GOLDEN AGES OR MAGIC MOMENTS?

ABSTRACT. The paper is an attempt to refute Quinn's ‘the Golden Age of fisheries population models has ended “hypothesis. The approach is to show it is possible to provide simple matrix based theory for use with delay difference equations applied to products of the 0th to 4th powers of length and numbers at length (Alias” proto‐moments“). It compares these to models just based upon numbers and biomass. It also shows examples (of comparatively little moment) indicating how using multiple proto‐moments could improve the ability of delay difference equations to handle the size dependent processes of maturity, selection, natural mortality rates and predation rates and thus improving the biological reality of these models.     

Preparation of a New Polyoxometalate-based Nanoparticles

Polyoxometalates (POMs) α-K8H6[Si2W18Ti6O77] (Si2W18Ti6) loaded starch nanoparticles have been prepared and structurally characterized by elemental analyses, IR spectra and ^29Si spectroscopy. The particle size of Si2W18Ti6/starch was estimated by a Transmission electron microscope (TEM) and a 1000HSA MALVIRN Zetasizer instrttment. The result shows that the polyoxometalate retained the parent structure after encapsulated by starch microspheres.     

Synthesis of a new salt containing polyoxometallate anion and M-Cu-S cluster cation [MS_4Cu_4(γ-MePy)_8][M_6O_19] (M = Mo,W).Crystal structure of [WS_4Cu_4(γ-MePy)_8][W_6O_19]

Reactions of (NH4)2MS4, AgBr and CuBr in r-methylpyridine produced one new compound, [MS4Cu4(r-MePy)8]M6O19] (1, M = W; 2, M = Mo), of which 1 was characterized by single crystal X-ray analysis. The crystal data: orthorhombic, Pbcn, a = 15.434(4),b= 16.732(2), c = 28.657(7) A, V = 7400.8(8) A3, Z = 4, R = 0.072 for 3121 independent data. The compound is the first example which contains both polyoxotnngstate anion and heteropolynuclear cluster cation. In the structure of the cation four edges of the tetrahedral WS42- core are coordinated by four copper atoms, giving a WS4Cu4 aggregate of approximate D2h symmetry. The differences between the reaction of Cu+ with MS42- and that of Ag+ with MS42- in pyridine and its derivatives are discussed.     

ChemInform Abstract: Polyoxometalate Diphosphate Complexes. Folded Macrocyclic Dodecatungstates, ((O3PXPO3)4W12O36)16- (X: O,CH2).

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