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[1] In the present paper, we first examine some interplanetary directional discontinuities with very small B n /B (<0.1) using intraspacecraft timing method. It is found that the velocity and magnetic field fluctuations of these directional discontinuities satisfy the Walén relation. We suggest that these directional discontinuities are rotational discontinuities. In addition, we investigate the stability of interplanetary rotational discontinuities using one-dimensional hybrid simulations and found that rotational discontinuities with all values of B n /B can stably exist in the solar wind. In one simulation run, we find that the rotational discontinuity (RD) is still stable when the ratio, B n /B, equals 0.0001. Finally, from one-dimensional hybrid simulation, we further find that the ratio is significantly reduced after interaction with interplanetary fast shocks. There are a few mechanisms for generation of RDs. Among them, two mechanisms are well accepted. One is nonlinear evolution of Alfvén waves in the solar wind, and another is magnetic reconnection near the solar surface. For magnetic reconnection, the reconnection rate, V 1n /V A1 (= B n /B), in the magnetosphere and solar wind, is usually <0.2. Therefore the generated RDs also have B n /B < 0.2. On the other hand, the nonlinear evolution of Alfvén waves in the solar wind can generate RDs at all values of B n /B, which contradicts to the Cluster results . We suggest that interplanetary RDs with small B n /B are likely been generated through magnetic reconnection.

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The vibrational modes of acoustic phonons and their corresponding eigenfrequencies in CdS/CdSe/CdS quantum-dot quantum wells (QDQWs) are obtained by taking on the continuum model. The energy spectra of the phonons in nanocrystals from the analytic solutions are checked by the finite-element method. Based on the spectrum of acoustic phonons and the Debye model, the temperature dependences of the specific heat contributed from lattice phonons are calculated to investigate the size-dependent effects. The lattice softening is also demonstrated and the results qualitatively agree with the experimental observations for fine particles and quantum dots. We found that the phonon density of states of a QDQW plays an important role in the calculation of specific heat, and the modification of the effective sound velocity in the nanocrystal is also suggested.

Frequencydependent complex permeability in rare earthsubstituted cobalt/nonmagnetic transition metal soft ferromagnetic amorphous thin films High permeability ironbased metallic glasses for line frequency applications Wall plane under the action of an external field, and its coordinate. (b) Picture used to calculate the demagnetization factor. 4627