Reaction of sodium amide with 1-chloromethylsilatrane

The reaction of 1-chloromethylsilatrane with sodium amide in benzene is accompanied by ring expansion with formation of 1-amino-2-carba-3-oxahomosilatrane.     

A co‐ordinate system independent streamwise upwind method for fluid flow computation

A new co‐ordinate invariant streamwise upwind formulation for convection dominated flows is developed. The eddy diffusivity/viscosity is added directly to the equations in order to remove the oscillations in the solution. The equations then can be solved by any high‐order scheme and the solution retains the accuracy of the high‐order scheme. The accuracy and reduced lateral thickness growth rate are demonstrated with several numerical examples, including pure convective flows and lid‐driven cavity flow. The lateral spreading due to the numerical diffusion is controlled by the anisotropic tensor. Copyright © 2004 John Wiley & Sons, Ltd.     

Properties of backscattered particles produced by protons of energy above 1 TeV in an iron absorber

Backscattered-particle production is studied by means of a detailed simulation of cascade processes in a dense medium. The energy dependence of the albedo and the spatial and angular distributions of various components of this flux are analyzed.     

Application of ultrafine-dispersed diamonds in electroplating

The results obtained upon the electrochemical deposition of composite coatings containing ultrafine-dispersed diamonds produced by detonation synthesis are generalized. The main advantages of such coatings over the well-known composite electrochemical coatings are revealed.     

Modeling of the structure and electronic structure of condensed phases of small fullerenes C<Subscript>28</Subscript> and Zn@C<Subscript>28</Subscript>

A comparative analysis of the stability factors and electronic structure of two possible crystalline forms of small fullerene C₂₈ and endohedral fullerene Zn@C₂₈ with diamond and lonsdaleite structures is performed using a cluster model. Atoms of elements that, when placed inside C₂₈ cages, have no significant effect on the stability of free small-fullerene molecules are shown to be able to dramatically change the electronic properties and reactivity of the C₂₈ skeleton and to be favorable for forming small-fullerene crystalline modifications, which are covalent crystals. In contrast, if the presence of foreign atoms inside C₂₈ cages stabilizes the isolated nanoparticles, then molecular crystals (such as C₆₀ fullerites) are formed due to weak van der Waals forces.     

Spatial macroscopic structure of a pulsed microsecond discharge in barrier-metal gaps with a nonuniform electric field distribution

Electric and spatial characteristics of a pulse-periodic microsecond barrier discharge are investigated in different geometries—triangular prism, plate, and corrugated electrode—that are in contact with a dielectric plate and form a dihedral angle with it. It is established that, in the space of the dihedral angle, the regions of discharge represent alternating cylindrical layers with the axes lying on the contact line. The first conducting layer is formed at some distance from the contact edge of the electrode. The number of layers and their localization are determined by the angle formed between an electrode and the dielectric plate. A physical model explaining the main features of the structure formation is proposed.     

Electron Metal-Dielectric Phase Transitions in Semiconductors under Pressure

The effect of uniform pressure on the character of metal-dielectric transitions in compensated weakly- and highly doped semiconductors (WHDCS) is considered. The influence of hybridization of resonance quasilocalized impurity states with band continuum states on the transition is shown. Minimum metallic conductivities in p-CdSnAs₂ are determined for Mott and Anderson transitions. Special features of the metal-dielectric transformation in weakly-doped narrow- and high energy-gap semiconductors are discussed for the case of hydrogen-like impurities. Anderson localization in WHDCS is also considered. Phase diagrams are presented.