In this study, we design a new kind of spherical robot named BYQ-X. This robot has two moving statuses. When the robot moving on flat terrain, the spherical shell is folding, robot moves in traditional way by the pendulum. When the robot climbing a slope the climbing links stretch out and the spherical shell is unfolding. In this status the spherical is driven by electromotor directly. So the o...

Metallic spherical dome shells have received much attention in recent years because they have proven to possess highly impressive optical properties. The expected distinctive changes occurring owing to quantum confinement of conduction electrons in these nanoparticles as their thickness is reduced, have not been properly investigated. Here we carry out a detailed analytical derivation of the qu...

The spectrum and wave functions of 44 Ti are studied in oblique-basis calculations using spherical and SU(3) shell-model states. Although the results for 44 Ti are not as good as those previously reported for 24 Mg, due primarily to the strong spin-orbit interaction that generates significant splitting of the single-particle energies that breaks the SU(3) symmetry, a more careful quantitative a...

Rayleigh-Bénard convection in rotating spherical shells can be considered as a simplified analogue of many astrophysical and geophysical fluid flows. Here, we use threedimensional direct numerical simulations to study this physical process. We construct a dataset of more than 200 numerical models that cover a broad parameter range with Ekman numbers spanning 3 × 10−7 ≤ E ≤ 10−1, Rayleigh number...

A conducting spherical shell with a circular orifice of half angle θ0 is at electric potential V0. Show that the difference between the charge densities on the inner and outer surfaces is independent of position, and estimate the ratio of the electric charge on the inner surface to that on the outer. Correct results can be inferred from “elementary” arguments based on superposition, and more “e...

RE PR INT The helicity constraint in spherical shell dynamos A. Brandenburg, P. J. Käpylä, D. Mitra, D. Moss, and R. Tavakol 1 NORDITA, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden 2 Observatory, University of Helsinki, PO Box 14, FI-00014 University of Helsinki, Finland 3 School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, UK 4 School of Mathem...

The multiplicity of stable convection patterns in a rotating spherical fluid shell heated from the inner boundary and driven by a central gravity field is presented. These solution branches that arise as rotating waves (RWs) are traced for varying Rayleigh number while their symmetry, stability, and bifurcations are studied. At increased Rayleigh numbers all the RWs undergo transitions to modul...

The Casimir energy for a conducting spherical shell of radius a is computed using a direct mode summation approach. An essential ingredient is the implementation of a recently proposed method based on Cauchy's theorem for an evaluation of the eigenfrequencies of the system. It is shown, however, that this earlier calculation uses an improper set of modes to describe the waves exterior to the sp...

In this work, we study the formation and evolution of dark matter halos by means of the spherical infall model with shell-crossing. We present a framework to tackle this effect properly, that does not involve the adiabatic approximation, and is based on the numerical follow-up, with time, of that individual shell of matter that contains always the same fraction of mass with respect to the total...