mndo semi-empirical scf mo calculations are used to study the pyramidal nitrogen atom inversion and configurational equilibria in the title compounds.

In this article we introduce the notion of n-capable groups. It is shown that every group G admits a uniquely determined subgroup (〖Z^n)〗^* (G) which is a characteristic subgroup and lies in the n-centre subgroup of the group G. This is the smallest subgroup of G whose factor group is n-capable. Moreover, some properties of n-central extension will be studied.

in order to investigate the effects of fertilizer types and irrigation regimes on quantitative criteria of three medicinal plants: lavander, rosemary and hyssop, an experiment was conducted at research field of faculty of agriculture, ferdowsi university of mashhad, during two growing years of 2007-2010. a split-split plot design with three replications was used. treatments were three irrigatio...

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introduction given the importance of nitrogen for improving the quantitative and qualitative yield of crops (rodrigues et al., 2006) and the need for application of chemical fertilizers in intensive agriculture to get the maximum production, nitrogen supply in adequate amounts by ecologically avowed resources is known as one of the main challenges during transition from conventional to organic ...

cover crops cultivation and application of plant growth rhizobacteria are the key factors to enhance agroecosystem health. a field experiment was conducted at the research farm of faculty of agriculture, ferdowsi university of mashhad, iran, during growing season of 2009-2010. a split plot arrangement based on a complete randomized block design with three replications was used. cultivation and ...

Let $nin mathbb{N}$. An additive map $h:Ato B$ between algebras $A$ and $B$ is called $n$-Jordan homomorphism if $h(a^n)=(h(a))^n$ for all $ain A$. We show that every $n$-Jordan homomorphism between commutative Banach algebras is a $n$-ring homomorphism when $n < 8$. For these cases, every involutive $n$-Jordan homomorphism between commutative C-algebras is norm continuous.

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