Photodischarge Characteristics of Polyvinylcarbazole Double-Layer Films

Abstract

Photodischarge characteristics of polyvinylcarbazole (PVK) double-layer (DL) films, consisting of a thick PVK layer and an overlying dye-doped thin PVK layer, were measured. The measured characteristic curves can be fitted well with the calculated ones, assuming the field proportional quantum efficiency for photo-hole generation and the hole mean range inversely proportional to the dye-concentration. The quantum efficiency is estimated to be 0.45 at 106 V/cm, and is nearly constant for a wide range of dye-concentration. The DL film has electrophotographical sensitivity only for positive charging and its sensitivity is further increased by negative charging and exposing the film previous to positive charging.

Differential geometry of viscoelastic models with fractional-order derivatives

“…Then, in a similar way to [18,19], the initial state of viscoelastic media before deformation is regarded as the Euclidean. In this case, the metric tensor in the deformed state can be constructed by the transformation matrix in (11):…”

“…From the geometrical studies of viscoelasticity [18,19], the deformation process can be expressed by the interaction between spatial and time variations. According to this line, we focus on the geometric objects that have spacetime components:…”

“…Geometrically, the deformation process of continuum media is expressed by the coordinate transformation [18,19,24]. Since the viscoelastic media have a property of the memory effect, the geometric framework of the viscoelasticity can be grasped by the rheonomic geometry [31,42].…”

“…Since the viscoelastic media have a property of the memory effect, the geometric framework of the viscoelasticity can be grasped by the rheonomic geometry [31,42]. Indeed, the viscoelastic constitutive equations can be constructed from the variation of energy function of the metric tensor (strain) and torsion tensor (strain rate) in the rheonomic space [18,19]. These geometric objects are defined in a non-Riemannian space [3,11,21,29,30].…”

“…Moreover, from a viewpoint of the fractional osculator bundle, the Liouville fractional vector fields, fractional spray and fractional nonlinear connection have been discussed [2]. Therefore, the previous geometric studies [18,19] can be generalized into the fractional case by using the fractional rheonomic geometry. Then, the behavior of fractional viscoelastic models is expressed by the geometric objects with fractional order.…”