74,824 research outputs found

    Abstract of the Journal of a Route Travelled by Captain S. F. Hannay, of the 40th Regiment, Native Infantry, in 1835-36, from the Capital of Ava to the Amber Mines of the Hukong Valley on the South-east Frontier of Assam by R. Boileau Pemberton, edited by Michael W. Charney

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    This abstract of Captain Hannay’s 1835-1836 journal appeared in several places in the late 1830s. This particular version was published in Selection of Papers Regarding the Hill Tracts Between Assam and Burmah and of the Upper Brahmaputra (Calcutta: Bengal Secretariat Press, 1873

    True and False Foodplants of \u3ci\u3eCallosamia Promethea\u3c/i\u3e (Lepidoptera: Saturniidae) in Southern Michigan

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    A survey in 1980 of the associations of over 400 cocoons of Callosamia promethea Drury in vegetation along and adjacent to southern Michigan roadsides gave evidence for seven species of true larval foodplants (not including two others known in the area from other studies) and 17 species of false foodplants, the latter determined by the (1) rarity of their association with cocoons, (2) only one or two cocoons per plant, and (3) their proximity to a well known true foodplant. Three species, sassafras, black cherry, and buttonbush, are evidently the most important true foodplants in this area. Comparisons are made of the foodplants in terms of past literature, geography, and taxonomic relationships

    Bimetallic Effects on Ethylene Polymerization in the Presence of Amines: Inhibition of the Deactivation by Lewis Bases

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    Dinickel complexes supported by terphenyl ligands appended with phenoxy and imine donors were synthesized. Full substitution of the central arene blocks rotation around the aryl–aryl bond and allows for the isolation of atropisomers. The reported complexes perform ethylene polymerization in the presence of amines. The inhibiting effect of polar additives is up to 250 times lower for the syn isomer than the anti isomer. Comparisons with mononuclear systems indicate that the proximity of the metal centers leads to the observed inhibitory effect on the deactivation of the catalysts

    THE RELATIONSHIP BETWEEN MANAGERIAL HEURISTICS AND ECONOMICS IN PRICING RETAIL MEATS

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    This study develops a theoretical model of the multiproduct firm which allows for imperfect competition in the output market. Hypotheses are tested for retail meat prices concerning the degree and speed of price transmission, the effects of interfirm competition, and the interrelationship between prices within the store. Empirical results indicated that meat prices within a store were highly interrelated. Further, the firm was found to be very responsive to prices of competitors in the short run, but more responsive to wholesale price changes in the long run.Demand and Price Analysis,

    Dinickel Bisphenoxyiminato Complexes for the Polymerization of Ethylene and α-Olefins

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    Dinuclear nickel phenoxyiminato olefin polymerization catalysts based on rigid p-terphenyl frameworks are reported. Permethylation of the central arene of the terphenyl unit and oxygen substitution of the peripheral rings ortho to the aryl–aryl linkages blocks rotation around these linkages, allowing atropisomers of the ligand to be isolated. The corresponding syn and anti dinickel complexes (25-s and 25-a) were synthesized and characterized by single-crystal X-ray diffraction. These frameworks limit the relative movement of the metal centers, restricting the metal–metal distance. Kinetics studies of isomerization of a ligand precursor (7-a) allowed the calculation of the activation parameters for the isomerization process (ΔH^‡ = 28.0 ± 0.4 kcal × mol^(–1) and ΔS^‡ = −12.3 ± 0.4 cal mol^(–1) K^(–1)). The reported nickel complexes are active for ethylene polymerization (TOF up to 3700 (mol C_2H_4) (mol Ni)^(−1) h^(–1)) and ethylene/α-olefin copolymerization. Only methyl branches are observed in the polymerization of ethylene, while α-olefins are incorporated without apparent chain walking. These catalysts are active in the presence of polar additives and in neat tetrahydrofuran. The syn and anti isomers differ in polymerization activity, polymer branching, and polymer molecular weight. For comparison, a series of mononuclear nickel complexes (26, 27-s, 27-a, 28, 30) was prepared and studied. The effects of structure and catalyst nuclearity on reactivity are discussed

    THE EVOLUTION OF THE TRANSCRIPTION APPARATUS

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