Addition of atomic hydrogen to acetylene. Chain reactions of the vinyl radical

The main reaction products resulting from the addition of atomic hydrogen to acetylene are shown to be ethylene, 1,3-butadiene, and benzene. The mechanism involves chain reactions of the vinyl and butadienyl radicals, which regenerate atomic hydrogen. Some of the rate parameters are estimated.     

Trimethylphosphine complexes of tungsten(O) and (IV). X-ray crystal structures of trimethylphosphine tris (phenylacetylene) tungsten(O); bis(trimethylphosphine) tetrakis (methylisocyanide) tungsten(O), and oxodichlorotris (trimethylphosphine) tungsten (IV)

The reduction of WCl₄(PMe₃)₃ by sodium amalgam in presence of phenylacetylene gives W(PMe₃)(PhCCH)₃ (A). Reduction in presence of methylisocyanide gives W(PMe₃)₂(MeNC)₄ (B), while in presence of excess PMe₃ in tetrahydrofuran under hydrogen, WH₂Cl₂(PMe₃)₄ (C) is formed. The reaction of WCl₂(PMe₃)₄ with methanol in tetrahydrofuran gives mixtures of WH₂Cl₂(PMe₃)₄ and WOC1₂(PMe₃)₃ (D).The structures of A, B, and D have been determined by X-ray diffraction.     

On the dynamics of plastic circular plates

The paper is concerned with the dynamics of a thin circular plate made of a plastic-rigid material that obeys the yield condition ofTresca and the associated flow rule. The basic equations are established in the case of rotational symmetry, and their complete solution is given for a simply supported plate subjected to a uniformly distributed load which is brought on suddenly and, after a certain time interval, removed suddenly.

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Résumé Cet article étudie la dynamique d'une plaque circulaire infiniment mince fabriquée avec un matériau plastique qui obéit à la condition de plasticité deTresca et à la loi d'écoulement associée. Les équations fondamentales sont établies dans le cas où existe une symétrie de révolution. Leur solution complète est donnée pour une plaque reposant sur des appuis simples, soumise à une charge uniformément répartie qui est appliquée rapidement et demeure constante pendant un certain temps, après lequel elle est rapidement retirée.

     

Paley graphs satisfy all first-order adjacency axioms

A graph satisfies Axiom n if, for any sequence of 2n of its points, there is another point adjacent to the first n and not to any of the last n. We show that, for each n, all sufficiently large Paley graphs satisfy Axiom n. From this we conclude at once that several properties of graphs are not first order, including self-complementarity and regularity.     

A Model of the Dynamics of the Third World War — An Exercise in Technology Transfer

The paper discusses two scenarios for a Third World War in Europe, and argues that it is often convenient to supplement a scenario by a formal model. The problems of creating such a model are examined, and a model is formulated for land, air, and sea combat in Europe and the Atlantic, using the System Dynamics approach, which has not hitherto been widely employed for military analysis.The model confirms the results of the two scenarios, and its use for the analysis of alternative force configurations is illustrated. Some implications in the interpretation of Soviet military literature are discussed, and the paper ends with speculations on the role and value of such models.     

The reaction of atomic oxygen O(3P) with isobutane

The reaction of O(³P) atoms with isobutane has been studied by using the discharge-flow system described previously [1]. The rate constant was measured from determinations of the isobutane concentration in the presence of an excess of O atoms and is given by k₁ = (7.9 ± 1.4) × 10⁷ dm³/mol·s at 307 K. In order to explain the observed reaction products, the mechanism requires that the principal process be the successive abstraction of H atoms from isobutane and from the t-butyl radical to give isobutene. A minor part of the reaction between O(³P) and the t-butyl radical gives the t-butoxy radical, which decomposes to acetone. The branching ratios are .     

Preparation and properties of a soluble polymeric aquo ion of molybdenum(V)

An orange/brown ionic and polymeric Mo(V) ion (Mo to Na ratio 2.3:1), soluble in H₂O to give stable solutions at pH～6, with UV visible spectrum λ_max 318nm, ?(per Mo) 330OM^?1 cm^?1, has been prepared and partially characterised. Various properties are described, including the conversion to the well established Mo(V) aquo dimer, MO₂O₄²⁺, on adjustment of [H⁺] to 0.17–0.50 M, I=0.50 M (H/LiClO₄). First-order rate constants, k_obs(25°C), determined by conventional spectrophotometry give a good fit to the empirical rate law,     

Bootstrapping the photon

A nontechnical review is given of a topological bootstrap theory, with emphasis on theraison d'être for an electromagnetism whose fine-structure constant is of order10 ^?2.