[en] Published in summary form only

[en] Paper discusses the problem of quantization of moments and spins under indirect spin-spin interaction between them. It is stressed that the mentioned quantization has more complex character than in case of separated spins in terms of theory of disturbances. 2 refs

[en] Full text: Filling spin-carrying species, e.g. fullerenes filled with N or transition metals, into single-wall carbon nanotubes opens the possibility to study 1D spin chains. In order to control the spin-spin interaction one has to be able to engineer the distance between two adjacent fullerenes. Here we will report on the first step where empty fullerenes were functionalized with various side groups in order to establish uniform distances between the cages inside the nanotube. (author)

[en] We have investigated the upper bound of the radiation energy in the head-on collision of two Myers-Perry black holes. Initially, the two black holes are far away from each other, and they become one black hole after the collision. We have obtained the upper bound of the radiation energy thermodynamically allowed in the process. The upper bound of the radiation energy is obtained in general dimensions. The radiation bound depends on the alignments of rotating axes for a given initial condition due to spin-spin interaction. We have found that the collision may not be occurred for a initially ultra-spinning black hole.

[en] The influence of intersubsystem coupling on the cyclic adiabatic geometric phase in bipartite systems is investigated. We examine the geometric phase effects for two uniaxially coupled spin-(1/2) particles, both driven by a slowly rotating magnetic field. It is demonstrated that the relation between the geometric phase and the solid angle enclosed by the magnetic field is broken by the spin-spin coupling, in particular leading to a quenching effect on the geometric phase in the strong coupling limit

[en] A variant of the one-dimensional t-J model with anisotropic spin interaction is studied by the nested algebraic Bethe ansatz method. The gapless charge excitations and the gapful spin excitations are obtained. It is shown that the singlet-superconducting correlation dominates in the low-density region by applying the finite-size scaling analysis in the conformal field theory. (author)

[en] The scope and organization of this Chapter is similar to that of the corresponding chapters in the previous two volumes of this Series. Section 2 reviews work dealing with the fundamental theory of couplings and with computational procedures. All non-empirical calculations are reviewed in this Section. Section 3 deals with application-oriented semi-empirical calculations of couplings in model compounds. Section 4 covers empirical correlations and similar work aimed at understanding the factors influencing couplings. Finally, Section 5 deals with intermolecular effects. Papers in which the coupling constants are used to extract information on other physical and chemical properties of molecular systems are not reviewed in this Chapter. Sections 3 and 4 are arranged according to the nature of the coupled nuclei. (author)

[en] The absence of certain LS states in atoms leads to the vanishing of several 6-j symbols. One of these vanishing 6-j's explains the absence of a certain jj coupling state in a nucleus, while the other explains the vanishing of a certain state for a system of three bosons. This is part of a continuing study of ''companion problems.'' It is noted that the vanishing 6-j's play an important role for establishing partial dynamical symmetries. Whenever possible we offer alternate explanations that do not involve 6-j symbols. Extensions to vanishing 9-j symbols are also shown. Regge symmetries help to make connections between different topics.

No abstract available

[en] Moessbauer studies of iron proteins provide information about the electronic structure of the enzymatically very interesting part of these molecules, i.e. the transition-metal sites. In many cases these catalytically active sites have been modelized, thus providing synthetic analogues for the various steps within an enzymatic reaction cycle. The present contribution describes Moessbauer investigations of model complexes, and emphasis is given to examples which exhibit spin coupling. Among the various types of spin coupling (spin+orbit, spin-lattice, spin-spin, exchange) we have selected two examples (superexchange and double exchange). The measured temperature and field-dependet Moessbauer spectra are analyzed on the basis of an electronic Hamiltonian which includes the appropriate coupling terms. (author)