500 research outputs found

    Cotorsion Pairs in C(R-Mod)

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    In [8] Salce introduced the notion of a co-torsion pair (A, B) in the category of abelian groups. But his definitions and basic results carry over to more general abelian categories and have proved useful in a variety of settings. In this article we will consider complete cotorsion pairs (C, D)in the category C(R-Mod) of complexes of left R-modules over some ring R.If(C, D) is such a pair, and if C is closed un-der taking suspensions, we will show when we regard K(C) and K(D) as subcategories of the homotopy category K(R-Mod), then the embedding functors K(C) → K(R-Mod) and K(D) → K(R-Mod) have left and right adjoints, respectively. In finding examples of such pairs, we will describe a procedure for using Hoveys results in [5] to find a new model structure on C(R-Mod)

    Dissociative recombination and rotational transitions of D2+_2^+ in collisions with slow electrons

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    Rate coefficients for dissociative recombination and state-to-state rotational transitions of the D2+_{2}^{+} ion induced by collisions with very low-energy electrons have been reported following our previous studies on HD+^{+} and H2+_{2}^{+} [9,10]. The same molecular structure data sets, excitations (Ni+N_{i}^{+} \rightarrow Nf+=Ni++2N_{f}^{+}=N_{i}^{+}+2 for Ni+=0N_{i}^{+}=0 to 1010) and de-excitations (Ni+N_{i}^{+} \rightarrow Nf+=Ni+2N_{f}^{+}=N_{i}^{+}-2, for Ni+=2N_{i}^{+}=2 to 1010) were used for collision energies ranging from 0.010.01 meV to 0.30.3 eV. Isotopic effects for dissociative recombination and rotational transitions of the vibrationally relaxed targets are presented.Comment: 7 pages, 7 figures, 4 table
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