Stereochemistry of 2, 7-disubstituted and 1,2,7-trisubstituted 4-alkyldecahydro-4-quinolols

The configurations of the 2 and 4 centers in 1,2,7-trimethyl-, 2,7-dimethyl-, and 1,2-dimethyl-7-tert-butyl-4-alkyldecahydro-4-quinolols were assigned on the basis of a comparison of the^I[M-CH₃] +/^I _[M] ⁺ and I_[m] + peak intensity ratios (the [M-CH₃) + and [M-C₂H₅]⁺ ions are due to elimination of 2-CH₃ and 4-C₂H₅ groups, respectively) in the mass spectra of the stereoisomers.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 809–811, June, 1976.     

Mass spectrometric determination of the configuration of 2-methyl-and 1,2-dimethyl-4-vinyl-ethinyl(n-butyl)-4-hydroxyperhydroquinolines

The configuration at C-2 and C-4 in the molecules of 2-methyl- and 1,2-dimethyl-4-vinylethinyl(n-butyl)-4-hydroxyperhydroquinolines was determined by mass spectrometry. The principal conclusions concerning the stereochemistry were made on the basis of differences in the values of the I_[M?15]⁺/I_[M]⁺·, I_[M?17]⁺/I_[M]⁺·, I[_M?43]⁺/I_[M]⁺· and I_[M?57]⁺/I_[M]⁺· ratios in the mass spectra of the epimeric vinylethinylic alcohols, and of the I_[M?15]⁺/I_[M]⁺· and I_[M?15]⁺/I_[M]⁺· ratios in the case of the n-butylic alcohols.     

Analysis of image of objective for formation of nanostructures by computer isophotometry method

The possibilities of using the computer isophotometry method to estimate the image quality of high-resolution projection objectives are considered. An experimental setup for measuring the point spread function is developed. A two-mirror objective of the Schwarzschild type with a numerical aperture of 0.36 designed for the use in an experimental nanolithographer is studied. Control measurements by the computer isophotometry method show that, at a wavelength of 13.4 nm, this objective is capable of resolving image features with a size of no larger than 50 nm.     

Distribution of adsorbed molecules along zeolitecavities

Conclusions From the experimental isotherm of adsorption on a zeolite, on the assumption of a quasiindependence of the molecules found in different cavities, it is possible to determine the distribution of the adsorbed molecules along the zeolite cavities. If the adsorption isotherm satisfies the Henry equation, then this distribution coincides with the Poisson distribution, while if it satisfies the Langmuir equation then the distribution coincides with the Bernoulli distribution.Translated from. Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 452–454, February, 1973.     

Maximum-norm estimates for resolvents of elliptic finite element operators

Let be a convex domain with smooth boundary in . It has been shown recently that the semigroup generated by the discrete Laplacian for quasi-uniform families of piecewise linear finite element spaces on is analytic with respect to the maximum-norm, uniformly in the mesh-width. This implies a resolvent estimate of standard form in the maximum-norm outside some sector in the right halfplane, and conversely. Here we show directly that such a resolvent estimate holds outside any sector around the positive real axis, with arbitrarily small angle. This is useful in the study of fully discrete approximations based on -stable rational functions, with small.

     

Determination of electron affinity of carbonyl radicals by means of negative ion mass spectrometry

Appearance energies of [M-H](-) ions from carbonyl compounds R-CO-R' (R,R' = H, CH(3), NH(2), OH) have been measured by means of negative ion mass spectrometry in resonant electron capture mode. Values of electron affinity of the corresponding radicals, CH(2)&dbond;C(X)O, NH&dbond;C(X)O and O&dbond;C(X)O, have been determined. Copyright 1999 John Wiley & Sons, Ltd.