Synthesis of phenols from metal-carbynes and diynes

Metal-carbynes RCM(CO)₄Br with diacetylenes give specific phenols in good yield. The reactions take only a few minutes at or below room temperature.     

Synthesis and properties of 3-vinyl-3-desmethyl chlorophyll a

The title compound 1 has been prepared from chlorophyll b by a highly chemoselective Wittig reaction, and its spectroscopic properties characterized.     

Computation of the homology ofΩ(X∨Y)

Summary We compute the homology of Ω(X∨Y) (the loop space of the wedge of the spaces X and Y), in terms of the homogies of ΩX and ΩY. To do this we use the fact that our problem is equivalent to the computation of the homology of the free product of two topological groups in terms of the homologies of the topological groups. We establish a multiple Kunneth formula with coefficients over a Dedekind domain, which is used to prove a Kunneth like formula involves homologies over a Dedekind domain and generalizes similar results with integral or field coefficients. Over a principal ideal domain the formula for a free product is made more specific. Entrata in Redazione il 31 maggio 1978.     

Thallium in organic synthesis. 63. A convenient synthesis of aromatic nitriles

Aromatic nitriles are readily formed by heating arylthallium bis(trifluoroacetates) with CuCN in acetonitrile.     

Another look atp-adicL-functions for totally real fields

Mathematische Annalen -     

Acoustic analysis of compensatory articulation in children

A study was undertaken to explore the effects of fixing the mandible with a bite block on the formant frequencies of the vowels [i a u] produced by two groups of children aged 4 and 5 and 7 and 8 years. Vowels produced in both normal and bite-block conditions were submitted to LPC analysis with windows placed over the first glottal pulse and at the vowel midpoint. For both groups of children, no differences were found in the frequencies of either the first or second formant between the normal and bite-block conditions. Results are discussed in relation to theories of the acquisition of speech motor control.     

Integer generalized inverses of incidence matrices

Graphical procedures are used to characterize the integral {1}- and {1, 2}-inverses of the incidence matrix A of a digraph, and to obtain a basis for the space of matrices X such that AXA = 0. These graphical procedures also produce the Smith canonical form of A and a full rank factorization of A using matrices with entries from {-1, 0, 1}. It is also shown how the results on incidence matrices of oriented graphs can be used to find generalized inverses of matrices of unoriented bipartite graphs.     

Boundary elements and symmetry

Summary This paper discusses the deficiencies of boundary element stiffness matrices, gives an account of the methods proposed to circumvent these defects and proposes a new procedure to obtain symmetric stiffness matrices.

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Randelemente und Symmetrie

Übersicht In diesem Aufsatz werden die Fehler diskutiert, die bei Steifigkeitsmatrizen, die mit Randelementen gewonnen wurden, auftreten, und es werden die Methoden vorgestellt, die vorgeschlagen wurden, um diese Fehler zu beheben. Ferner wird eine neue Methode vorgestellt, symmetrische Steifigkeitsmatrizen zu erhalten.