2014 The electrical properties of polycrystalline silicon resistors in the non-linear regime are examined. The adopted model is based on a thermionic-diffusion transport mechanism, and assumes charge trapping at the grain boundary. The theory closely fits experimental I-V characteristics, and allows for the determination of the average grain size. REVUE DE PHYSIQUE APPLIQUÉE TOME 13, DÉCEMBRE 1...

A crack trapping model is developed for the fracture resistance of high-angle grain boundaries in free-standing brittle thin films, based on which a new size effect is predicted. In addition to the crystallographic misorientations, the grain boundary toughness is also dependent on the film thickness, primarily due to the geometrically necessary crack front branching. 2007 Elsevier Ltd. All righ...

In recent years, food security, especially supply, has been an important issue in China’s agricultural production. The stability of grain prices is related to the stability and development of the grain market. Based on agricultural production data from 1970 to 2015, this paper explores the influence of agricultural product price fluctuation on grain production by using the cobweb theory and vec...

We present an analysis, based upon atomistic simulation data, of the effect of Fe impurities on grain boundary migration in Al. The first step is the development of a new interatomic potential for Fe in Al. This potential provides an accurate description of Al–Fe liquid diffraction data and the bulk diffusivity of Fe in Al. We use this potential to determine the physical parameters in the Cahn–...

In the microcrystalline regime, the electrical (impedance/dielectric) behavior of grain boundarycontrolled electroceramics is well described by the “brick-layer model” (BLM). In the nanocrystalline regime, however, grain boundary layers can represent a significant volume fraction of the overall microstructure. Simple boundary-layer models no longer adequately describe the electrical properties ...

We study the combined effects of grain size and texture on the strength of nanocrystalline copper (Cu) and nickel (Ni) using a crystal-plasticity based mechanics model. Within the model, slip occurs in discrete slip events exclusively by individual dislocations emitted statistically from the grain boundaries. We show that a Hall-Petch relationship emerges in both initially texture and non-textu...

This study focuses on the estimation of the mean grain size of mechanically induced Hydroxyapatite (HA) through the artificial neural network (ANN) model. The mean grain size of HA and HA based nanocomposites at different milling parameters were obtained from previous studies. The data were trained and tested by the neural network modeling. Accordingly, all data (55 sets) were based on the mecha...

Nanocrystalline materials show a higher strain-rate sensitivity in contrast to the conventional coarse-grained materials and a different grain size dependency. To explain these phenomenon, a finite element model is constructed that considers both grain interior and grain boundary deformation of nanocrystalline materials. The model consist of several crystalline cores with different orientations...