Structures and relative stability of four families of low-lying silicon clusters in the size range of Sin(n=21-30) are studied, wherein two families of the clusters show prolate structures while the third one shows near-spherical structures. The prolate clusters in the first family can be assembled by connecting two small-sized magic clusters Sin (n=6, 7, 9, or 10) via a fused-puckered-hexagona...

the study describes the synthesis and characterization of zinc(ii) minoxidil nanocomposite (1). the reaction between zinc(ii) acetate, minoxidil, {c9h15n5o=minoxidil=(2,4-diamino-6-piperidine-1-yl) pyrimidine n-oxide)} as a ligand and ki as bridging agent, in methanol at 60°c leads to the formation of nano-sized zn(ii) minoxidil nanocomposite, 1. characterization of (1) was carried out by eleme...

The NbSe2 nanoplates with novel hexagonal morphology have been obtained via solid-state assembly of NbSe2 ultrathin nanosheets, which were prepared by a simple calcination process using micro-sized Nb and Se powders as the precursors. The influence of high-temperature annealing upon morphology of single-crystal NbSe2 was investigated. On the basis of experimental results of different temperatur...

in this paper, zno thin film is deposited on slide glass substrate using the sol-gel process. presenting well-defined orientation of zno thin films nanostructure were obtained by dip coating of zinc acetate dihydrate, monoethanolamine (mea), de-ionized water and isopropanol alcohol. the annealed zno thin films were transparent ca 85-90% in visible range with an absorption edges at about 375 nm....

Quaternary cubic (Ti x Cr 1-x Al ~0.60) 1 N 1 coatings with 0<x<0.33 have been grown using reactive cathodic arc evaporation. When adding Ti the hardness was retained after annealing up to 1100 ºC which is a dramatic improvement compared to CrAlN coatings. The coatings showed an age hardening process caused by spinodal decomposition into coherent TiCr-and Al-rich cubic TiCrAlN domains and the f...

Photoelectron spectroscopy and ab initio calculations have been carried out to probe the structures and chemical bonding of the B27 (-) cluster. Comparison between the experimental spectrum and the theoretical results reveals a two-dimensional (2D) global minimum with a triangular lattice containing a tetragonal defect (I) and two low-lying 2D isomers (II and III), each with a hexagonal vacancy...

In Euclidean d-spaces, the container problem asks to pack n equally sized spheres into a minimal dilate of a fixed container. If the container is a smooth convex body and d ≥ 2 we show that sequences of solutions to the container problem can not have a “simple structure”. By this we in particular find that there exist arbitrary small r > 0 such that packings with spheres of radius r into a smoo...

In an Euclidean d-space, the container problem asks to pack n equally sized spheres into a minimal dilate of a fixed container. If the container is a smooth convex body and d ≥ 2 we show that solutions to the container problem can not have a “simple structure” for large n. By this we in particular find that there exist arbitrary small r > 0, such that packings in a smooth, 3-dimensional convex ...