Two new oxides have been unambiguously identified as Bi2Tc2O7-delta with delta = 0.14(1) and Bi3TcO8 through X-ray absorption near-edge structure spectroscopy and neutron powder diffraction. The compound Bi2Tc2O7-delta has a cubic pyrochlore-type structure with a = 10.4746(1) A, space group Fd3m (origin choice 2), and Z = 8. The compound Bi3TcO8 is also cubic, a = 11.5749(1) A, space group P2(1...

The structure of the porous three-dimensional reticulated pattern in the wing scales of the butterfly Callophrys rubi (the Green Hairstreak) is explored in detail, via scanning and transmission electron microscopy. A full 3D tomographic reconstruction of a section of this material reveals that the predominantly chitin material is assembled in the wing scale to form a structure whose geometry be...

A symmetry analysis of the 2a phase recently observed in some samples of C60 is presented. This phase is described by a unit cell with eight molecules in inequivalent orientations. We first show that if this structure is assumed to be exactly cubic, there are only three allowed space groups, none of which corresponds to the Pa3 ̄ arrangement of threefold axes previously established for C60 by se...

Colloidal lipid particles such as solid lipid nanoparticles and liquid crystalline nanoparticles have great opportunities as drug carriers especially for lipophilic drugs intended for intravenous administration. In order to evaluate drug release from these nanoparticles and determine their behavior after administration, emulsion droplets were used as a lipophilic compartment to which the transf...

Transition-metal (TM) nitrides are a class of compounds with a wide range of properties and applications. Hard superconducting nitrides are of particular interest for electronic applications under working conditions such as coating and high stress (e.g., electromechanical systems). However, most of the known TM nitrides crystallize in the rock-salt structure, a structure that is unfavorable to ...

We study partially and totally associative ternary algebras of first and second kind. Assuming the vector space underlying a ternary algebra to be a topological space and a triple product to be continuous mapping we consider the trivial vector bundle over a ternary algebra and show that a triple product induces a structure of binary algebra in each fiber of this vector bundle. We find the suffi...

Thin films of ZnS have been deposited by MOCVD on both BaTa206/ITO/glass and Si substrates. Diethylzinc (DEZn) and H2S are used for deposition on substrates heated to the 250-400°C temperature range. The microstructure and properties of ZnS films were studied by X-ray diffractometry (XRD), ultraviolet/visible spectrophotometry (UVS) and scanning electron microscopy (SEM). Films prepared on BaTa...

The structure and elastic properties of MgSiOa, a major mantle-forming phase, have been simulated using computer models which predict the minimum energy structure by using interatomic pair potentials to describe the net forces acting between the atoms. Four such interatomic potentials were developed in this study, and are compared with potential NI of Miyamoto and Takeda (1984). The most succes...

We construct nontrivial homomorphisms from the quasi group of some cubic surfaces over Fp into a group. We show experimentally that the homomorphisms constructed are the only possible ones and that there are no nontrivial homomorphisms in the other cases. Thereby, we follow the classification of cubic surfaces, due to A.Cayley. 1 The quasi group of a cubic surface 1.1. –––– According to Yu. I. ...

Manuscript received September 27, 1999. Manuscript revised October 20, 1999. † The authors are with NTT Cyber Space Laboratories, Musashino-shi, 180-8585 Japan. a) E-mail: [email protected] SUMMARY We studied Si and Mg doping characteristics in cubic GaN and fabricated a light emitting diode of cubic GaN on a GaAs substrate by metalorganic vapor-phase epitaxy. The diode structure con...