The electronic structure as a function of the chirality and deformations for various carbon nanotori is theoretically investigated by the tight-binding method. It has been found that for the various metallic tori the deformation-dependent energy gap displays almost the same changing features versus the deformations, whereas for the various semiconducting tori the deformation-dependent energy gap does not show the distinctive regularity associated with the deformed parameters and geometric parameters, but if the deformed parameters have some particular values the energy gap would be narrowed and even approach zero, causing the semiconducting torus to be quasi-metallic. Under the circumstances of tanα = 0 and εL = εJ, the electronic structure seems to be very insensitive to the existence of deformations.

Abstract. We investigated the relations between the yield stress of polar-molecule dominated electrorheological (PM-ER) fluids and the shape of ellipsoidal particles of the fluids. It is found that, when the short axis of an ellipsoidal particle is along an external electric field while the volume of the particle keeps constant, the shorter of the short axis is, the stronger the attraction between the two adjacent particles would be. The equipment used for yield stress determination, the experiment and calculation of the condition under which the sample are short-axis chained, the detailed process of sample preparation and sample characterization will be described and discussed in an extended form of this paper.

We simulate the effect of the chaining direction of ellipsoidal particles of polar molecule dominated electrorheological (PM-ER) fluids using commercially available COMSOL Multiphysics® software for the distribution of electric field and the total electrostatic energy. It is proved that adding ferroelectric materials to the channels parallel to the short axis would make the short axis parallel to the field direction when the ellipsoidal particles are chained under an electric field. According to our simulation, while the concentration of the channels stays constant, the greater the dielectric constant of the inserted material, the stronger the maximum local electric field will be.

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