Single crystals of trizirconium nickel hepta-anti-monide were synthesized from the constituent elements by arc-melting. The compound crystallizes in a unique structure type and belongs to the family of two-layer structures. All crystallographically unique atoms (3 × Zr, 1 × Ni and 7 × Sb) are located at sites with m symmetry. The structure contains 'Zr(2)Ni(2)Sb(5)' and 'Zr(4)Sb(9)' fragments a...

A preparação, o grau de dispersão, estabilidade térmica e a acidez de Lewis e de Brφnsted do óxido de antimônio (V) adsorvido sobre SiO 2 /ZrO 2 , preparado previamente pelo processo sol-gel, são descritas neste trabalho. Amostras de SiO 2 /ZrO 2 /Sb 2 O 5 de composições (% em massa): (a) Zr= 8,1 e Sb= 6,3; (b) Zr= 11,4 e Sb= 11,4, foram preparadas. As imagens de microscopia eletrônica de varre...

It is shown that for 2 ≤ t ≤ n− 3, a strict t-SB(n, n− 1) design does not exist, but for n ≥ 3, a non-strict 2-SB(n, n−1) design exists. The concept of large sets for Steiner triple systems is extended to SB designs and examples of a large sets for SB designs are given.

We report a simple and efficient method for replacing germanium atoms in deltahedral Ge(9)(4-) clusters with Sb or Bi. While reactions of Ge(9)(4-) with EPh(3) (E = Sb, Bi) at room temperature are known to produce mono- and disubstituted clusters [Ph(2)E-Ge(9)-Ge(9)-EPh(2)](4-) and [Ph(2)E-Ge(9)-EPh(2)](2-), respectively, at elevated temperatures or with sonication they result in exchange of Ge...

This paper investigates face perception in a visual agnosic and prosopagnosic patient (SB). Despite very extensive lesions of visual areas, SB remains capable of some visual processing [Brain 125 (2002) 58]. However, in everyday situations SB does not exhibit signs of specific face recognition. To investigate how SB may process faces, we tested two hypotheses. According to the 'spared module hy...