9 research outputs found
Exact ground states for the four-electron problem in a Hubbard ladder
The exact ground state of four electrons in an arbitrary large two leg
Hubbard ladder is deduced from nine analytic and explicit linear equations. The
used procedure is described, and the properties of the ground state are
analyzed. The method is based on the construction in r-space of the different
type of orthogonal basis wave vectors which span the subspace of the Hilbert
space containing the ground state. In order to do this, we start from the
possible microconfigurations of the four particles within the system. These
microconfigurations are then rotated, translated and spin-reversed in order to
build up the basis vectors of the problem. A closed system of nine analytic
linear equations is obtained whose secular equation, by its minimum energy
solution, provides the ground state energy and the ground state wave function
of the model.Comment: 10 pages, 7 figure
Focal Contact Formation of Vascular Smooth Muscle Cells on Langmuir–Blodgett and Solvent-Cast Films of Biodegradable Poly(ester amide)s
Rhinoviruses
Picornaviruses, which include the human rhinoviruses (HRVs) and enteroviruses (EVs), are the most frequent cause of acute human illness worldwide. HRVs are the most prevalent cause of acute respiratory tract illnesses (ARIs) which usually commence in the upper respiratory tract (URT). ARIs are the leading cause of morbidity in children under 5 years and occur in all seasons. ARIs linked to HRV infections are associated with excessive and perhaps inappropriate antibiotic prescribing and with significant direct and indirect healthcare expenditure. ARI incidence is highest in the first 2 years of life, with up to thirteen episodes per year including up to six positive for an HRV, and it is not uncommon to average one infection per child-month