Simultaneous production of K1o (892) and Δ++(1236) in the reaction K+p→K+π+π−p from 4.3 to 5.0 GeV/c

The reaction $\text{K}{}^{\mathrm{+}}\text{d}\text{→}\text{K}{}^{\mathrm{1o}}\text{(892) Δ}{}^{\mathrm{++}}\text{(1236)}\text{n}{}_{\mathrm{s}}$ from a K⁺d experiment with the CERN 2 m bubble chamber at 4.6 GeV/c is compared with the reaction $\text{K}{}^{\mathrm{+}}\text{p}\text{→}\text{K}{}^{\mathrm{1o}}\text{(892)Δ}{}^{\mathrm{++}}\text{(1236)}$ from a K⁺p experiment at the same energy. In addition, predictions of an absorption model, a Regge pole model and a quark model for the production and decay characteristics of the reaction $\text{K}{}^{\mathrm{+}}\text{p}\text{→}\text{K}{}^{\mathrm{1o}}\text{(892)Δ}{}^{\mathrm{++}}\text{(1236)}$ are tested with the combined statistics of the K⁺d experiment and three K⁺p experiments between 4.3 and 5.0 GeV/c.     

Three digit accurate multiple normal probabilities

Summary Computer algorithms are presented for evaluating the multidimensional normal distribution function by Monte Carlo techniques. The computation of such probabilities is frequently required in stochastic programming models and in multivariate statistical problems. Using a medium size computer, three significant digits can be obtained up to ten dimensions in five seconds, up to twenty dimensions in one minute and up to fifty dimensions in ten minutes. Results of the detailed computer experiences are also reported together with some numerical examples.     

Effects of relativity in the He(I) photoelectron spectroscopy of the transient species TeCI2 and TeBr2

Valence ionization energies of the transient species TeCl₂ and TeBr₂, obtained with He(I) photoelectron (PE) spectroscopy, are presented. The interpretation is based on the results of Hartree-Fock-Slater calculations, using STF basis sets of double zeta quality. Implementation of relativistic corrections to the ionization energies of TeBr₂ show that off-diagonal matrix-elements of the spin-orbit operator give rise to a splitting in the non-relativistically almost degenerate bromine “lone pair” orbitals. This splitting is observed experimentally. The assignments find additional support in a comparison with PE results of related oxygen-, sulphur- and seleniumdihalogenides, a simple LCBO model, sum rule considerations and a modified Walsh empirical diagram for AB₂ molecules with 20 valence electrons.     

Synthesis and characterization of some ω-dimethylamino-1-alkynylzing compounds

Ethyl (ω-dimethylamino-1 -alkynyl)zinc compounds and bis (ω-dimethylamino-l-alkynyl)zinc compounds were prepared by metalation of the dimethyl amino alkynes HCC(CH₂)_n,NMe₂ (n = 1–4) with diethylzinc and diphenylzinc. All compounds show oligomeric or polymeric association in benzene, the degree of association being dependent on the value of n. The presence of coordinating dimethylamino groups and/or bridging alkynyl groups was established by IR and NMR spectroscopy. Plausible structures for all compounds, based on spectroscopic and molecular weight data, are presented.     

High molecular weight polyacetylenes from the nudibranch Peltodoris actromaculata and the sponge Petrosia ficiformis

Two series of high molecular weight straight chain polyacetylenes (C₄₆, C₄₉ and C₄₉, C₅₂, C₅₅) have been isolated from two marine invertebrates and partially characterized.     

Benzolactams. II. Synthesis of tetrahydrobenz[d]indeno-[1,2-b]azepines and their 12-Oxo derivatives

Aromatic methoxy and/or methylenedioxy substituted 7-methyltetrahydrobenz[d]indeno[1,2-b]-azepines 7 and their 12-oxo derivatives 8 were efficiently synthesized by the general method consisting of two types of intramolecular dehydrative cyclizations, as follows. N-Methyl-N-β-phenethylacetamides 1 were cyanomethylated in the two-step process of chloromethylation and treatment of the resultant benzyl chlorides with sodium cyanide. The condensation of the benzyl cyanides 2 with the appropriate benzaldehydes, followed by reduction of the benzylidene function, gave α,β-diphenylpropionitriles 3 . Successively, hydrolysis to the amino acids 4 and the thermal cyclization converted 3 to the benzylbenzazepinones 5 , which were also prepared by benzylation of the benzazepinones 6 smoothly by heating of 5 with phosphoryl chloride to afford the title azepines 7 . Further, these tetracyclic enamines 7 underwent autoxidation to the corresponding 12-oxo derivatives 8 , on exposure to oxygen in the presence of Triton B.     

Generalized inverses on normed vector spaces

We extend the concepts, introduced by C.R. Rao for Euclidean norms, of minimum g-inverses and least square g-inverses, using arbitrary norms. We give a characterization of such generalized inverses and an application to the case in which the norm is l_∞. As a result of this application we obtain that when $\text{A?}\text{C}{}^{\mathrm{(n+1)\times n}}$ has rank n, there exists a generalized inverse of A, which serves the same purpose as the Moore-Penrose inverse, when the norm is l_∞.     

Self-centering combined aperture- and scatter-slit for powder diffractometry with constant effective specimen area

Summary A self-centering moving slit is described, which is used in the forward region to keep the effective specimen area constant. Construction and adjustment are simple. Stray radiation is entirely suppressed with appropriate sample holders.