Diagrammatic structure of the general coupled cluster equations

The general formula for the number of diagrammatic terms occurring in the T_n equation within a particular coupled cluster model is derived. Both the antisymmetrized and Goldstone diagrams are considered. In addition to the full coupled cluster equation approximate approaches are discussed, and for each the general formula for the number of terms is given. Analogous expressions are presented for the number of diagrammatic terms contributing to the elements of the transformed Hamiltonian [Hbar] = e^?T He^T .     

Dielectrophoretic alignment of metal and metal oxide nanowires and nanotubes: a universal set of parameters for bridging prepatterned microelectrodes

Nanowires and nanotubes were synthesized from metals and metal oxides using templated cathodic electrodeposition. With templated electrodeposition, small structures are electrodeposited using a template that is the inverse of the final desired shape. Dielectrophoresis was used for the alignment of the as-formed nanowires and nanotubes between prepatterned electrodes. For reproducible nanowire alignment, a universal set of dielectrophoresis parameters to align any arbitrary nanowire material was determined. The parameters include peak-to-peak potential and frequency, thickness of the silicon oxide layer, grounding of the silicon substrate, and nature of the solvent medium used. It involves applying a field with a frequency >10(5) Hz, an insulating silicon oxide layer with a thickness of 2.5 μm or more, grounding of the underlying silicon substrate, and the use of a solvent medium with a low dielectric constant. In our experiments, we obtained good results by using a peak-to-peak potential of 2.1 V at a frequency of 1.2 × 10(5) Hz. Furthermore, an indirect alignment technique is proposed that prevents short circuiting of nanowires after contacting both electrodes. After alignment, a considerably lower resistivity was found for ZnO nanowires made by templated electrodeposition (2.2-3.4 × 10(-3) Ωm) compared to ZnO nanorods synthesized by electrodeposition (10 Ωm) or molecular beam epitaxy (MBE) (500 Ωm).     

Plane Sources of Waves in the Presence of Magnetic Field

In this paper the generation of harmonic waves in an elastic magneticmaterial, which is a perfect conductor of electricity, isconsidered. It has been assumed that an infinite body is subjected tothe action of an initially constant magnetic fieldH = (H,0,0) and in the plane ax+by=0 acts a source ofdistortion. It has been shown that this source may produce bothtransverse and longitudinal waves and each of them consists of two parts,which propagate with different speeds. The amplitudes and speeds in dependence on theangle between the direction of wave propagation and the magnetic fieldintensity H have been discussed.     

Kinetics of Degradation of Biapenem

The kinetic and thermodynamic analysis of biapenem degradation was conducted during acid–base hydrolysis, under the influence of buffer components and in the solid state at increased temperature (dry air) and relative air humidity (RH > 50%). The effects of the initial concentration of biapenem and the formation of degradation products on its stability were investigated.