Artículos de revistas: Recent submissions
Now showing items 861-880 of 4968
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(1977)The role of naturally-occurring soil organic matter (SOM) in the translocation of metal ions from parent materials to biological systems is discussed. To explain the movement of essential elements, a hypothesis or model ...
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(1977)An experimental technique was devised to measure the maximum binding ability (MBA) of any macromolecule having electron donor groups. It is a dialysis technique wherein polymer portions are isolated in dialysis bags and ...
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(2000)A new formula for the conserved charges in 3+1 gravity for spacetimes with local anti-de Sitter asymptotic geometry is proposed. It is shown that requiring the action to have an extremum for this class of asymptotia sets ...
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(Amer Inst Physics, 1987)The gravitational field equations for a spherical symmetric perfect fluid are completely solved. The general analytical solution obtained depends on an arbitrary function of the radial coordinate. As illustrations of the ...
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(1984)As part of a systematic chemical investigation of Chilean Compositae (1-3), we examined the secondar chemistry of a member of the genus Gochnatia (tribe Mutisieae, subtribe Gochnatiinae): Gochnatia foliosa var. fscicularia ...
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(1996)Aldol reactions lithium alkyl acetates (LiCRR″CO2R′) with (RS)-2-(p-tolylsulfinyl)cyclohexanone (1) (as an epimeric mixture at C-2) take place with very efficient control of the configuration at the tertiary hydroxylic ...
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(1984)The indole bases N∞-methyltryptamine, 5-methoxy-N, N-dimethyltryptamine, 3-N,N-dimethylaminomethylindole (gramine) and 5-methoxytryptamine decreased survival of nymphs of Rhopalosiphum maidis with LD50 of 3.8, 3.5, 2.9 and ...
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(1991)The aerial parts of Haplopappus parvifolius afforded 30 new diterpenes including 21 labdane derivatives, four nor-diterpenes, three rearranged ones, four seco-labdanes and one with a new carbon skeleton whose structure was ...
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(American Chemical Society, 1986)Acid-catalyzed conversion of linalool into geraniol, nerol, and a-terpineol is slower than the corresponding reactions of geraniol and nerol, because the tertiary linalyl carbocation reverts to linalool rather than going ...
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(1984)Kinetic analysis of the nonenzymic solvolysis of neryl and geranyl pyrophosphate (NPP and GPP, respectively) showed that the dissociation constants of the bis-metallic complexes with Mg2+ and Mn2+ were larger for NPP than ...
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(1995)A model for cross relaxation in high symmetry systems is developed. The positions of all acceptor ions and all multipole-multipole interactions may be included. The geometric factors are explicitly considered. A feature ...
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(John Wiley and Sons Inc., 1998)Using some relationships derived from the density functional version of the virial theorem, an approximated kinetic energy density is constructed. This is used to implement a modified version of the electron localization ...
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(1998)We study the dependence of the intramolecular M I-M I interaction on electron correlation effects in eight-membered rings of type [M 2(PH 2CH 2PH 2) 2] 2+, [M 2(NHCHNH) 2], [M 2(SCHS) 2] (M = Au, Ag, Cu), [Au 2(PH 2CH 2PH ...
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(1986)Relationships among the chlorophyll-specific photosynthetic behaviour of a Melosira-dominated phytoplankton, net variations in the quantity of Melosira in suspension, the rates of sinking loss of Melosira cells and did ...
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(American Chemical Society, 2000)The validity of the minimum polarizability principle upon electronic excitation is studied as a companion principle of that obtained by Chattaraj and Poddar in the case of the maximum hardness principle. Twelve diatomic ...
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(Entomological Society of America, 1997)Aphid genotype has been shown to be a source of variability in the induction of phytochemical responses in wheat after aphid infestation as well as in their performance on wheat lines. Two clones of the aphid Sitobion ...
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(Elsevier, 2000)The three new organometallic hydrazines [Fe(η5-Cp)(η6-RC6H4NHNH 2)]+PF6 -, Cp=C5H5, R=H, [1]+PF6 -; m-Me, [2]+PF6 -; p-MeO, [3]+PF6 -, were synthesised and characterised. They were obtained in CH2Cl2 by reaction of the ...
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(1983)A new quinolizidine alkaloid, (+)-9α-hydroxymatrine, was isolated from the leaves of Sophora macrocarpa. Its structure was determined by a combination of spectroscopic methods, among which nuclear Overhauser enhancement ...
