We report a comprehensive study on the molecular conformation and dynamics of very large poly(ethylene oxide) rings in melt: (i) for all rings, independent ring size, by small angle neutron scattering we observe crossover from strong Q-dependence at intermediate Q to Q?2 dependence higher Q. Constructing generic model including Gaussian statistics short distances more compact structures larger ...

In this paper, an atomistic based finite element model is developed to investigate the influence of topological defects on mechanical properties of graphene. The general in-plane stiffness matrix of the hexagonal network structure of graphene is found. Effective elastic modulus of a carbon ring is determined from the equivalence of molecular potential energy related to stretch and angular defor...

in this paper, a new design of optical channel drop filter based on two- dimensional photonic crystal ring resonators with triangular lattice is proposed. the rods of this structure is silicon with the refractive index nsi=3.46 and the surrounding environment is air with the refractive index of nair=1.the widest photonic band gap obtains for the filling ratio of r/a = 0.2. the filter’s transmis...

let r be an associative ring with unity. an element a in r is said to be r-clean if a = e+r, where e is an idempotent and r is a regular (von neumann) element in r. if every element of r is r-clean, then r is called an r-clean ring. in this paper, we prove that the concepts of clean ring and r-clean ring are equivalent for abelian rings. further we prove that if 0 and 1 are the only idempotents...

let r be an associative ring with unity. an element a in r is said to be r-clean if a = e+r, where e is an idempotent and r is a regular (von neumann) element in r. if every element of r is r-clean, then r is called an r-clean ring. in this paper, we prove that the concepts of clean ring and r-clean ring are equivalent for abelian rings. further we prove that if 0 and 1 are the only idempotents...

The network structure of a silica bilayer film at monolayer-bilayer transition and across supporting metal step edge was studied the atomic scale by scanning tunneling microscopy. ring size distribution, ring-ring distances, height profiles are analyzed region. Density functional theory proposes two models to explain observed structure: pinning lower layer substrate carpetlike mode. results ind...