The present work considers (4+1)-dimensional spatially homogeneous vacuum cosmological models. Exact solutions-some already existing in the literature, and others believed to be new-are exhibited. Some of them are the most general for the corresponding Lie group with which each homogeneous slice is endowed, and some others are quite general. The characterization 'general' is given based on the counting of the essential constants, the line element of each model must contain; indeed, this is the basic contribution of the work. We give two different ways of calculating the number of essential constants for the simply transitive spatially homogeneous (4+1)-dimensional models. The first uses the initial value theorem; the second uses, through Peano's theorem, the so-called time-dependent automorphism inducing diffeomorphisms.

Ncw soluble m-carborane-containing polymeric SCHIFF bases are prepared by polycondensation of m-carboranylenediamine, 1,7-bis(4-aminophenylcarboxy)-m-carborane, and 1,7-bis(4-aminophenylamido)-m-carborane with different dialdehydes in solution. Optimum conditions for polymer synthesis are found. The structure of the resulting polymers is confirmed by the synthesis of model compounds not described earlier, IR spectroscopy, and elemental analysis data. Some properties of m-carborane-containing polymeric SCHIFF bases and their model compounds have been studied. Neue na-Carboran enthaltende polymere Schiffsche BasenNeue liisliche, m-Carboran enthaltende polymere SCHIFFsche Basen wurden durch Polykondensation von m-Carboranylendiamin, 1,7-Bis-(4-aminophenylcarboxy)-m-carboran und 1,7-Bis-(4-aminophenylamido)-m-carboran mit unterschiedlichen Dialdehyden in Losung hergestellt. Die optimalen Bedingungen fur die Synthese der Polymere wurden ermittelt. Die Struktur der erhaltenen Polymere wurde durch die Synthese von bisher nicht beschriebenen Modellverbindungen, durch IR-Spektroskopie und durch Elementaranalyse bestatigt. Einige Eigenschaften der m-Carboran enthaltenden polymeren SCHIFFschen Basen und ihrer Modellverbindungen wurden untersucht. Hoebte m -~a p 6 o p a n c o d e p~a q u e noAuuu$$oebce ocnoeafimHOBbIe PaCTBOPMMbIe M-Kap6OpaHCOnepxtanHe IIOJIHIUH@@OBbIe OCHOBaHHR IIOJIyqeHbI IIOJIIXHOHAqeIICaqHet M-Kap6OpaHAneHAAaMHHa, 1,7-6HC-( 4-aMIIHO-@C!HHJIKap6OKCH)-M-Ka~6OpaHa II 1,7-6AC-(4-aMIIHO@eHHnaMHAO)-M-Kap6OpaHa C pa3JIAYHbIMII AHaJIbAeI'HAaMH B paCTBOpe. OCy~eCTBJIeH non6op OIITHMaJIbHbIX J'CJIOBHm CEIHTe3a IIOJIAM~?pOB. CTpOeHHe IIOJIyqeHHbIX IIOJIHMepOB IIOnTBePHcAeHO CHHTe30M PaHee HeOIIHCaHHbIX MOAeJlbHbIX COeAH-HeHAa, AaHHbIMII u~-CIIeKTpOCKOIIHH A 3JIeMeHTHOrO aHaJIII3a. u3YqeHbI HeKOTOpbIe CBOPCTBa M-Kap6OpaHCOJ(ep-XawHX IIOJIAIIIH@@OBbIX OCHOBaHHa A HX MOAeJIbHbIX COeAHHeHHfi.

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