the question of the purity or impurity of non-muslims has always attracted the attention of the islamic jurists. the importance of this question has been due to the fact that the social and political interactions between muslims and non-muslims were quite inevitable. the present article is concerned first to examine the notion of purity and impurity as viewed by the sunni and shiite jurists and...

Boron-doped bulk diamond and the boron-doped hydrogen terminated (001) surface of diamond were investigated using the cyclic cluster model. Structure and stability of the hydrogen-terminated (001) surface were calculated and compared with experimental and other theoretical results from the literature. Boron-doping was modeled by substitution of a carbon atom by a boron atom in different positio...

Macroscopic description of the diffusion of interstitial impurity atoms considering the influence of elastic stress on the drift of interstitial species Abstract The diffusion equation for nonequilibrium interstitial impurity atoms taking into account their charge states and drift of all mobile interstitial species in the built-in electric field and in the field of elastic stress was obtained. ...

We study an Anderson impurity in a semiconducting host using the density matrix renormalization group technique. We use the U50 one-dimensional Anderson Hamiltonian at half filling as the semiconducting host since it has a hybridization gap. By varying the hybridization of the host, we can control the size of the semiconducting gap D . We consider chains with 25 sites and we place the Anderson ...

This review covers the application of cycloaddition reactions in forming the boron-containing compounds such as symmetric star-shaped boron-enriched dendritic molecules, nano-structured boron materials and aromatic boronic esters. The resulting boron compounds are potentially important reagents for both materials science and medical applications such as in boron neutron capture therapy (BNCT) i...

The insulator characteristic of hexagonal boron nitride limits its applications in microelectronics. In this paper, the fluorinated hexagonal boron nitride nanosheets were prepared by doping fluorine into the boron nitride nanosheets exfoliated from the bulk boron nitride in isopropanol via a facile chemical solution method with fluoboric acid; interestingly, these boron nitride nanosheets demo...

The isotopic analysis of boron from material that carries only trace amounts of boron requires low boron blank levels. Large efforts are taken to keep blank levels low by purifying reagents. We performed exposure experiments and determined procedure blanks before and after the air-handling system was modified from silicate glass filters to polyethylene/polystyrole and active carbon filters. Our...

A family of unusually stable boron cages was identified and examined using first-principles local-density functional method. The structure of the fullerenes is similar to that of the B12 icosahedron and consists of six crossing double-rings. The energetically most stable fullerene is made up of 180 boron atoms. A connection between the fullerene family and its precursors, boron sheets, is made....

Based on an ab initio study, we present a structure model for a broad boron sheet, which is the precursor of boron nanotubes. Furthermore we could show that, in contrast to the armchair types, zigzag boron nanotubes have no surface tension (strain energy). As result, we predict that boron nanotubes will exhibit a chirality dependent stability, something that is unique among all nanotubular mate...

Boron strongly modifies electronic and diffusion properties of graphite. We report the first ab initio study of boron interaction with the point defects in graphite, which includes structures, thermodynamics, and diffusion. A number of possible diffusion mechanisms of boron in graphite are suggested. We conclude that boron diffuses in graphite by a kick-out mechanism. This mechanism explains th...