we present simultaneous measurements of electron current, gas pressure, and sample load in response to periodic bombardment of the sample. Experiments involving the bombardment of un-notched polymers under stress are also described. Fractography of the unique structures obtained by fracture due to the combination of electron bombardment and stress are presented and interpreted in terms of a crosslinking mechanism.     

Projective deformation and biholomorphic equivalence of real hypersurfaces

The concepts of first order projective deformation, biholomorphic equivalence, and equivalence of induced Cauchy-Riemann structure are all equivalent for real analytic hypersurfaces in complex projective space. Studying the first concept leads to a realization of the Cauchy-Riemann structure bundle as a submanifold of the projective group. The Chern-Moser connection on this bundle can then be given in terms of the Maurer-Cartan form of the projective group, and equations analogous to the Gauss equations of Euclidean geometry give the Chern-Moser invariants. Research supported by the National Science Foundation under Grant Number MCS-8103370.     

MC SCF optimization using the direct,restricted step,second-order norm-extended optimization method

The potential of a direct, restricted step, second order MC SCF computer program is illustrated with a large configuration space calculation containing 24156 configuration state functions on the ³B₁ state of methylene.     

Scattered C1-algebras with almost finite spectrum

The paper gives a complete classification of all separable C¹-algebras with countable spectrum, for which each point in the spectrum has a finite neighbourhood.     

Direct limits of semi-simple rings

Necessary and sufficient conditions are found for a commutative regular ring to be the direct limit of classical semi-simple rings.Translated from Matematicheskie Zametki, Vol. 7, No. 4, pp. 461–468, April, 1970.     

Structural revision of barlerin and acetyl barlerin

¹H- and ¹³C-NMR data as well as chemical evidence show that the structures of barlerin and acetyl should be corrected to 8-O-acetyl shanzhiside methylester and 6,8-di-O-acetyl-shanzshiside methylester, respectively.